盐度、C：N对SBR工艺处理海水产品养殖场废水的影响

海水产品养殖场废水中碳、氮的浓度很高，通过序批式反应器（SBR）处理，能有效的降低碳、氮的浓度。在常温（20℃-25℃）条件下，我们检测了不同盐度、C：N下的处理效果，以期实现SBR工艺运行参数的最优化。实验结果表明：盐度为2．5％～3．5％，C：N为10：1的条件下，除碳和生物脱氮的效果最佳。实验验证了SBR工艺在海水产品养殖场废水处理中可以作为一个非常有效的处理手段而应用。     

Experimental Variability in Characterization of Cyfluthrin Sorption to Soil

To assess the risk of a pesticide to leach to groundwater or to run off to surface water after application, it is necessary to characterize the sorption of the pesticide to soil. For pyrethroids, their hydrophobicity, strong sorption to various materials, and low solubility make it difficult to accurately characterize sorption processes. The objective of this research was to evaluate the variability in cyfluthrin ((RS)-α -cyano-4-fluoro-3-phenoxybenzyl (1RS,3RS;1RS,3SR)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate) sorption to soil as affected by experiment conditions. To minimize cyfluthrin sorption on the walls of glass, silanized-glass, stainless steel, and PTFE centrifuge tubes, cyfluthrin solution was added to aqueous soil slurries or directly to soil, after which it was equilibrated with aqueous solution. Depending on the soil, variation in sorption coefficients, K _oc, obtained using different experimental methodologies with one soil can be comparable to the variation in K _oc values obtained for soils with different physical and chemical properties using one method. K _oc values for cyfluthrin ranged from 56,000 to 300,000 L kg^?1. Sorption methodology needs to be evaluated before sorption coefficients are used in predictive transport models.     

紫外消毒系统的应用及其研究进展

介绍了紫外消毒系统的一般结构,综述了消毒反应器的发展及分类,讨论了国内外常用的消毒反应器结构,提出未采设计消毒系统的研究重点.     

Isolation and characterization of a thermophilic Bacillus shackletonii K5 from a biotrickling filter for the production of polyhydroxybutyrate

Polyhydroxyalkanoates（PHAs） are aliphatic polyesters accumulated intracellularly by both Gram-negative and Gram-positive bacteria. However, compared to the PHAs of Gramnegative bacteria, few endotoxins（lipopolysaccharides, LPS）, which would be co-purified with PHAs and cause immunogenic reactions, are found in the PHAs produced by Gram-positive bacteria. A thermophilic Gram-positive bacterium K5, which exhibited good growth and polyhydroxybutyrate（PHB）-accumulating ability, has been isolated and characterized from a biotrickling filter designed for the removal of NOx from flue gas in a coal-fired power plant in China. Based on the biochemical characterization and 16 S rRNA gene sequence（Genbank accession no. JX437933）, the strain K5 has been identified as Bacillus shackletonii, which has rarely been reported in the literature, and this report is the first time that B. shackletonii has been found to accumulate PHB. The strain K5 was able to utilize glucose as carbon source to synthesize PHB at a broad range of temperatures（from 35 to 50 °C）, and the ideal temperature was 45 °C. The strain K5 could effectively yield PHB of up to 69.9% of its cell dry weight（CDW）（2.28 g/L） in flask experiments employing glucose as carbon source at 45 °C, followed by 56.8% and 52.3% of its CDW when using sodium succinate and glycerol as carbon source, respectively. For batch cultivation, the strain K5 was able to produce PHB of up to 72.6% of its cell dry weight（9.76 g/L） employing glucose as carbon source at 45 °C and pH 7.0.     

