污泥果肥利用中重金属迁移特征研究

为了厦门城市污泥的安全利用,将石渭头污水处理厂污泥经过好氧堆肥后施用于柚子树,对重金属元素在土壤、树叶及果肉中的迁移特征进行了研究。结果表明：Cd在土壤中的富集能力强;重金属元素从土壤向树叶迁移累积能力比向果肉的大得多,污泥肥料不能用于叶类食用植物的施用;Cr向树叶、Ni向果肉的迁移累积能力强;泥肥的施用加重了土壤中Cd的污染,提高了Cr向树叶、Ni向果肉的迁移能力;污泥果肥利用需降低Ni的浓度,对污泥中含量较高的Cu、Zn、Ni、Cr和Cd需进行跟踪检测。     

Co3O4/介孔分子筛催化剂对苯催化完全氧化的研究

分别以介孔分子筛MCM-41、MCM-48、SBA-15为载体,采用等体积浸渍法制备了氧化钴/介孔分子筛催化剂,利用N₂吸附、X射线衍射、程序升温还原等技术对催化剂进行了表征,考察了Co₃O₄的负载量及载体的孔结构对催化剂完全催化氧化苯的性能的影响。结果表明,Co₃O₄的负载量为20%时,催化剂的催化活性最好;载体的孔径和催化剂的可还原性能是影响催化活性的主要因素,催化剂活性顺序为Co₃O₄ /SBA-15> Co₃O₄ /MCM41> Co₃O₄ /MCM-48。     

Changes in plasma thyroid hormones and cortisol levels in crucian carp (Carassius auratus) exposed to the extracted microcystins

The endocrine response of crucian carp injected intraperitoneally with extracted microcystins (MC) was investigated in this study. Fish were injected intraperitoneally either with 0.75% NaCl (control) and Microcystis extract corresponding to 150 and 600 microg microcystins per kg body weight. The plasma levels of triiodothyronine (T(3)), thyroxine (T(4)), free triiodothyronine (FT(3)), free thyroxine (FT(4)), and cortisol were determined at 0, 1, 3, 12, 24, and 48h post-administration of MC-containing extract. Treated fish displayed abnormal behaviors, such as a startle response and disoriented swimming, as well as changes in ventilation rates. Plasma cortisol concentrations of fish in both dose groups significantly increased after administration of extracted MC and remained high throughout the experiment, which suggested that MC elicited a stress response in treated fish. The profiles of cortisol changes in treated fish appeared to be dose dependent, indicating that fish in the high dose group experienced greater MC-induced disturbance. Mortality occurred after 12h in the high dose group. Plasma levels of T(4), T(3), FT(4), and FT(3) did not vary significantly between the control fish. In contrast to this, fish exposed to MC-containing extract showed significant declines in T(3), FT(4), and FT(3) levels in a dose-dependent manner throughout the experiment. Plasma T(4) levels, however, did not vary significantly in the low dose group, whereas they decreased significantly at 48h post injection in the high dose group. This study demonstrates that administration of microcystins-containing extract causes a stress response and reduces the plasma levels of thyroid hormones in crucian carp. These results illustrate that microcystins exerted potent effects on the endocrine system of crucian carp, through activating their hypothalamus-pituitary- interrenal axis and disturbing thyroid function.     

环境雌激素双酚A暴露现状及其雄性生殖毒性研究概况

双酚A(bisphenol A,BPA)作为典型的环境雌激素,在环境中广泛存在,具有接触机会频繁、剂量累积、潜伏期长等特点,是对生殖系统危害极大的一类污染物。研究表明BPA可在地表水、野生动物体内检测出,甚至在健康人群的体液中存在,尤其在婴儿体内含量较高。BPA进入机体后可通过I相和II相代谢酶分解,其分解产物的毒性目前仍不清楚。BPA在体内发挥雌激素样作用,与雌二醇竞争性地结合到雌激素受体上,阻碍雄激素受体的活性,促进促黄体生成素与催乳素的合成,最终抑制雄性激素的合成。BPA可破坏血睾屏障,直接刺激睾丸细胞的凋亡并导致精子质量下降,其中主要通过影响下丘脑-垂体-性腺轴(HPG)上促性腺激素释放激素受体(Gn RHR)、促黄体生成素受体(LHRβ)和促卵泡雌激素(Fshb)的表达和直接刺激睾丸和附睾细胞,降低睾酮合成酶的表达及活性,抑制与精子生成相关蛋白的表达,从而影响生殖能力。同时,BPA代谢过程中消耗大量的抗氧化酶,产生氧自由基,其氧化产物可能会对睾丸和附睾的损伤形成二次打击。总之,双酚A造成雄性生殖损伤障碍主要是损伤HPG轴正负反馈调节的平衡以及影响调节激素相关基因的表达和直接损伤睾丸细胞和精子质量。     

