Among the waste that is produced by the Food Industry, the liquid waste is characterised as the more important concerning to its pollutant charge. Excluding the presence of a few toxic cleaning substances, the liquid waste is organic and it is treated with conventional methods.

In almost all the food industries, the BOD is relatively high in the liquid waste. Moreover, pathogenic organisms constitute another important source of pollution of the liquid waste in industries processing meat and fishes. The liquid waste with high level of pathogenic organisms must be disinfected before its disposal.

The pH of the liquid waste is also a significant parameter for the streams that are led to treatment plants. The microorganisms that are developed in the process of the biological cleaning are particularly sensitive in fluctuations of the pH. The value of pH should be between 5 nad 9 in order to be acceptable.

The solid waste contains mainly organic subtances and waste from packages. Some organic solids are the peels, leathers, bones and kernels from the raw materials. The inorganic waste usually consists of retails from packages such as plastic, glass and metals. It is possible to process again a large part of the solid waste and convert it to valuable by-products that can be used as fertilisers, forages, etc.

The gas emissions do not consist a particular problem to the food industry. Excluding breweries, the rest of the plants emit a small amount of gas pollutants.