Sub-Task 1.1.- The pollutant contents of alpeorujo and alpechín together with their environmental effects were described. The study of treatment procedures in the last period of 1998 was completed with the help of national and international literature. Informative pages about olive oil production in the EU member states were created and presented on the Internet and filled with the project results (http://www.fiw.rwth-aachen.de/improlive/improlive.html).

Sub-Task 1.2.- Three ways of data collection were chosen to fill the structure of the database established in 1998. At first an inquiry was started using mail and telephone. Secondly, an in-situ inquiry was made in Spain and Greece, both main olive oil producing countries. The third means was an interactive database, integrated into the project Internet Web pages.

To develop the structure of the database, an ecological balance of both systems, olive oil production and treatment of the resulting waste, was established with all inputs, outputs and relevant criteria.

The Improlive database serves the following purposes:

• Information pool,
• Exchange of experience,
• Remarks on own or outsourced treatment can be made, and possibly
• Advantages and disadvantages of the individual procedures.

Sub-Task 1.3.- The treatment procedures listed in Sub-task 1.1 were described in a more detailed way with the help of the results from tasks 2, 3 and 4, and from various pilot tests. Different evaluation methods were used to assess the individual procedures related to European policy and with view to economic and ecological aspects. In addition a new cost analysis was established. Finally a general evaluation was carried out with the help of the features resulting from the previous assessment.

Sub-Task 1.4.- With the help of results from pilot tests, Participant 3 described the possible anaerobic treatment of alpeorujo. This procedure, too, was evaluated with view to technical, economic and ecological aspects.

Sub-Task 2.1.- Completed in the second period.

Sub-Task 2.2.- Completed in the second period.

Sub-Task 2.3.- Completed in the second period.

Sub-Task 3.1.- Completed in the second period.

Sub-Task 3.2.- Completed in the second period.

Sub-Task 3.3.- Participant 6 has made the analysis of the bacterial flora changes in a pilot-scale compost bioremediation process. A full phenotypic and genotypic analysis of the dominant bacteria present has been carried out as has a comparison of a range of available community analysis procedures (classical microbiology, fatty acid analysis, and molecular biology, eg SSCP). This made it possible to detect changes in the major microbial components during the composting process.

Sub-Task 3.4.- Participant 7 studied the alpeorujo liquid fraction of alpeorujo. This fraction contains mostly the water-soluble constituents of the pulp plus some residual olive oil and the endosperm oil of the olive fruits. The water fraction resembles a highly concentrated alpechín e.g. the wastewater effluent of the 3-phase decanter. The fresh material is very phytotoxic, and strongly inhibits the growth of Pleurotus and other fungi and many bacteria too. When diluted with water (10-fold or more) it can be used as substrate for Azotobacter, Fusarium, Geotrichum, Pleurotus and some yeasts (Candida). A detailed chemical analysis of alpechín was carried out before and after bioremediation with Azotobacter vinelandii.

Sub-Task 3.5.- For alpeorujo and de-oiled alpeorujo a self-sustainable composting process was elaborated by Participant 7. Bulky material is only required for the initiation of the process. When the thermophilic phase is established the operation is switched to a fed-batch system with a cycle time of 7 days and a ratio of residual to removal volume c. 0.30. Under these conditions no additional bulky material is required. Thus fresh alpeorujo can be fed for practically an unlimited time, and after the necessary maturation period the process yields a final product (alpeorujo-compost) of good quality.

The olive pulp on wet basis represents the 60% of alpeorujo. It is acidic (pH 4.6 – 4.8), almost black in colour mass with a moisture content c. 65-67% (on wet basis), having a smooth -like dough- structure. It is rich in organic and inorganic constituents, especially in potassium. Its chemical composition though not its structure is compatible with the composting process. Thus the olive pulp poses quite a serious waste obstacle and hinders the full realisation of the alpeorujo-recycling scheme described above (Sub-Task 3.4).

The Greek cotton ginning industry generates each year about 50 thousand metric tones of waste. At present in the best of the cases it is used as fuel for heating. However, its chemical composition and texture make it suitable for composting either alone or mixed with other residues. Laboratory scale studies showed that the olive pulp and the cotton gin trash could be readily co-composted to yield agriculturally valuable compost.

An important development in this connection that exceeds the initial objectives, was the finding that hydrogen peroxide exerts a triggering effect on the composting process.

The effect of hydrogen peroxide on the microbial population profile of the end product was also examined.

Sub-Task 3.6.- The mature compost was examined by Participant 7 as potting substrate for various cultivated plants, and its water extract was used as a biological control agent against the potato blight (Phytophthora infestans (Mont.) de Bari). During this period special attention was paid to analyse the mature compost for the detection and isolation in pure culture members of its microflora that exert an inhibitory effect against the root pathogenic fungus Rhizoctonia solani.

Sub-Task 3.7.- Alpeorujo was found unsuitable for growing Pleurotus. This sub-task was therefore not pursued any further. Instead it was considered worthwhile to exploit the finding of the hydrogen peroxide triggering effect on composting and to investigate the possibility of using the alpeorujo compost as substrate for growing the common white mushroom Agaricus bisporus. Moreover, since "Messiniaki" had no the expertise to carry out this part, it was decided to approach the Company "Hellenic Mushrooms Farm" to undertake this part of the work. The scientist in charge is Mr. L. Lachouvaris, scientific officer of the Company and he is presently carrying out tests using alpeorujo compost as substrate and casing layer in the facilities of the Mushroom Farm.

Sub-Task 4.1.- More runs were carried out by Participant 1 to validate the instrumentation and control systems of the flumov drier and the industrial grade controller developed by Participant 5. One of the members of the team of Participant 1 visited the lab of Participant 5 to perform the final actions to configure and finally implement the controller in the drier fluidised/moving bed drier of Participant 1.

