Bioaccumulation, depuration and oxidative stress in fish Carassius auratus under phenanthrene exposure

In this study, laboratory experiment was carried out to determine phenanthrene bioaccumulation, depuration in whole fish and oxidative stress in the liver of freshwater fish Carassius auratus. Fish were exposed to 0.05 mg/l phenanthrene for different periods, while one control group was designated for each exposure group. Some fish after 7 days of exposure were transferred to diluted water. The concentrations of phenanthrene in fish were analyzed by HPLC. Twenty-four hours after the exposure, reactive oxygen species (ROS) were trapped by phenyl-tert-butylnitrone and detected by electron paramagnetic resonance (EPR). The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione-s-transferase (GST) were also determined. The concentrations of phenanthrene in fish increased rapidly shortly after the start of the exposure, reached a maximum level at the 2 days, and then it declined quickly to low-level-steady state. The elimination process of phenanthrene could be divided into two periods-a fast elimination period following a slower loss period. The elimination curve could be fitted mathematically as the sum of two exponential functions according to two-compartment model: C(t)=2.72e(-1.065t) + 0.68e(-0.0364t). The PBN-radical adducts were detected in fish liver samples following the exposure 24h. The hyperfine splitting constants for the PBN-radical adducts were aN = 13.5 G, aH = 1.77 G and g value was 2.0058, which were consistent with those of PBN/()OH. The results indicated that the hydroxyl radical was probably significantly induced during the exposure of phenanthrene, as compared to the control group. The changes of activities of the antioxidant enzymes also were observed. In addition, after fish were removed from phenanthrene exposure, the recovery status of these antioxidant indices was explored. These results clearly indicated phenanthrene could be accumulated in fish and similar redox cyclings were produced, resulting in the changes of the activities of the antioxidant enzymes and the production of ROS with the oxidative stress.     

重庆大气酸沉降对材料腐蚀危害的研究

在重庆对金属、油漆、橡胶等材料大气曝露试验表明,大气酸沉降已对材料产生广泛的危害影响:加速金属腐蚀,促进油漆、橡胶等高分子材料的老化、恶化性能。     

雅克拉凝析气田集气管道腐蚀研究与治理

对雅克拉凝析气田单井集输系统腐蚀状况进行分析,得出该腐蚀主要是CO_2腐蚀和冲刷腐蚀综合作用的结论,提出并实施相应的防腐对策。     

一株碱性果胶酶高产细菌的分离、系统发育分析和产酶条件的初步优化

从腐烂的苹果表皮筛选到一株碱性果胶酶的高产菌株,命名为WSHB04-02.分离菌株为革兰氏阳性细菌,有芽孢,菌落颜色为乳白色.分离菌株WSHB04-02的16SrDNA全序列分析表明,该菌株与Bacillussubtilus具有99%的相似性,并与其他13株产碱性果胶酶菌株的16SrDNA结果进行同源性分析,并构建系统发育树.发现菌株WSHB04-02在不含果胶类物质与Mg2 的培养基上能高产碱性果胶酶,在优化的培养条件下,碱性果胶酶的酶活达到34U/mL,在国内还未见报道.图6表2参15     

复合塔式生态滤池中氮素迁移转化

构建复合塔式生态滤池进行污水处理实验,对含氮污水通过系统各处理单元前后4种氮形态变化和浓度分布进行探讨。比较各单元进出水水质变化,研究各单元总氮和硝氮的去除效果以及对系统总去除率的贡献。结合装置构造特点,系统分析了氮素在复合塔式生态滤池中的迁移转化规律及除氮机制,并创新性应用δ15N-NO3-方法加以佐证。研究结果表明,复合塔式生态滤池工艺对总氮和硝氮均有很好的去除作用,实验污水中氮污染以硝氮为主,总氮去除主要取决于硝氮的去除;复合塔式生态滤池中硝化-反硝化交替作用明显,为不同形态氮的相关转化以及氮的去除创造了优越的条件。     

