Short-chain chlorinated paraffins (SCCPs) in surface soil from a background area in China: occurrence, distribution, and congener profiles

Short-chain chlorinated paraffins (SCCPs) are extremely complex technical mixtures of polychlorinated n-alkanes with carbon chain lengths from C₁₀ to C₁₃ and chlorine content between 49 and 70 %. SCCPs are under consideration for inclusion in the Stockholm Convention on persistent organic pollutants. SCCPs have been used extensively in industrial production, but little is known about the pollution level in soil environment in China. In this study, levels and distribution of SCCPs in soil samples from Chongming Island were analyzed. Concentrations of total SCCPs in soil samples ranged from 0.42 to 420 ng?g^?1, with a median of 9.6 ng?g^?1. The ubiquitous occurrence of SCCPs in Chongming Island implied that long-range atmospheric transport and soil–air exchange may be the most important pathways for SCCP contamination in the background area. The localized SCCP contamination could be derived from an unidentified source. Hierarchical cluster analysis indicated that C₁₃- and C₁₁-congeners were predominant in most soils and C₁₀- and C₁₂-congeners dominated in the remaining soils. Cl₇- and Cl₈-congeners were on the average the most dominant chlorine congeners in nearly all soils. Principal component analysis suggested that the separation of even and odd carbon chain congeners occurred during long-range atmospheric transport and aging in soil in the study area.     

醌介体催化强化酸性红B生物脱色

考察了5种结构相似的醌介体(AQS、2,7-AQDS、AQDS、1,5-AQDS和α-AQS)对酸性红B生物脱色的催化强化作用。结果表明,反应进行至5 h,在0～0.24 mmol/L AQS的浓度范围内,最高脱色率达89%(0.24 mmol/L),相对于空白组(28%)提高约3.2倍,且零级反应速率常数K与介体浓度呈正相关线性关系,K=56.571CAQS+22.616(R2=0.9012);最适实验条件为AQS浓度0.24 mmol/L,0.25%NaCl,温度35℃,pH 7;在此实验条件下,5种醌介体相对于空白组脱色效率分别提高了1.14～1.53倍,体系氧化还原电位降低了38～87 mV。本研究为解决偶氮染料生物脱色技术存在的降解速率低的问题提供了新的思路。     

The effects of Herba Andrographitis hedgerows on soil erodibility and fractal features on sloping cropland in the Three Gorges Reservoir Area

To evaluate if hedgerows could improve the soil physicochemical properties and enhance the soil anti-scouring and anti-shearing capabilities, the effects of Herba Andrographitis hedgerows on soil erodibility and fractal features on sloping cropland in the Three Gorges Reservoir Area were investigated. Results showed that: (1) the clay particle accumulation around the hedgerows was significantly affected by the hedgerows; (2) the fractal dimension of soil particles was positively correlated with both silt and clay contents and had a negative linear correlation with sand content; (3) fine-grained content significantly influenced fractal dimension of the soil particles; (4) soil erodibility K was significantly and positively correlated with the sand content (correlation coefficient r?=?0.870), but significantly and negatively correlated with the silt content (r?=??0.538), clay content (r?=??0.739), organic carbon content (r?=??0.603), the aggregation degree (r?=??0.486), and soil fractal dimension (r?=??0.538); and (5) the contents of organic matter and clay particles in the soil were found to be the effective indicators for soil erodibility at the Three Gorges Reservoir Area. The hedgerows may improve soil fractal features and decrease soil erodibility. The effective distance between hedgerows on a slope of 10° was less than 6 m.     

降解菌ZQ5与紫茉莉对芘污染土壤的联合修复

在温室盆栽条件下,通过单独种植紫茉莉、单独接种多环芳烃(PAHs)模式化合物芘的专性降解菌ZQ5和两者的联合修复的3种处理,对芘污染土壤的修复效果进行了研究。结果表明,经90 d修复后,植物-微生物联合修复可将人工污染土壤中的芘降解81.1%,将石油污染土壤中的芘降解50.3%,其修复效率明显高于其他2种处理,是紫茉莉修复的1.98倍,是降解菌ZQ5修复的1.39倍。ZQ5的不同接菌量对于修复60 d后的降解率影响不大。外源生物修复条件下,10～20 cm土壤的修复效率要高于5 cm土壤;自然降解条件下,5 cm土层降解率略高于其他土层。     

