Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of PR China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen, 361005, PR China.
School of Environmental Science and Engineering, Hainan University, Haikou, 570028, PR China.
Chemosphere. 2020 May;247:125977. doi: 10.1016/j.chemosphere.2020.125977. Epub 2020 Jan 20.
Great progresses have been made to carry out Fenton oxidation under neutral or alkaline pH in which, nevertheless, organic acids and other acidic intermediates usually result in acidic Fenton effluent. To eliminate the classical neutralization step prior to biological treatment, acid-tolerant microbes were here screened and used for purification of acidic Fenton effluent to achieve pH increase and further COD (chemical oxygen demand) removal. The bacterial and fungal community diversity was analyzed before and after screening for acid-tolerant microbes. After screening the bacterial diversity sharply decreased while the fungal diversity at the genus level became richer, mainly including Phialemoniopsis (relative abundance 38.69%), Vanrija (20.08%), Hypocreaceae (18.44%) and Candida (14.74%). Acidic pH and residual HO are the features of Fenton effluent; hence, effects of pH and HO on the screened acid-tolerant microbes were investigated in the aspects of growth rate and oxygen uptake rate. The kinetic parameters, including Y-biomass yield coefficient; K-biomass decay coefficient; μ-specific maximum COD removal rate; K-half saturation constant for COD removal, of the acid-tolerant microbes using 1/5 YM (yeast extract and malt extract culture medium) as substrate at 25 °C were measured by respirometric methodology. In BAC (biological activated carbon) inoculated with acid-tolerant microbes to treat actual Fenton effluent, the average COD removal efficiency was 72% at HRT (hydraulic retention time) of 3 h and the effluent pH was above 6 after removing the dissolved CO by air stripping. This study will provide a basis for developing a new combined process including Fenton and biological oxidation without pH adjustment.
在中性或碱性 pH 条件下进行芬顿氧化已经取得了很大进展，但在这种情况下，有机酸和其他酸性中间体会导致酸性芬顿流出物。为了在进行生物处理之前消除经典的中和步骤，本研究筛选了耐酸微生物，并将其用于酸性芬顿流出物的净化，以实现 pH 值升高和进一步去除 COD（化学需氧量）。在筛选耐酸微生物前后分析了细菌和真菌群落多样性。筛选后，细菌多样性急剧下降，而真菌多样性在属水平上变得更加丰富，主要包括 Phialemoniopsis（相对丰度 38.69%）、Vanrija（20.08%）、Hypocreaceae（18.44%）和 Candida（14.74%）。酸性 pH 和残留的 HO 是芬顿流出物的特征；因此，研究了 pH 和 HO 对筛选出的耐酸微生物在生长速率和耗氧速率方面的影响。采用呼吸测量法测定了耐酸微生物在 25°C 下以 1/5 YM（酵母提取物和麦芽提取物培养基）为底物时的动力学参数，包括 Y-生物量产率系数；K-生物量衰减系数；μ-最大 COD 去除率；COD 去除 K-半饱和常数。在生物活性炭（BAC）中接种耐酸微生物处理实际芬顿流出物时，在水力停留时间为 3 小时的情况下，COD 去除效率平均为 72%，并且在通过空气吹脱去除溶解的 CO 后，流出物的 pH 值高于 6。本研究将为开发无需 pH 调节的芬顿和生物氧化相结合的新工艺提供依据。
