Space-time Dynamic Characteristics Of Suspended Solids And Water Quality Improvement Under The Operation Of Biological Nitrification Pool In An Important Reservoir

The reservoir is a type of pumping water reservoir which using for water supply. FromJuly2010to June2011, we studied spatial and temporal variations of suspended solids (SS) insurface water, and its main influence factors. Our results demonstrated that concentration of SSshows a typically longitudinal gradient. Average concentration of SS in raw water is20.8mg/L,and then water flow passing sedimentation pool (18.4mg/L), island (11.7mg/L), middle ofreservoir (8.8mg/L), finally, when water flow arrive the dam, average concentration of SSreduced to8.4mg/L. Concentration of SS showed a significantly negative correlation betweenSecchi depth (SD) and chlorophyll a (P<0.05). Particle size of SS showed a different variationcompared to its concentration. Average of D (0.5) in raw water was250.7μm and D (0.9) was391.3μm, respectively. It was mainly composed of small phytoplankton, clay and sand powderparticles. After reaction with biological nitrification pool, average of D (0.5) was144.3μm andD (0.9) was363.5μm, and it was mainly composed of powder sand, sand and littlepico-plankton. Island is located in the transition area where powder sand, clay and smallphytoplankton were the main components. Average of D (0.5) and D (0.9) were329.1μm and802.6μm near the dam, SS were mainly composed of Chlorophyta, and filamentouscyanobacteria, single-celled algae (such as chlorella sp., etc).A biological treatment engineering project had been built in tail area of the reservoir, inorder to degrade ammonia and organic pollutants with biological contact oxidation method.This study analyzed change of physical-chemical parameters, chlorophyll a, SS before and afterbiological reaction. Our results showed that ammonia could be bio-transferred effectively whenits concentration was high. Under running biological treatment, concentration of chlorophyll awould be reduced and some algae would be removed, concentration of DO would be increasedsignificantly. Finally, we assess the effect of water quality improvement under differentoperating conditions, and we also proposed the optimal diversion and management for theoperation of biological treatment.