重金属污染下龟壳攀鲈组织中ACP和AKP的活力比较

龟壳攀鲈是一种在极端污染水域中具备生存优势的鱼类,收集重污染区和轻污染区的龟壳攀鲈,并通过比较其体内各组织中的酸性磷酸酶(ACP)及碱性磷酸酶(AKP)活性来揭示其耐污能力。贵屿作为重污染区有4个采样点:大陇村、市上村、联堤村和北林村;潮州作为轻污染区有2个采样点:卧石村和洗马桥。水质结果表明,贵屿采样地水中的Pb、Cd、Cr、As、Hg含量分别是潮州采样点的27.6倍、3.9倍、5.8倍、3.9倍和3.5倍,说明贵屿采样地的污染远高于潮州的。酶活结果表明,在龟壳攀鲈所有组织中,内脏组织(胃肠、性腺、肝脏、脾脏、肾脏)中的ACP和AKP活力均高于外周组织(肌肉、鳞片、鳃);重金属污染均能提高攀鲈体内所有组织的ACP和AKP活力;AKP活性更容易受到重金属的影响,各组织的AKP活力增幅普遍超过ACP活力增幅;其中,受重金属影响最大的组织是脾脏,ACP和AKP活力可增长到2.37倍和6.21倍。这些结果说明了龟壳攀鲈可以通过显著升高内脏组织(如肠胃、肝脏、肾脏等)中ACP和AKP活性,以便更好地应对高污染环境;其中AKP更容易受到重金属的影响,适合用于作为评估污染的指标。     

Effects of freshwater leaching on potential bioavailability of heavy metals in tidal flat soils

Environmental Geochemistry and Health - Leaching experiments were conducted to investigate the effects of desalination levels and sediment depths on potential bioavailability of heavy metal (Cd,...     

不同量子化学算法在多环芳烃光解行为定量结构-性质关系(QSPR)中的应用

以采用MINDO/3、MNDO和AMI算法计算的17种多环芳烃（PAHs）的前线分子轨道能为分子结构参数,进行了这些PAHs光解速率常数的定量结构－性质相关（QSPR）的研究,并与基于PM3算法得到的QSPR模型进行了比较,研究结果表明,应用PM3算法得到的前线分子轨道能进行这些PAHs光解速率常数QSPR拟合的结果最好,其次是AMI算法,而MINDO/3和MNDO算法得到的结果较差。     

废水中氨氮的去除与利用

化学沉淀剂可去除废水中的氨氮，并得到有用复合肥ＭｇＮＨ４ＰＯ４。探讨了诸反应对氨氮去除率的影响。     

高浓度甲基橙溶液的低压湿式催化氧化处理

以高浓度甲基橙溶液模拟偶氮染料废水,采用低压湿式催化氧化法(LPWCO)进行处理,考察了H2O2投量、温度、FeSO4投量、硫酸浓度、甲基橙浓度等因素对甲基橙脱色率的影响。结果表明,LPWCO法能有效地使高浓度(大于400mg/L)甲基橙溶液脱色,脱色率大于95%,而H2O2投量不到Fenton法的5%。     

染料废水在旋转式光催化反应器中的降解研究

采用旋转式光催化反应器处理染料废水,探讨染料ｐＨ值,液层厚度,反应器转速,光照时间对脱色效率的影响．结果表明,对所试染料品种,ｐＨ６为最佳值,２０ｍｉｎ为最佳反应时间．液层厚度和反应器旋转速度对半导体光催化氧化反应有一定影响．在优化条件下采用悬浮态ＴｉＯ２时,偶氮染料的脱色率为９８％,采用ＴｉＯ２器壁固定时为７８．５％～９１．５％