成组生物毒性测试法综合评价典型工业废水毒性

为了更加准确地评估典型工业废水的综合生物毒性以及处理工艺对废水毒性的削减情况,采用发光细菌急性毒性实验、大型溞急性毒性实验和单细胞凝胶电泳实验,结合潜在生态毒性效应探测(potential ecotoxic effects probe,PEEP)指数对常州市7种典型工业废水的综合生物毒性进行了评价。结果表明,7种工业原水都表现出了急性毒性或遗传毒性,综合生物毒性强度的排序为电子厂>电镀厂>综合污水处理厂>印染厂>化工厂>食品厂>制药厂。而7种工业废水的处理后出水综合生物毒性强度的排序为印染厂>化工厂>电子厂>综合污水处理厂>食品厂>制药厂>电镀厂。其中,印染和化工厂出水综合生物毒性高于原水,分别增加了43.3%和38.7%,PEEP评价结果显示分别属于剧毒和高毒,而电镀、电子、综合污水处理和食品厂出水的综合生物毒性削减明显,分别比原水削减了76.9%、53.1%、48.3%和26.6%,PEEP结果表明基本无毒。建立在成组生物毒性实验基础上的PEEP评价方法可全面反映工业废水的综合生物毒性,进而更客观地评价废水对水生态系统乃至人类健康的潜在影响。     

环境激素烯菌酮引发小鼠前列腺癌细胞的毒性机制

为探讨环境激素烯菌酮引发小鼠前列腺癌(RM-1)细胞毒性机制,设计了3组实验,分别为对照组、烯菌酮染毒组(染毒组)和烯菌酮染毒后添加维生素E组(实验组),各组给药培养48h后,观察细胞形态变化。检测细胞增殖活性、丙二醛(MDA)含量、抑制羟自由基能力、乳酸脱氢酶(LDH)活性、Na+-K+-ATP酶活性和Ca2+-Mg2+-ATP酶活性。结果表明,与对照组相比,染毒组RM-1细胞圆缩脱落明显,贴壁细胞减少;细胞增殖率、抑制羟自由基能力、Na+-K+-ATP酶活性和Ca2+-Mg2+-ATP酶活性明显降低(p<0.05),LDH活性和MDA含量显著升高(p<0.05)。与染毒组相比,染毒后添加维生素E,圆缩脱落细胞减少,而梭形贴壁细胞明显增加;细胞增殖率、抑制羟自由基能力、Na+-K+-ATP酶活性和Ca2+-Mg2+-ATP酶活性显著升高(p<0.05),LDH活性和MDA含量明显下降(p<0.05)。这表明维生素E可能通过其抗氧化性拮抗了烯菌酮引发的氧化应激,缓解了细胞膜的损伤,维持了细胞膜的完整性和膜蛋白的功能,防止了细胞内LDH外逸、Na+-K+-ATP酶和Ca2+-Mg2+-ATP酶活性的下降,从而逆转了烯菌酮引发的细胞死亡和增殖率的下降。     

响应面法优化固定化细胞催化α-羟基苯乙酸的合成

采用Plackett-Burman试验设计法及响应面分析法(RSM),对固定化Bacillus sp.ULi-11菌株生物不对称合成(R)-α-羟基苯乙酸((R)-HPA)进行优化.首先采用Plackett-Burman试验设计筛选影响产率的主要因素,再用最陡爬坡方法逼近最大响应区域后用Box-Behnken试验设计及RSM进行回归分析,得到的最佳条件为温度33℃,增殖时间9.3h,装液量18 mL,转速180 r/min,pH 7.2,接种量2%,种龄16 h,在此条件下(R)-HPA的产率为49.61%,比优化前的产率提高了23.7%.图3表6参16     

混凝过程中微絮体形貌的AFM液池成像观测与表征

采用扫描探针显微镜液池成像技术,对混凝过程中絮体的微观形貌进行了观测与表征.结果表明,原子力显微镜液池成像技术可以对混凝过程中的微絮体进行形貌表征和数字描述,并证实在实际印染工业尾水的微絮凝过滤试验处理过程中,微絮凝时间为2min,搅拌强度为100s-1时可以达到优化的处理效果.这也说明液池成像技术能够较好的反映混凝过程中微絮体的形貌变化特征,从而实现对环境微观界面过程的原位观测与表征.     

Sediment microbial fuel cell with floating biocathode for organic removal and energy recovery

A sediment microbial fuel cell (SMFC) with three dimensional floating biocathode (FBC) was developed for the electricity generation and biodegradation of sediment organic matter in order to avoid negative effect of dissolved oxygen (DO) depletion in aqueous environments on cathode performance and search cost-effective cathode materials. The biocathode was made from graphite granules with microbial attachment to replace platinum (Pt)-coated carbon paper cathode in a laboratory-scale SMFC (3 L in volume) filled with river sediment (organic content 49±4 g·kg^-1 dry weight). After start-up of 10 days, the maximum power density of 1.00W·m^-3 (based on anode volume) was achieved. The biocathode was better than carbon paper cathode catalyzed by Pt. The attached biofilm on cathode enhanced power generation significantly. The FBC enhanced SMFC performance further in the presence aeration. The SMFC was continuously operated for an over 120-day period. Power generation peaked within 24 days, declined gradually and stabilized at a level of 1/6 peak power output. At the end, the sediment organic matter content near the anode was removed by 29% and the total electricity generated was equal to 0.251 g of chemical oxygen demand (COD) removed.     

