含油污泥生物电化学系统的产电性能及阳极膜菌群变化特征

Electricity Production Performance of Oily Sludge Bioelectrochemical system and Anodic Membrane Flora Characteristics

含油污泥是影响油田及周边环境质量的一大难题,现有资源化方法处理过程复杂、成本高,且存在二次污染风险,生物电化学系统能资源化利用含油污泥同时发电。为探讨含油污泥生物电化学系统的产电效能及阳极膜微生物变化特征,构筑了以含油污泥为阳极底物的单室无膜沉积型生物电化学系统。通过系统电压产出、功率密度、极化曲线及循环伏安(CV)曲线,考察系统的产电效能;同时,采用生物宏基因组分类测序分析产电稳定阳极碳毡上和初始含油污泥的微生物群落组成及丰度。结果发现,系统最大输出电压、输出功率为320.7 mV、3 353.7 mW/m^2,阳极生物膜具有较强电活性,CV曲线呈"S"形状,氧化还原峰分别在0 V和-0.5 V,极限电流值为0.12 A/cm^2;系统产电稳定期阳极膜(TZ)的多样性指数Seq数、AEC指数、Chao1均低于相应的初始沉积物(YN1),说明TZ的微生物菌群多样性降低,且两者微生物种类及丰度差异性显著,TZ的优势菌群为Proteobacteria,YN1优势菌群为Firmicutes。生物电化学系统为油泥处理提供一种新技术,能有效资源化利用油泥同时发电,从而实现双赢。

Oily sludge is a major problem affecting the quality of the oilfield and its surrounding environment. The existing resource-recycling method has complex processing and high cost, and there is a risk of secondary pollution. The bioelectrochemical system can utilize oil-bearing sludge to generate electricity at the same time. A single-chamber, membrane-free deposition bioelectrochemical system supplied with oily sludge was constructed to investigate the electricity production efficiency and anodic membrane microbial variation characteristics of oil-containing sludge bioelectrochemical system. The output voltage, power density curve, polarization curve and cyclic voltammetry(CV) test were used to verify the power generation performance of the system. At the same time, the biometanomic classification analysis was used to analyse the abundance and composition of microbial aggregation in the carbon felt and the initial oily sludge. The results show that the maximum output voltage and output power density of the system are 320.7 mV and 3 353.7 mW/m^2, respectively. The anode biofilm has electrical activity, the CV curve is "S" shape, and the redox peaks are at 0 V and-0.5 V, respectively, the limit current value is 0.12 A/cm^2.The number of Seq numbers, AEC index and Chao1 mean value of the anodic film(TZ) in the stable period of the system electricity generation are lower to the initial sediment(YN1), indicating that the microbial diversity of TZ is reduced, and the difference in the composition of the two groups is obvious. The dominant flora of TZ is Proteobacteria, and the dominant flora of YN1 is Firmicutes. The bioelectrochemical system of bacteria can effectively treat oily sludge and generate electricity at the same time, which provides a new method for the utilization of oily sludge.