生物炭固定微生物对草甘膦的去除效果研究

Removal effect of glyphosate by microorganisms-immobilized biochar

以芦苇生物炭为载体固定草甘膦降解微生物制备复合材料。将材料加入到草甘膦培养液中,探究单一生物炭、游离微生物和复合材料去除草甘膦的效果和机理。结果表明:草甘膦会抑制微生物生长,72 h去除量为19.52~26.71 mg;生物炭对草甘膦的去除量随草甘膦初始浓度提高而增大,72 h去除量为23.56~32.78 mg;复合材料较单一生物炭或单一微生物可去除更多草甘膦,72 h时200、400、800 mg/L草甘膦的去除量分别为40.69、52.12、64.14 mg,比微生物组提高52.34%、128.20%、228.59%,比生物炭组提高72.71%、72.58%、95.67%。微生物会改变生物炭表面形态、改善物理化学性质,提高生物炭对草甘膦的静电和化学吸附能力;生物炭可为微生物提供养分和附着空间,提高微生物抵御高浓度草甘膦的能力,有利于微生物通过乙醛酸和氨甲基膦酸途径降解草甘膦。

The reed biochar was used as a carrier to fix the glyphosate-degrading microorganism to prepare a composite material.The material was added to the glyphosate wastewater to investigate whether biochar and microorganisms could synergistically remove glyphosate and its removal effect and mechanism.The results showed that glyphosate inhibited the growth of microorganisms.The degradation amount in 72 h was 19.52-26.71 mg.The amount of glyphosate adsorbed by biochar increased with the intial concentration of glyphosate,and the amount adsorbed in 72 h ranged from 23.56 mg to 32.78 mg.The composite removed more glyphosate than single biochar or single microorganism.At the initial glyphosate concentration of 200,400,800 mg/L,the removal amount of glyphosate was 40.69,52.12,64.14 mg,which were 52.34%,128.20%,228.59%respectively higher than microorganism group and 72.71%,72.58%,95.67%respectively higher than biochar group at 72 hours.Microorganisms changed the surface morphology of biochar,and increase the electrostatic and chemical adsorption of biochar to glyphosate.Biochar provided nutrients and attachment space for microorganisms,improve the ability of microorganism to resist high concentrations of glyphosate,and was beneficial for microorganisms to degrade glyphosate into glyoxylic acid and aminomethylphosphonic acid.