黑藻对含重金属废水中锌离子的吸附性能

黑藻能吸附重金属废水中的Zn2+,但对其的报道鲜见.研究了生物吸附剂黑藻对废水中Zn2+的吸附去除性能,考察了溶液pH值、Zn2+初始浓度、黑藻加入量和吸附时间对吸附效果的影响.同时通过EDX分析和等温吸附模型对黑藻吸附Zn2+的机理进行了研究.结果表明:在溶液pH值为6.0、黑藻加入量为2 g/L,吸附时间为30 min,Zn2+质量浓度为20 mg/L的条件下,黑藻对Zn2+的吸附率为85%,并且发现黑藻对Zn2+的吸附是阳离子交换过程,吸附符合Langmuir,Freuncllich和D-R等温吸附模型.     

木质素降解菌对腐殖质形成的影响的研究

采用接种培养方法研究了不同木质素降解菌对木质素降解率、腐殖质总量、各组分含量及胡敏酸E4/E6的影响.结果表明,接种黄孢原毛平革菌和栗褐链霉菌对稻草的降解均有所提高,56天培养后,二者的木质素降解率分别达到40.86%和31.04%,而对照组(只含有土著微生物)只有10.56%.接种黄孢原毛平革菌和栗褐链霉菌显著提高了腐殖质产量,这两种不同木质素降解菌产生腐殖质的最大值分别是对照组的2.10和2.13倍,但二者降解木质素形成腐殖质的途径有所不同.培养结束后,各条件下土壤中胡敏酸E4/E6均有所增加,表明胡敏酸的芳构化程度有所减弱.     

Transformation behavior of lead fractions during composting of lead-contaminated waste

The transformation behaviors of Pb fractions during composting of Pb-polluted waste without inoculants and with the inoculants of Phanerochaete chrysosporium were studied. Results show that the active Pb ions with high toxicity and transferability are transformed into the inactive Pb with low toxicity and transferability, confirming that Pb ions can be efficiently immobilized during composting without or with the inoculants. The soluble-exchangeable Pb in composting without inoculants reaches 49.0 mg/kg at day 60, while that with the inoculants is reduced to 0 mg/kg dry mass compost. The higher contents of organic-bound Pb (59.0 mg/kg) and residual Pb (69.2 mg/kg) with low toxicity are found after 60-day composting with inoculants, compared with those without inoculants. The above data indicate the better immobilization effect of Pb and the greater alleviation of Pb hazards in composting with the inoculants of Phanerochaete chrysosporium than without inoculants, which may be due to the more microbial biomass and the higher pH value in composting of Pb-polluted waste with inoculants.     

基于计算流体力学的坐便器节水方法研究

利用计算流体力学(CFD)构建卫生器具坐便器冲洗过程的仿真模型,并用粒子图像测速(PIV)试验验证该模型,将验证后的模型应用于坐便器冲洗过程的仿真试验来预测内部流道压力场变化,并根据预测值优化与冲洗性能密切相关的虹吸管道.结果表明,虹吸管出口段长度为177～227 mm时,虹吸过程的负压值随长度增加而升高,虹吸作用随之增强、冲洗性能趋好;长度达227 mm时,可使坐便器用水量从6 L降至5L,所排污水量随之减少.这有望为基于流体力学仿真优化法的用水节水与污水减排技术的发展提供有益信息.     

黄孢原毛平革菌与重金属交互作用的研究进展与展望

对黄孢原毛平革菌吸附重金属的机理作了简要的阐述,在此基础上,以重金属对黄孢原毛平革菌的毒性与黄孢原毛平革菌对重金属的抗性为主线,系统地综述了该领域的研究现状,对目前尚存在的问题进行了深入探讨,并针对黄孢原毛平革菌对重金属吸附的机理研究和技术开发等方面做了展望.黄孢原毛平革菌是研究白腐真菌的典型菌种,由于它能有效吸附和富积重金属,且在固态、液态中都具有生长优势,近年来利用黄孢原毛平革菌处理重金属污染成为国内外的研究热点.     

