Application of the system which combines coagulation, activated sludge and reverse osmosis to the treatment of the wastewater produced by the meat industry

The wastewater from the meat industry was treated in the system linking the processes of: coagulation, biological treatment using the activated sludge method, simultaneous precipitation of phosphor and reverse osmosis. The carried out investigation studies showed that after the simultaneous precipitation of phosphor the sewage could be returned to the natural receiving water, since its pollution ratio did not exceed the permissible values for sewage waters which can be returned to natural receiving waters. By cleaning up the wastewater in the process of reverse osmosis, it was possible to use it again in the technological cycle.

The combination of various unit processes yielding partial removal of phosphor during the coagulation process and biodegradation of organic compounds, their nitrification and further removal of phosphor in the biological process aimed to increase the efficiency involving the disposal of sewage from the meat industry. The analysis of operating results of two bioreactors, i.e. biological treatment using the method of activated sludge and simultaneous precipitation of phosphor showed that better efficiency of sewage treatment could be achieved by linking the biological system with the chemical one. The highest removal level of pollution was obtained by the application of the simultaneous process: • Coagulant ALF of the concentration 1.15 g/gP, • Loading of the sludge 0.15 kg COD/gT.S.d, • Average aeration intensity 630 dm3/h, • Operating cycle: aeration – 10.5 h, mixing – 10.5 h, aeration – 1 h. As a result of the carried out investigation, it was reported that the treatment level of wastewater in the system linking a chemical and biological process is respectively high and it can be returned to the natural receiving waters. By the application of final treatment of sewage using the method of reverse osmosis the obtained water had the level of purity high enough to be again applied in the technological cycle.