Removal of Ammonia from a Biologically Treated Pesticide Wastewater by Struvite Precipitation

Abstract:

The aim of this study was to investigate ammonia removal from the effluent of a full-scale biofilm reactor treating pesticide wastewater through the formation of struvite (MgNH₄PO₄•6H₂O). The requirement of magnesium and phosphate ions for precipitation was met by adding MgO and Na₂HPO₄. Different NH₄⁺:Mg²⁺:PO₄^3- molar ratios were tested in batch reactors to optimize the precipitation conditions. Ammonia was reduced to 25 mg/L from an initial concentration of 210 mg/L at the highest ratio tested (1:1.2:1.3), equating to 88% removal. However, the extent of ammonia removal was only slightly affected when the N:Mg ratio was reduced from 1:1.2 to 1:0.6; dropping to 83% from 88% on a percentage basis. Struvite precipitation can be easily incorporated within the existing post-treatment section of the full-scale plant, providing the pesticide manufacturing facility with a reliable backup process for its nitrification system.

• Periodical: Advanced Materials Research (Volumes 550-553)
• Pages: 2059-2062
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.550-553.2059
• Online since: July 2012
• Authors: Khim Hoong Chu, Xiao Feng, Eui Yong Kim
• Keywords: Biofilm Reactor, Chemical Precipitation, Industrial Waste Water, Nitrification

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