蒽降解菌与铜绿假单胞菌融合子的特性研究

将蒽降解菌An815和绿色荧光蛋白标记铜绿假单胞菌(Pseudomonas aeruginosa/EGFP)P原生质体融合,得到了既能高效降解蒽,又能产生生物表面活性剂的融合子F。研究了它的形态特征、生理生化特性、产表面活性剂的能力、对蒽的降解性能及生长繁殖情况。结果表明,融合子菌落和菌体形态,产脓青素,荧光色素的特性类似于铜绿假单胞菌亲本,但其大多生理生化特性酷似An815亲本而不同于铜绿假单胞菌亲本;融合子有较好产表面活性剂的能力,72 h内将表面张力由70.2 mN/m降至36.5mN/m;在蒽的反应体系中,32h内融合子和亲本An815对蒽的降解转化率分别为86.7%,59.4%,融合子对蒽的降解速率比An815提高了27.3%;在蒽的反应体系中融合子和亲本生长曲线相似。     

家蝇AChE检测毒死蜱残留的最佳条件研究

以纯化的家蝇(Museadomestica)乙酰胆碱酯酶(AChE)为试验材料,研究了缓冲液pH值、底物(ATCh)浓度、温度三个因素对酶活性的影响。结果表明:在pH值为8.5￣9.0,温度为30℃,底物浓度为2.5mmol/L的条件下,该酶具有最大活性。在此基础上,测定了不同pH值的缓冲反应体系和不同抑制时间条件下毒死蜱(Chiorpyifos)对AChE活性的抑制,发现pH值为8.0时AChE对毒死蜱最为敏感,而且对毒死蜱具有良好的线性响应关系(R2=0.9973),半抑制浓度仅为39.1μg/(L抑制时间为20min),检测下限为4.4μg/L。随着抑制时间的延长,毒死蜱对AChE的抑制程度逐渐增强,检测限可进一步降低。可见家蝇AChE是指示环境中毒死蜱污染程度的良好材料。     

鱼吸收富集LAS的分析研究进展

LAS对鱼等水生生物均产生有害影响,会破坏鱼鳃上皮组织、影响其相关功能(如通透性等)。LAS经由鱼鳃吸收、并通过血液输送到鱼体中各组织。LAS疏水性越大,其在鱼体中生物富集系数越大。水硬度等影响鱼吸收、富集LAS。鱼体中LAS生物转化过程减小了LAS生物富集。鱼体中LAS及其生物转化产物大多是经过固相萃取或基质固相分散萃取后,采用HPLC或HPLC/MS等方法进行分析。     

反渗透技术在小便池废水回用中的试验研究

首先将自配模拟尿液稀释不同的倍数后进行反渗透处理,确定了适宜的操作压力和合理的稀释倍数,然后用实际的人体尿液进行验证试验,经反渗透处理后,BOD5去除率达到98.3%、氨氮去除率达到97.7%、电导率降低了96.1%,产水投碱和二氧化氯后可达到城市杂用水水质标准(GB/T18920-2002)的要求,回用作冲厕用水。最后指出了值得关注的研究方向,以期能为小便池废水的循环利用提供一定的参考。     

生物过滤法处理挥发性有机物气体研究进展

生物过滤法是一种高效、廉价的废气处理技术。介绍了近年来生物过滤法处理挥发性有机物(VOCs)气体的研究进展。重点讨论了生物过滤法处理VOCs气体的性能、影响因素和运行模拟等内容。     

高浓度有机废水酵母菌低氧处理技术初探

在开放式环境中,在低氧条件(DO=0-0.2mg/L)下通过连续小试试验考察了利用酵母Candidatropicalis处理高浓度有机废水的可行性。54d低氧连续小试结果表明:进水COD、NH4+-N、TP浓度分别为11000～30000、1000、230mg/L时,其去除率分别为67%～88%,18%～68%,23%～68%,氮磷去除率取决于进水COD、TN、TP的水平。污泥微观形态观察表明反应柱内微生物基本上是酵母,但运行过程中优势酵母形态发生了变化。低氧(DO=0.1-0.4mg/L)和无氧条件下C.tropicalis批量培养试验表明污染物去除和酵母生长与氧的供给关系密切,低氧条件下C.tropicalis有很高的活性,能有效去除COD(去除率为91%);无氧条件则导致C.tropicalis生物量下降,COD去除率仅为12%。     

填埋场沼气发电的温室气体减排效益分析

填埋场沼气是垃圾卫生填埋场产生的可利用资源.以深圳下坪垃圾填埋场为例,定量分析垃圾填埋气体发电的温室气体减排效益.结果表明,填埋场沼气发电具有很好的经济效益和环境效益,可作为与发达国家进行CDM(清洁发展机制)项目合作的优先技术领域.     

