Humic acid and free radical in environment of Kaschin-Beck disease areas

The humic acid contents in drinking water and soil in Kaschin-Beck disease areas were found more than that of non-disease areas in this research. Changes of free radical concentration in drinking water were agreed with that of humic acid contents in drinking water of Kaschin-Beck disease areas. A positive correlation of free radical concentration and humic acid content in drinking water has been shown (r=0.913) . The structure of I. R. spectra of humic acid under ultraviolet light has been changed. Thus it indicated that free radical was resulted from benzoqiunonyl groups of humic acid in environment.     

碳纳米管电极原位产生过氧化氢及其对亚甲基蓝脱色效果简

将碳纳米管固定化制成多孔疏水性导电薄膜构建电化学阴极还原体系,实现过氧化氢在阴极的原位产生。电极特性研究表明,电极在较宽的电压范围内均具有较好的活性。考察了阴极电位、电极成分、氧气流量和电解质浓度对过氧化氢原位产生的影响,在优化条件下经过120 min后过氧化氢达到66.17 mg/L,并探讨过氧化氢原位产生的机理。在此基础上考察原位过氧化氢氧化工艺下对亚甲基蓝的脱色效果,并分析其脱色机理。     

提供生物稳定饮用水的最佳工艺

研究由预处理、常规处理和深度处理组合而成的 7种不同工艺对饮用水源水中可生物同化有机碳 ( AOC)的去除效果 .试验表明 :生物陶粒预处理对 AOC具有较高的去除率 ,达到 45%左右 ,如果在它之前先经过预臭氧化 ,生物处理的去除率可增大到 58.4% ;常规处理对 AOC的去除非常有限 ,去除率平均在 2 0 %左右 ;新活性炭单元因其吸附作用对 AOC的去除效果稳定在30 %左右 ,如和臭氧氧化连用 ,去除效果能提高到 50 %以上 ;包括了常规处理、生物预处理、预臭氧和臭氧活性炭的组合工艺对AOC的去除效果最好 ,达到 86% .因此臭氧氧化、生物炭和生物处理是提高饮用水生物稳定性的重要手段 ,并以本试验结果为依据提出了对于不同的水源水所采用的最佳工艺 .     

我国生态环境资产负债表编制框架研究*

本文根据生态环境资产负债表的基本概念和理论,提出了生态环境资产负债表编制的总体框架,同时,针对环境容量资产、环境质量产品、生态产品资产的特点,分别建立了相应框架体系,提出了环境资产负债表的应用决策方向。本文研究成果对于确立统一的生态环境资产核算标准和方法、使我国生态环境资产负债核算工作逐步规范化、制度化的轨道具有重要的现实意义。     

Efficiency of surfactant-enhanced desorption for contaminated soils depending on the component characteristics of soil-surfactant--PAHs system

The sorption of surfactants onto soils has a significant effect on the performance of surfactant enhanced desorption. In this study, the efficiency of surfactants in enhancing desorption for polycyclic aromatic hydrocarbons (PAHs) contaminated soils relative to water was evaluated with a term of relative efficiency coefficient (REC). Since the sorption of surfactants onto soils, surfactants only enhanced PAH desorption when REC values were larger than 1 and the added surfactant concentration was greater than the corresponding critical enhance desorption concentration (CEDC), which was defined as the corresponding surfactant concentration with REC=1. A model was utilized to describe and predict the REC and CEDC values for PAH desorption. The model and experimental results indicated that the efficiency of surfactants in enhancing PAH desorption showed strong dependence on the soil composition, surfactant structure and PAH properties. These results are of practical interest for the selection of surfactant to optimize soil remediation technologies.     

吸附增效低温等离子体法去除甲苯废气的研究

采用150Hz中频高压交流电源作为低温等离子体发生源,选用典型的微孔γ-Al2O3球形颗粒吸附剂(以下简称γ-Al2O3)作为等离子体反应器填充材料,协同低温等离子体法催化降解甲苯废气。考察了在不同条件下,γ-Al2O3的甲苯吸脱附效果和吸附增效低温等离子体法的甲苯去除效果。结果表明,甲苯降解反应主要发生在γ-Al2O3的表面,甲苯的去除率在一定的浓度范围内与γ-Al2O3表面吸附的甲苯量成正比关系;填充γ-Al2O3有利于提高甲苯去除率及等离子体反应器能量利用率;γ-Al2O3对臭氧的降解表现出一定的促进作用。     