Sub-Task 4.2.- Based on the results of the previous research, Westfalia Separator has continued the tests for de-oiling the orujo. For this purpose, the pilot plant in South Spain was used. This pilot plant has a capacity of 1 m³. In the tests of 1999, the daily quality of alpeorujo had to be determined as basis for the assessment of the test results. The basic tests followed these standard process steps:

• Classical de-oiling with the ecological line (two-phase decanter) in a common olive mill, as a by-product alpeorujo was produced.
• Pumping of a part of the alpeorujo into storage tanks.
• Malaxing of alpeorujo.
• De-oiling of alpeorujo by means of a second decanter.

It was investigated, if and how the yield of oil coming out of the second machine could be reached and improved. Different process parameters were modified. Furthermore, the quality of the different recovered oils was analysed.

It is of special interest to know if a direct second de-oiling, i. e. carried out immediately after the first de-oiling, gives oil of the quality "olive oil" or only of the quality "orujo oil". For this purpose, the basic variant was compared to the following procedures:

• Milling the alpeorujo before the second de-oiling
• De-pitting the alpeorujo before the second de-oiling
• Combination of a) and b)

Sub-Task 4.3 .- Several tests on gasification of orujillo were carried out. The operating conditions tested are:

Sub-Task 4.4 .- Participants 1 and 5 met in June 99 at UCM to finalise the design of the industrial grade instrumentation and Panel Controller which operate unattended and feature all the required robust protection mechanisms. The prototype hardware and software was completed, tested and sent to Participant 1 in September 99. They met again in October 99 at CQ to discuss controller application. The Panel Controller was then placed in operational service in the laboratory of Participant 1 and demonstrated to all the participants at the meeting of 3 December 99.

Sub-Task 5.1.- The overall and particular results of every task and Participant has been evaluated.

Sub-Task 5.2.- The integration of results and cost assessment has been used to develop industrial standards and the elaboration of feasibility recommendations for the construction of large-scale plants. A series of strategies of production have been defined and a list of most feasible treatments useful for interested parties (industry, olive oil co-operative, etc.). A series of scenarios including geographical/regional characteristics, level of production, and market dependence have been defined to help producers on the decision of which treatment fits best their particular need. More detailed strategies are being prepared to be presented in the Final Report.

Sub-Task 1.1.- Five main procedures suitable for alpeorujo treatment were identified: drying (natural, mechanical), combustion, aerobic treatment (composting), anaerobic treatment, treatment by fungi. Other technical and relatively expensive procedures are listed under "Treatment of liquid waste from olive oil production".

Sub-Task 1.2.- No information resulted from the inquiry by mail and telephone. The in-situ inquiry resulted in 11 data records collected in Greece and 18 in Spain. This low response is due to very sceptical reactions of the olive oil producers that can be explained by the rather obscure situation of the legislation in their countries concerning waste treatment. Alpeorujo is mainly treated in large evaporation lagoons and/or used as fuel. This does not comply with the ecological principles of the EU or the respective countries. Therefore the information flow, especially of confidential material, was insufficient.

A third measure for data collection exists through the forms of the interactive database on the project Internet Web pages and the direct possibility to contact participant 3. This way of data collection is operative and will continue to exist after the project has been achieved.

Sub-Task 1.3.- The description of the procedures for alpeorujo treatment mentioned above would be too extensive within the framework of this progress report, therefore only the result is presented.

With view to economic and ecological aspects, composting is the best method to treat alpeorujo. Especially the composting process developed by Participant 7. It is ideal due to recycling of the compost as structuring material, low water- and air emissions and a final product of high quality, which can be used successfully in agriculture. Investment and operating costs may be compensated considerably by the receipts from compost sales. However, this strongly depends on the local market sales potential.

Sub-Task 1.4.- Anaerobic treatment of the waste is well suited because of its high organic content. However, problems in process engineering have to be expected when solid waste like alpeorujo is treated, for example in mixing and pumping. Moreover, the waste is produced only during the olive processing campaign, but the biological process needs a long starting-up time, which is unfavourable from the economic point of view. Here co-fermentation with other bio-waste or municipal waste would be more useful.

Sub-Task 2.1.- Completed in the second period.

Sub-Task 2.2.- Completed in the second period.

Sub-Task 2.3. Completed in the second period.

Sub-Task 2.4 - 2.5. From all the bacterial and yeast strains that have been isolated from alpeorujo, the strain that has been selected for further study was P.variotii, not only because it has been proven capable of increasing the protein content in some preliminary experiments, but also because it has already been reported in the past for its excellent ability to grow in a variety of highly-polluted industrial effluents, such as molasses, wood hydrolysates and spent sulphite liquor.

The physiological study of the specific fungus is the first necessary step for the optimisation of the fermentation parameters. The study of the growth cycle of the specific strain grown in Malt Extract Broth, at 300 C, gave a maximum specific growth rate of 0.06 h^-1 and the doubling time was 11.55h (Figure 1, annex III). The fungus has an optimum growth at 350 ºC (Figure 2 annex III), while the optimum pH was 4 (Figure 3, annex III).

A new set of experiments, concerning the enrichment of alpeorujo with molasses was designed. Molasses is a cheap, renewable industrial by-product with a very high sugar concentration. Under the optimal pH and temperature conditions, different sucrose concentrations of diluted sugar beet molasses have been studied. The optimal sucrose concentration is 12.5% (Figure 4, annex III).

When all the optimal parameters were established, solid state fermentation experiments were performed using alpeorujo as substrate and adjusting the humidity by addition of diluted sugar beet molasses with sucrose concentration 12.5%. In order to study the metabolic activity of the micro-organism, the CO₂ production has been measured using a gas chromatograph connected to the solid fermentation system. The study of the respiration of P.variotii growing on alpeorujo-molasses waste showed that the metabolic activity is intense in the first 20 h and even though it declines later on, the inoculum remains still active (Figure 5, annex III). Samples were taken every 2 days and were chemically tested in order to define the differences that occur in the waste during the fermentation procedure.

