Optimum doses of Mg and P salts for precipitating ammonia into struvite crystals in aerobic composting.
It was previously reported that struvite crystals could be formed in the aerobic composting reaction provided that Mg and P salts are added [Bioresource Technology 79 (2001) 129]. The formation of struvite crystals significantly reduced gaseous loss of ammonia and resulted in substantial increase in the ammonia content in the compost, attaining 1.5%. In this context, the present study was conducted to determine the optimal doses of Mg and P salts for struvite crystallization. It was found that cumulative ammonia production was about 33-36% of the initial total nitrogen in the aerobic composting reaction, irrespective of the amounts of Mg and P salts added. The theoretical doses for complete conversion of ammonia into struvite crystals seemed to be about 33-36% of the initial nitrogen. The addition of Mg and P salts at this level, however, caused adverse effects on the degradation of organic materials. Therefore, it was concluded that the optimal doses of Mg and P salts should be about 20% of the initial nitrogen in the compost mixture not to cause any harmful effects on the composting reaction.
Jeong
Yeon-Koo
YK
School of Civil and Environmental Engineering, Kumoh National Institute of Technology, 188 Shinpyung-dong, Gumi, Gyungbuk 730-701, Korea.
Hwang
Sun-Jin
SJ
D000641:Ammonia / Q000378:metabolism*; D019149:Bioreactors; D011232:Chemical Precipitation; D006863:Hydrogen-Ion Concentration; D007723:Korea; D008274:Magnesium / Q000378:metabolism; D017616:Magnesium Compounds / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism; D012492:Salts / Q000378:metabolism*; D012987:Soil; D000069877:Struvite; D013696:Temperature; D013997:Time Factors
D017616:Magnesium Compounds; D010710:Phosphates; D012492:Salts; D012987:Soil; D010758:Phosphorus; D000641:Ammonia; D000069877:Struvite; D008274:Magnesium