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| Influence on activated sludge characteristics of anthraquinones before and after pre-treatment by heterogeneous Fenton-like |
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Abstract With reactive brilliant blue and rhein as anthraquinones model pollutants, the effects of heterogeneous Fenton-like pre-treatment on the biodegradability of anthraquinones and characteristics of activated sludge such as extracellular polymeric substances, intracellular substances, dehydrogenase activity, urease activity, and distribution of the microbial community were investigated. Based on Zahn-Wellens test, the biodegradation of reactive brilliant blue and rhein without the pre-treatment was not effective. The biodegradation of the pollutants with the pre-treatment were 84.44% and 86.72%, and the respiration curves were above the endogenous respiration curves. Without the pre-treatment, the absorption peak intensity of tyrosine protein was decreased significantly in the EEM spectra of extracellular polymeric substances, and amino absorption peak was widened in the FTIR spectra of intracellular material. With heterogeneous Fenton-like pre-treatment, the characteristics of activated sludge were not significant changed. The relative activity of urease still remained 80%. The relative activity of dehydrogenase was decreased, especially for rhein, and the relative activity was only 67.5%. The microbial community of the activated sludge was dramatically changed without the pre-treatment. Gram positive increased from 40.15% to 47.72% and 45.78%, respectively. And gram negative reduced from 39.57% to 37% and 37.15%, respectively. But after heterogeneous Fenton-like pre-treatment, the microbial community was not obviously changed.
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Received: 18 December 2014
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