TTPC对铜绿微囊藻生长及生理的影响

试验设定了6个TTPC浓度梯度处理组和1个对照组,研究十四烷基三丁基氯化鏻(TTPC)对铜绿微囊藻(FACHB469)生长及生理的影响。结果表明当TTPC浓度超过0.6 mg/L时能有效地抑杀铜绿微囊藻,当TTPC浓度为0.8 mg/L,藻细胞与药剂接触时间96 h,相对抑制率达84.68%,同时铜绿微囊藻的可溶性蛋白质量分数、叶绿素a含量及总糖质量分数与对照组相比均显著下降(p<0.05)。根据以上实验结果,我们结果推测TTPC杀藻机理可能是通过阻碍藻细胞生命活动所必需的蛋白合成,抑制叶绿素a的合成,导致藻细胞生命活动所需糖类等物质含量急剧降低,从而使藻细胞生命过程受到阻塞,最终破坏整个藻细胞。     

河蚬(Corbicula fluminea)扰动对湖泊沉积物性质及磷迁移的影响

为探讨河蚬(Corbicula fluminea)扰动对湖泊沉积物性质及磷在沉积物-水界面迁移转化过程,以太湖西岸富营养化湖区大浦口为对象,开展室内培养实验,利用Rhizon间隙水采集器获取实时间隙水,测定溶解活性磷(soluble reactive phosphorus,SRP)在沉积物-水界面通量、分析沉积物基本性...     

蛋白质对PVDF超滤膜污染行为的界面微观作用力解析

采用原子力显微镜,结合自制微颗粒探针,对膜-污染物及污染物-污染物间微观作用力进行了检测分析,考察了不同p H条件下牛血清蛋白(BSA)在不同界面特性PVDF超滤膜上的膜污染行为.结果表明,在膜过滤初期,通量剧烈衰减主要由BSA和膜之间黏附力作用导致,在膜过滤后期,BSA与BSA之间的黏聚作用则是影响后期膜污染行为的主要因素;PA膜-BSA和PP膜-BSA之间的黏附作用力均大于BSA-BSA之间的黏聚作用力,说明在整个膜过滤过程中,BSA与PVDF超滤膜之间的黏附作用对膜污染起主导作用;相同p H条件下,PA膜-BSA之间的微观作用小于PP膜-BSA之间的相互作用力,说明亲水性较强的PA膜具有较强的抗污染性;而PA膜和PP膜过滤后期BSA-BSA之间黏聚力相差不大,也进一步说明膜过滤过程中膜-污染物之间的微观作用力是影响膜污染行为的主要因素.     

Na2S胁迫/诱导下Bacillus vallismortis sp.EPS组分变化及其对铜锌的吸附

为研究胞外聚合物（EPS）对重金属吸附效果的影响,本文通过Na₂S胁迫/诱导Bacillus vallismortis sp.EPS的化学组成变化来强化其对典型重金属的吸附.结果表明,Na₂S胁迫/诱导强度为20mg/L时,S-EPS产量最高,达到105.58mg/gVSS,蛋白质较Control-EPS提高了近一倍,其中巯基含量达到154.36μmol/L,比胁迫前提高了48.2%.在此条件下,S-EPS对Cu（Ⅱ）和Zn（Ⅱ）的吸附效果最好,对重金属离子的吸附与Langmuir等温式拟合较好,拟合理论最大吸附量分别达到1428.57和979.09mg/g EPS,且吸附过程符合二级动力学规律.三维荧光（3D-EEM）和红外光谱（FTIR）分析表明,巯基、蛋白质酰胺I带与酰胺Ⅱ带在吸附Cu（Ⅱ）和Zn（Ⅱ）中起到了主要作用,尤其是对Zn（Ⅱ）的吸附.说明外加硫源提高了巯基蛋白含量,大大提高了重金属去除效果.该生物吸附剂在重金属污染防治中显示出极大的应用前景.     

长沙市秋季PM2.5中水溶性离子特征及其来源解析

为探究长沙市秋季PM_(2.5)水溶性无机离子组成特征和来源,于2017年9月～11月在长沙城区连续采集大气颗粒物PM_(2.5)样品共85个,并用离子色谱仪分析样品中的9种水溶性无机离子(F~-、Cl~-、NO_3~-、SO_4~(2-)、K~+、Na~+、Ca~(2+)、Mg~(2+)、NH_4~+)。结果表明,长沙市秋季PM_(2.5)质量浓度的平均值为56. 3±39. 6μg/m~3,总水溶性无机离子质量浓度平均值为29. 47±19. 10μg/m~3,占PM_(2.5)的52. 3%,其中NO_3~-、SO_4~(2-)、NH_4~+是PM_(2.5)中最主要的离子成分。霾天PM_(2.5)平均质量浓度约是清洁天的3倍,NO_3~-、NH_4~+、K~+、Cl~-四种离子的快速增长对霾天PM_(2.5)中离子的贡献最大。由PMF模型解析可知,秋季大气PM_(2.5)主要来源于机动车尾气和燃煤源,而扬尘、生物质燃烧源、工业源和海盐的贡献不到30%。长沙市秋季大气污染呈现机动车尾气等移动源和燃煤等固定源的混合型污染为主。     

Structural and molecular alterations in arsenic-induced hepatic oxidative stress in rats: a FTIR study

