Treatment by biological processes
The aerobic waste water treatment is the most widely used and proven technology. A decomposition/conversion of the organic and chemical pollutants ( BOD , COD, nitrogen N and phosphate as P by aerobic biological processes, i.e. by various microorganisms (mainly bacteria) that require elementary oxygen to live as oxidative metabolism. The phosphate reduction is carried out by sedimentation.
The reduction of BOD and COD and the conversion to activated sludge is possible up to 95-98%, the reduction of N and P up to 50 %. As outlet value for BOD <50 mg/l is reached.
By the activated sludge in the presence of oxygen , the conversion of non- suspended solids in colloidal or dissolved form to biological flocs which are removed by sedimentation and sludge from the system is accomplished. This results in a substantial secondary clarification of the waste water. In blending the incoming waste water with return activated sludge, a fast reduction of the organic pollutants is achieved.
The excess sludge formed in the process will be treated and disposed of by means of sludge thickeners and dewatering chamber- or belt filter presses . The excess sludge can possibly be sold as fertilizer or seed sludge for other plants.The proven CUSS aerobic technology includes, for example:
Inlet screening grit, sand- oil- and grease trap, intake pumping station, static or rotary drum screens, screenings compaction, biological mixing and equalization tanks (BENB), pH adjustment/neutralization, lamella separators, emergency storage tanks, biological treatment by so-called SBRs ( sequential batch reactors ), aeration tanks, sludge sedimentation and extraction. Water aeration is accomplished by submerged or special membrane aerators, driven by side channel blowers, monitoring and control instrumentation, sludge thickeners, sludge dewatering.The customer benefits are:
Small necessary reactor volume, high process reliability, easy maintenance and process technology, low investment and operating costs , precise controllability of the cleaning process. If necessary, a variable process flow is possible. By sufficiently sized and carefully operated mechanical-biological waste water treatment plants the waste water can be cleaned to the extent that fish can live in the fish pond or effluent and control aquarium.