磺胺和四环素类抗生素对活性污泥性能的影响

废水处理工艺中抗生素类污染物的存在可能会对生物处理过程产生长期而深远的影响，为探明此类污染物对废水生物处理主体活性污泥性能等方面的影响，采用间歇培养法研究了活性污泥法处理污水时，抗生素类污染物的存在对活性污泥性能如胞外聚合物（EPS）、污染物处理能力、脱氢酶活性和群落结构的影响。结果表明，抗生素的存在会导致活性污泥的胞外聚合物总量及其主要组分蛋白质和多糖增加，以产生保护屏障；且由于污泥絮体解体，细胞破裂导致EPS中DNA和色氨酸含量增加。同时，由于蛋白质大量增加引起的表面负电荷的增加，使污泥疏水性增强，絮凝性能恶化；污泥絮体解体导致污泥颗粒变小，SVI也随之下降；在活性污泥脱氢酶活性急剧下降的同时，出水TOC迅速升高。此外，抗生素类污染物在抑制活性污泥中大部分细菌的同时，对部分菌群也有刺激生长作用，最终导致活性污泥生物群落结构的改变。四环素类抗生素对活性污泥的EPS和絮凝沉降性能的影响大于磺胺类，而对污水处理能力和群落结构的影响则不如磺胺类。抗生素类污染物的长期存在会对活性污泥沉降性能、絮凝性能、脱氢酶活性以及活性污泥群落结构等产生一系列负面影响，进而影响污染物去除效果，导致出水水质恶化。

Effect of sulfonamides and tetracycline antibiotics on performance of activated sludge

The antibiotic pollutants in wastewater treatment process might have negative impact on activated sludge. The impacts of the above pollutants on the performance of activated sludge, such as flocculation and set- tling, pollutants-removal ability, dehydrogenase activity and community structure were revealed with batch cul- tured activated sludge in order to explore the biological toxicity of the above pollutants on activated sludge. The results indicated that extracellular polymeric substances （EPS） and its main components （proteins and polysac- charides） in activated sludge all increased rapidly when shocked by antibiotic pollutants. DNA and tryptophan in EPS were also generated considerably as the result of the disintegration of the activated sludge flocs. Meanwhile, the sludge surface was more negatively charged because of the substantial increase of the proportion of protein in EPS, which led to the enhancement of sludge hydrophobicity and the deterioration of sludge flocculation. The SVI value of activated sludge decreased sharply based on the disintegration of flocs and the decrease of sludge par- ticles. Meanwhile, the effluent TOC increased sharply, and the dehydrogenase activity of activated sludge declined irreversibly. In addition, the analysis on the community structure of activated sludge revealed that antibiotic con- taminants could inhibit the majority of bacteria in the sludge, but at the same time, they could also stimulate the growth of certain types of bacteria, which ultimately resulted in great changes of the community structure of activa- ted sludge. The impacts of tetracyclines on the performance of activated sludge were greater than that of sulfona- mides. On the contrary, the sulfonamides had greater influence on the pollutants-removal ability and community structure of activated sludge than tetracyclines. Generally, the antibiotic pollutants present in wastewater might bring a series of negative effects on the performance of activated sludge, such as flocculation, settlement, dehydro- genase activity, community structure of activated sludge, which ultimately led to the deterioration of effluent.