磺胺甲恶唑污染对颤蚓的氧化胁迫

在实验室模拟条件下分别采用动、静态生物实验方法,研究了不同浓度的磺胺甲恶唑(sulfamethoxazole,SMZ)对颤蚓(Monopyle phorus limosus)体内抗氧化防御系统的影响以及颤蚓暴露于单一浓度的SMZ后,其体内典型的抗氧化酶,超氧化物歧化酶(SOD)的活性随时间的响应。结果显示:染毒8d后,颤蚓体内SOD的活性先降低后逐渐升高。SMZ染毒浓度达到1.00mg·L-1时,SOD的活性被显著诱导(P<0.01),为对照组的1.30倍。过氧化物酶(POD)活性的变化趋势明显分为先升高、再降低2个阶段。染毒浓度达到0.25mg·L-1时,POD的活性受到最大诱导(P<0.01),约为对照组的1.40倍。各处理组过氧化氢酶(CAT)的活性均高于对照组,并且随着SMZ暴露浓度的增加,CAT活性的变化趋势是逐渐降低的,与SMZ染毒浓度间存在较好的剂量-效应关系。随着SMZ暴露时间的延长,SOD、POD和CAT的活性变化趋势类似,均为先升高后降低,并在第8天时达到最大值(P<0.01),增长率分别为32%、26%和82%。综上,SMZ能诱导颤蚓体内产生氧化胁迫,而CAT在活性氧自由基的清除中发挥主要作用。     

用白泥和赤泥制备烟气脱硫剂

以碱厂白泥和钢厂赤泥为主要原料,研究了制备复合金属氧化物成型烟气脱硫剂的工艺;考察了m（白泥）：m（赤泥）、白泥和赤泥平均粒径、黏结剂、造孔剂对脱硫剂活性的影响。脱硫剂最佳制备工艺条件为m（白泥）：m（赤泥）=2：1,白泥和赤泥粒径越小越好,黏结剂为Na,造孔剂为Zb,加水混匀,挤条成型,烘干后高温焙烧制得;脱硫剂的最高脱硫率为99．83％,脱硫剂脱硫12．30h后穿透硫容为15．20％。     

澳门松山市政公园物种多样性特征

根据实际情况.将澳门松山市政公园植物群落分为阴香群落、假萍婆群落、假萍婆+石栗群落,调查并分析了各群落的物种多样性特征.结果表明,乔木层、灌木层和草本层的物种多样性水平表现为灌木层较高.草本层与乔木层较低.但总体而言.这些群落的植物种类都较少,物种多样性水平尤其乔木层物种多样性水平低.因此,应加强抚育,可通过生态恢复改善环境条件,为生物多样性的发展创造条件;通过林分改造促进群落物种多样性水平的提高,同时也能丰富森林景观.     

Polystyrene microplastics induce blood–testis barrier disruption regulated by the MAPK-Nrf2 signaling pathway in rats

Environmental Science and Pollution Research - As a persistent pollutant, microplastics (MPs) have been reported to induce sperm quantity decrease in mice. However, the related mechanism remains...     

ZnO-TiO_2光催化还原亚硝酸盐

利用水热法制备了ZnO-TiO2复合材料,采用XRD、SEM、EDS对催化剂进行了表征分析。实验考察了复合材料催化还原亚硝酸盐的效果,结果表明,pH=5,ZnO-TiO2浓度为1.00g/L,亚硝酸盐初始浓度为50mg/L(以氮元素计算),0.03mol/L的甲酸作空穴捕获剂,反应150min后,亚硝酸盐转化率为94.64%,氮气选择性为79.12%。对光催化亚硝酸盐反应动力学进行研究,拟和出了反应动力学方程,结果表明该催化反应为一级反应。     

基于多中心治理理论的农村环境污染防治对策

由于过度重视经济指标及政府环境治理方式的局限,中国农村环境污染越来越严重,为此,本文在分析中国农村环境污染现状的基础上,运用多中心治理理论,从政府、市场、社群组织及农民意识等角度,探讨了农村环境污染的原因,并从多中心治理视角提出了中国农村环境污染防治的对策,这些对策包括转换政府角色,发挥市场机制的支持作用,完善社群组织在环境污染治理中的作用,及强化农民环境污染治理的参与意识等。提出的污染防治对策可为社会主义新农村建设时期的环境污染治理工作提供参考。     

五氟磺草胺的光解特性研究

通过室内模拟的试验方法研究了五氟磺草胺在高压汞灯下的光解特性。五氟磺草胺在pH5、7、9的缓冲溶液中光解半衰期分别为23 min、20.6 min、18.7 min,随着pH的升高光解速率加快。在五氟磺草胺浓度为1 mg/kg、2 mg/kg、5 mg/kg的水溶液中半衰期分别为14.2 min、17.5 min、22.1 min,光解速率随着浓度的升高而减慢。在1 g/L、2 g/L的腐殖酸溶液中五氟磺草胺的半衰期分别为6.6 min、4.6 min,其光解速度是水中的4～5倍。五氟磺草胺在0.1 g/L的UV531溶液中半衰期为27.8 min,在0.2 g/L的溶液中半衰期为35.8 min,半衰期比在水溶液中延长60%。     

Occurrence of human pathogenic bacteria carrying antibiotic resistance genes revealed by metagenomic approach: A case study from an aquatic environment

Antibiotic resistance genes(ARGs), human pathogenic bacteria(HPB), and HPB carrying ARGs are public issues that pose a high risk to aquatic environments and public health. Their diversity and abundance in water, intestine, and sediments of shrimp culture pond were investigated using metagenomic approach. A total of 19 classes of ARGs, 52 HPB species, and 7 species of HPB carrying ARGs were found. Additionally, 157, 104, and 86 subtypes of ARGs were detected in shrimp intestine, pond water, and sediment samples, respectively. In all the samples, multidrug resistance genes were the highest abundant class of ARGs. The dominant HPB was Enterococcus faecalis in shrimp intestine, Vibrio parahaemolyticus in sediments, and Mycobacterium yongonense in water, respectively. Moreover, E. faecalis(contig Intestine_364647)and Enterococcus faecium(contig Intestine_80272) carrying efr A, efr B and ANT(6)-Ia were found in shrimp intestine, Desulfosaricina cetonica(contig Sediment_825143) and Escherichia coli(contig Sediment_188430) carrying mex B and APH(3′)-IIa were found in sediments, and Laribacter hongkongensis(contig Water_478168 and Water_369477), Shigella sonnei(contig Water_880246),and Acinetobacter baumannii(contig Water_525520) carrying sul1, sul2, ere A, qac H, OXA-21, and mph D were found in pond water. Mobile genetic elements(MGEs) analysis indicated that horizontal gene transfer(HGT) of integrons, insertion sequences, and plasmids existed in shrimp intestine, sediment, and water samples, and the abundance of integrons was higher than that of other two MGEs. The results suggested that HPB carrying ARGs potentially existed in aquatic environments, and that these contributed to the environment and public health risk evaluation.     

煤气化是削减重庆SO2污染的重要途径

解决重庆ＳＯ２污染的较好途径是采用德士古煤气化技术，文中对有关煤气化的投资和经济评估进行了探讨。     

炼油污水中油的性状与除油效率关系探讨

通过对炼油污水的油性剖析和主要除油设施的净化效率评价，探讨了除油效率与油特性的关系，对现有除油设施存在的问题进行了分析，并提出对策建议。