三峡库区香溪河流域磷矿废石磷素浸出特性

为评价三峡库区香溪河流域内所堆存的磷矿废石对地表水体的磷污染风险,以香溪河支流高岚河流域内磷矿废石为研究对象,依据EPA M1316所规定的实验方法,开展了5种不同液固比(0.5~10.0 mL/g-dry)条件下磷矿废石磷素浸出特性的实验研究,探讨了液固比条件对磷矿废石磷素浸出浓度以及浸出率的影响。结果表明,磷矿废石浸出液中总磷浓度随液固比的增加而减小,其变化范围为0.74~0.47 mg/L;在液固比<7 mL/g-dry的条件下,浸出液中的总磷浓度均超出《污水综合排放标准(GB 8978-1996)》中所规定的最高允许排放浓度(0.5 mg/L);磷矿废石中磷素浸出率随液固比的增加而增大,其变化范围为0.37~4.70 mg/kg;磷矿废石将以点源的形式对其附近的地表水体形成长期的磷污染,属于第II类一般工业固体废物,应考虑在其堆置场顶部设置封盖层以降低其环境污染风险。     

SBR工艺用于焦化纳滤浓盐水生物脱氮

以焦化废水超滤/纳滤/反渗透的"三膜法"深度处理工艺产生的高电导率纳滤(NF)浓盐水为研究对象,采用SBR脱氮工艺对NF浓盐水中有机污染物和总氮(TN)的去除性能进行了研究。实验结果表明,SBR脱氮工况为进水5 min,缺氧搅拌8 h,好氧曝气12 h,静置2 h,出水5 min,闲置1 h 50 min,污泥浓度(MLSS)为3 000 mg/L左右时,TN平均去除率为45.45%,COD平均去除率为45.36%。通过烧杯实验研究了不同C/N比对反硝化脱氮效率的影响及其中氮形态的变化,在C/N为4:1时,出水TN可降低至14.8 mg/L,其中NO3--N为5.0 mg/L。研究结果证明,SBR可将电导率为12 000~16 000 μS/cm的焦化纳滤浓盐水TN降低至15 mg/L以下。     

生物吸附-多级A/O-活性焦组合工艺对污水中氮磷及有机污染物的去除

利用生物吸附(biological absorption,AB）-多级缺氧/好氧（anaerobic/oxic,A/O）-活性焦滤池组合工艺对城市污水进行处理研究。结果表明：该组合工艺出水COD、TN、TP平均浓度为20、8.5、0.25 mg·L-1,对COD、TN、TP平均去除率为95%、76.5%、80%,3个工艺段对有机污染物的平均去除率分别为55%、26%、14%。其中生物吸附段主要去除粒径较大的颗粒态有机物,多级A/O段可以去除进水中53%左右溶解性有机物;活性焦滤池利用活性焦丰富的中孔结构有效吸附多级A/O出水中难生物降解的芳香类及环烷类有机物。该组合工艺能实现高标准出水、高效脱氮除磷、能源节约、资源回收,是具有良好应用前景的污水处理工艺。     

化工园区爆炸事故高苯胺河水脱毒预处理技术比较与应用

江苏某化工园区发生爆炸,造成周边河道积聚大量高苯胺河水,该类受污染河水具有较高的活性污泥抑制性,需在进入园区污水处理厂应急处理前进行脱毒预处理。研究对比了芬顿氧化法、活性炭吸附法和生物处理法对受污染河水的预处理效果。结果表明,芬顿氧化法处理效率较高、运行成本中等,且现场处理设施易于改造利用,最终被选为高苯胺河水的脱毒预处理工艺。实际应急处置工程运行效果表明,芬顿氧化预处理实现了重污染河水中苯胺类的有效去除,在苯胺类浓度为30~90 mg/L的情况下,批次出水苯胺类浓度基本稳定在1 mg/L以下,保证了园区污水处理厂的稳定运行,最终实现其出水达标。