黑藻对铜离子和镍离子的生物吸附性能

为了经济实用地对废水进行处理,将来源广泛的黑藻制成粉末加入到含铜、镍离子的废水中,研究了其对废水中铜、镍离子的吸附作用,考察了溶液pH值、金属离子初始浓度、吸附剂用量、吸附时间和干扰离子等因素对吸附性能的影响.结果表明:黑藻吸附2种重金属离子的速度快,30 min即达到吸附平衡,适宜的pH值为5.0～6.0,干扰离子对Ni2+的影响大于对Cu2+的影响;黑藻对2种重金属的吸附均符合Langmiur,FreunoUich和Dubinin-Radushkevich(D-R)模型,对2种金属离子的吸附能力顺序是:Cu2+>Ni2+.     

接种白腐菌堆制法修复Pb污染土壤的研究

采用接种白腐菌堆制法对模拟Pb污染土壤进行了生物修复.通过监测土壤基本理化性状、土壤中Pb的各形态含量及微生物学指标(微生物生物量、微生物代谢商、微生物商、微生物C/N、微生物群落代谢能力),系统地研究了白腐菌修复作用下土壤理化性状的动态变化、Pb生物有效性的改变以及土壤微生物学效应的变化.结果表明,接种白腐菌堆制法能有效地修复Pb污染土壤,降低Pb的生物有效性,减小Pb对土壤微生物的抑制,改善土壤中微生物效应.污染土壤经接种白腐菌堆制法修复后,土壤中Pb主要以残留态和铁锰氧化物结合态存在,水溶交换态Pb分配系数为0;微生物生物量较高,达2.258 mg/g;微生物群落代谢能力较强,丰富度为72目,群落指数为4.995.     

Fluorescence spectroscopy characteristics of humic acid by inoculating white-rot fungus during different phases of agricultural waste composting

The white-rot fungus, Phanerochaete chrysosporium (P. chrysosporium), was inoculated during different phases of agricultural waste composting, and its effect on the fluorescence spectroscopy characteristics of humic acid (HA) was studied. The results show that the emission spectra have a sharp peak at 400 nm and a broad shoulder with the maximum centered at 460 nm. The excitation spectra have two peaks and exhibit red shift (shift to longer wavelengths) at 470 nm. The synchronous scan spectra present a number of peaks and shoulders, and the peaks at shorter wavelengths disappear gradually and form a shoulder. At the final stage of composting, the fluorescence spectra have similar shapes, but the fluorescence intensities decrease. P. chrysosporium increases the degree of aromatization and polymerization of HA when it is inoculated during the second fermentation phase, while it does not produce an obvious change on the humification degree of HA when it is inoculated during the first fermentation phase. Compared with the fluorescence spectroscopy characteristics of HA from soil, the structure of HA from compost is simpler and the activity is higher. Foundation item: Project(2005CB724203) supported by the Major State Basic Research and Development Program of China; Project(IRT0719) supported by the Program for Changjiang Scholars and Innovative Research Team in University of China; Projects(50608029, 50808073) supported by the National Natural Science Foundation of China; Project(2007185) supported by the Environmental Protection Technology Research Program of Hunan Province, China     

水厂虹吸滤池进水流道水力特性的数值模拟

在计算流体力学(CFD)的基础上,采用重正化群(RNG)湍流模型建立虹吸滤池虹吸流动过程的仿真模型,对真空负荷加载过程及真空负荷去除之后的水流流动过程进行模拟,探讨了真空负荷对虹吸过滤启动和虹吸发展过程的影响.结果表明,所建模型能有效地仿真虹吸滤池的进水虹吸管在特定压力启动负荷下的水力特性,当真空度为进水渠液面与虹吸管顶部中心线之间的水头高度(-5 000 Pa)时,能够较快地促使虹吸产生.