Journal of Ecology and Rural Environment ›› 2019, Vol. 35 ›› Issue (6): 795-800.doi: 10.19741/j.issn.1673-4831.2018.0208

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Phosphate Removal Efficiency of Kaolin in Livestock and Poultry Wastewater and Its Cost-Benefit Analysis

GAN Fang-qun1, XU Zi-hao1, YANG Yi-fan1, QIN Pin-zhu1, TANG Rong1, HANG Xiao-shuai2   

  1. 1. College of Environment and Ecology, Jiangsu Open University/The City Vocational College of Jiangsu, Nanjing 210017, China;
    2. Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
  • Received:2018-04-10 Online:2019-06-25 Published:2019-06-25

Abstract:

The ability and purification efficiency of different modified kaolins for phosphate adsorption in livestock and poultry wastewater were detected. Batch adsorption experiment and dynamic column adsorption experiment were used to evaluate the cost-benefit of kaolin used in the purification of phosphate-containing livestock and poultry wastewater. The results show that different modification treatments could significantly improve the adsorption performance of kaolin on phosphate, but there are some differences between the different modification methods. For hydrochloric acid modification, with the increase of acid dosage, the adsorption capacity of modified kaolin to phosphate has gradually increased. When the heating temperature was lower than 500℃, the adsorption performance of kaolin increased gradually with the temperature, and could be increased by about 3 times. When the calcination temperature was 500~600℃, the adsorption capacity kept no change with the increase of temperature, then when the temperature was higher than 600℃, it showed a downward trend. The saturation adsorption of phosphate on layered double hydroxide-modified kaolin is significantly higher than that of 500℃ thermally modified kaolin. However, on comprehensive consideration of modification cost, residual solution concentration, adsorption capacity, removal rate and other purification effects, in the treatment of 20 mg·L-1 phosphate-containing livestock and poultry wastewater or so, adsorption performance of 500℃ thermally modified kaolin is the best, and the cost is lowest and the cost-benefit ratio is the highest, which is about 1421 mg P·yuan-1.

Key words: kaolin, phosphate, livestock and poultry wastewater, adsorption, cost-benefit analysis

CLC Number: