人工湿地磷吸附饱和基质的化学再生研究

Chemical regeneration of substrates saturated with phosphorus adsorption for constructed wetlands

长期处理了生活污水后的人工湿地基质对磷素的吸附会达到饱和,通过化学浸提方法,研究了2种无机酸(盐酸和硫酸),酸和碱(盐酸和氢氧化钠溶液)对饱和吸附磷基质的释磷效果以及再生后基质吸附磷效果。结果表明:盐酸和硫酸对基质释磷的差异性不大,硫酸的释磷效果略好于盐酸,对3种基质的释磷效果几乎都大于80%;碱对砂和煤渣释磷效果好,对高炉渣释磷效果差,但经碱再生后的高炉渣、砂基质对磷素的吸收率极高,磷素初始浓度在1～50mg·L-1范围内时,吸收率在95.18%～99.04%范围内,对基质的再生能力好,而经碱再生后的煤渣基质对磷素的吸收率却很低,吸收率不超过21.14%。

After the long-term treatment of sewage the substrates of constructed wetlands will be saturated with phosphorus adsorption.The effects of two inorganic acid（hydrochloric acid and sulphuric acid）,acid and alkali（sodium hydroxide and hydrochloric acid solution）used as P desorption from the substrates of constructed wetlands were investigated with chemical extraction,as well as the adsorption of regeneration substrates on P.The results showed that the release of P was no obvious differences between hydrochloric and sulfuric acid,but more than 80%,sulfuric acid had much higher capacity than hydrochloric;alkaline showed good P desorption capacity on sand and coal burn slag,bad P desorption capacity on blast furnace slag,but the regeneration substrates of blast furnace slag and sand by alkaline had strong P adsorption capacity.When phosphorus in the initial concentration of 1-50 mg·L-1 range,the absorption rate was from 95.18%to 99.04%,the alkaline showed good regeneration effect on them except coal burn slag, the P adsorption rate of regeneration coal burn slag was no more than 21.14%.