BACKGROUND This study investigated the feasibility of enhancing anaerobic digestion of sewage sludge with triple, dual, and individual pretreatment of waste activated sludge with heat, alkalinity, and hydrogen peroxide. These pretreatments disrupt sludge flocs, organisms' cell walls, extracellular polymeric substance, and intracellular organic matter, which increase biodegradability and hydrolysis rate of activate sludge. In addition, the influence of various variables on methane production was analyzed using the response surface methodology with the quadratic model. Eventually, an optimized temperature and chemical concentration for the highest methane production and lowest chemical usage is suggested. RESULTS The highest amount of methane production was obtained from the sludge pretreated with triple pretreatment (heat (90 °C), alkaline (pH = 12), and hydrogen peroxide (30 mg H2O2/g TS)), which had better performance with 96% higher methane production than that of the control sample with temperature of 25 °C approximately and a pH = 8. Response surface methodology with a quadratic model was also used for analyzing the influence of temperature, pH, and hydrogen peroxide concentration on anaerobic digestion efficiency. It was revealed that the optimized temperature, pH, and hydrogen peroxide concentration for maximizing methane production and solubilization of sludge and minimizing thermal energy and chemical additives of the pretreatments are 83.2 °C, pH = 10.6 and 34.8 mg H2O2/g TS, respectively, has the desirability of 0.67. CONCLUSION This study reveals that triple pretreatment of waste activated sludge performed better than dual and individual pretreatment, respectively, in all desirable output parameters including increasing methane production as the most important output, increasing in COD solubilization, protein and polysaccharide, and decreasing in VSS solubilization.

中文翻译：

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污水污泥热氧化、碱氧化、H2O2氧化和组合预处理的工艺优化及对溶解和厌氧消化的影响。


背景本研究调查了通过用热、碱度和过氧化氢对废活性污泥进行三重、双重和单独预处理来增强污水污泥厌氧消化的可行性。这些预处理破坏污泥絮体、生物体细胞壁、细胞外聚合物和细胞内有机物，从而提高活性污泥的生物降解性和水解率。此外，利用响应面法和二次模型分析了各种变量对甲烷产量的影响。最终，建议了最佳的温度和化学品浓度，以获得最高的甲烷产量和最低的化学品使用量。结果 经过三重预处理（加热（90 °C）、碱（pH = 12）和过氧化氢（30 mg H2O2/g TS））的污泥获得了最高的甲烷产量，具有更好的性能，96与温度约为 25 °C、pH = 8 的对照样品相比，甲烷产量高 %。还使用二次模型的响应面方法来分析温度、pH 和过氧化氢浓度对厌氧消化效率的影响。结果表明，最大化甲烷产量和溶解污泥并最小化预处理的热能和化学添加剂的最佳温度、pH 和过氧化氢浓度分别为 83.2 °C、pH = 10.6 和 34.8 mg H2O2/g TS，期望值为 0.67。 结论 本研究表明，在所有所需的输出参数中，废弃活性污泥的三重预处理分别优于双重预处理和单独预处理，包括增加作为最重要输出的甲烷产量、增加 COD 溶解、蛋白质和多糖以及降低 VSS 溶解。