Using mRNA to investigate the effect of low-pressure ultraviolet disinfection on the viability of E. coli

UV can induce damages on mRNA consistently among different genes. SOS response was more active after UV treatment. Programmed cell death was not found to be more active after UV treatment. The efficacy of ultraviolet (UV) disinfection has been analyzed and validated by numerous studies using culture-based methods, yet the discovery of the viable but nonculturable state necessitates the investigation of UV disinfection based on viability parameters. Paired regulators of the SOS response system, recA-lexA, and the programmed cell death system, mazEF, in Escherichia coli were chosen as the target genes, and the effect of UV irradiation on the mRNAs of the four genes was studied. This research showed that, after UV irradiation, the responses of the mRNAs were highly consistent, with reduction percentages of approximately 60% at 20 mJ/cm², 70% at 40 mJ/cm², and 90% at 80 mJ/cm², and these reductions were believed to be the result of direct UV damage to nucleic acids. After 24 h of dark incubation, recA and lexA were both upregulated but to a lesser extent for repressor lexA; and mazE and mazF were both downregulated. This result implies that UV irradiation induces the dark repair system more actively, and the cells will proceed to death at a rate similar to that associated with natural decay.     

赣江流域山丘荒地的形成、危害和开发途径

赣江流域的山丘荒地总面积约为 2902×10⁴亩,除 35×10⁴亩属于“十边草地”零星分布于路边、河边、田边、村边、沟边之外,比较成片的约有 2867×10⁴亩（见表 1）,略多于现有耕地,而且相当于现有林地的一半。这些荒地 3/4以上分布在红壤丘陵（低丘岗地 388×10⁴亩,占13.5％;中低丘1236×10⁴亩,占43.1％;高丘605×10⁴亩,占21.2％;山地638×10⁴亩,占22.3％）,而且主要分于于上、中游地区（上游地区占60.2％,中游地区占25.4％,下游地区占14.4％）。综合开发治理、合理利用这些山丘荒地,是赣江流域、特别是上、中游地区的农民摆脱贫穷落后困境、实现小康目标的重要环节之一。     

Monoclonal antibody produced by heterologous indirect enzyme-linked immunosorbent assay and its application for parathion residue determination in agricultural and environmental samples

A heterologous indirect enzyme-linked immunosorbent assay (ELISA) was developed, which was based on monoclonal antibody (Mab) to determine parathion residue in agricultural and environmental samples. Eight Mabs were produced by introducing the heterologous indirect ELISA into the screening procedure. It was shown that these Mabs had more broad-reactivity with twenty competitors than that of 5H7 (Mab produced by homologous screening). So it became much easier using these new Mabs to develop heterologous immunoassays. In addition, all the developed heterologous ELISAs could be used to determine parathion residue in semiquantitative or quantitative level, and their detection limitation (LOD) was around 2 ng/mL. Compared with the previous heterologous ELISA (hapten 11/5H7) with IC₅₀ of 13.3 ng/mL, a better heterologous ELISA (hapten 11/1E1) was obtained with IC₅₀ of 3.8 ng/mL, which improved the sensitivity 3.5 times. Finally, the latter was applied to parathion residue determination in spiked agricultural and environmental samples without extraction or cleanup. The average recoveries of parathion added to water, soil, cucumber, Chinese cabbage and carrot were between 80.4 % and 111.8 %. The LOD for water and soil samples was 5 ng/mL, and the LOD for cucumber, rice and corn samples was 10 ng/mL.     

质子化壳聚糖的除磷性能

壳聚糖是一类无毒无害的天然高分子絮凝剂,为了提高壳聚糖在污水处理中的除磷性能,采用硫酸溶液对壳聚糖进行质子化改性;考察了质子化度(硫酸溶液pH值)、吸附时间以及原水pH值对除磷效率的影响。研究结果表明,质子化度越大,总磷去除效率越高;在吸附时间为40～50 min的范围内,总磷去除率最大;原水pH值对质子化壳聚糖的总磷去除效率有明显影响,在质子化度较低时(硫酸溶液pH值≥3),随着原水pH值的增加,总磷去除率降低,在质子化度较高时(硫酸溶液pH值=2),在原水pH=6时,总磷去除率最大;质子化壳聚糖的吸附过程较好地遵循Lagergren准二级动力学模型和Langmuir吸附等温方程,吸附热力学参数ΔH<0,ΔG<0,ΔS<0,吸附过程表现为放热、自发的单分子层化学吸附过程。