All fermentation products were chemically tested and the results were compared with those of the original unfermented alpeorujo. Sugars concentration decreases rapidly after 2 days of fermentation (Figure 6, annex III). The tannin concentration seems to increase slightly (Figure 7, annex III), while the total lipids concentration decrease in the fermented products about 40% (Figure 8, annex III). The protein concentration in the fermented product increases from 14.75% in the initial dried alpeorujo sample to 21.65% in the 10 days fermented product (Figure 9, annex III). This represents a 46% increase of proteins, which is a very promising result for the potential of this substrate to be used as an animal feed.

Sub-Task 2.6.- Increase in quantities and change in profile of the present aminoacids of alpeorujo has been observed in the fermented product due to the growth of the fungus. The change in the total protein content as well as the content of aminoacids in raw alpeorujo and in the fermented product is shown in Figure 10 of annex III. The increase of 46% in the total protein content is very well reflected in the increase of the amounts of aminoacids in the fermented product. Apart from this increase, there is a change in the profile of the protein content after the fermentation showing that the protein produced has a different aminoacid composition from that of the raw alpeorujo.

The concentration of all aminoacids in the fermented product has increased except glutamic acid. In the FAO listed aminoacids, the higher increase appears in Tyrosine and Methionine, whose amounts are tripled in the protein of the fermented product, while Threonine increases by 30% and Valine by 12.5%. A lower increase appears in Isoleucine (8%) and Aspartic acid 7%. It can also be observed that in the fermented product, we have the appearance of Lysine (1.34g/100g protein) which is not present in the unfermented sample.

Sub-Task 3.1.- Completed in the second period.

Sub-Task 3.2.- Completed in the second period.

Sub-Task 3.3.- The main results concerned the analysis of the bacterial flora changes in a pilot-scale compost bioremediation process. A full phenotypic and genotypic analysis of the dominant bacteria present has been carried out as has a comparison of a range available community analysis procedures (classical microbiology, fatty acid analysis and molecular biology, eg SSCP). In particular, the molecular method of SSCP was modified and developed for use with the composting samples, which made it possible to detect changes in the major microbial components during the composting process. However, there were problems of quantifying the components by molecular biological means, which were not overcome during the time-frame of the project.

Sub-Task 3.4.- The alpeorujo liquid fraction (ALF) represents the 37% of alpeorujo and contains mostly the water soluble constituents of the pulp plus some residual olive oil and the endosperm oil of the olive fruits. The water fraction resembles a highly concentrated wastewater effluent of the 3-phase decanter. It is very phytotoxic, and it strongly inhibits the growth of Pleurotus and other fungi and many bacteria too. When diluted with water (10-fold or more) it can be used as substrate for Azotobacter, Fusarium, Geotrichum, Pleurotus and some yeasts (Candida). However, with the "repaso" system that is applied presently, the alpeorujo is subjected to a second centrifugal process to obtain the residual olive oil. Subsequently, the de-oiled alpeorujo can be further separated by centrifugation into (a) the woody particulate fraction that contains the woody fragments of the endosperm, and (b) the pulp, a smooth in structure paste that contains the soft tissues of the olives including the water soluble constituents. Thus, alpeorujo unlike the extracted press cake of the 3-phase decanters is highly unsuitable and cannot be used as Pleurotus substrate, unless it is supplemented with bran, molasses or other suitable substrates, with ambiguous even then results. The woody fraction is not considered as waste because it has many valuable applications.

Given time and OMWW composition, the Azotobacter based bio-remediation system is in all respects beneficial and environmentally friendly. The phytotoxicity is eliminated and the processed end product can be used for the fertilisation of plants. In fact, the product was used for the fertilisation of olive and orange trees. The progress and/or completion of the degradation of most of the compounds that are responsible for its phytotoxicity is confirmed by the obtained degradation yields; several other compounds occurring in OMWW undergo noncommittally degradation and biotransformation. At this point it worth saying that the process is rather simple, cost effective and most importantly, is capable of achieving mean removal yields as high as 90% and 96% after 3 and 7 days of treatment, respectively. Finally, statistical analysis of the results showed that between the periods of operation no significant difference occurs with respect to the degradation yield. Likewise, the degradation yield from three to seven days remains almost unaltered during two consequent years.

Sub-Task 3.5.- The 2-phase olive oil mills combined with the "repaso" system and the mechanical separation of the de-oiled alpeorujo generate three types of wastes: (a) alpeorujo, (b) de-oiled alpeorujo, and (c) pulp.. The solid state thermophilic fermentation (composting) of all three types of waste was studied extensively.

For alpeorujo and de-oiled alpeorujo a self-sustainable composting process was elaborated. Bulky material is only required for the initiation of the process. When the thermophilic phase is established the operation is switched to a fed-batch system with a cycle time of 7 days and a ratio of residual to removal volume c. 0.30. Under these conditions no additional bulky material is required. Thus fresh alpeorujo can be fed for practically an unlimited time, and after the necessary maturation period the process yields a final product (alpeorujo-compost) of good quality.

The composting process was monitored by recording the temperature, the sugars level, the polyphenol content, the EC and by using the thermogradient respirometric technique. The assessment of the quality was based on the Germination Index using Lepidium sativum (Zucconi et al 1981), the pH, the EC, and the degradation of polyphenols. The alpeorujo and the orujo composts in particular are alkaline in reaction. For this reason the kinetics of their acidification using elemental sulphur was investigated and a regression formula that allows calculations to be made for the amount of sulphur that is required for adjusting the pH of compost during the maturation phase at the desired level was derived.

