Degradation kinetics of terephthalic acid wastewater with the hybrid strains constructed with Phanerochaete chrysosporium

The degradation kinetic parameters in terephthalic acid (TPA) wastewater for the hybrid strains of Fhh and Fhhh obtained through the protoplast fusion of the fungi Phanerochaete chrysosporium (PC) and Saccharomyces cerevisiae Y99, and the native bacteria YZ1 were measured in this research. The highest level of the specific degradation rate for Fhhh and Fhh during 20h reaction were 0.2238 and 0.2163 h^‐1, which were higher than that of their three parental strains and that of the anaerobic bacteria reported. It suggested that the abilities of growth and degradation for Fhh and Fhhh in TPA wastewater were better than their three parental strains. They could create potentials for the purification of TPA wastewater with higher efficiency.     

BDE-47对斑马鱼胚胎-幼鱼的急性毒性及氧化应激作用

为研究2,2',4,4'-四溴联苯醚(BDE-47)对斑马鱼胚胎-幼鱼急性毒性、氧化应激及细胞凋亡的影响,以受精后3 h的斑马鱼胚胎为染毒对象,用概率单位法计算BDE-47对斑马鱼胚胎-幼鱼的96 h-LC₅₀;再参照96 h-LC₅₀按一定比例级差设置0.25、0.5、1.0、2.0 mg·L^-1 4个浓度组和1个对照组(0 mg·L^-1)进行96 h半静水式毒性试验,检测斑马鱼超氧化物歧化酶(SOD)及过氧化氢酶(CAT)活性、丙二醛(MDA)含量和细胞凋亡情况。结果表明,BDE-47对斑马鱼96 h的急性毒性LC₅₀为3.77 mg·L^-1(95%可信区间1.93～10.27 mg·L^-1);2.0 mg·L^-1剂量组与对照组相比,SOD活性和MDA含量显著增加,且CAT活性与BDE-47染毒浓度之间存在明显的剂量-效应关系;0.5 mg·L^-1 BDE-47染毒96 h后,即观察到斑马鱼幼鱼出现明显细胞凋亡,主要集中于神经管和脑部。研究表明,BDE-47可以影响斑马鱼体内抗氧化防御系统,并能诱导细胞凋亡;BDE-47导致神经组织的氧化损伤可能在动物神经毒性中起重要作用。     

Improvement of the assimilable organic carbon (AOC) analytical method for reclaimed water

Microbial growth is an issue of concern that may cause hygienic and aesthetic problems during the transportation and usage of reclaimed water. Assimilable organic carbon (AOC) is an important parameter which determines the heterotrophic bacterial growth potential of water. Pseudomonas fluorescens P17 and Spirillum sp. NOX are widely used to measure AOC in drinking water. The AOC values of various reclaimed water samples determined by P17 and NOX were compared with those determined by the new strains isolated from reclaimed water in this study. It showed that the conventional test strains were not suitable for AOC measurement of reclaimed water in certain cases. In addition to P17 and NOX, Stenotrophomonas sp. ZJ2, Pseudomonas saponiphila G3 and Enterobacter sp. G6, were selected as test strains for AOC measurement of reclaimed water. Key aspects of the bioassay including inoculum cell density, incubation temperature, incubation time and the pH of samples were evaluated for the newly selected test strains. Higher inoculum density (10⁴ CFU·mL^-1) and higher incubation temperature (25°C) could reduce the time required for the tests. The AOC results of various collected samples showed the advantages of the method proposed based on those five strains in evaluating the biologic stability of reclaimed water.     

2,4-D二甲胺盐对莲草直胸跳甲生存和繁殖的影响

为探究除草剂在防治喜旱莲子草(Alternanthera philoxeroides)的过程中对其天敌昆虫的影响,采用不同浓度的2,4-D二甲胺盐浸叶处理的喜旱莲子草饲喂莲草直胸跳甲,连续饲喂7d后,考察了莲草直胸跳甲的繁殖、存活和发育情况。结果表明,2,4-D二甲胺盐可显著降低莲草直胸跳甲成虫的取食量,且抑制作用随药剂浓度升高和取食时间延长而显著增强;较高浓度(1.72～3.44g·L~(-1))的2,4-D二甲胺盐还会导致莲草直胸跳甲雌成虫存活率和产卵量的明显降低,卵孵化率、幼虫存活率和蛹羽化率也显著降低。可见,高浓度(1.72～3.44g·L~(-1))的2,4-D二甲胺盐对莲草直胸跳甲的生长发育和繁殖有显著不利影响,在防治喜旱莲子草时,应将2,4-D二甲胺盐的施用浓度控制在0.22～0.86g·L~(-1)内。     

环糊精在环境污染治理中的应用分析

环糊精独特的结构特征使其在环境污染治理领域表现出越来越广泛的应用前景。主要综述了环糊精促进水体中有机污染物去除的应用研究,对土壤中污染物的修复应用研究,以及在其他环境污染治理方面的应用。展望了环糊精及其衍生物在环境保护等领域的应用前景。     

基于反赋权与MBCT-SR多维云模型算法岩爆预测研究

基于岩爆事故的模糊性与随机性特征,为解决在当前岩爆烈度等级预测研究中,通过正向云发生器经验式计算多维云模型特征值进而导致预测结果主观性较强的问题.本文选取应力比Ts=σθ/σt、岩石脆性指数B=σc/σt以及弹性应变储能指数Wet作为评价指标,结合机器学习理论,采用多维逆向MBCT-SR云发生器算法对岩爆等级进行预测,...     

天然气汽车加气站压缩机房火灾爆炸事故故障树分析

压缩天然气汽车加气站压缩机房具有高压、易泄漏、易爆炸等危险性特点。根据其运行的实际情况,对压缩机房火灾爆炸事故原因运用故障树进行了深入分析,提出了压缩机房火灾爆炸事故预防对策。     

观历史印尼的几次大地震

印尼苏门答腊南部海域地震 1994年2月16日0时07分,印尼苏门答腊南部发生里氏6．5级地震。震中位于首都雅加达西北250公里,直落勿洞西北36公里处的海域,震源深度为58公里。地震造成215人死亡,3000多人受伤,40010多间房屋彻底被毁,6500座建筑物遭到不同程度的破坏;数以万计的人无家归;震后又降起大雨,多处山体发生塌方,交通、电力和通讯中断,经济损失达1．7亿美元。距里哇市24公里拥有近千名居民的辛加岛还遭到了海啸的袭击,致使150人丧生。     

AB法在虹桥污水处理厂的应用

乌鲁木齐虹桥污水处理厂采用AB活性污泥工艺,设计处理污水3×104m3/d,介绍了虹桥污水处理厂的工艺流程、设计参数、主要处理构筑物、运行状况、影响因素,并对AB活性污泥法的发展运行状况进行了分析和探讨。     

超临界水氧化法处理制浆黑液

造纸黑液是较难处理的工业废水。以工业纯氧为氧化剂,采用自制的间歇式超临界水氧化系统对麦草制浆黑液进行处理,根据实验数据分析了超临界水氧化过程中不同反应温度,时间,氧气浓度对该废水COD处理效率的影响。实验结果表明,选定合理的实验参数,COD去除率可达99.8%。