In the present study, the effect of phosphorus removal pellets containing alum as a main component on the phosphorus removal efficiency in various on-site treatment systems for domestic wastewater was evaluated. When 400 g/week or 800 g/week of phosphorus removal pellets were put into the aeration tank and the raw water tank of three types of Johkasous (Tandoku-shori Johkasou, conventional Johkasou and nitrogen removal type Johkasou), total phosphorus (T-P) and phosphate phosphorus (PO 4-P ) in the effluent water were decreased after one week. In addition, there was no adverse effect of phosphorus removal pellets on the removal of biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total nitrogen (T-N) in the effluent water. Depending on the conditions of the Johkasou, the T-P concentration tended to be higher when the suspended solids (SS) concentrations were increased. When the phosphorus removal pellet was applied to the aeration tank and the raw water tank of the Tandoku-shori Johkasou and the conventional Johkasou, the ratio of T-P concentration in each effluent water after addition of pellets to that before the pellets addition (T-P ratio) ranged from 0.3 to 0.6. In contrast, the phosphorus removal effect was low in the nitrogen removal type Johkasou, despite that pellets were put into the aeration tank, whereas when the pellets were put into the raw water tank, the T-P ratio was around 0.6.
Phosphorus removal and collection from domestic wastewater will make a great contribution to conservation of water environment and saving phosphorus as a valuable resource. Iron electrolytic method, one of the practicalized phosphorus removal technologies, brings about increment in electrical consumption. In this study, energy-saving operation was examined on a small-scale anaerobic-oxic domestic wastewater treatment "Johkaso" system with iron electrolytic method. The obtained results were as follows. The increment in electrical consumption by introduction of the iron electrolytic system could be offset by turning off the blower for aeration in the oxic tank during the hours when there might be almost no wastewater inflow; 4 hours per day. Besides, further development for reduction of electrical consumption would be achieved by control of operation of the phosphorus removal device and the number of working blowers. From the point of wastewater treatment performance, there was little observed bad influence to the suspension of aeration in the oxic tank on the removal of phosphorus and BOD. In contrast, there observed slight decrease in both the nitrification activity and the nitrogen removal efficiency especially in winter. Further it may be required for the development of such as shortening of acclimation of the sludge in the treatment system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.