The olive pulp on wet basis represents the 60% of alpeorujo. It is acidic (pH 4.6 – 4.8), almost black in colour mass with a moisture content c. 65-67% (on wet basis), having a smooth -like dough- structure. It is reach in organic and inorganic constituents, especially in potassium. Its chemical composition though not its structure is compatible with the composting process. Thus the olive pulp poses quite a serious waste obstacle and hinders the full realisation of the alpeorujo-recycling scheme described above (Sub-Task 3.4).

The Greek cotton ginning industry each year generates an estimated 50 thousand metric tones of waste. At present in the best of the cases it is used as fuel for heating. However, its chemical composition and texture make it suitable for composting either alone or mixed with other residues. Laboratory scale studies showed that the olive pulp and the cotton gin trash could be readily co-composted to yield agriculturally valuable compost.

An important development in this connection that exceeds the initial objectives, was the finding that hydrogen peroxide exerts a triggering effect on the composting process. This is reflected by the fact that on treatment with hydrogen peroxide the temperature in the composting mass commences to ascend with a significantly faster pace than in the control–untreated–series. Similar in response triggering effects were observed in all cases of compostable materials examined so far that include: immature orujo compost, orujo co-composted with alpechín, cotton gin trash, and cotton gin trash mixed with olive pulp (i.e. the de-stoned by centrifugation fraction of de-oiled alpeorujo). The long-term rise of temperature however, reflects intensification of microbiological activity in the catabolic processes. The triggering effect of hydrogen peroxide on the initiation and advancement of composting cannot be ascribed solely to the extra oxygen that is liberated shortly after the addition of hydrogen peroxide. It is more likely that hydrogen peroxide, being a reactive oxygen intermediate by itself, elicits the formation of highly reactive hydroxyl radicals. Such mechanisms are well known now to operate in the biological realm. The lignin moiety of lignocellulose is decomposed by Phanerochaete chrysosporium through a mechanism of co-metabolism. The formation of glucose from the cellulose yields hydrogen peroxide, hydroxyl and superoxide radicals that are needed to initiate in a snowball reaction the breakdown of the lignin skeleton. Similar evidence has been reported in the case of the brown rot fungus Gloeophyllum trabeum. The fungal chelator fosters the production of reduced metals which when in proximity to reactive oxygen species such as hydrogen peroxide or other oxidants, will react to form hydroxyl radicals which are capable of depolymerising and oxidising lignocellulose compounds.

This finding led us to develop a new method for assessing compost stability.

The proposed conditions for carrying out the stability test are as follows:

1. A volume of 1.5 L of the under test material is seeded with mature compost at a rate 10% v/v.
2. The mixture is placed in a thermally insulated container of 2 L capacity where is moistened up to 60% of its field water capacity with hydrogen peroxide solution 5%.
3. Subsequently the flask is placed in constant temperature room (20 °C).
4. The temperature in the mass is followed using a suitable thermometer (preferably an electronic one equipped with a thin and long temperature probe).

A Thermal Stability Index (TSI) is proposed that can be calculated through the following simple formula:

The TSI values produced by this formula range from one (fully stable compost) down to zero (unstable compost). In rare occasions it may yield negative values, This occurs when the peak temperature exceeds the level of 60 °C; an indication of a strongly unstable material.

The effect of hydrogen peroxide on the microbial population profile of the end product was also examined.

Sub-Task 3.6.- Three lines of investigation were adopted. In the first, the mature compost was used as potting substrate for various cultivated plants. In the second, compost extract was used as a biological control agent against the potato blight (Phytophthora infestans (Mont.) de Bari). In the third, the compost was analysed for the detection and isolation in pure culture members of its microflora that exert an inhibitory effect against the root pathogenic fungus Rhizoctonia solani. The results from the first two lines of investigation are altogether promising. In fact, the product (compost) is much liked by the farmers and already there is an expressed commercial interest for its exploitation. The compost extract gave similar or even better control against potato blight when compared with a commercial organic preparation (Biosolã ). The third line of investigation yielded a number of isolates that are inhibiting in vitro the growth of Rhizoctonia solani. Most of the isolates were identified using the Bio-Log System, and most of them belong to the genus Streptomyces. All isolates are kept in our Culture Collection.

Sub-Task 3.7.- Alpeorujo was found unsuitable for growing Pleurotus. This sub-task was therefore not pursued any further. Instead it was considered worthwhile to exploit the finding of the hydrogen peroxide triggering effect on composting and to investigate the possibility of using the alpeorujo compost as substrate for growing the common white mushroom Agaricus bisporus. Moreover, since "Messiniaki" had no the expertise to carry out this part of the work, it was decided to approach the Company "Hellenic Mushrooms Farm" to undertake this part of the work. The company became particularly interested and is already involved on the subject The scientist in charge is Mr. L. Lachouvaris, scientific officer of the Company who is presently carrying out tests using alpeorujo compost as substrate and casing layer in the facilities of the Mushroom Farm.

Sub-Task 4.1.- The new controller developed by Participant 5 was tested. The performance of the controller is adequate. The temperature inside the drier and the moisture of the dried solid are well controlled. The controller is suitable for controlling the operation and is very versatile to be adapted hopefully to other different operations and processes.