Optimization of mixture ratio of electrolyte for reducing activation resistance of proton exchange membrane fuel cell

The purpose of this study is to find an optimal mixture ratio of the platinum-loaded carbon catalyst and the electrolyte in a membrane electrode assembly (MEA) of a proton exchange membrane fuel cell for reducing the activation resistance, which influences the electrochemical surface area, activation polarization, and maximum power density of the MEA. First, mixture ratios of 10, 20, 40, and 60 wt% platinum-loaded carbon catalysts and electrolyte were examined. The results indicated that the fuel cell performance improved for mixing weight ratios of 1.0:2.0 in 10 wt% Pt/C, 1.0:1.8 in 20 wt% Pt/C, 1.0:1.1 in 40 wt% Pt/C, and 1.0:0.5 in 60 wt% Pt/C. Next, we evaluated the activation resistances of the MEA from the AC impedance characteristics using the optimal mixing weight ratio of the platinum-loaded carbon catalyst and the electrolyte. It was found that the activation resistances of the anode and cathode decrease with an increase in the weight ratio of platinum-loaded carbon in the catalyst layer.     

盐酸小檗碱对小鼠脾细胞的DNA损伤和氧化性损伤

为了探讨盐酸小檗碱对小鼠的DNA损伤和氧化性损伤.随机选取30只小鼠分成对照组以及7.5,15,30,60与120mg· kg-1实验组,处理后,应用小鼠脾细胞进行彗星实验与抗氧化酶实验.测定DNA损伤情况以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性以及丙二醛(MDA)含量变化.对盐酸小檗碱的DNA损伤与氧化性损伤作用进行比较研究.研究结果表明:彗星实验中,随着盐酸小檗碱浓度的增加,尾部DNA含量、尾长与尾矩均增加,与阴性对照组相比差异有统计学意义(p ＜0.05或p＜0.01),且呈剂量-效应关系;超氧化物歧化酶(SOD)与过氧化氢酶(CAT)活性随盐酸小檗碱剂量增加逐渐降低,丙二醛(MDA)含量明显上升,过氧化物酶(POD)活性在7.5 mg·kg-1时上升,而后逐渐下降.在60 mg·kg-1和120 mg· kg-1时,有极显著性差异(p＜0.01)产生.由此可见,盐酸小檗碱对小鼠脾细胞有一定的损伤作用,能够引起小鼠脾细胞的DNA损伤和氧化性损伤.     

Microalgae Scenedesmus obliquus as renewable biomass feedstock for electricity generation in microbial fuel cells （MFCs）

Renewable algae biomass, Scenedesmus obliquus, was used as substrate for generating electricity in two chamber microbial fuel cells （MFCs）. From polarization test, maximum power density with pretreated algal biomass was 102mW·m^2 （951mW·m^3） at current generation of 276mA·m^-2. The individual electrode potential as a function of current generation suggested that anodic oxidation process of algae substrate had limitation for high current generation in MFC. Total chemical oxygen demand （TCOD） reduction of 74% was obtained when initial TCOD concentration was 534mg · L^-1 for 150 h of operation. The main organic compounds of algae oriented biomass were lactate and acetate, which were mainly used for electricity generation. Other byproducts such as propionate and butyrate were formed at a negligible amount. Electrochemical Impedance Spectroscopy （EIS） analysis pinpointed the charge transfer resistance （112Ω ） of anode electrode, and the exchange current density of anode electrode was 1214 nA·cm^-2.     

厌氧发酵污泥燃料电池处理含铬废水的效能及机理

以厌氧发酵污泥为阳极底物、Cr(VI)为阴极电子受体构建双室微生物燃料电池(MFC),考察厌氧发酵污泥MFC系统处理含铬废水的性能及机理,并与原污泥MFC系统进行比较.发酵污泥MFC系统的开路电压为1.05V,最大功率密度为5722mW/m3,比原污泥MFC系统提高了57.8%.发酵污泥MFC系统的表观内阻为119.1Ω,比原污泥MFC系统降低了8.5%.发酵污泥MFC系统对Cr(VI)的去除符合一级动力学模型,速率常数为0.0514h-1,比原污泥MFC系统提高了36.7%.污泥经厌氧发酵后可溶性有机物浓度增加,产生了大量短链脂肪酸,它们是产电微生物易于摄取的阳极底物,因而提高了MFC系统的产电性能及Cr(VI)去除效果.