一株高效MC—RR降解菌的分离鉴定及其降解特性

为了得到一株具有降解微囊藻毒素一RR（MC—RR）特性的产芽孢菌株,采用加热富集芽孢菌的方法,从太湖分离到一株MC．RR降解菌CMl,该菌对MC—RR具有强烈的降解特性。通过形态学特征、生理生化特征及16SrDNA序列分析鉴定该菌株属于耐硼赖氨酸芽孢杆菌（Lysinibacillusb oronitolerans）。通过研究温度和pH值对菌株CMl降解MC—RR能力的影响,发现菌株CMl在60h将MC—RR由12．77μg／mL降解到1．67μg／mL,降解率达86．90％,最适降解温度为37℃,最适pH值为7．0。CMl菌株的胞外物质和胞内物质均能降解MC—RR,但胞内物质具有更强烈的降解特性,12h可以将7．27μg／mL的MC-RR完全降解。为丰富MC-RR降解菌纯菌种研究以及在去除水体中MC—RR应用研究方面提供了理论基础。     

曝气对两种人工湿地污水净化效果的影响

采用复合垂直流和水平潜流2种人工湿地处理混合污水,研究了在气水比(曝气体积/湿地进水体积)为2、4、6、8和10时2种人工湿地对污水的净化效果.结果显示:(1)复合垂直流人工湿地以气水比为2进行曝气时,对污水的净化效果最好,上行池出水的COD、TN、NH4+-N、NO3--N平均去除率比不曝气时分别提高了16.47%、...     

一株芴降解菌的分离鉴定及其对多环芳烃的降解广谱性研究

从某焦化厂活性污泥中筛选出一株芴的优势降解菌株W-1,经形态学观察、生理生化实验和16S rDNA基因序列分析,确定W-1为粪产碱杆菌.在接种量10%(V/V),初始芴浓度40 mg/L,pH 7.0,温度30℃的条件下,接种培养11 d后,菌株W-1对芴的降解效率达到87.8%.菌株W-1对多环芳烃的降解具有广谱性,...     

脱硫后净烟气携带浆液量监测的实验研究

在WFGD系统中,净烟气携带的浆液液滴引起后续设备的腐蚀堵塞,带来的景观污染问题影响周围居民的正常生活.为了精确量化脱硫后净烟气携带浆液量,提出了适用于环境监测专业的测试取样分析方法,并对该方法进行了讨论分析.实验结果表明:该方法的适用范围为净烟气浆液液滴含量在1.1 mg/Nm3以上,通过对取样分析关键环节的讨论分析...     

Effects of malathion and chlorpyrifos on acetylcholinesterase and antioxidant defense system in Oxya chinensis (Thunberg) (Orthoptera: Acrididae)

The study was undertaken to evaluate the effects of malathion and chlorpyrifos on acetylcholinesterase (AChE), esterase (EST) activity and antioxidant system after topical application with different concentration to Oxya chinensis. The results showed that malathion and chlorpyrifos inhibited EST, AChE activity and increased malondialdehyde (MDA) contents. A change in superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR) activity combined with reduced glutathione (GSH) and total glutathione (tGSH) contents was found in O. chinensis after malathion and chlorpyrifos treatments. Malathion and chlorpyrifos increased SOD and CAT activity compared with the control. With the concentrations increasing, SOD and CAT activity showed the similar tendency, namely, SOD and CAT activity increased at the lower concentrations and decreased at the higher concentrations. The results showed that malathion and chlorpyrifos decreased significantly GR activity. GST and GPx activity at the studied concentrations of chlorpyrifos was lower than that of the control. However, no significance was observed. GPx and GST activity in malathion treated grasshoppers showed a biphasic response with an initial increase followed by a decline in its activity. Malathion and chlorpyrifos decreased GSH contents and the ratio of GSH/GSSG. The present findings indicated that the toxicity of malathion and chlorpyrifos might be associated with oxidative stress.     

应用化学质量平衡模型解析烟台市污染源的排放贡献率

根据烟台地区污染排放特点,应用化学质量平衡模型（CMB8）进行污染源解析分析,得出每个污染源对于受体地区颗粒物体样本的排放贡献率。最终的模型结果显示,建筑尘和居民烯煤锅炉排放,海洋尘和冶炼厂排放对于大气环境污染也有一定的贡献,以上分析可以为城市污染源治理提供一定的依据。