嫌気ろ床・生物ろ過法における物理化学的りん除去法導入による処理性能の評価

Abstract

A simultaneous removal of nitrogen and phosphorus technology in small-scale domestic wastewater treatment was developed. Physicochemical phosphorus removal systems such as the coagulation method, electrolysis of iron method and electrolysis of aluminum method were combined with anaerobic filter bed-biological filtration process and removal efficiencies of organic matter, nitrogen and phosphorus as well as sludge generation were investigate.It was demonstrated that these systems improved the organic matter and phosphorus removal efficiencies. Moreover, the denitrification rate improved, which could contribute to stabilizing the nitrogen removal efficiency in this process, as well as reducing the volume of the anaerobic filter bed tank. The water quality of the effluent was less than BOD10mg⋅l-1, T-N10mg⋅l1 and T-P1 mg⋅l1. To achieve this efficiency with the coagulation method, it was necessary to closely manage the generated sludge. With the electrolysis of iron method, a high phosphorus removal efficiency was achieved under the general maintenance and management of generated sludge. With the electrolysis of aluminum method, although an extremely high removal efficiency was achieved, it was necessary to investigate the conditions for controlling the elution of aluminum ion to stabilize the phosphorus removal efficiency. These findings clarified that by incorporating the physicochemical phosphorus removal system with anaerobic filter bed-biological filtration process, the simultaneous nitrogen and phosphorus removal system could be established.