纳米级铁粉脱氯降解四氯化碳

四氯化碳的生产和使用,给人类带来了较大危害.为此,采用纳米铁粉这一新方法对其进行脱氯处理.试验以纳米级铁粉对四氯化碳的脱氯率为考察指标,选用L25(56)正交试验方案,考察了降解介质的初始pH值、纳米铁粉的质量、降解温度、摇床转速和脱氯时间5个影响因素.结果表明,pH值这一因素有极显著影响;在得出的纳米铁粉对四氯化碳脱氯的最佳工艺条件下,获得了99.5%的脱氯率,为有机氯化物脱氯开辟了一条新途径.     

Toluene removal characteristics by a superimposed wire-plate dielectric barrier discharge plasma reactor

A superimposed wire-plate dielectric barrier discharge reactor was used to remove toluene in this study. The effects of oxygen content, gas flow rate, gas initial concentration and with/without catalyst on toluene decomposition were investigated. It was found that an optimal toluene removal was achieved when the oxygen content was about 5%. Under this condition, the highest toluene removal efficiency of 80.8% was achieved when the gas concentration was 80 mg/m^3. The toluene removal efficiency decreased with the increase of the gas flow rate and the initial concentration of toluene. In addition, the ozone concentration decreased with the increase of the initial concentration of toluene. It suggested that combining DBD （dielectric barrier discharge） with Co3O4/Al2O3/foam nickel catalyst in-situ could improve the toluene removal efficiency and suppress ozone formation. Products analysis showed that the main products were CO and CO2 when oxygen was more than 5%.     

Effects of cerium on growth and physiological mechanism in plants under enhanced ultraviolet-B radiation

Effect of cerium （Ce^3＋） on the growth, photosynthesis and antioxidant enzyme system in rape seedlings （Brassica juncea L.） exposed to two levels of UV-B radiation （T1： 0.15 W/m^2 and T2：0.35 W/m^2） was studied by hydroponics under laboratory conditions. After 5 d of UV-B treatment, the aboveground growth indices were obviously decreased by 13.2%-44. 1%（T1） and 21.4%-49.3% （T2）, compared to CK, and except active absorption area of roots, the belowground indices by 14.1%-35.6%（T1） and 20.3%-42.6% （T2）. For Ce＋UV-B treatments, the aboveground and belowground growth indices were decreased respectively by 4.1%-23.6%, 5.2% -23.3%（Ce＋T1） and 10.8%-28.4%, 7.0%-27.8%（Ce＋T2）, lower than those of UV-B treatments. The decrease of growth indices appeared to be the result of changes of physiological processes. Two levels of UV-B radiation induced the decrease in chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency by 11.2%-25.9%（T1） and 20.9%- 56.9%（T2）, whereas increase in membrane permeability and activities of antioxidant enzymes including superoxide dismutase（SOD）, catalase （CAT） and peroxidase （POD） by 6.9%, 22.8%, 21.5%, 9.5%（T1） and 36.6%, 122.3%, 103.5%, 208.9%（T2）, respectively. The reduction of the photosynthetic parameters in Ce＋UV-B treatments was lessened to 3.2%-13.8%（Ce＋T1） and 4.9%-27.6%（Ce＋T2）, and the increase of membrane permeability and activities of antioxidant enzymes except POD in the same treatments were lessened to 2.4%, 8.4%, 6.6%（Ce＋T1） and 30.1%, 116.7%, 75.4%（Ce＋T2）. These results indicate that the regulative effect of Ce on photosynthesis and antioxidant enzymatic function is the ecophysiological basis of alleviating the suppression of UV-B radiation on growth of seedlings. Furthermore, the protective effect of Ce on seedlings exposed to TI level of UV-B radiation is superior to T2 level.