褶牡蛎对悬沙胁迫的生理响应研究

研究了不同浓度的悬沙处理液对褶牡蛎体内超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的影响。结果表明：在96h内对照组和所有处理组中褶牡蛎均未出现死亡；96h后对照组与各处理组SOD活性值差异极显著（P〈0．01）．在开始阶段的低浓度处理组中褶牡蛎体内SOD表现为下降趋势。8g／L浓度组的SOD活性值最小。之后有小幅上升．并趋于平衡．但总体水平明显低于对照组；96h后褶牡蛎对照组与各处理组CAT活性值差异极显著（P〈0．01），其CAT-浓度值曲线趋势与SOD-浓度值曲线相一致，同样在低浓度明显下降。2g／L浓度组CAT活性值最小。之后有小幅回升，并存在一定的“毒理兴奋”作用，各浓度水平CAT活性均明显低于对照组。因此．悬沙对褶牡蛎的生理生化存在着一定的影响，建议可把褶牡蛎CAT活性变化作为水环境监测的生物指标。从而达到评价水生生态环境的目的。

“葡萄糖酸钙的合成实验”的改进

介绍了实验教学中对葡萄糖酸钙合成实验的一些探索和经验,通过反应温度、反应时间、氧化剂的用量、碳酸钙的添加时间和催化剂的用量等实验条件的优化,提高了葡萄糖酸钙的产率和纯度,有益于该实验教学效果的提高和推广。

己二酸合成中催化剂重复使用稳定性研究

以 Na_2WO_4为催化剂前驱体,原位制备了均相钨催化剂,并用于 H_2O_2氧化环己烯制备己二酸的反应。主要考察了反应条件和催化剂母液处理条件对催化剂重复使用稳定性的影响。结果表明,催化剂溶液在50℃下进行浓缩处理,浓缩倍数为1.875,采用适当的 H_2O_2加入方式,并在反应回流结束后控制适当的反应温度和反应时间,可以获得较好的催化反应稳定性。

Process Development and Design of Chlorine Dioxide Production Based on Hydrogen Peroxide

This paper presents a process development and design of chlorine dioxide production based on hydrogen peroxide. The process is characterized by cleaner production, high efficiency, and waste minimization. Optimization of process conditions, selection of equipment, and experiment of recycle of waste acid are carried out. The process design is realized in consideration of several aspects such as operation, material, equipment design and safety. An industrialized process flowsheet is developed according to experiment. A pilot testing is carried out to confirm the lab results. Process design of chlorine dioxide production based on hydrogen peroxide is realized.

Synthesis of TS-1 Films on Porous Supports for Epoxidation ofAllyl Chloride by Hydrogen Peroxide

Titanium silicalite-1(TS-1)films were synthesized on stainless steel plate,glass slide and monolith supports via an in-situ hydrothermal method.Characterization data showed that the formation of TS-1 films was easier on the porous flat support with rough surface such as monolith than on the smooth non-porous supports like glass slide and stainless steel plate.The film on the monolith had the highest uniformity and smallest size of crystals.The catalytic property of monolithsupported film was tested for epoxidation of allyl chloride(ACH)by H2O2in a fixed bed reactor.Under the condition of a methanol(solvent)/ACH(90% )/H2O2(30% )ratio of 12:1:1,a LHSV of 1.35 h-1and a temperature of 318 K,the conversion of allyl chloride and the selectivity to epichlorohydrin reached 79% and 51% ,respectively.

Effects of Mercuric Chloride on Antioxidant System and DNA Integrity of the Crab Charybdis japonica

Mercury （Hg） is one of the commonly encountered heavy metals, which is widespread in inshore sediments of China. In order to investigate the toxicity of Hg on marine invertebrates, we studied the effects of the divalent mercuricion （Hg2＋） （at two final concentrations of 0.0025 and 0.0050mgL-1, prepared with HgC12） on metallothionein （MT） content, DNA integrity （DNA strand breaks） and catalase （CAT） in the gills and hepatopancreas, antioxidant enzyme activities of superoxide dismutase （SOD）, catalase （CAT） and glutathione peroxidase （GPx）, in the hemolymph, gills and hepatopancreas of the portunid crab Chao,bdisjaponica for an experiment period up to 15 d. The results indicated that MT was significantly induced after 3 d, with a positive correlation with Hg2＋ dose and time in the hepatopancreas and a negative correlation with Hg2＋ dose and time in the gills. While CAT in the hemolymph was not detected, it increased in the hepatopancreas during the entire experiment; SOD and GPx in the three tissues were stimulated after 12h, both attained peak value and then reduced during the experimental period. Meanwhile, DNA strand breaks were all induced significantly after 12 h. These results suggested the detoxification strategies against Hg2＋ in three tissues of C. japonica.

Mathematical model and reaction mechanism of molybdenum and tungsten extraction with TRPO from peroxide solution

To understand the behavior of molybdenum and tungsten extracted by tri-alkyl phosphine oxide(TRPO)from peroxide solution,the extraction mechanism was studied by slope method and Raman and FTIR spectroscopy.The empirical formulas of molybdenum and tungsten extraction distribution ratio(D_(Mo)and D_(W))as functions of equilibrium pH,TRPO concentration and temperature were obtained by establishing mathematical models.Furthermore,the reliability of the empirical formula was verified in the H^(+)-W-Mo-H_(2)O_(2) solution.The results indicate that the calculated values of D_(Mo)or D_(W)were consistent with the experimental values.The apparent extraction equilibrium constants of molybdenum and tungsten wereK_(Mo)^(app)=8.51×10^(3)(0.74≤pH_(e)≤1.7),K_(Mo)^(app)=99.89×10^(3)(1.7<pH_(e)≤4.62)andK_(W)^(app)=2.65×10^(3)(0.92<pH_(e)<2.16)at 20°C,respectively.The main extraction complex of molybdenum or tungsten was[H_(2)(Mo or W)_(2)O_(3)(O_(2))_(4)(H_(2)O)_(2)]·2TRPO.These empirical formulas can be used to analyze and estimate the extraction and separation of Mo and W from low molybdenum and tungsten concentration solutions.

Dechlorination Behavior of Mixed Plastic Waste by Employing Hydrothermal Process and Limestone Additive

The usage of plastic-impregnated waste derived solid fuel in conventional combustor is hindered by many technical factors, especially its organic chlorine content. In this paper, experimental study of hydrothermal treatment on mixed plastic waste using the mixture of polypropylene, polystyrene, polyethylene and polyvinyl chloride （PVC） has been performed to observe the dechlorination effect of hydrothermal treatment on the waste. The system was generally applying saturated steam at around 2.4 MPa in a stirring reactor for about 90 minutes. After undergoing the process, the organic chlorine in treated plastic waste was reduced to 1,700 ppm level while the inorganic chlorine content was increased, suggesting an organic chlorine conversion phenomenon to inorganic chlorine, accompanied with low pH due to dehydrochlorination process. Additional limestone （Ca（OH）2） in subsequent experiment showed that the similar phenomenon was occurred but with higher pH and lower chlorine content in the condensed water, suggesting the production of inorganic salt rather than hydrochloric acid. Laboratory scale experiment was also performed to confirm the dechlorination phenomena especially for PVC, and the result showed that the main parameter which affected the dechlorination phenomena was the amount of water in hydrothermal process rather than limestone addition. It is suggested that a combination ofhydrothermal process and alkali addition would produce a low-chlorine solid product from plastic waste, promoting its usage as alternative solid fuel.

Effective Treatment of Trichloroethylene-Contaminated Soil by Hydrogen Peroxide in Soil Slurries

Trichloroethylene （TCE）, as one of the most common chlorinated organic compounds in soils and aquifers at many industrial sites, is carcinogenic and often recalcitrant in environment. TCE degradation in artificially contaminated soil samples was conducted using Fenton-like processes, i.e., by addition of excess hydrogen peroxide （H2O2）. H2O2 could directly oxidize TCE without addition of ferrous iron in contaminated soil. Under the optimal condition （H2O2 concentration of 300 mg kg^-1, pH at 5.0, and reaction time of 30 rain）, the removal efficiency of TCE in the soil was up to 92.3%. When the initial TCE concentration increased from 30 to 480 mg kg^-1 in soil, the TCE removal rates varied from 89.2% to 86.6%; while the residual TCE in soil ranged from 2.28 to 47.57 mg kg^-1. Results from successive oxidations showed that the TCE removal rate with the TCE concentration of 180 mg kg^-1 increased slightly from 91.6% to 96.2% as the number of successive oxidation cycle increased from one to four. Therefore, increasing the frequency of H2O2 oxidation was perhaps a feasible way to increase TCE removal rate for TCE-contaminated soil.