太湖不同湖区沉积物重金属含量季节变化及其影响因素

以太湖东北部梅梁湾、胥口湾、贡湖沉积物中重金属为研究对象,研究各湖区沉积物中As、Cd、Cu、Pb、Zn含量的年际变化规律及其与沉积物间隙水温度、pH、Eh值以及沉积物有机质、总氮、总磷、粒径等理化指标的相关关系.结果表明:沉积物中重金属含量及其年际的变化与其污染状况有一定的相关关系;富营养化程度较高的梅梁湾沉积物中重金属含量的最大值出现在9月,其他两个湖区的最大值均出现在6月;沉积物中重金属含量受到温度、pH值、Eh值等物理因素的影响,且与温度、pH值和Eh值有一定的正相关关系;沉积物有机质、总氮、总磷、粒径等因素也会对沉积物中重金属含量产生影响;有机质含量与重金属含量有很好的正相关性,粒径与重金属含量呈正相关,总氮、总磷与重金属含量呈负相关.     

MnO_2催化KMnO_4氧化降解酚类化合物

研究了MnO2强化KMnO4氧化降解酚类化合物的效能与机制.在假一级动力学实验条件下(KMnO4初始浓度是目标有机物初始浓度的10倍),考察了KMnO4对酚类化合物(2-氯酚和4-氯酚)的氧化降解规律.发现在KMnO4氧化降解酚类化合物过程中存在着明显的自催化现象,即原位产生的胶体MnO2可以促进KMnO4对有机物的氧化降解.实验进一步考察了MnO2浓度、粒径大小和溶液pH对MnO2催化KMnO4氧化降解酚类化合物的影响.结果表明,外加胶体MnO2和颗粒MnO2都可以催化KMnO4氧化降解酚类化合物,而且假一级动力学常数(K)随着MnO2浓度(30～180μmol·L-1)的增加呈线性增加;与胶体MnO2相比,颗粒MnO2的催化能力较弱;随着溶液pH的增加,MnO2催化能力逐渐减弱.实验中还发现外加MnO2能够催化KMnO4氧化降解2-硝基酚(单独MnO2和KMnO4均不能将其氧化),但对于二甲基亚砜(其不具有与金属离子络合配位的能力)则没有催化作用.由此推测MnO2催化KMnO4氧化降解有机物的作用机制可能为表面吸附络合催化,即吸附在MnO2表面形成的络合物比存在于溶液中的有机物本身更易被KMnO4氧化.     

Nitrification characteristics of nitrobacteria immobilized in waterborne polyurethane in wastewater of corn-based ethanol fuel production

A technology to achieve stable and high ammonia nitrogen removal rates for corn distillery wastewater (ethanol fuel production) treatment has been designed. The characteristics of nitrifying bacteria entrapped in a waterborne polyurethane (WPU) gel carrier were evaluated after acclimation. In the acclimation period, nitrification rates of WPU-immobilized nitrobacteria were monitored and polymerase chain reaction (PCR) was also carried out to investigate the change in ammonium-oxidizing bacteria. The results showed that the pellet nitrification rates increased from 21 to 228 mg-N/(L-pellet. hr) and the quantity of the ammonia oxidation bacteria increased substantially during the acclimation. A continuous ammonia removal experiment with the anaerobic pond effluent of a distillery wastewater system was conducted with immobilized nitrifying bacteria for 30 days using an 80 L airlift reactor with pellets at a fill ratio of 15% (V/V). Under the conditions of 75 mg/L influent ammonia, hydraulic retention time (HRT) of 3.7--5.6 hr, and dissolved oxygen (DO) of 4 mg/L, the effluent ammonia concentration was lower than 10 mg/L and the ammonia removal efficiency was 90%. While the highest ammonia removal rate, 162 mg-N/(L-pellet.hr), was observed when the HRT was 1.3 hr.     

在Pt/Al2O3催化剂上丁烷、反-丁烯-2及顺-丁烯-2深度氧化动力学

在Pt/Al_2O_3催化剂用玻璃外循环无梯度反应器研究了丁烷、反-丁烯-2及顺-丁烯-2深度氧化动力学。深度氧化服从L-H机理模型。用正交设计法估计了动力学方程中的参数值。用脉冲色谱法研究深度氧化的L-H机理,并测定了吸附热。求出了深度氧化的CO_2生成速度。     

烟道气中二氧化硫的干扰消除

烟道气中的二氧化硫干扰因素多,不容易测准．本文通过对比实验认为．影响采样精度和分析准确度的干扰因素有：（１）转子流量计的影响;（２）冷凝水对二氧化硫的吸附;（３）氮氧化物对测定的干扰。严格控制上述实验条件,即可得到准确的二氧化硫浓度值。     

