The Dechlorination of H6CDD,OCDD and OCDF on an Alumina support: Elucidation of the isomer pattern by multi linear regression and thermodynamic data

The dechlorination of OCDD, OCDF and 1,2,3,4,7,8‐H₆CDD is studies on an alumina support impregnated with activated carbon, copper chloride and potassium chloride. There is a high correlation between the isomer pattern found after dechlorination and molecular structure properties. We also found a substantial correlation between the isomer pattern and the Gibbs free energy of formation of the individual isomers. This suggests a thermodynamically controlled process.     

应用线性自由能关系估算药用活性化合物的生物碳质-水吸附系数

线性自由能关系(LFER)可以用来预测生物碳质对水中药用活性化合物(Ph ACs)的吸附系数,并确定不同分子间作用力对生物碳质吸附性能的相对贡献.利用商业水稻秸秆生物碳质(碳化温度400~500℃,200目)与14种带有不同表面官能团的Ph ACs(羧酸类、羟基类、氮杂环类)进行了吸附等温实验.各物质的等温吸附实验数据均可用Freundlich方程进行很好地拟合.通过建立的LFER模型,可以预测吸附质任一化学饱和水平(CW/SW)下的lg Kd,activity.利用复相关系数(R2=0.93)、回归系数标准偏差(SE=0.23)、F统计量(268)、去一法交叉验证系数(Q2LOO=0.90)以及外部样本交叉验证相关系数(Q2EXT=0.92)等方法对该模型进行验证,结果表明,其显著性与稳健性较好,具有预测能力.模型结果表明在低浓度范围内,空穴作用(V)与氢键碱作用(B)在整个吸附过程中起到主导作用,其中空穴作用为正贡献,氢键碱作用为负贡献.     

高浓度游离氨冲击负荷对生物硝化的影响机制

工业废水厂或含工业废水较多的城市污水处理厂,在运行过程中可能会意外受到高浓度氨氮废水急性冲击负荷的影响,造成生物硝化反应受到抑制,出水不能稳定达标.为了指导实际污水处理厂应对游离氨(FA)急性冲击负荷造成的出水不达标问题,本文探究高浓度氨氮废水对污水生物硝化系统的影响机制.本文利用序批式活性污泥反应器(SBR)处理模拟高氨氮废水,通过监测氨氮最大比降解速率、硝酸盐氮最大比生成速率、亚硝化和硝化比耗氧速率,硝化菌丰度等指标,研究高浓度氨氮废水中FA对硝化菌活性的影响规律.结果表明,FA在低浓度范围内,增加FA急性负荷能够促进硝化活性,而当FA急性冲击负荷大于一定值时,会对硝化作用造成抑制;FA浓度越大,受到抑制的硝化生物活性所需要的恢复周期越长.利用荧光原位杂交分析技术,发现当进水FA浓度(以N计)从3.6 mg·L~(-1)升高到8.1 mg·L~(-1)时,氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)菌群数量都略微升高,而当FA浓度大于8.1 mg·L~(-1)时,AOB和NOB菌群数量明显下降.FA对AOB和NOB菌群的临界抑制浓度分别为8.1 mg·L~(-1)和6.6 mg·L~(-1),NOB相对于AOB菌群更敏感.     

2010年2月27日智利地震地球球型自由振荡研究

利用中国数字地震台网（CDSN）5个台站的波形资料,采用功率谱密度估计方法,提取了智利地震激发的地球球型自由振荡,并与地球初步参考模型（PREM）的理论自由振荡周期进行对比,发现球型振荡振型周期与地球初步参考模型预测的球型自由振荡周期基本吻合。所得结果可以进一步用来研究地震震源机制和地球内部结构,并对大地震的震源破裂分布给出一定的约束。     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

煤化工煤焦油逸出废气回收利用技术研究

通过对河北省秦皇岛市耀华玻璃工业园有限公司地下300m,储油罐煤焦油逸出废油气进行实验室模拟实验,现场实际工程设计、制造、安装、调试、检验等实践研究,采用“冷凝＋自激吸收器＋吸收＋活性炭吸附”油气处理回收技术,并独创了自激吸收器新技术,处理后的煤焦油逸出废气完全达到了国家《炼焦化学工业污染物排放标准》（GB16171—2012）的相关要求。     

不同母质发育土壤团聚体分布对外源输入秸秆的响应及其与有机碳矿化的关系

土壤团聚体的形成和稳定对于有机碳的转化和积累具有重要意义,然而不同母质发育土壤团聚体对有机碳的物理保护作用及其与有机碳矿化之间的关系仍不清楚.本文以石灰岩、第四纪红土、花岗岩、玄武岩和红砂岩母质发育的典型土壤为对象,研究添加玉米秸秆7 d和184 d时土壤团聚体和各组分有机碳的变化规律,分析不同母质土壤有机碳矿化的主要影响因素.结果表明,不添加秸秆时,所有母质土壤以1.0～0.5、 0.5～0.25和<0.25 mm粒级团聚体为主,添加玉米秸秆有效促进了>2 mm和2～1 mm粒级团聚体的形成.石灰岩、第四纪红土和玄武岩土壤形成水稳性大团聚体并且保持其稳定的能力高于花岗岩和红砂岩土壤.添加玉米秸秆培养184 d,石灰岩、第四纪红土和玄武岩土壤有机碳的累积矿化率显著(P<0.05)低于花岗岩和红砂岩土壤.相关性分析表明,土壤有机碳的累积矿化率与游离态有机碳的比例极显著(P<0.01)正相关,而与>0.25 mm团聚体有机碳的比例极显著(P<0.01)负相关.利用¹³C核磁共振(¹³C-NMR)技术对土壤有机碳...