Efficient degradation of solid yeast biomass from ethanol industry by Fenton and UV-Fenton processes applying multivariate analysis

Abstract Organic agro-industrial residues have been successfully used as biosorbents and promoting new uses from agricultural wastes benefits the economy. However, the allocation of a solid waste biosorbent after the sorption of contaminants has limited their effective application on a large scale as an alternative treatment of water and wastewaters. One solution could be degradation to convert the biosorbent material and adsorbed organic contaminants into environmental friendly compounds suitable for discharge. This study used an experimental design to evaluate the Fenton degradation of yeast biomass (YB) from the alcohol industry as a potential biosorbent. The efficiency of degradation was monitored according to the degraded mass (DM) and total organic carbon (TOC) remaining in the solution. The ANOVA showed an error of 9.7% for the effects and the media of interaction for the employed model for DM. Conducting the experiments with the best-predicted conditions (60 min, 25 g of YB, pH 3, 8,000 mg L-1 H2O2 and 40 mg L-1 Fe2+) with 30 W UV irradiation resulted in a YB reduction of 72 ( 2% with a TOC of 30 ( 2%. This suggests that an advanced oxidative process is an alternative for degradation of a biosorbent after sorption.

摘要 有机农业工业残渣已被成功用作生物吸附剂，开发农业废弃物的新用途有助于推动经济发展。然而，吸附污染物后的固体废弃生物吸附剂的后续处置难题，限制了其作为水与废水替代处理技术的大规模有效应用。一种可行的解决方案是通过降解过程，将生物吸附剂材料与吸附的有机污染物转化为可安全排放的环境友好型化合物。本研究采用实验设计方法，评估了酒精工业来源的酵母生物质（Yeast Biomass, YB）作为潜在生物吸附剂的芬顿（Fenton）降解效果。本研究以降解质量（Degraded Mass, DM）与溶液中残留总有机碳（Total Organic Carbon, TOC）作为评价指标，对降解效率进行监测。针对降解质量所采用的模型，方差分析（Analysis of Variance, ANOVA）结果显示其效应与交互项的误差为9.7%。在最优预测条件（60 min、25 g酵母生物质、pH=3、8000 mg/L H₂O₂与40 mg/L Fe²+）下辅以30 W紫外辐照开展实验，结果显示酵母生物质去除率达72%±2%，残留总有机碳为30%±2%。这表明高级氧化工艺可作为吸附污染物后生物吸附剂降解的替代方案。