汞蒸汽被动式检气管的初步研制

初步研制的汞蒸汽被动式检气管是建立在气体分子扩散和化学吸收原理基础上的,新制备的碘化亚铜沉淀和乙醇、甘油、硝酸混合、研碎,伴入经活化的层析硅胶,填充到检气管中,当汞蒸气进入管内时,发生显色反应,检气管显色长度的平方与汞蒸汽浓度及采样时间的乘积成线性关系,检测下限为0.001ug/mL(1h)。该法集采样与分析于一体,结构简单,不需动力,便于携带,操作方便,实验室模拟运用,其灵敏度和标准偏差令人满意。     

Enhanced bioaccumulation of cadmium in carp in the presence of titanium dioxide nanoparticles

In this study adsorption of Cd onto TiO2 nanoparticles and natural sediment particles (SP) were studied and the facilitated transports of Cd into carp by TiO2 nanoparticles and SP were assessed by bioaccumulation tests exposing carp (Cyprinus carpio) to Cd contaminated water in the presence of TiO2 and SP respectively. The results show that TiO2 nanoparticles had a significantly stronger adsorption capacity for Cd than SP. The presence of SP did not have significant influence on the accumulation of Cd in carp during the 25 d of exposure. However, the presence of TiO2 nanoparticles greatly enhanced the accumulation of Cd in carp. After 25 d of exposure Cd concentration in carp increased by 146%, and the value was 22.3 and 9.07 microg/g, respectively. And there is a positive correlation between Cd and TiO2 concentration. Considerable Cd and TiO2 accumulated in viscera and gills of the fish.     

DO C/N对同步硝化反硝化影响的试验研究

在序批式活性污泥反应器(SBR)内,以模拟的城市污水为处理对象,研究DO、C/N等因素对同步硝化反硝化脱氮效率的影响。研究表明:采用连续曝气工艺,在进水COD=200mg/L,NH4+-N=30mg/L条件下,控制DO在0.5～1.5mg/L范围内时,出水TN浓度为1.98～6.3mg/L,TN的平均去除率在80%以上,最高去除率达到93.74%,并可推断出在反应系统内存在好氧反硝化菌;C/N在3.3～10之间时,C/N越高,出水NO3--N浓度越低,SND效果越好。     

造纸黑液处理与多糖资源分级利用研究——分离条件对多糖含量的影响

草浆造纸黑液中含有丰富的聚糖资源,对其中低聚糖进行提取与纯化也是获得功能性低聚糖经济、有效的途径.本文提出了在分离木素的同时,最大限度回收多糖资源的工艺路线,并探讨了pH值、温度、陈放时间等对分离液中多糖含量的影响规律.在酸析黑液pH为4.0～5.0,65～70 ℃并陈化3～4 h的条件下,可从黑液固含量为49.87 g/L的麦草浆中回收多糖7.43 g/L;稻草浆中回收多糖4.91 g/L.这可为草浆造纸黑液的资源多级利用提供技术支撑.     

两性木质素接枝共聚物的聚合反应与离子化改性

研究碱木质素与复合单体在水相中接枝共聚,以Mannich反应进一步对接枝产物进行阳离子化改性.结果表明:在70℃±5℃下进行木质素与复合单体接枝共聚反应,当pH值为7.0-8.0、反应时间为2h-2.5h,获得较理想的接枝效果,过硫酸盐引发效果优于过氧化氢,引发剂适宜的反应浓度约为10mmol·l-1.共聚物阳离子化改性的适宜条件为:醛、胺与木质素的质量比为0.5∶1.2∶1,反应温度60℃-70℃,反应时间2h,反应产物为一种具有阴、阳离子两性基团的木质素聚合物. 以丙酮分离产物,当体积比为0.75时,获得产物与水较好的分离效果. 红外光谱分析表明,木质素与复合单体实现了有效的接枝共聚和离子化改性.     

餐厨垃圾厌氧产氢综述

针对餐厨垃圾厌氧产氢过程,从工艺、单组分底物厌氧产氢和过程机理研究阐述了国内外进展,并对未来研究发展方向进行了展望.研究成果表明,餐厨垃圾厌氧发酵产氢过程可行,但影响因素多,系统不稳定,大部分研究停留在实验室小试阶段.尚需针对餐厨垃圾厌氧发酵产氢优势菌种选育、生态因子调控、代谢机理、反应器改进和系统控制模拟等方面开展研究,为该技术的大规模应用提供研究基础.     

Enhanced biohydrogen generation from organic wastewater containing NH 4+ by phototrophic bacteria Rhodobacter sphaeroides AR-3

NH₄⁺ is typically an inhibitor to hydrogen production from organic wastewater by photo-bacteria. In this experiment, biohydrogen generation with wild-type anoxygenic phototrophic bacterium Rhodobacter sphaeroideswas found to be sensitive to NH₄⁺ due to the significant inhibition of NH₄⁺ to its nitrogenase. In order to avoid the inhibition of NH₄⁺ to biohydrogen generation by R. sphaeroides, a glutamine auxotrophic mutant R. sphaeroides AR-3 was obtained by mutagenizing with ethyl methane sulfonate. The AR-3 mutant could generate biohydrogen efficiently in the hydrogen production medium with a higher NH₄⁺ concentration, because the inhibition of NH₄⁺ to nitrogenase of AR-3 was released. Under suitable conditions, AR-3 effectively produced biohydrogen from tofu wastewater, which normally contains 50–60 mg/L NH₄⁺, with an average generation rate of 14.2 mL/L·h. This generation rate was increased by more than 100% compared with that from wild-type R. sphaeroides.     

重金属Pb在煤矸石-土壤-菠菜体系中的迁移规律

采用盆栽法,以菠菜作为受试作物,通过对其不同生长时期矸石-土壤各层中重金属含量的测定,研究煤矸石中Pb在2系统中的迁移规律,并利用SPSS软件进行土壤深度对土壤中Pb含量的显著性分析.结果表明,Pb在2个系统中的迁移分布有差异,这种差异主要表现在时间和空间上；经显著性分析后土壤深度对土壤中Pb含量有极显著性影响(P＜0.01),且在菠菜生长的幼苗期和开花期,土壤各层中的Pb含量随土壤深度的变化呈显著性直线相关关系.对菠菜植株中Pb含量进行污染评价后发现,充填覆土后矸石中的Pb易在植株中积累.