Study On The Characteristics Of Protozoan Community And The Operating Efficiency Of The Shaying Stabilization Pond

Compared to traditional wastewater treatment technologies which are featured by huge investment and high cost of energy, stabilization lagoons have many advantages, such as simple structure and low cost of energy, and strong ability to loading shock. In particular, lagoons do not employ a solids settler, solids recycling, and independently controlled solids wasting. Stabilization ponds are widely used for treatment of domestic and industrial wastewater.The protozoa from the Shaying stabilization ponds, the largest stabilization pond in China, were sampled separately in different seasons by PFU(Polyurethane Foam Unit) method, and the changes of the shapes and dominant taxa were observed by optical microscope. The relationship between the diversities, structure and function of protozoa with the purifying result was studied while combining the operation of the ponds into consideration. This research compared the operation result in theory simulated by the VB program with the actual operation result, then analyzed stabilization-pond running performance. The research is very important for the operation of the stabilization-pond and the similar engineering in design, operation and process management.Total 172(including 4 sp.) species of protozoa were identified. Among them, 24 phytoflagelates, 4 zooflagelates, 25 sarcodina and 119 ciliates.Monoid of protozoan community had seasonal distribution characteristics in Shaying stabilization pond. The largest monoid was in summer, the lowest in winter. Meanwhile, dominant taxa were obtained at each sampling site.In Shaying stabilization pond, the results showed that structural parameters of protozoan community possessed the obvious seasonal change and spatial distribution. It is the highest in summer, and it is the lowest in winter. At the same season, it was highest in aerated fish lagoon, the lowest in inlet. In addition, species and numbers of protozoa show vertical distribution characteristics.The seasonal change of the functional parameters of protozoan community was coincide with the structural parameter. The structural parameters of protozoan community that indicate the water quality were identical with its functional parameters, and all of them were found to give a clear comparative indications of the water purify processing in the lagoons. The simulated calculation of the operation at aerated lagoon and aerated fish lagoon was done by the tailored VB program. The water quality characteristics was predicted. This research compared the operation result in theory simulated with the actual operation result, then analyzed stabilization-pond running performance.