可溶性有机物对土霉素在土壤中吸附-解吸的影响

利用废弃木薯渣分别于350、550、750℃温度下制得3种不同生物质炭,并以这3种生物质炭为前驱物提取可溶性有机物(DOM)。将土霉素(OTC)作为污染物,研究DOM对土霉素在土壤中吸附-解吸的影响。结果表明:来源于木薯渣生物质炭的DOM均能降低土霉素在土壤中的吸附量,促进土霉素在土壤中的解吸作用;随着DOM浓度、炭化和外界温度的升高,土霉素在土壤中的吸附量逐渐减少,并且易从土壤中解吸出来。DOM降低了土霉素在土壤中的吸附能力,而且增强了土霉素在土壤中的解吸能力,从而可能增强土霉素在土壤中的迁移能力。若在土霉素污染较为严重的地区施用有机物料,可能会促进土壤中土霉素的迁移,并对地下水及周边环境造成威胁。 

Eeffects of Dissolved Organic Matter on Adsorption-desorption Behavior of Oxytetracycline in Soil System

Three kinds of Biochar were prepared using cassava peel at 350 ℃, 550 ℃ and 750 ℃. The dissolved organic matter (DOM) was extracted from the three kinds of biochar.The effect of DOM on the adsorption-desorption Behavior of oxytetracycline (OTC) in soil system was studied. DOM from cassava peel biochar could reduce the adsorption capacity of OTC in soil and promote the desorption of OTC in soil. With the increase of DOM concentration, carbonization and external temperature, the adsorption capacity of OTC in soil gradually decreased, and OTC much easily desorbed from soil. DOM reduced the adsorption capacity of OTC in soil and enhanced the desorption capacity of OTC in soil, which would enhance the transport of OTC in soil. If the use of organic materials in areas where OTC pollution is more severe may promote the transport of OTC in soil, and poses a threat to groundwater and the surrounding environment.