Sub-Task 4.2.- The de-oiling of the fresh alpeorujo in a second decanter step is possible, also directly after the first de-oiling step. By means of an additional fine milling step, a better release of the oil contained in the alpeorujo is reached (the finer the milling, the higher the yield). By means of a pit separator, the alpeorujo quantity is reduced by 10%-15%. The reduction depends on the mesh size of the pit separator. Consequently, the throughput of the second de-oiling step, compared to the basic variant, increases by these 10%-15%. At the same time, the oil content and the moisture of the alpeorujo increase, as the separated pits contain less oil and water. Thus the oil quantity is by 20%–30% higher than in the alpeorujo after the first de-oiling and/or in the alpeorujo of the basic variant. However, referred to this higher oil quantity, the yield is lower compared to the basic variant. That means, if fresh (pit-containing) alpeorujo is de-oiled in the second decanter, up to 50% of the oil contained therein can be recovered. However, if pit-reduced alpeorujo is de-oiled in the second decanter, only up to 40% of the oil contained therein are recovered. Nevertheless, the recovered oil quantity for pit-reduced alpeorujo is equal or higher compared to the basic variant, because – as it is known – the oil content in the pit-reduced alpeorujo (second decanter input) is higher. The longer the alpeorujo is stored, the higher is the oil quantity that can be recovered. However, also the ffa-content can rise within the first 6-8 hours from less than 1% up to more than 2 %. Alpeorujo, which is de-oiled directly, gives an oil which, with regard to the ffa-content, would reach the quality stage "olive oil". However, the content of Erythrodiol and Uvaol increases from approx. 1% to more than 4%. On the other hand, the peroxide number increases up to the admitted value for olive oil of 20.

The effects on the composition and low heating power of the flue gas were tested. The gasification yield is about 50%; this means that about 50% of the solid must suffer burning to maintain the auto-thermal process conditions inside the gasifier; the other 50% is actually gasified to give useful flue gas. The low heating value of the flue gas is between 4 and 6 MJ/Nm3. The effects of both the temperature, equivalent ratio (ER) and air/water ratio on the composition of the flue gas have been studied (see more details in the supplementary documentation). The typical flue gas composition in the gasification with air/water is 7%-10% H₂; 2.5%-6% CH₄; 6%-18% CO; 0.06%-1.6% C₂H₄ and 64%-84% of no combustible gases, mainly CO₂, N₂, H₂O. The presence of sand and dolomite in the fluidised bed does not affect appreciably the tar production in the moving bed nor the flue gas composition (10%H₂, 2%CH₄, 8%CO). In collaboration with Oleícola El Tejar and assessment of the energetic validation by combustion and gasification of orujillo and pits were made.

Sub-Task 4.4 .- The Panel Controller performs as designed, intended and expected. The moisture sensor was redeployed successfully. As implemented at UCM, the developed Panel Controller uses the following inputs:

• two operator commands (toggle "start/stop", "control"),
• air input temperature,
• three temperature points in the fluidised volume,
• three temperature points in the "moving" volume,
• moisture from the developed humidity sensor, and
• pressure switch (alarm) at air input.

The employed temperature sensors are Pt100’s (chosen for their robustness and endurance characteristics). Of interest is the inclusion of the pressostatic switch input which is a very simple (and elegant) way of protecting against the anticipated causes (air supply failure, material blockage etc.) of catastrophic problems such as localised heat-pockets and reactor overheating. The controller will drive the following outputs:

• material in (feedscrew etc.),
• cleaning cycle,
• material out,
• two mid-level pneumatic valves, and
• two alarm conditions ("yellow", "red").

The inclusion of a cleaning cycle is a novel idea for this type of plant and its purpose is similar to a soot blowing cycle in combustion installations. By using the existing pneumatic valves (controlling the material position and movement in the reactor) air will be driven in the reverse direction with the whole procedure aiming to eliminate (or minimise) production downtime to remove stuck/clogged material in the installation piping, and maintain the system performance/accuracy by keeping the sensor and reactor surfaces clean.

The conditions to launch a cleaning cycle are a function of the input states/magnitudes and are configured by the system parameter file/data block (as is the case with the other outputs). The parameter (or configuration) file contains a comparison table from all inputs to all outputs thus allowing for adjustment in the field.

It is to be noted that such a system is inherently stable as it is of first order nature (on-off actuation based on magnitude comparison, with hysteresis).

All inputs and outputs are accessible via the system serial port for slave operation and out-of-production or laboratory testing and experiments.

When budgeting for such an installation, the following figures should be used:

• Panel Controller in wired/installed cabinet: 1.500 Euro,
• Pt100 with 50 m wiring: 500 Euro each,
• Pressostat switch with 50 m wiring: 500 Euro each,
• Solid-state relay actuators with 50 m wiring: 500 Euro each,
• Humidity sensor with 50 m wiring: 1.500 Euro, and
• General installation costs: 1000 Euro.

Sub-Task 5.1.- Results and integration of tasks:

From task 1.-

• The data collection about already tested treatments of wastewater from three-phase decanting process showed that the two-phase decanting process has unequivocal advantages. Nevertheless, the treatment of wastewater from the two-phase decanters does not exist at this time and it is difficult to design and compare former treatment processes.
• For each type of waste (liquid and solid) from olive oil production one treatment procedure was chosen. Based on the results of participant 7, the composting procedure was chosen for alpeorujo from the two-phase decanter. For alpechín, liquid waste from the three-phase decanter, the anaerobic-aerobic treatment procedure is favoured.
• The database has been developed and filled with real data from olive oil producers.

• The input to the interactive database is still open through on-line forms, which are integrated into the Internet page to get a continuous possibility for data collection.

