Methods for water waste treatment for the production of edible oil

Water waste treatment. Rational use of raw materials and energy resources is an urgent problem of today. It is closely related to the protection of environment, and water resources. The large amounts of highly concentrated wastewater come from the food industry. Such water in municipal drainage system or discharged directly into the environment can pose a serious threat to natural waters. The worst wastewater treatment problems belong to the butter, margarine and mayonnaise production. It is due to the high concentrations of grease in these products and inefficient technologies for degreasing of wastewater.

Edible oil is produced by washing raw oils and fats, generating acidic wastewater with high content of organic components (fats, oils and the like). The other type of wastewater comes from washing equipment and transport. All wastewater varies in content and pollutant composition.

The complexity of the cleaning system for such production depends on a variable composition of wastewater. It should take into account that organic compounds disintegrate rapidly, causing acid fermentation and decay.

Enterprises neutralize their average wastewater with sodium hydroxide to a neutral pH, and then pass it through gravel before discharging it into the environment. This kind of treatment is ineffective, since it virtually does not trap pollutants and pollutes the environment with highly concentrated vegetable fat wastewater.

Wastewater of edible oil production is diverse both in component composition, and in concentration. It is a complex physical-chemical system with dissolved organic matter and disperse particles of varying fineness that require complex cleaning methods.

The particles may be removed by the simple methods of settling and filtration.

The organic substances can be removed only by a chemical or biochemical methods.

The processing rate of a biochemical method (biodegradation of contaminants in the wastewater) depends on water nature, dispersity and concentration, but biodegradation requires more time than chemical purification. Also, the wastewater can be purified by adsorption methods, using polytetrafluoroethylene, activated carbon and clay as adsorbents.

For best results, oxidants are introduced into the system. They gradually destroy organic structures. These oxidizing agents include solutions of sodium hypochlorite, bleaching powder, chlorine and its oxides. However, these methods are effective only for low concentrations of organic pollutants and are mainly used in the final stages of cleaning.

Chemical methods are based on the introduction of chemical reagents into the system. They serve as binders for organic soluble compounds resulting in precipitation of heavy organic acids. Such chemical agents may be acids, bases, and iron salts. For better sedimentation of inorganic coagulants A12 (SO4) 3, FeSO4, Fe2 (SO4) 3 or flocculants are also added.

For separation of suspensions electrocoagulation and electroflotation are also used.

обновлено: March 29, 2017 автором: dannik