Arsenic (As) is an ubiquitously distributed environmental toxicant predominantly contaminating drinking water. A number of studies indicated that oral exposure of humans to inorganic As produced damage to various body tissues including liver. Oxidative stress is thought to play a major role in As-induced hepatotoxicity. In this study, Fourier transforms infrared (FTIR) spectroscopy approach was applied to determine whether chronic As exposure at 25 ppm, intragastrically for 12 weeks, affected oxidative stress status in rat liver. Data demonstrated that chronic As administration exacerbated oxidative stress as was evidenced by suppressed antioxidant defense system and increased lipid peroxidation and protein oxidation. The FTIR study showed that peak area value of amide A decreased significantly followed by reduced amide I and amide II peak area in an As-treated rat liver suggesting altered protein profile. The change of Olefinic?CH stretching band and C?O stretching of triglycerides band indicated the altered lipid levels due to metallic exposure. The fall in the peak area of PO₂^? asymmetric stretching in the As-treated group might be due to compositional changes of nucleic acids. Hence, the results of this study indicate that As-induced oxidative stress was associated with structural and molecular modifications in proteins, lipids, and glycogen in a rat liver that may help to elucidate molecular mechanisms underlying metal-mediated hepatic damage.     

邯郸市PM_(2.5)中水溶性无机离子污染特征及来源解析

本研究通过对邯郸市环境空气中PM2.5样本进行采集和成分检测,分析了该地区PM2.5中水溶性无机离子的污染特征,并结合气象要素(风速、温度)、气态污染物(O3、NO2、SO2、CO)、SOR(硫氧化率)、NOR(氮氧化率)对其主要来源进行了解析.研究结果表明:总水溶性无机离子(TWSII)浓度季节变化特征明显,秋、冬季高于春、夏季.SO2-4、NO-3、NH+4是PM2.5中主要的水溶性无机离子,在TWSII中所占的比例为夏(93.2%)冬(85.6%)秋(85.5%)春(84.0%).春、夏、秋三季PM2.5呈酸性,冬季显碱性.此外还分析得到,SO2-4在四季中均以(NH4)2SO4的形式存在.NO-3在冬季以NH4NO3的形式存在,其余季节中以NH4NO3、HNO3等共存.绝大部分Cl-在冬季以NH4Cl的形式存在,其它季节中以NH4Cl、KCl等的形式存在.均相反应是SO2-4的主要生成途径,夏、冬季也伴随有非均相反应.NO-3的生成以均相反应为主(春、夏、秋),在冬季均相反应与非均相反应同时存在.应用因子分析法解析出4个主因子,其中,工业、燃煤、交通、生物质燃烧等综合源是PM2.5中水溶性无机离子的主要来源.     

Bioaugmentation of DDT-contaminated soil by dissemination of the catabolic plasmid pDOD

A plasmid transfer-mediated bioaugmentation method for the enhancement of dichlorodiphenyltrichloroethane (DDT) degradation in soil was developed using the catabolic plasmid pDOD from Sphingobacterium sp. D-6. The pDOD plasmid could be transferred to soil bacteria, such as members of Cellulomonas, to form DDT degraders and thus accelerate DDT degradation. The transfer efficiency of pDOD was affected by the donor, temperature, moisture, and soil type. Approximately 50.7% of the DDT in the contaminated field was removed 210 days after the application of Escherichia coli TG I (pDOD-gfp). The results suggested that seeding pDOD into soil is an effective bioaugmentation method for enhancing the degradation of DDT.     

Deoxynivalenol impairs proliferation and induces apoptosis in primary murine osteoblasts

The effects of deoxynivalenol in different dose including 100, 200, 500, 1000, and 1500 µg/L on primary cranial osteoblasts from fetal mice were investigated. Fluorescence staining, flow cytometric measurement, 3-(4,5-dimethylthiazol 2-y1)-3,5-di-phenyltetrazolium bromide assay, quantitative PCR, and Western blot were used for the test. Mineralization and proliferation of osteoblasts decreased upon 100 µg/L and higher deoxynivalenol treatment and apoptosis of osteoblasts was increased upon 500, 1000, and 1500 µg/L deoxynivalenol treatment. Karyopyknosis, membrane breakage, and a decreased number of calcium nodes were also observed upon 500 µg/L deoxynivalenol treatment. The mRNA and protein levels of B-cell lymphoma-2-associated X protein were upregulated, B-cell lymphoma-2 protein downregulated with increasing concentrations of deoxynivalenol treatment and their ratio increased. Deoxynivalenol induces apoptosis of osteoblasts, suggesting a mechanism by which deoxynivalenol can affect murine skeletal development.     

南通市PM2.5中水溶性离子季节分布特征

对南通市2016年12月-2018年10月大气污染季节分布特征进行了分析。结果表明,南通市ρ(PM2.5)和ρ(水溶性离子)为冬、春季高,夏、秋季低。春夏秋冬四季ρ(水溶性离子)占ρ(PM2.5)百分比分别为68.2%,70.6%,64.5%和74.5%,其中二次离子SNA(NO3-、SO42-和NH4+)占ρ(PM2.5)的百分比分别为63.1%,67.0%,59.3%和66.8%;ρ(NO3-)/ρ(SO42-)表明,移动源已成为南通市春、秋、冬季的主要污染源,四季均存在不同程度的二次转化,且SO2的转化率均大于NO2,NO2冬季转化率最大、夏季最小,SO2夏季转化率最大、秋季最小。南通市NO2转化为硝酸盐的主要形式是气相均相反应,非均相反应和均相反应对SO2转化为硫酸盐的贡献差异不大。