(DE4412890-A1)      Water, esp. condensate, from a compost plant, is oxygenated, especially by aeration. It is then filtered by reverse osmosis. The raw condensate is first modified, to facilitate biological clarification. The content of the water, determining oxygen demand, is measured; the quantity of material to be separated out is determined. Raw condensate is inoculated, to set the metabolic functions of the micro-organisms. The predetermined material to be separated, is filtered out. Metabolism in the bio-reactor is oxygen-controlled, esp. by air input, and/or the nutrient input, and/or pH control, and/or temperature control. Filter performance, esp. membrane filter performance, is controlled by pressure and/or throughput. Also claimed are: The use of a bio-reactor, a composting process, and composting equipment.    USE -   For the efficient purification and ultrafiltration of water condensed from a composting process, and to construct and use the necessary bio-reactor for the purpose. To integrate the system with, and run the compositing process.    ADVANTAGE -   Processes are known where the water from compositing is condensed on a cool surface, sufficiently cool to prevent external pollution and odours. The resulting fluid is difficult to treat, has a high oxygen demand and can cause equipment blockage. The present system takes the condensate through a controlled, improved cleaning process, reducing the chemical and biological oxygen demand in the bio-reactor. The process is well controlled through measurements of key parameters, pH, temperature, etc. with judicious oxygen and nutrient addition. Air is circulated in a largely closed cycle, preventing odour. Ultrafiltration results in a particularly clean, useful product, sufficiently pure to make up, e.g. the cooling water circuit.    (WO9528359-A1)      Water, esp. condensate, from a compost plant, is oxygenated, especially by aeration. It is then filtered by reverse osmosis. The raw condensate is first modified, to facilitate biological clarification. The content of the water, determining oxygen demand, is measured; the quantity of material to be separated out is determined. Raw condensate is inoculated, to set the metabolic functions of the micro-organisms. The predetermined material to be separated, is filtered out. Metabolism in the bio-reactor is oxygen-controlled, esp. by air input, and/or the nutrient input, and/or pH control, and/or temperature control. Filter performance, esp. membrane filter performance, is controlled by pressure and/or throughput. Also claimed are: The use of a bio-reactor, a composting process, and composting equipment.    USE -   For the efficient purification and ultrafiltration of water condensed from a composting process, and to construct and use the necessary bio-reactor for the purpose. To integrate the system with, and run the compositing process.    ADVANTAGE -   Processes are known where the water from compositing is condensed on a cool surface, sufficiently cool to prevent external pollution and odours. The resulting fluid is difficult to treat, has a high oxygen demand and can cause equipment blockage. The present system takes the condensate through a controlled, improved cleaning process, reducing the chemical and biological oxygen demand in the bio-reactor. The process is well controlled through measurements of key parameters, pH, temperature, etc. with judicious oxygen and nutrient addition. Air is circulated in a largely closed cycle, preventing odour. Ultrafiltration results in a particularly clean, useful product, sufficiently pure to make up, e.g. the cooling water circuit.    (US5961829-A)      Water, esp. condensate, from a compost plant, is oxygenated, especially by aeration. It is then filtered by reverse osmosis. The raw condensate is first modified, to facilitate biological clarification. The content of the water, determining oxygen demand, is measured; the quantity of material to be separated out is determined. Raw condensate is inoculated, to set the metabolic functions of the micro-organisms. The predetermined material to be separated, is filtered out. Metabolism in the bio-reactor is oxygen-controlled, esp. by air input, and/or the nutrient input, and/or pH control, and/or temperature control. Filter performance, esp. membrane filter performance, is controlled by pressure and/or throughput. Also claimed are: The use of a bio-reactor, a composting process, and composting equipment.    USE -   For the efficient purification and ultrafiltration of water condensed from a composting process, and to construct and use the necessary bio-reactor for the purpose. To integrate the system with, and run the compositing process.    ADVANTAGE -   Processes are known where the water from compositing is condensed on a cool surface, sufficiently cool to prevent external pollution and odours. The resulting fluid is difficult to treat, has a high oxygen demand and can cause equipment blockage. The present system takes the condensate through a controlled, improved cleaning process, reducing the chemical and biological oxygen demand in the bio-reactor. The process is well controlled through measurements of key parameters, pH, temperature, etc. with judicious oxygen and nutrient addition. Air is circulated in a largely closed cycle, preventing odour. Ultrafiltration results in a particularly clean, useful product, sufficiently pure to make up, e.g. the cooling water circuit.    (EP677484-B1)      Water, esp. condensate, from a compost plant, is oxygenated, especially by aeration. It is then filtered by reverse osmosis. The raw condensate is first modified, to facilitate biological clarification. The content of the water, determining oxygen demand, is measured; the quantity of material to be separated out is determined. Raw condensate is inoculated, to set the metabolic functions of the micro-organisms. The predetermined material to be separated, is filtered out. Metabolism in the bio-reactor is oxygen-controlled, esp. by air input, and/or the nutrient input, and/or pH control, and/or temperature control. Filter performance, esp. membrane filter performance, is controlled by pressure and/or throughput. Also claimed are: The use of a bio-reactor, a composting process, and composting equipment.    USE -   For the efficient purification and ultrafiltration of water condensed from a composting process, and to construct and use the necessary bio-reactor for the purpose. To integrate the system with, and run the compositing process.    ADVANTAGE -   Processes are known where the water from compositing is condensed on a cool surface, sufficiently cool to prevent external pollution and odours. The resulting fluid is difficult to treat, has a high oxygen demand and can cause equipment blockage. The present system takes the condensate through a controlled, improved cleaning process, reducing the chemical and biological oxygen demand in the bio-reactor. The process is well controlled through measurements of key parameters, pH, temperature, etc. with judicious oxygen and nutrient addition. Air is circulated in a largely closed cycle, preventing odour. Ultrafiltration results in a particularly clean, useful product, sufficiently pure to make up, e.g. the cooling water circuit.