Phosphorus removal from synthetic and actual livestock/poultry farm wastewater by red clay
红色粘土对模拟及畜禽养殖废水中磷的去除

In order to intensify water pollution control and enhance red clay resource development and utilization, this study identified the adsorption capacities and mechanisms of phosphorus (P) in synthetic and livestock and poultry farm wastewater by 3 red clay samples. The application possibility of livestock and poultry farm wastewater treated by red clay was then analyzed. Results indicated that the P removal capacities of 3 red clay samples were all beyond 90% in 35 mg·L-1 P synthetic wastewater, and the removal capacities all exceeded 85% in 50 mg·L-1 P synthetic wastewater. The removal capacities of 3 red clay samples were higher than removal capacities of active carbon, and the removal efficiency of R-3 sample was the highest. The Fe-P and Al-P were readily formed by the combination of ferric and aluminum oxides in red clay with P. It was favorable for P adsorption with small mechanical composition of red clay. The P contents in initial livestock and poultry farm wastewater (29.3 mg·L-1 P) treated with R-3 and R-2 samples were lower than the corresponding discharge standard of China. The P contents can attain the standard when initial livestock and poultry farm wastewater of 93.7 mg·L-1 P was treated with R-3 and R-2 samples for two times. We concluded that red clay could serve as an appropriate P adsorption and purification material in wastewater. Particularly, red clay showed good application perspective on P removal in livestock and poultry farm wastewater.