Thermal risk in batch reactors: Theoretical framework for runaway and accident

Thermal safety and risk of accidents are still challenging topics in the case of batch reactors carrying exothermic reactions. In the present paper, the authors develop an integrated framework focusing on defining the governing parameters for the thermal runaway and evaluating the subsequent risk of accident. A relevant set of criteria are identified in order to find the prior conditions for a thermal runaway: failure of the cooling system, critical temperature threshold, successive derivatives of the temperature (first and second namely) vs. time and no detection in due time (reaction time) of the runaway initiation. For illustrative purposes, the synthesis of peracetic acid (PAA) with hydrogen peroxide (HP) and acetic acid (AA) is considered as case study. The critical and threshold values for the runaway accident are identified for selected sets of input data. Under the conditional probability of prior cooling system failure, Monte Carlo simulations are performed in order to estimate the risk of thermal runaway accident in batch reactors. It becomes then possible to predict the ratio of reactors, within an industrial plant, potentially subject to thermal runaway accident.     

ERIC-PCR指纹图谱技术对低温下SUFR反应器中菌群结构分析

使用ERIC-PCR指纹图谱技术对螺旋升流式反应器(Spiral Up-Flow Reactor,SUFR)在低温下的微生物群落结构进行了分析.结果表明,低温下反应器中微生物菌群呈多样性分布,优势菌群突出;在遭受约5℃低温条件冲击后,反应器中菌群多样性和反应器脱氮除磷效率都有所降低,但TN去除率和TP去除率仍然达到了72.35%和93.28%,维持了反应器的正常功能.不同温度下对比分析可以看出,在低温和常温下反应器中优势菌群发生了一定变化,常温条件下的优势菌群比低温条件下更丰富多样.总体看来,SUFR反应器良好的螺旋升流特质有利于不同菌群在不同温度下的功能发挥,特别是低温下脱氮除磷功能的维持.     

光电催化反应器的研究进展

介绍了国内外近年来有关光电催化反应器设计与研究的进展情况,按催化荆在反应中的存在形式分类讨论了各种反应器的结构、原理和主要特点,并探讨了光电催化反应器设计中存在的问题和今后的研究方向。     

ABR处理低浓度废水的污泥颗粒化研究

通过两个ABR反应器不同启动方式的对比,考察了污泥颗粒化的进程。试验以污水厂的厌氧污泥为对象,以颗粒污泥的粒径、形成特征等作为评价污泥颗粒化的指标,分析了控制进水CODcr浓度和改变水力停留时间两种运行方式对污泥颗粒化的影响。试验结果表明,两种启动运行方式均能够实现污泥的颗粒化,但在颗粒粒径和颗粒化程度上有所区别。培养出的颗粒污泥形状一般为球形或椭球形,直径在1 mm～2 mm。污泥结构紧密,表面较光滑,以丝状产甲烷菌为主。     

分置式膜-生物反应器处理生活污水的抗冲击负荷能力

分置式膜 -生物反应器处理生活污水的运行结果表明 ,在 3倍于正常水平的冲击负荷下 ,分置式膜 -生物反应器能够正常运行 ,膜过滤出水 COD维持在 1 0 mg/ L以下 ,生物反应器污泥上清液 COD和透膜压力 TMP比正常水平略微上升 ,但在冲击负荷消除后能够恢复正常水平 ,呈现出较强的抗冲击负荷能力 .分置式膜 -生物反应器与普通活性污泥法相比 ,在冲击负荷下 ,其有机物去除速率、污泥浓度都呈现较快增长 ,而污泥混合液 COD浓度上升幅度较小 ,并且在冲击负荷消除后迅速恢复稳态运行 .分析表明分置式膜 -生物反应器的强抗冲击负荷能力来自于膜对污泥的完全截流作用 .膜 -生物反应器的强抗冲击负荷能力意味着该技术出水水质的安全稳定性和操作简便性 .     

石化厂皂化废水厌氧降解的试验研究

石化厂以氯醇法生产环氧乙烷过程中排出的皂化废水有机物含量高?含盐量高,并呈强碱性?废水中的物质对厌氧微生物产生强烈的抑制?静态试验表明,消除无机物后,抑制程度减轻?动态试验表明,在水力停留时间≥4d,有机容积负荷COD≤2.0kg/(m2·d)的条件下,取得了较好的厌氧处理效果?