Treatment Of Excess Sludge By UV-Fenton

With the rapid development of China’s economy, China has gradually accelerate urbanization, environmental pollution is getting worse, where sewage treatment is an important and serious problem. In order to prevent water pollution and improve our environment, most of the city built a number of sewage treatment plants. Among them, how to properly dispose of surplus sludge generated during the production has become a hot topic of wastewater treatment.Anaerobic digestion technology can effectively reduce the moisture content of the sludge, achieve the sludge reduction, harmless and resources. Anaerobic digestion into hydrolysis, acidification, methanation three stages, wherein the hydrolysis stage is a rate-limiting step of anaerobic digestion. Research scholars from various countries are actively accelerate hydrolysis pretreatment method, by taking a series of methods for sludge pretreatment aimed sludge microbial cell wall membrane damage, the release of intracellular substances to enhance the biodegradability of sludge, increase the rate of hydrolysis of the sludge..Fenton and Fenton-like reaction in sewage and wastewater treatment specialty has been studied. Which UV-Fenton (light-Fenton) reaction by UV and Fe2+co-catalytic decomposition of H2O2to produce hydroxyl groups with strong oxidizing free radicals under acidic conditions·OH,·OH degradation of organic matter in the water. UV-Fenton reaction under UV light and iron salts common catalytic, greatly improves the yield of·OH, while reducing the dosage of ferrous salt and H2O2. By Fenton and Fenton-generated hydroxyl radical reaction·OH can effectively break the sludge so that the rapid release of intracellular substances, promote the hydrolysis of sludge and to improve the efficiency of anaerobic digestion. The realization of sludge stabilization,reduction, harmless and resources have great significance.In this paper, UV-Fenton method of sludge treatment, H2O2and Fe2+by changing the dosage, pH, reaction time, examine its impact on the nature of the sludge, sludge analysis post-processing parameter changes to determine the optimum pretreatment conditions, thus anaerobic sludge digestion, analyze trends anaerobic sludge digestion process gas production and total alkalinity, VFA, SCOD, TP, pH and other parameters, the study of anaerobic pretreatment oxygen generated by digestion.The results showed that sludge treatment by UV-Fenton method can quickly destroy the cell walls of microorganisms in the sludge, thereby accelerating sludge crack. When H2O2dosage of4g/L, Fe2+dosage of0.06g/L, reaction time was120min, pH3, the sludge reached the maximum break of20.8%:sludge supernatant SCOD concentration of126mg/L to867mg/L, the concentration of polysaccharide33.4mg/L to108.9mg/L. the protein concentration from41.2mg/L to71.4mg/L; TN content than pretreatment increased1.62times; SRF decreased from7.46x109s2/g to4.03x109s2/g. In the anaerobic digestion process, the pretreated sludge mud than the original total gas production334mL, and daily gas production peak has2d earlier than the unpretreated sludge; After pretreatment. sludge the maximum concentration of the supernatant SCOD reached781.3mg/L, TP concentration showed a significant upward trend; anaerobic digestion process consists of acidogenic and methanogenic phase, the initial reaction pH decreases at first and then tends to increase, the corresponding after the first increases the concentration of volatile fatty acids decreased, total alkalinity in the1792mg/L to2764mg/L range.