From task 2.-

• The chemical composition of alpeorujo has been examined. The main constituents of alpeorujo are tannins, lipids, proteins, sugars and lignocellulosic materials. The chemical profile of alpeorujo makes it adequate to support microbial growth, by providing plenty of carbon, nitrogen and energy sources. The results agree with this assumption: alpeorujo is a suitable substrate for the growth of fungi and yeasts and metabolite production.
• Apart from the aerobic bacteria growing at 30ºC, several thermophilic bacteria have been isolated and identified: Bacillus brevis, Aeromonas salmonicida, Corynebacterium group B. The anaerobic bacteria existing in the alpeorujo seem to be in close relation to Lactobacillus acidophilus (44%) and Bifidobacterium spp.(33%). As far as the yeasts are concerned, Candida genus was found to be the predominant one. Saccharomyces cerevisiae appeared in a low frequency, while Candida valida showed the highest frequency in the total isolated yeast population.
• Fungi were isolated from alpeorujo: Rhizopus, Penicillium and Synchephalastrum and Paecilomyces.
• A solid state system has been developed and used to examine the growth and activity of selected strains of yeasts and fungi under controlled conditions (growth of Paecilomyces variotii and Saccharomyces cerevisiae).
• The strain of P.variotii has been selected for further studies. It has been proven capable of increasing the protein content and has an excellent ability to grow in a variety of highly polluted industrial effluents, such as molasses, wood hydrolysates and spent sulphite liquor. The growth cycle in Malt Extract Broth, at 30 ºC, gave a maximum specific growth rate of 0.06 h^-1 and the doubling time was 11.55h. The fungus has an optimum growth at 35 ºC, while the optimum pH was 4.
• The enrichment of alpeorujo with molasses, which is a cheap, renewable industrial by-product with a very high sugar concentration, gave satisfactory results. The increase in the final protein content is around 45%. This increase, which has never been achieved in previous fermentation experiments, is a very positive result for the optimisation of the waste material in order to be used as an animal feed or a food additive.

From task 3.-

• Bacteria which are capable of growing in acidic pH of alpeorujo were isolated from alpeorujo.
• Pure bacterial cultures have been obtained using commercially prepared bacterial growth media and alpeorujo based media. From bacterial isolates three groups of bacteria have been identified.
• Specific free-living N₂-fixing bacteria of the genus Azotobacter grow well in olive mill waste waters and can transform the wastes into a useful organic fertiliser and soil conditioner. Since no fresh alpeorujo was available during this phase of the project, it was decided to use as model substrate of the liquid fraction of alpeorujo concentrated undiluted.
• The isolates showed a great ability to adapt to low water activity and were also able to best tolerate the physiologically-stressful conditions (for bacterial growth) that are presented by the alpeorujo and the composting systems.
• Data on bacteria isolated directly from the alpeorujo composting system of Participant 7 were also used to demonstrate the relevance to bioremediation conditions so that such information can be used in a predictive fashion.
• The monitoring of Azotobacter vinelandii strain A population was studied. There is an initial adaptation phase. The presence of phenolic compounds limit A. vinelandii growth but stimulate dinitrogen fixation, followed by a rapid growth phase as phytotoxicity declines and leading to a detoxified product suitable to be used as soil fertiliser.
• A composting process has been developed to make the transformation of alpeorujo under thermophilic conditions into a humidified organic substrate suitable for agricultural use. Unlike most other organic residues and wastes, alpeorujo through its organic nature resists the microbial succession that could lead to the establishment of a functional composting process.
• It has been demonstrated that composting of alpeorujo is feasible under the conditions developed during this investigation. The thermophilic phase is carried out in a continuous batch-fed system using composted alpeorujo as bulky agent. The process is greatly enhanced by treating the pile with dilute solution of hydrogen peroxide.
• Cultivation of edible mushrooms (Pleurotus) is possible on composted alpeorujo. The row material yields erratic results, and the heat-dry alpeorujo is inhibitory. Trials are in progress to expand the tests over other fungal species.
• The mature alpeorujo compost is suitable as soil fertiliser and presently is used in large scale trials over a variety of plants. A number of bacterial species with antifungal properties have been obtained in pure culture in a screening programme from soils enriched with OMW
• The analysis of the bacterial flora changes in a pilot-scale compost bioremediation process was studied and a full genotypic analysis of the dominant bacteria present has been carried out
• The alpeorujo liquid fraction (ALF) diluted with water can be used as substrate for Azotobacter, Fusarium, Geotrichum, Pleurotus and some yeasts (Candida).
• De-oiled alpeorujo is highly unsuitable and cannot be used as Pleurotus substrate, unless it is supplemented with bran, molasses or other suitable substrates, with ambiguous even then results. The woody fraction has many valuable applications.
• The Azotobacter based bio-remediation system is in all respects beneficial and environmentally friendly. The phytotoxicity is eliminated and the processed end product can be used for the fertilisation of plants. The product was used for the fertilisation of olive and orange trees. The process is rather simple, cost effective and capable of achieving mean removal yields as high as 96% after 7 days of treatment.
• For alpeorujo and de-oiled alpeorujo a self-sustainable composting process was elaborated. Bulky material is only required for the initiation of the process. When the thermophilic phase is established the operation is switched to a fed-batch system with a cycle time of 7 days and a ratio of residual to removal volume of 30%. Under these conditions no additional bulky material is required. Thus fresh alpeorujo can be fed for practically an unlimited time, and after the necessary maturation period the process yields a final product (alpeorujo-compost) of good quality.
• The composting process was monitored and assessed. The kinetics of acidification by sulphur was investigated and a regression formula that allows calculations to be made for the amount of sulphur that is required for adjusting the pH of compost during the maturation phase at the desired level was derived.
• Laboratory scale studies showed that the olive pulp and the cotton gin trash could be readily co-composted to yield agriculturally valuable compost.
• An important development was the finding that hydrogen peroxide exerts a triggering effect on the composting process. This finding led us to develop a new method for assessing compost stability. The effect of hydrogen peroxide on the microbial population profile of the end product was also examined.
• The use of mature compost as potting substrate for various cultivated plants was studied also. The results are promising. The compost is much liked by the farmers and already there is an expressed commercial interest for its exploitation. The compost extract gave similar or even better control against potato blight when compared with a commercial organic preparation (Biosol).
• Alpeorujo was found unsuitable for growing Pleurotus. Nevertheless, two new facts were studied: the hydrogen peroxide triggering effect on composting, which is considered an innovative aspect of composting control, and the use of alpeorujo compost as substrate for growing the common white mushroom Agaricus bisporus.

