大气中SO2的液相氧化研究

大气中ＳＯ２液相氧化是形成酸雨的重要途径，降雨中含有各种无机离子和有机物质，它们可能催化或抑制液相氧化反应的进行。本文根据四川酸雨样品组成，进行了ＳＯ２在模拟雨水及实际雨水中的氧化实验，考查了Ｖ，Ｆｅ，Ｍｎ等离子对ＳＯ２氧化的催化作用，Ｈ２Ｏ２对ＳＯ２的氧化以及降水中有机物质甲醛对各反应的影响。实验结果为了解酸雨的成固，研究酸雨控制对策提供了科学依据。     

钢桁架-钢筋混凝土管柱结构风参数试验研究

结构下部空旷,上部挡风墙承担的风荷载对结构下部产生较大作用。我国规范没有对该类结构及其顶部透气性A型架的风参数作具体规定。为解决工程设计中风参数取值问题,进行了刚性模型风洞试验研究,得到了不同工况下挡风墙、A型架、管柱的体型系数及挡风墙的阵风系数,分析了风机、周围建筑物、风向角对相关风参数的影响,给出了相关参数的建议值。并将试验结果与数值模拟计算结果进行了对比分析,结果表明,二者吻合较好,研究结果为工程设计提供了基础资料,可供同类工程参考。     

旱地长期定位施肥对土壤剖面硝态氮分布与累积的影响

在 １５ ａ长期定位试验基础上研究了黄土高原旱地长期施用不同用量和配比的氮、磷肥对土壤剖面中硝态氮分布和累积的影响。结果表明：长期大量施用氮肥,在土壤剖面 １００～１８０ ｃｍ之间形成硝态氮累积层,峰值出现在 １４０ ｃｍ处,最大值为 ６７．９２ｍｇ／ｋｇ（单施 Ｎ １８０ ｋｇ／ｈｍ~２）; 配合施用磷肥可以降低土壤剖面硝态氮质量分数,根据试验,提出了旱地合理施肥的氮磷肥用量。     

载铁沸石催化H2O2降解阳离子红X-GRL染料废水

以天然沸石为载体,FeSO₄·7H₂O溶液为浸渍液,采用浸渍蒸干法制备载铁沸石非均相类Fenton反应催化剂,并用其催化H₂O₂降解阳离子红X-GRL染料废水。结果表明,浸渍液浓度为0.18 mg/L、煅烧温度为300 ℃时制备的催化剂铁含量较高、催化效果和稳定性较好。当反应时间为120 min、溶液pH为3.0、催化剂投加量为20.0 g/L、H₂O₂投加量为30.0 mmol/L时,催化降解效果最佳,对染料废水TOC、色度、COD_Cr和TN的去除率分别为60.3%、99.4%、55.5%和49.9%;载铁沸石催化剂重复使用3次后,仍具有一定的催化效果。     

介质阻挡放电降解环境污染物CF2ClBr的等离子体系电子密度

在利用介质阻挡放电对污染物质ＣＦ２ＣｌＢｒ进行等离子体降解产物分析的基础上,进一步研究等离子体系中的电子密度。采用动态反应装置,以平行板电极法直接测量。在ＣＦ２ＣｌＢｒ的压力为２ｋＰａ时,得出该实验条件下的电子密度约为５．０×１０＾１３／ｍ＾３。     

用于农村厕所黑水处理的铱钽涂层电极的优化制备及其对析氯性能的影响

农村厕所黑水通常采用生物法进行处理,存在处理效果不稳定、运行管理复杂等问题。通过对传统钛铱电极进行优化制备,成功构筑了铱钽涂层系列电极 (Tx) 和铱钽锡锑钴涂层系列电极 (Cx) 。利用电化学原位产氯,实现了有机物的氧化降解并同步去除氨氮。优化电极复合氧化物涂层的配方,发现喷涂T3电极 (IrTa氧化物涂层0.6 mg·cm⁻²,Ti氧化物涂层0.75 mg·cm⁻²) 在2.4 V的工作电压下表现了最高效的净水效能,60 min内去除了厕所黑臭水生化处理出水50%的COD。系统研究了表面清洁工艺和烧结工艺对电极析氯效能的影响,发现喷砂结合酸洗的表面清洁过程、滚涂的涂层固定过程、500 °C的烧结过程构筑的T3电极具有最高的析氯效能和强化寿命。本研究为分散式污水排放存在的富营养化问题提供了可行的解决思路。     

Detection of Class I and II integrons for the assessment of antibiotic and multidrug resistance among Escherichia coli isolates from agricultural irrigation waters in Bulacan,Philippines

Contaminated irrigation water may greatly affect not only the quality of produce but also the people exposed to it. In this study, agricultural irrigation waters in Bulacan, Philippines were assessed and found to be contaminated with Escherichia coli (E. coli) ranging from 0.58 to 4.51 log₁₀ CFU/mL. A total of 79 isolates of E. coli were confirmed through polymerase chain reaction (PCR) amplifying the uidA gene and were tested for phenotypic resistance using 10 antimicrobials through the Kirby–Bauer disc diffusion method. Forty-six isolates (58.22%) were noted to be multidrug resistant (MDR) with high resistance rate to cephalothin, tetracycline, streptomycin, ampicillin, trimethoprim, nalidixic acid, and chloramphenicol. Moreover, this study also examined the prevalence of Class I and II integrons accounting to 67.39% and 17.39%, respectively, of the MDR E. coli strains using multiplex PCR. The results imply that the agricultural water used in Bulacan is contaminated with the fecal material of man or other animals present in the area, and the presence of MDR bacteria, which pose a potential threat to individuals in these areas, is alarming. In addition, detection of integrons could be a good marker for the identification of MDR isolates. Lastly, this study could develop strategies for the proper management of farming sites leading to the detection of food-borne pathogens and prevention of infectious diseases.     

典型进口再生塑料颗粒中重金属溶出特性及其影响因素

为了解我国进口再生塑料颗粒中重金属溶出特性,以某检测机构的5种再生塑料颗粒PP、PE、PS、PET和ABS为研究对象,研究不同温度、不同接触时间和不同模拟液等条件下,再生塑料颗粒中重金属溶出特性。结果表明,在25、40、70 ℃这3种温度下,PP、PE、PET和ABS再生塑料颗粒中重金属铬、铅、锰、镉、汞和铜的溶出量随着温度的升高而增加,PS中重金属浓度随温度升高变化不大;随着接触时间的增长,样品中的6种重金属Cr、Pb、Mn、Cu、Cd、Hg溶出量增长趋势由快至慢,5种再生塑料颗粒中重金属Cr的溶出浓度最高;PE、PS、PET和ABS再生塑料颗粒在4种模拟液中重金属溶出量大小整体呈现出：50%乙酸>3%乙酸>10%乙醇>95%乙醇,但PP再生塑料颗粒中重金属Cu在3%乙酸中的溶出量比10%乙醇中的多。本研究结果可为建立塑料接触材料及制品中重金属溶出量的标准方法提供依据。     

Biodegradability of organic substances by ATP test

The aerobic biodegradability of organic substances in water is characterized by determination of energy change ‐ ATP content in microbial cells during biodegradation. A satisfactory result is obtained under the following conditions: the initial concentration of tested substance is 100mg/l (as DOC), the amount of the inoculum in the biological medium is 500mg/l (as MLSS), and the duration of test time is 14 days. The evaluating system (peak time, peak height and IA index) is proposed to assess the biodegradability of 46 organic compounds and 7 wastewaters.