Specific characteristics of phosphorus removal in biological wastewater treatment

Summary

It is shown that in using chemicals for deep phosphorus removal in biological wastewater treatment or effluent polishing one must take into account the effect of added metal ions on biological treatment process. A technique is suggested for estimating chemical consumption depending on the selected flow scheme of biological and chemical treatment; adjusting factors with account of this effect are given.

Key words

wastewater , biological treatment , aluminium salts , chemical treatment , biogene substances , phosphates , total phosphorus , chemicals , ferrum salts

Phosphorus compounds in municipal wastewater

Summary

The analysis of the results of determining phosphorus compounds in wastewater at the treatment facilities is presented. In order to remove phosphorus compounds different methods of municipal wastewater treatment are used. The efficiency of eliminating some or other phosphorus forms depends on the technology used. The ratio of separate phosphorus forms in raw sewage differ much from effluent; therefore their impact on the water body also differs even if the discharged effluent quality is meeting the maximum permissible concentration of phosphates. Addition of chemical into wastewater provides for the fast and reliable removal of phosphates. The efficient reduction of total phosphorus and phosphates occurs only under the combination of biological and chemical wastewater treatment, or under the use of the modified biological treatment with alternating aerobic and anaerobic conditions of activated sludge retention.

Key words

wastewater , biological treatment , chemical treatment , phosphates , total phosphorus , biological and chemical treatment