基于AMD回收的生物炭修饰LDHs降解土霉素研究

Degradation of Oxytetracycline by Biochar-modified LDHs Based on AMD Recovery

采用共沉淀法模拟酸性矿山废水(Acid Mine Drainage,AMD)的中和处理过程,利用生物炭优化调控中和过程,负载修饰获得层状双氢氧化物-生物炭复合材料(Recovered Layered Double Hydroxides,RLDH@BC),用于活化过一硫酸盐(PMS)降解水中土霉素(OTC)。各项表征结果证明,该方法可成功从AMD中回收RLDH@BC。降解实验表明,RLDH@BC可在广泛的pH范围(3~11)高效活化PMS降解OTC,最高去除效率达到88%;共存离子实验表明,NO-3和HCO-3共存条件下OTC的去除率从86.2%分别降至82.3%、82.2%,影响较小;而Cl^(-)和H_(2)PO_(4)^(-)共存时,OTC的去除率分别降至76.1%、68.7%,产生一定影响。猝灭实验表明,在RLDH@BC/PMS体系中,自由基和非自由基共同作用,其中自由基占主导作用。经过5个循环后,70%的OTC在20 min内被去除,说明材料具有良好的循环利用性。该研究对拓展AMD的资源化处置以及抗生素废水的高效修复均具有重大意义。

The co-precipitation method was used to simulate the neutralization process of acid mine drainage(AMD),and the biochar loading modification was used to obtain the layered double hydroxide-biochar(RLDH@BC)composite for the activated peroxymonosulfate(PMS)degradation of oxytetracycline(OTC)in water.Various characterization results demonstrated that the method can successfully recover RLDH@BC from AMD.Batch degradation experiments showed that RLDH@BC can efficiently activate PMS to degrade OTC in a wide pH range(3~11),with a maximum removal efficiency of 88%;coexistence ion experiment showed that the removal of OTC under the coexistence of NO_(3)^(-) and HCO_(3)^(-) decreased from 86.2%to 82.3%and 82.2%,respectively,with less effect,while the removal of OTC under the coexistence of Cl^(-)and H_(2)PO_(4)^(-) decreased to 76.1%and 68.7%,respectively,which had some effect.The bursting experiments showed that in the RLDH@BC/PMS system,free radicals and non-free radicals joined together to degrade OTC,with free radicals dominating.After 5 cycles,70%of the OTC was removed within 20 min,indicating that the material has good recyclability.This study has significant implications for expanding the resource utilization of AMD as well as the efficient remediation of antibiotic wastewater.