From task 4.-

• The fluid dynamics of a new system based on the combination of fluidised/moving beds (flumov) has been studied. Seven different cold models of flumov systems were made and tested. Six "J-valves" for solid feeding/output were designed and calibrated.
• A flumov drier was constructed and used to treat 1-5 kg/h of alpeorujo. The Sub-contractor "Oleícola El Tejar" assessed the quality of dried solids. A series of faults/solutions during the operation of the drier were identified. A comparative assessment between the flumov drying system and driers based on rotary drums was made. Estimations were made concerning the heating and transport costs, size and cost of industrial driers. I was estimated that flumov systems could be about 40% cheaper than rotary driers. Besides, the fluidised/moving bed systems is very attractive to combine with processes that generate low temperature streams of gases.
• A pilot plant was designed and operated for studying the de-oiling and drying of alpeorujo. Three different modifications of the drying process were explored: a) Reduction of the oil content by a further liquid-liquid-separation; b) Volume reduction by means of pit separation; and c) Optimisation of the raw material for drier feed by mixing dried material with wet primary material before drying. The results show a reduction of the oil content in the pulp by 50 %, by means of a two-phase decanter in a second step. The pit separation results in a reduction of the orujo quantity by 15 %. The air-dried pits can be used as fuel and the wet solids have to be pre-treated for a following drying process. Designing the drier, the different material characteristics have been considered. Additional mixing systems will be installed. The drying process has to start with a backmixing of dry orujillo powder into the wet alpeorujo. The wet alpeorujo has to be oil-reduced and pit-reduced. The oil quality depending on the modified process parameters was judged. It was found out that most of the parameters of the oil recovered from the alpeorujo do not show a difference to the olive oil from the first de-oiling stage, however, the parameters Erythrodial, Uvaol, PON and ffa-content show considerable changes.
• A flumov system was designed and operated to study the combustion/gasification of orujillo and pits. Participant 1 carried out several tests on combustion and gasification of orujillo and olive pits. The Sub-contracted Oleícola El Tejar assessed the results.
• The combustion is only feasible in fluidised conditions. In the combined fluidised/moving bed the combustion tends towards gasification due to the particular combination of vessels: the combustion takes place in the fluidised bed (in the bottom of the system) and the gasification in the moving bed (in the upper part of the system.
• The gasification is positively feasible in the fluidised/moving bed system. The yield is about 50%. The low heating value of the flue gas is 4-6 MJ/Nm³. The effects of temperature, presence of sand and dolomite, equivalent ratio (ER) and steam/air ratio on the composition of the flue gas were studied.
• The typical flue gas composition is: 7%-10% H₂; 2.5%-6% CH₄; 6%-18% CO; 0.06%-1.6% C₂H₄ and 64%-84% of CO₂, N₂, H₂O. Technical assessment and economical estimation were made by Oleícola El Tejar concerning the application of this flue gas to explosion motors.
• Different monitoring/control systems were tested (PID, prototypes of moisture probe and advanced control). The moisture sensor performance has been shown to be stable and reliable.
• From the obtained operational experience, an industrial grade controller was designed to incorporate the necessary sensors, alarms and actuators that will operate unattended and feature all the required robust protection mechanisms. The controller is simple and stand-alone, unattended operation by non-specialist personnel, fully, field programmable parameters and transfer function/equation for each output, complete, "seamless" integration as a slave to an external master, and standard DIN panel cut-out dimensions. The controller is parametrically programmable via the serial port of a PC and comes with all the necessary software, which includes an off-line simulator.
• After evaluating the obtained results, the developed instrumentation and control equipment performs well. It is readily up/down-scalable and can easily be employed in all foreseeable duty conditions.

Sub-Task 5.2.-

• Information on possible treatment procedures for alpeorujo was completed with data from national and international literature and with the results of tasks 2, 3 and 4.
• Olive oil production in the EU member states, related factors (legislation, economic aspects, and waste production) and treatment procedures were presented in detail on the Internet (http://www.fiw.rwth-aachen.de/improlive/improlive.html).

• The industrial applications of P.variotii as a means of increasing the protein content seem feasible, given the excellent ability to grow in a variety of highly-polluted industrial effluents, such as molasses, wood hydrolysates and spent sulphite liquor. The enrichment of alpeorujo with molasses, which is a cheap, renewable industrial by-product with a very high sugar concentration could be a good solution to increase the final protein content and for the optimisation of waste materials in order to be used as an animal feed or a food additive.

• Economical and industrial estimations were made on the industrial design of driers and gasifiers. The heating and transport costs for drying (18€/t), size and cost of a drier for 15 t/h of capacity (fluidised bed 1.5´ 2m, moving bed 3.5´ 6m, 0.6 M€), size and cost of a gasifier for treating 15 t/h of solids capacity (fluidised bed 2.6´ 8m, moving bed 8´ 8m, 3.6 M€). The main conclusions are that drying in fluidised/moving bed systems is very attractive to combine this operation with other ones that generate low temperature streams, and that gasification would increase the effectiveness of power plants.
• Information on size, costs and mechanical engineering of a composting plant can be given by Participant 7.
• To optimise the de-oiling of alpeorujo, the following two methods can be recommended to oil mills:

• De-oiling of alpeorujo after the pit-separator. In this case, the pits can be used as fuel, up to 40 % of the oil content can be recovered. The quantity of alpeorujo de-oiled by a decanter compared to untreated alpeorujo increases by approx. 10 %–15 % , i. e. by the percentage of the pits separated.
• De-oiling of alpeorujo. Preferably, the alpeorujo should be de-oiled after an additional milling and a short storage time. Yields of up to 50 % can be reached, however, increasing the storage time brings a higher yield, but the quality goes down considerably.

• The developed instrumentation, moisture sensor and Panel Controller were designed for the process control environment (typical IMPROLIVE duty) and are fully and readily scalable to production scale plants. The applicable legal/standards EU frame is provided by the Low-Voltage, Electromagnetic Compatibility and Machine Directives. Applicable standards originate from IEC/CENELEC work.
• Existing standards on industrial equipment, machinery and practice cover completely the developed Sensor and Panel Controller. Because of their inherent scalability, the developed instrumentation and controller are not limited by plant size. Their communication capabilities also allow them to be used as members of a plant-wide data network.

