针对含铬废水带来的问题,如环境污染,生物毒性,和人类健康风险。基于粉煤灰吸附和纳米FeS还原特性,采用矿物负载改性技术和超声沉淀法合成了粉煤灰负载纳米FeS复合材料(nFeS-FA)。吸附剂用量的影响,初始pH值,接触时间,研究了溶液初始浓度对nFeS-FA吸附Cr(VI)和总Cr的影响。利用吸附等温线研究了nFeS-FA对Cr(VI)和总Cr的吸附特性,吸附动力学原理,以及XRD,TEM,SEM-EDS,和BET分析。结果表明,在nFeS-FA为8g/L的条件下,初始pH为4,接触时间为150分钟,溶液的初始浓度为100mg/L,nFeS-FA对Cr(VI)的去除率为87.85%,对总Cr的去除率为71.77%。nFeS-FA对Cr(VI)和总Cr的吸附遵循Langmuir模型和拟二级动力学模型,表明单层吸附以化学吸附为主导机制。XRD,TEM,SEM-EDS,BET表明片状纳米FeS均匀分布在粉煤灰表面,表现出良好的分散性,从而增加比表面积。在吸附实验中,nFeS-FA与Cr(VI)反应,生成的Fe3+主要以FeOOH沉淀的形式存在,而S2-与Cr(III)反应产生Cr2S3沉淀。因此,nFeS-FA对Cr(VI)和总Cr具有优异的吸附性能。可作为水处理领域重金属铬污染修复的技术参考。
In view of the problems caused by chromium-containing wastewater, such as environmental pollution, biological toxicity, and human health risks. Based on fly ash adsorption and nano-FeS reduction characteristics, fly ash loaded nano-FeS composite (nFeS-FA) was synthesized using mineral supported modification technology and ultrasonic precipitation method. The effect of adsorbent dosage, initial pH, contact time, and initial concentration of the solution on the adsorption of Cr(VI) and total Cr by nFeS-FA was investigated. The characteristics of Cr(VI) and total Cr adsorption by nFeS-FA were studied using adsorption isotherms, adsorption kinetics principles, as well as XRD, TEM, SEM-EDS, and BET analysis. The results demonstrated that under the conditions of nFeS-FA of 8 g/L, initial pH of 4, contact time of 150 min, and initial concentration of the solution at 100 mg/L, nFeS-FA achieved removal efficiency of 87.85 % for Cr(VI) and 71.77 % for total Cr. The adsorption of Cr(VI) and total Cr by nFeS-FA followed the Langmuir model and pseudo-second-order kinetic model, indicating monolayer adsorption with chemical adsorption as the dominant mechanism. XRD, TEM, SEM-EDS, and BET revealed that the flaky nano-FeS was uniformly distributed on the surface of fly ash, exhibiting good dispersion and thereby increasing the specific surface area. During the adsorption experiments, nFeS-FA reacted with Cr(VI), and the generated Fe3+ mainly existed as FeOOH precipitation, while S2- reacted with Cr(III) to produce Cr2S3 precipitation. Therefore, nFeS-FA exhibited excellent adsorption performance towards Cr(VI) and total Cr. It can serve as a technological reference for the remediation of heavy metal chromium pollution in the field of water treatment.