纳米二氧化钛(nTiO_2)与双酚A对斜生栅藻(Scenedes-mus obliquus)的联合毒性效应

纳米二氧化钛(n Ti O2)在被人们广泛使用的同时,其潜在的环境影响也受到越来越多的关注。为深入探讨n Ti O2与环境中现有污染物的相互作用及生物效应,以斜生栅藻(Scenedesmus obliquus)为受试生物,按照毒性单位法、相加指数法和混合毒性指数法,研究了n Ti O2与双酚A(BPA,一种常见的环境类雌激素)的联合毒性效应。结果显示,n Ti O2与BPA对S.obliquus生长的72 h半抑制浓度(EC50)分别为28.7 mg·L-1与1.81 mg·L-1。而n Ti O2与BPA共存时,在不同毒性比(4:1,3:1,2:1,1:1,1:2和1:3)下,其联合毒性作用(以BPA计)的72 h EC50值分别为2.198,1.58,1.153,0.428,0.306和0.189 mg·L-1。两者的联合毒性作用不仅仅是简单的相加,而是随着两者毒性比的变化,由拮抗作用转变为相加作用,继而转变为协同作用。这表明,n Ti O2进入环境后与现有污染物的毒性比(浓度比)可能是其联合毒性作用模式的一个重要影响因素。     

一种海洋气候环境-摩擦载荷耦合试验设备的研制

目的研制一台海洋气候环境-摩擦载荷耦合试验设备。方法针对相对运动部件在海洋环境下的服役条件,为评价其材料腐蚀磨损性能,分析摩擦载荷与气候环境可能对运动部件造成的交互作用,从机械结构上进行创新,研制一台海洋气候环境-摩擦载荷耦合试验设备。结果该设备可在一定范围内实行载荷、速度控制,利用传感器和数据采集系统完成对摩擦力、摩擦系数、温湿度的采集。设备包含6套下试样夹具,可实现6个样品轮转试验。结论该设备适用于研究服役于海洋气候环境下的材料的腐蚀磨损性能。     

Speciation and bioaccessibility of lead and cadmium in soil treated with metal-enriched Indian mustard leaves

Indian mustard (Brassica juncea (L.) Czern.) has shown good potential for the phytoremediation of soil contaminated with heavy metals. However, there is little information about the speciation and bioaccessibility of heavy metals in soil during the decomposition of metal-rich Indian mustard leaves. Incubation experiments (1-, 3-, and 6-month) were carried out in Beijing and Hunan soil with metal-rich Indian mustard leaves addition (1% and 3%) and the e ects of mustard leaves addition on the speciation and bioaccessibility of heavy metals were studied. The results showed that the addition of mustard leaves led to significant increases in pH and DOC in the Hunan soil. Both 1% and 3% of mustard leaf amendment caused the percentage of the exchangeable (F1), precipitated with carbonates (F2), bound to Fe/Mn oxides (F3) and bound to organic matter (F4) fractions of Pb and Cd to increase dramatically, while the percentage of the residual fraction (F5) of Cd and Pb significantly dropped in both Beijing and Hunan soils. Mustard leaf addition caused the bioaccessibility of Pb to decrease in the gastric phase, whereas the values increased in the small intestinal phase. The Cd bioaccessibility increased with mustard leaf addition in both the gastric and small intestinal phases. In conclusion, the metal-enriched mustard leaves addition induces Pb and Cd concentrations and their mobility increasing in the Beijing and Hunan soils. Therefore, heavy metal risk in metal-enriched plant leaves should be considered in phytoremediation system in which heavy metal might be brought back to soil and changed over time.     

钻井废水的生物强化处理简

从受钻井废水污染的土壤样品中筛选菌株进行生物处理实验,确定7株菌进行菌剂配伍。通过正交实验剔除可能有抑制作用的菌株,并确定菌剂各组成菌株的最佳配比,制成复合微生物菌剂。考察5种添加物对菌剂的影响,结果显示,当硫酸铵的添加量为20 mg/L时降解率为60%,高于其他添加物。生物强化实验结果显示,投加菌剂的反应器对钻井废水的平均降解率为42%,比未投加菌剂的对照实验的平均降解率（16%）高,而且耐冲击负荷性和降解性能稳定性优于对照实验。     

工厂的氟污染对蔬菜含氟量的影响

上海某厂生产氟利昂和氢氟酸等化工产品,排放的废水、废气中含有大量氟化物。该厂排放的废气中氟化氢的量相当于全市氟化氢总排放量的50％左右。