镁改性污泥基生物炭去除水中磷和抗生素

为解决废水磷回收和污泥资源化利用问题,以污水处理厂污泥为前驱体,采用镁盐溶液浸渍和高温热解方法,制备系列镁改性污泥基生物炭(Mg_xBC),研究了Mg_xBC对水中磷酸盐的吸附性能,以及在过一硫酸氢钾复合盐(PMS)氧化剂存在下对共存抗生素的催化降解性能.结果显示:氮气氛、1mol/L镁盐加入量制备的Mg₁BC相比于未改性污泥基生物炭(BC),对磷的Langmuir饱和吸附容量可达63.2mg/g(为BC的近3倍);除极酸条件下(pH₀<4),Mg₁BC的磷去除率均大于99%;水中共存离子对Mg₁BC吸附磷影响较小,Mg₁BC具有较强的适用性.此外,Mg₁BC可催化活化PMS,显著提高与磷共存抗生素(如四环素(TC)、磺胺二甲基嘧啶(SMT))的降解性能,实现吸附磷和高效去除抗生素的双重目的.

Removal of phosphate and antibiotics by magnesium modified sludge - derived biochar

A series of Mg modified biochar (Mg_xBC) were prepared from calcination of municipal waste sludge after being impregnated with MgCl₂ to serve as the adsorbent for P recovery and as the catalyst for peroxymonosulfate (PMS) activation and antibiotic degradation. Results showed that calcination atmosphere (i.e., air-deficient, N₂, vacuum) and MgCl₂ concentration exhibited significant influence on P adsorption. The Mg₁BC prepared in N₂ atmosphere after being treated with 1mol/L MgCl₂ could become the best adsorbent. According to the Langmuir equation, the maximum adsorption capacity of Mg₁BC for P was 63.2mg/g, about three times the unmodified BC. Under the studied conditions, Mg₁BC could remove 99% of P above pH₀ 4, and all of the common water co-existing constituents showed no substantial influence on P adsorption, indicating that Mg₁BC is applicable for practical wastewater treatment. Besides, Mg₁BC could also activate PMS and enhance the degradation of the co-existing antibiotics like TC and SMT.