The most representative conclusions of the whole project are:

• The two-phase decanting process has unequivocal advantages. Nevertheless, there are unsolved problems about treatment of the wastewater generated from the second decanting in two-phase decanters (so-called "repaso" in Spanish).
• The composting procedure for alpeorujo anaerobic-aerobic treatment for liquid fractions seem the most favoured treatments.

• It is not easy to get real results from producers involving useful technical and economical data.

• Alpeorujo is adequate to support microbial growth and is a suitable substrate for the growth of yeasts and fungi and metabolite production.
• The P.variotii is capable of increasing the protein content in alpeorujo. The enrichment of alpeorujo with molasses allows to 45% increase in the final protein content and make material potentially useful for animal feed and/or food additive.

• A composting process has been developed to make the transformation of alpeorujo under thermophilic conditions into a humidified organic substrate suitable for agricultural use. Bulky material is only required for the initiation of the process. The process is greatly enhanced by treating the pile with dilute solution of hydrogen peroxide.
• The mature alpeorujo compost is suitable as soil fertiliser and presently is used in large scale trials over a variety of plants. A number of bacterial species with antifungal properties have been obtained in pure culture in a screening programme from soils enriched with OMW
• The bioremediation process of the alpeorujo liquid fraction diluted with water can be made by using it as substrate for Azotobacter, Fusarium, Geotrichum, Pleurotus and some yeasts (Candida). The Azotobacter based bio-remediation system is beneficial and environmentally friendly. The phytotoxicity is eliminated and the processed end product can be used for the fertilization of plants. The use for the fertilization of olive and orange trees show tha the process is rather simple, cost effective and capable of achieving mean removal yields as high as 96% after 7 days of treatment.
• De-oiled alpeorujo is highly unsuitable and cannot be used as Pleurotus substrate, unless it is supplemented with bran, molasses or other suitable substrates, with ambiguous even then results.

• A new system based on the combination of fluidised/moving beds (flumov) has been developed and tested suitable for drying alpeorujo. Drying in fluidised/moving bed systems is very attractive to combine this operation with other ones that generate low temperature streams.
• De-oiling and drying of alpeorujo can be optimised by optimising the liquid-liquid separation, by reducing the amount of material by pit separation and by mixing dried material with wet primary material before drying.
• A new system based on the combination of fluidised/moving beds (flumov) has been developed and tested suitable for gasification of orujillo and pits. The gasification is positively feasible in the fluidised/moving bed system. The flue gas is similar to other gasification processes and could be used in suitable special motors to produce electricity.
• A moisture sensor was developed which is able to monitoring on-line the moisture of solids. An industrial grade controller was designed. It is readily up/down-scalable and can easily be employed in all foreseeable duty conditions.

• The results have made possible to reach a very complete picture of possible treatment procedures for alpeorujo with data from national and international literature and with the results of tasks 2, 3 and 4.
• The dissemination of results from the whole project, as well as a particular information about olive oil production in the EU and treatment procedures were presented in detail on the Internet.

• The enrichment of alpeorujo with molasses could be a good solution to increase the final protein content after the fermentation procedure in order to be used as an animal feed or a food additive.

• Industrial estimations about drying and gasification were made. Particular calculations were made in order to reach values of heating and transport costs for drying, size and cost of driers and gasifiers based on flumov systems. The main conclusions are that drying in fluidised/moving bed systems is very attractive to combine this operation with other ones that generate low temperature gas streams, and that gasification would increase the effectiveness of power plants.
• Information on size, costs and mechanical engineering of a composting plant can be given by Participant 7.
• To optimise the de-oiling of alpeorujo, two methods can be recommended to oil mills: De-oiling of alpeorujo after the pit-separator and de-oiling of alpeorujo (after an additional milling and a short storage time).
• The developed instrumentation, moisture sensor and Panel Controller designed for the process control environment are fully and readily scalable to production scale plants. The applicable legal/standards EU frame is provided by the Low-Voltage, Electromagnetic Compatibility and Machine Directives. Applicable standards originate from IEC/CENELEC work.
• Existing standards on industrial equipment, machinery and practice cover completely the developed Sensor and Panel Controller. Because of their inherent scalability, the developed instrumentation and controller are not limited by plant size. Their communication capabilities also allow them to be used as members of a plant-wide data network.

___________________________________________________________________________________

Diversity and osmoregulatory responses of bacteria isolated from two-phase olive oil extraction waste products, C.E. Jones, P.J. Murphy and N.J. Russell, submitted to World Journal of Microbiology and Biotechnology, 2000.

Flow control system for granular solids, José M. Aragón, María C. Palancar, José S. Torrecilla and Miguel Serrano, Patent Application nº P9901236 June 4th, 1999.

Drier for very wet solids, J. M. Aragón, María C. Palancar, Miguel Serrano and José S. Torrecilla, Patent Application nº P9902333 October 22nd, 1999.

Project Improlive. José M. Aragón, Alimentacion, Equipos y Tecnologias, April 1999, pp 117-123.

Adaptation and Population Dynamics of Azotobacter vinelandii During Aerobic Biological Treatment of Olive-Mill Wastewater, Ehaliotis, C., Papadopoulou, K., Kotsou, M., Mari, I. And Balis, C.; FEMS Microbiology Ecology 00 (1999) 1-11.

Moisture Sensor and Panel Controller, P. Daniil. Presented and promoted at the Brandenburg Europartenariat 99 on 28 and 29 October 1999. Brief descriptions were also posted in the IMPROLIVE site at the UCM web server.

WEB PAGES: updating

• http://www.ucm.es/info/improliv/index.htm
• http://www.fiw.rwth-aachen.de/improlive/improlive.html