NaCl盐度对耐盐活性污泥沉降性能及脱氮的影响

针对海水冲厕工程的实施,采用序批式活性污泥反应器(SBR)处理实际含盐生活污水,考察了盐度对耐盐活性污泥沉降性能及脱氮效能的影响。研究发现,经过长期盐度驯化后的污泥系统也会出现丝状菌污泥膨胀。在经过10 g/L盐度长期驯化的污泥系统中,污泥容积指数(SVI)随着盐度的升高而降低,盐度升高使丝状菌减少,污泥絮体变小变密实。但是,盐度降低时会引发更严重的污泥膨胀,导致污泥流失。对脱氮性能的研究表明,硝化菌的耐盐能力较强。当盐度由10 g/L改变为0、5、15、20 g/L时,氨氮去除率依然可以维持在99%以上。但亚硝酸盐积累率无论是盐度升高或降低时都升高,这表明驯化后污泥中的亚硝酸氧化菌(NOB)对盐度变化的耐受能力比氨氧化菌(AOB)弱,无论盐度升高或降低都会对其产生较大的影响。     

Excretion stereoselectivity of triticonazole in rat urine and faeces

Abstract

The purpose of this study was to study the excretion stereoselectivity of triticonazole enantiomers in rat urine and faeces. Six male Sprague-Dawley (SD) rats were administrated 50?mg/kg rac-triticonazole. Rats urine and faeces were separately and quantitatively collected at the following intervals: 0–3, 3–6, 6–9, 9–12, 12–24, 24–36 and 36–48?h. The faeces samples were homogenized in an aqueous solution containing 0.2% DMSO at the ratio of 1?g: 40?mL. An aliquot of 100?μL rats urine or faeces homogenate was spiked and mixed with 6.0?μL of 1.00?μg/mL flusilazole as an internal standard. The triticonazole enantiomers in urine and faeces were determined by using an HPLC/MS–MS after samples preparation. The excreted amounts of enantiomers in the urine showed a significant difference (P?<?0.05) except for 3–6?h. The cumulative excretion rate (Xu_0→24) in urine was 26.43?±?0.08% and 37.58?±?0.11% for R-(?)- and S-(+)-triticonazole, respectively, indicating high enantioselectivity (P?<?0.001). The cumulative excretion rate (Xu_0→72) in faeces was 6.93?±?0.03% and 6.77?±?0.03% for R-(?)- and S-(+)-triticonazole, respectively, without a difference. The results showed that the total cumulative percentage of triticonazole enantiomers accounted for in urine and faeces was 64.00?±?0.13% and 13.70?±?0.32%, the urinary excretion of R-(?)- and S-(+)-triticonazole were significantly different and S-(+)-triticonazole was preferentially excreted. However, the faecal excretion of the enantiomers showed no difference.     

基于非本地物种毒性数据推导出的水质基准可为本地物种提供适当保护吗？

基于非本地物种的毒性数据推导出的水质基准一直存在争议,质疑者提出应有针对不同生物区系的水质基准。而这个问题在中国尤为突出。本文作者搜集了38种污染物对本地物种和非本地物种的毒性数据,比较了这些生物的HC₅和物种敏感度分布,结果显示,基于非本地物种推导的水质基准有74%的确定性可以有效保护中国的水生态系统。如果采用评价因子(AF=5)来校正基准,那么可以获得90%的确定性。
精选自Xiaowei Jin, Zijian Wang, Yeyao Wang, Yibing Lv, Kaifeng Rao, Wei Jin, John P. Giesy and Kenneth M. Y. Leung. Do water quality criteria based on nonnative species provide appropriate protection for native species? Environmental Toxicology and Chemistry: Volume 34, Issue 8, pages 1744–1750, August 2015. DOI: 10.1002/etc.2985
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2985/full     

Comparative toxicity study of a novel non-ionic surfactant, vanillin ethoxylates, and nonylphenol ethoxylates in Chinese hamster ovary cells in vitro

Surfactants such as alkylphenol polyethoxylates (APEOs) and nonylphenol ethoxylates (NPEOs) are commonly used worldwide, but the majority of these compounds, together with their metabolites, have been reported to induce severe biological toxicity. Here, we evaluated for the first time the cytotoxicity, genotoxicity and mitochondrial damage in Chinese hamster ovary (CHO-K1) cells caused by a novel non-ionic surfactant, vanillin ethoxylates (VAEOs), an alternative to APEOs. In parallel, the same in vitro bioassays were conducted on NPEOs along with their metabolic byproducts 4-nonylphenol (4-NP) and vanillin. The results showed that the cytotoxic potency order was NPEOs?>?4-NP?>?VAEOs > vanillin using CCK-8 assays. Also, 4-NP showed potential direct DNA damage in SOS/umu tests, whereas NPEOs, VAEOs and vanillin showed no positive result with and without S9 addition. In addition, none of the test compounds showed obvious genotoxic effects with low olive tail moment value using comet assays. However, all test compounds were shown to cause mitochondrial impairment by increasing mitochondrial mass and decreasing mitochondrial membrane potential in a concentration-dependent manner. And further analysis of reactive oxygen species (ROS) and mitochondrial superoxide (MNSOD) measurement showed that mitochondrial impairment was induced by oxidative stress with intracellular ROS and MNSOD overproduction. It's worth noting that VAEOs and vanillin cause relative lower cytotoxic, genotoxic and mitochondrial damage effects than NPEOs and 4-NP, indicating that VAEOs have the potential to substitute NPEOs as suitable surfactants. Take together, this study elucidates the toxicity profiles of VAEOs and NPEOs relatively comprehensively, and further toxicity analyses are suggested in the population, community and ecosystem.     

