A Review of Anoxic Wastewater Treatment: An Overlooked Aspect in Wastewater Treatment in Nigeria

Abstract

This paper presented an overview of different methods for nitrogen and phosphorus removal from wastewater effluents in Nigeria. Research data indicated that wastewater effluents in Nigeria contain high concentrations of nitrogen and phosphorus, which contributed to the eutrophication of many surface water bodies in the country. Study of wastewater characteristics in Nigeria showed that wastewater effluents in Nigeria contain an average of 650mg/l of total nitrogen, 120mg/l of total phosphate and 55,000mg/l of COD; nitrate-nitrogen and phosphorus ranged between 43mg/l and 56mg/l; ammonium nitrogen ranged between 52mg/l and 107mg/l; nitrate nitrogen from ranged 34.5mg/l and 58.5mg/l. The technologies and principles of anoxic treatment of wastewater are presented. The stoichiometry of nitrification and denitrification reactions are presented. State and Federal Ministry of Environment in Nigeria should enforce relevant regulations to ensure that wastewater effluents are treated to reduce nitrogen and phosphorus content to acceptable standards before discharge into watercourses.