Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Reaction mode between Si and Fe and evaluation of optimal species in poly-silicic-ferric coagulant

A kind of Fe-polysilicate polymer, poly-silicic-ferric （PSF） coagulant was prepared by co-polymerization （hydroxylation of mixture of Fe^3＋ and fresh polysilicic acid （PS））, in which PSF0.5, PSF1 or PSF3 denotes Si/Fe molar ratio of 0.5, 1 or 3, respectively. The effects of Si/Fe ratio and reaction time （co-polymerization time or aging time） on the reaction mode between Si and Fe were studies, and the optimal species of PSF was evaluated by pH change during the preparation of PSF and coagulation tests. The results showed that the characteristics of PSF are largely affected by both reaction time and Si/Fe ratio. PSF is found to be a essential complex of Si, Fe, and many other ions. The reaction mode between Si and Fe differs with various Si/Fe ratios. The pH of PSF0.5, PSF1 or PSF3 tended to be stable when reaction time is 10, 25 or 55 rain, respectively, which is almost consistent with the time reaching the relative stable morphology that is just the optimal species of higher coagulation efficiency. The optimal reaction time reaching optimal species can be evaluated by measuring the pH change during the polymerization process.     

中试试验对比PAC和PAFC处理低温饮用水的混凝性能

低温降低了混凝剂的混凝性能,为保持传统混凝沉淀工艺中低温条件下饮用水的出水水质,需要优选混凝性能更好的混凝剂。本试验选用了小试试验中性能更优的无机高分子复合混凝剂PAFC（聚合氯化铝铁）与无机高分子混凝剂PAC（聚合氯化铝）进行中试对比试验。试验结果表明铁铝复合混凝剂PAFC在低温条件下的混凝性能要优于铝盐PAC。使用PAFC时混凝澄清池的出水浊度能保持在3NTU以内,在0．55～2．87NTU之间变化。而使用PAC的出水浊度在1．44～3．87NTU之间。比较其他出水指标如色度、氨氮、pH、电导率、铁和CODM。后发现,当PAFC比PAC平均节省药剂12．3％时,PAFC的处理效果仍旧比PAC好。     

黑河流域地域系统的下游绿洲带资源-环境安全

额济纳绿洲是我国西北干旱区中心的一道生态防线。20世纪后半叶绿洲生态系统严重受损,景观结构急剧恶化,黑河的供水量逐年下降,由50年代的12.25×108m3下降到90年代的7.24×108m3。地下水位也相应降低,土地盐化也在加剧。各种禾草草甸严重退化,并多已演替成为苦豆子群落。为了维护我国西北的这一生态屏障,论文认为必须坚持以恢复与保护自然绿洲为主,恢复胡杨林、沙枣林、红柳灌丛与梭梭林的覆盖率;建立人工草地,改善土地覆盖,建设自然-人工复合绿洲。在绿洲建设与保育工程中必须保证供水,保持地下水位的临界高度,调控水盐动态,发挥生物-景观多样性的系统耦合效应,实现绿洲生态系统健康与资源-环境安全。     

PACS中铝的形态分布及其经验公式

利用AlCl₃·6H₂O,Na₂SO₄和NaOH为原料制备了一系列具有不同Al3+/SO2₄-摩尔比及碱化度的PACS样品,利用Al-Ferron逐时络合比色法就Al3+/SO2_４-摩尔比及碱化度对PACS中铝的形态分布影响进行了实验研究,得到了一系列实验结果,建立了PACS中铝的水解形态分布与Al3+/SO2₄-摩尔比和碱化度之间的数学模型,数据拟合结果与实验结果比较,证明二者基本吻合。      

复杂电磁环境下装备保障训练效果评估研究

介绍了复杂电磁环境下装备保障训练效果评估的主要内容,建立了复杂电磁环境下装备保障训练效果评估指标体系。基于模糊综合评判方法,建立了复杂电磁环境下装备保障训练效果评估模型,并给出了具体计算步骤。该模型可为部队开展复杂电磁环境下装备保障训练效果评估提供方法支持。     

交通噪声在建筑群中的传播与衰减

以等效连续A声级L_(eq)为交通噪声的评价量,使用一种经过适当简化的计算模型和几何声学方法,在仅考虑直达声和有限数目的前次反射声的情况下,给出了交通噪声在沿道路(或河道)分布的建筑群中纵深方向的传揩与衰减规律,并说明了其物理机制。所得理论结果与实测数据相符,其标准偏差小于1.5dB,平均偏差在±1.0dB范围内。     

复合铁铝氢氧化物的制备及其对水中砷(V)的去除

以Fe(Ⅲ)和Al(Ⅲ)对砷有较强的亲和性为理论基础,用沉淀法制备了9种同时含有Fe(Ⅲ)和Al(Ⅲ)的砷吸附剂--复合铁铝氢氧化物.X射线衍射和扫描电镜测定结果表明,有5种复合铁铝氢氧化物具有微晶-无定形态的结构特征.比表面测定结果表明,复合铁铝氢氧化物的孔体积和孔径明显低于相同实验条件下制得的氢氧化铁,说明铝的掺杂能明显改变氢氧化铁中规则的晶体结构和表面性质.用复合铁铝氢氧化物进行了水中砷的吸附研究,结果表明,该复合材料具有优良的除砷效能,吸附容量大;当pH为5.0～9.0、溶液中初始砷浓度为2 mg·L-1时,不同组成的铁铝复合氢氧化物都能使溶液中的砷含量降到世界卫生组织标准0.01 mg·L-1以下,其中以Fe(Ⅲ)/Al(Ⅲ)摩尔比为7:3的复合物吸附除砷能力最强.pH为5.0～9.0时各复合物对砷的吸附模式均符合Freundlich和Langmuir等温吸附方程.     

系统级可靠性试验技术探讨

论述了开展系统级可靠性试验的重要意义,分析了系统级可靠性试验中需要解决的主要技术问题.首先进行系统可靠度验证,然后根据系统结构及工作环境设计试验方案及试验剖面,并合理设计试验夹具以保证试验评估结果的准确性.用实例证明了系统级可靠性试验的实用性与有效性.     

环糊精对苯砜基乙酸酯的增溶作用及QSPR研究

以10种苯砜基乙酸酯化合物为对象,测定了β-环糊精(β-CD)对该类化合物的增溶作用效应;并应用K_ow和电性拓扑态指数对包合物稳定常数(Ks)进行了模拟分析,构建了QSPR模型.模型的相关系数(R²_adj)和标准偏差(SD)分别为0.972、0.971和0.057、0.059,模型具有较高的预测能力和可靠性.研究表明,β-CD与该类化合物形成1:1包合物,增加了苯砜基乙酸酯类化合物的水溶性;包合物形成类似于化合物在辛醇相和水相之间的分配,CD腔体内高能水分子的释放、化合物苯基与CD腔体间的范德华相互作用及砜基氧原子和CD端口羟基的氢键作用是包合物稳定性的决定因素.