钢渣在复合胶凝材料水化过程中的作用机理研究

在相同掺加比例、相同水胶比条件下,通过测试胶砂试块力学性能、浆体Zeta电位、水化反应热及硬化浆体微观分析,对比研究了具有相同细度的钢渣粉与惰性掺合料石英粉对于复合胶凝材料水化硬化过程与技术性能的影响.试验结果表明,钢渣在复合胶凝材料中积极地参与水化反应过程,水化反应迅速,水化产物均匀交错,凝胶结构致密,形成的水泥石力学性能好.     

微波消解技术及其在环境监测中的应用

本文概述了微波技术的独特优势及微波技术在环境监测领域的应用现状和发展趋势。     

Estrogen-related receptor disruption of source water and drinking water treatment processes extracts

Environmental chemicals in drinking water can impact human health through nuclear receptors. Additionally, estrogen-related receptors (ERRs) are vulnerable to endocrine-disrupting e ects. To date, however, ERR disruption of drinking water potency has not been reported. We used ERR two-hybrid yeast assay to screen ERR disrupting activities in a drinking water treatment plant (DWTP) located in north China and in source water from a reservoir, focusing on agonistic, antagonistic, and inverse agonistic activity to 4-hydroxytamoxifen (4-OHT). Water treatment processes in the DWTP consisted of pre-chlorination, coagulation, coal and sand filtration, activated carbon filtration, and secondary chlorination processes. Samples were extracted by solid phase extraction. Results showed that ERR antagonistic activities were found in all sample extracts, but agonistic and inverse agonistic activity to 4-OHT was not found. When calibrated with the toxic equivalent of 4-OHT, antagonistic e uent e ects ranged from 3.4 to 33.1 g/L. In the treatment processes, secondary chlorination was e ective in removing ERR antagonists, but the coagulation process led to significantly increased ERR antagonistic activity. The drinking water treatment processes removed 73.5% of ERR antagonists. To our knowledge, the occurrence of ERR disruption activities on source and drinking water in vitro had not been reported previously. It is vital, therefore, to increase our understanding of ERR disrupting activities in drinking water.     

有机磷农药的构效关系及其对浮游生物的毒性效应

以定量构效关系理论和实验室内急性毒性试验相结合研究了六种有机磷农药对四尾栅藻（S.quadricanda）和多刺裸腹溞（Moina macrocopa）的生态毒性。有机磷农药的毒性取决于磷原子的电正性,各取代基种类和构象对电荷分布作用显著。根据构效关系原理,磷氧双键（P=O）被磷硫双键（P=S）取代后毒性降低;羟基（-OH）被甲、乙、丙氧基（-CH3O、-CH3CH2O、-CH3CH2CH2O）取代后有机磷农药毒性依次增强;磷氧单键（P-O）毒性高于磷碳单键（P-C）。该实验中毒死蜱、辛硫磷（-CH3CH2O）毒性高于其它四种（-CH3O）,敌敌畏和敌百虫（P=O）毒性高于乐果（P=S）,敌敌畏（P-O）又高于敌百虫（P-C）,甘氨酸异丙胺盐取代羟基（-OH）的草甘膦毒性最低。毒性试验结果表明,毒死蜱、辛硫磷、敌百虫、敌敌畏、乐果、草甘膦异丙胺盐对四尾栅藻的96 h EC50分别为6.34、6.62、59.53、82.12、141.37和7.25 mg.L-1。它们对多刺裸腹溞的48 h LC50分别为0.20、0.12、0.28、0.17、1.12和5.03 mg.L-1。六种有机磷农药对多刺裸腹溞的毒性强度结果与QSAR分析具有较高的一致性,即表征有机磷农药毒性特征的取代基团作用的毒性强弱顺序为：-OH〉=O〉-O;对四尾栅藻毒性试验结果中,由于草甘膦异丙胺盐作用于植物类靶位点的特殊性,导致其对四尾栅藻毒性显著增强。综合以上研究,以构效关系理论和浮游生物毒性试验相结合进行有机磷农药的生态风险评价将更加便捷和准确。     

昆嵛山盐肤木Rhus chinensis Mill.群落特征及其物种多样性

根据野外典型样方调查结果,以群落植物种类组成、群落外貌特征、群落垂直结构特征、群落多样性几项指标,分析山东半岛昆嵛山国家级自然保护区盐肤木Rhus chinensis群落特征。结果表明:盐肤木群落共出现种子植物66种,隶属于32科57属。在盐肤木群落属的区系组成中,群落植物主要由温带区系和热带区系成分组成,其中温带植物属占显著优势,其次为热带分布属,说明该群落具有明显的温带性质,并具有过渡特征。群落层次分明,有乔木层、灌木层、草本层3个层次,各层次的优势种依次为盐肤木和赤松Pinus densiflora、麻栎Quercus acutissima、披针叶苔草Carex lanceolata。盐肤木群落的物种多样性由高到低依次为灌木层、乔木层、草本层,低均匀度导致物种丰富度最高的草本层具有最低的物种多样性。调查显示盐肤木幼苗幼树多,自我更新良好,群落处于稳定增长状态。通过对群落特征和物种多样性的研究,揭示了昆嵛山盐肤木群落的自然生态规律,为保护和开发利用盐肤木提供了科学依据。