利用斑马鱼胚胎研究污水处理工艺中DOM与DBPs的关系

Study on Relationship between DOM and DBPs in the Wastewater Treatment Process Based on Zebrafish Embryos

以模式生物斑马鱼胚胎为试验材料,通过暴露试验研究了污水处理工艺不同阶段出水中溶解性有机物(DOM)与消毒副产物(DBPs)毒性效应关系,揭示污水处理工艺中DBPs前体物DOM的生成变化规律以及对再生水生态安全性的影响。结果表明,污水处理各阶段DOM和DBPs水样对斑马鱼胚胎均有不同程度的致死效应,改良A2/O工艺段水样暴露的斑马鱼胚胎死亡率较大,DOM暴露的斑马鱼胚胎致死毒性效应低于DBPs,且DBPs对斑马鱼胚胎的半致死毒性效应较大;污水处理过程中增加的腐殖酸类物质主要来自于好氧过程微生物的生化合成;污水处理各阶段水样中腐殖酸类物质含量水平与斑马鱼胚胎的致死毒性效应存在正相关关系,因此污水生物处理会增大水中消毒前体物(DOM)特别是腐殖酸类物质的含量,从而增加了DBPs的产生量和再生水的生物毒性及环境风险。

The relationship between dissolved organic matter （DOM） and disinfection by-products （DBPs） in wastewater treatment process based on zebrafish embryos was studied, to reveal the variation and generation of DOM and the effluence to the ecological safe of reclaimed water. Results showed that both DOM and DBPs can make the zebrafish embryos to death in different degrees, and the total mortality is lager in A2/O process. DOM is lower than DBPs of toxic effects on zebrafish embryos, and DBPs can make the zebrafish embryos to semi-lethal toxicity. The increasing humic substances are mainly from the microorganism＇s biochemical synthesis of aerobic process in wastewater treatment process, and it is positive correlation between the content of humic substances of water and toxic effects on zebrafish embryos, indicating biological treatment of wastewater will increase the content especially humic substances of water disinfection precursor （DOM）, thus increasing the generation of DBPs and biological toxicity and environmental risks of reclaimed water.