染料探针技术对二级出水中优势污染物的定量检测

分别以刚果红和中性红为染料探针,建立了牛血清蛋白质(BSA)和海藻酸多糖(SA)含量与共振光散射(RLS)发射光谱强度间的线性关系;以甲苯胺蓝为染料探针,建立了腐殖酸(HA)含量与紫外吸光度间的线性关系;优化了3种标准物质的检测浓度范围及溶液p H值条件;考察了染料探针分析方法对标准物的二元和三元混合样品中的回收率.结果表明在适宜的浓度范围内,BSA、HA、SA浓度与染料探针光谱强度间的线性相关系数R0.98,3种标准物在混合样品中的回收率不小于95%,标准误差低于0.11%.以紫外光谱和3D-EEM光谱特征作为城市污水二级出水样品中蛋白质、多糖和腐殖酸的定性依据,确认了4种二级出水样品中的优势污染物.通过染料-探针技术与国标法测得的多糖和蛋白质质量浓度的相对偏差在1.2%~0.04%之间.     

Role of Amino Acids on <Emphasis Type="Italic">In Situ</Emphasis> Photografting of Jute Yarn with 3-(Trimethoxysilyl) Propylmethacrylate

To improve the mechanical performance of natural lignocellulosic jute yarn, grafting with [3-(trimethoxysilyl) propylmethacrylate] (TMSPM) monomer has been performed on in situ UV radiation and optimized the monomer concentration (30%) and irradiation time (30 min). Effect of various amino acids (1%) as additives in TMSPM with photografted jute yarn at optimized system has been studied. The polymer loading (PL) and tensile properties like tensile strength (TS) and elongation at break (Eb) of treated samples were enhanced by incorporation of amino acids and the highest properties (TS = 300% and Eb = 386%) achieved by the sample treated with l-Arginine (Arg) with 32.5% PL value. Weak acid like 3% acetic acid and inorganic acid like 1% sulfuric acid were also incorporated in the optimized system of TMSPM grafting and compared their effect on the tensile properties with amino acid treated samples. Water absorption and weathering resistance of treated and untreated samples were also performed and treated sample showed lesser water uptake as well as less weight loss and mechanical properties as compared to untreated samples.     

紫外吸收剂在湖泊中的分布及其对底栖动物的毒性效应

紫外吸收剂大量用于工业材料和个人护理品中,近年来在水体中不断被检出,同时由于其高度亲脂性,易在底泥和水生生物体内富集,产生潜在的毒性效应,已成为一类新型污染物。本文综述了紫外吸收剂在湖泊环境中的分布和生物富集效应,重点分析了二苯甲酮类等典型紫外吸收剂对底栖动物的药物代谢系统、抗氧化系统及其生长发育的影响及其毒性作用机制,并对未来该领域的研究进行了展望。     

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.     

水质对UV/H_2O_2降解2,4-二氯酚的影响

研究了UV/H2O2工艺对2,4-二氯酚(2,4-DCP)的去除效果和水中阴离子、腐殖酸对该工艺降解2,4-DCP的影响。结果表明:UV/H2O2工艺可以有效的去除水中2,4-DCP,光降解过程符合一级反应动力学模型;在H2O2投加量为8mg/L,1个30W低压汞灯照射下,2,4-DCP在蒸馏水和自来水中光降解速率常数分别为0.0232/min和0.0162/min;NO3-、Cl-、HCO3-对2,4-DCP光降解有抑制作用;当3种离子浓度为0.5mmol/L、10mmol/L、20mmol/L时,对2,4-DCP光降解的抑制程度为HCO3->NO3->Cl-;随着离子浓度增大,抑制作用增强;自来水中的光降解速率常数低于蒸馏水中的光降解速率常数是由于水中多种离子影响的结果;腐殖酸在低浓度时,促进光降解反应的进行,在高浓度时,2,4-DCP的光降解氧化受到抑制。     

四种净水工艺对水源水微量有机物去除的研究

以UV254和CODMn代表饮用水源水中有机物替代指标.对常规处理、生物陶粒预处理、生物滤池、生物活性炭(BAC)、颗粒活性炭(GAC)、纳滤和光催化氧化进行组合,形成不同的处理流程,研究各流程对UV254和CODMn的去除效果.结果表明,各工艺流程都有一定的处理效率,其中以生物滤池和纳滤为主的组合流程处理效果最佳.此流程对UV254的去除率接近100%,CODMn的去除率达到78.6%,大大提高了饮用水的安全性.     

API MODEL 100A光路系统对二氧化硫测定值的影响

通过比较二氧化硫测定值与紫外灯强度、紫外检测器调节值及光电倍增管高压值的关系，提出二氧化硫测定值与紫外灯强度、光电倍增管高压值成正比，与紫外检测调节值成反比的结论，并对仪器校准提出了有效性建议。     

Comparative study of the oxidation of atrazine and acetone by H2O2/UV, Fe(III)/UV, Fe(iii)/H2O2/UV and Fe(II) or Fe(III)/H2O2

In this study, the rates of degradation of organic compounds by several AOPs (H₂O₂/UV, Fe(III)/UV, Fe(III)/H₂O₂/UV, Fe(II)/H₂O₂ and Fe(III)/H₂O₂) have been compared. Experiments were carried out at pH ≈ 3 (perchloric acid / sodium perchlorate solutions) and with UV reactors equipped with a low-pressure mercury vapour lamp (emission at 253.7 run). The data obtained with atrazine ([Atrazine]_o = 100 μg/L) showed that the rate of degradation of atrazine in very dilute aqueous solution is much more rapid with Fe(III)/UV than with H₂O₂/UV. Photo-Fenton process (Fe(III)/H₂O₂/UV) was found to be more efficient than H₂O₂/UV and Fe(II)/H₂O₂ for the mineralization of acetone ([Acetone]_o = 1 mM).     

Reductive dechlorination of non-ortho substituted polychlorinated biphenyls by ultraviolet irradiation in alkaline 2-propanol

The photodechlorination pathways of 3,3′,4,5,5′-pentachlorobiphenyl (3,3′,4,5,5′-PentaCB) and the related lower polychlorinated biphenyl congeners irradiated at 254 nm in alkaline 2-propanol were elucidated. Steric effect is the most important factor for controlling the dechlorination pattern of these substrates. Electronic effect also influences the photoreactivity of chlorine substituents.     

萃取比色法测定水中的丁基黄原酸盐

利用萃取比色法测定水中丁基黄原酸盐的含量，发现该方法的灵敏度、准确度和稳定性都可以满足样品分析的要求，并利用不同方法对样品进行比对分析，无明显差异。