絮凝与生物强化组合技术处理油田含聚污水

针对河南油田采油污水,室内选择4种常用无机絮凝剂与阳离子聚丙烯酰胺(CPAM)复配,筛选出最佳的絮凝剂用量:聚合氯化铝(PAC)用量为300 mg/L,CPAM用量为10 mg/L。研究了投加HPAM降解菌对油田含聚污水中COD的去除效果,优选出2株以聚合物(HPAM)为唯一碳源的降解菌,通过分子生物学16SrDNA鉴定,XL-1和XL-2菌分别为苏云金芽孢杆菌和溶血不动杆菌。实验结果表明,在温度为30℃,pH为7.5,降解72 h的条件下,XL-1菌的B/C增大了0.11,COD去除率提高了11.03%;XL-2菌的B/C增大了0.07,COD去除率提高了6.3%。油田污水经絮凝-生物强化组合工艺处理后,出水COD平均值为77.1 mg/L,总去除率为73.2%,絮凝段和生化段工艺的COD去除率分别为54.1%和19.1%,达到《污水综合排放标准(GB/T 8978-1996)》排放标准。     

无机材料对固定化微生物凝胶球性能的影响

为了提高固定化微生物凝胶球的性能,实验研究了在凝胶球中添加无机材料粉末活性炭、SiO2、CaCO3和人造沸石,并从固定化微生物凝胶球的生物活性、机械强度、微观结构和溶出性多方面考核,比较不同无机材料对凝胶球性能的影响。研究结果表明,添加CaCO3能明显提高凝胶球的传质性能,进而提高凝胶球对氨氮的处理效果,添加人造沸石能提高凝胶球的抗拉强度,添加SiO2能提高凝胶球的密度,添加粉末活性炭能提高凝胶球的压缩强度。     

西安夏季PM2.5中碳组分与水溶性无机离子特征分析

2012年8月6日—22日利用大气细颗粒物水溶性组分在线监测分析系统和大气气溶胶OC/EC在线分析仪在线分析了西安PM2.5中的水溶性无机离子和OC、EC,并结合气溶胶前体物SO2、NO2和部分气象参数的监测数据进行了分析。结果表明,PM2.5中OC、EC和主要水溶性组分SO2-4、NH+4和NO-3的比重分别为:14.34%、5.35%、26.32%、12.90%和11.28%;以有机物(OM)为主要成分的总碳气溶胶(TCA)在PM2.5中的质量分数为28.30%,其中光化学反应导致OM中二次组分(SOC)高达45.30%;对主要水溶性组分之间的相关性分析发现,NO-3、SO2-4、NH+43种主要组分之间的结合形态为(NH4)2SO4和NH4NO3,对Mg2+和Ca2+的相关分析反映其有多种共同源;此外,硫氧化率(SOR)和氮氧化率(NOR)均较高,表明大气中存在较强的光化学反应。PM2.5的各组分因子分析得到4个主要来源(机动车尾气和燃煤、土壤建筑尘和生物质燃烧、二次硝酸盐气溶胶、二次硫酸盐气溶胶)。     

Fe~0协同生物麦饭石的PRB系统井下原位处理煤矿酸性废水

针对煤矿酸性废水(AMD)具有污染组分多、危害程度严重、地面处理成本高等特点,以固定SRB污泥的生物麦饭石作为PRB活性填料,并添加Fe0构建生物-非生物协同去污的新型PRB井下原位修复系统,对AMD开展了连续动态、变负荷的模拟修复研究。实验结果表明,3个动态柱对p H均具有较强的调节能力,同时仅以麦饭石作为活性填料的PRB-3对Fe2+、Mn2+、NH3-N具有较好的去除效果,最大去除速率分别为45.77、9.23和12.10 mg/(L·d);以Fe0协同生物麦饭石的PRB-2在碳源充足时对SO2-4、Fe2+、Mn2+、NH3-N最高去除速率分别为552.29、57.64、14.51和7.05mg/(L·d),而相同条件下只以生物麦饭石作为活性填料的PRB-1对上述污染物的最高去除速率分别为446.62、57.20、10.87和3.53 mg/(L·d);应用PRB-2系统处理AMD不仅可以实现多种污染物的同步去除,还能实现无外加碳源的井下原位长效修复。     

Sorption–desorption and transport of trimethoprim and sulfonamide antibiotics in agricultural soil: effect of soil type,dissolved organic matter,and pH

Use of animal manure is a main source of veterinary pharmaceuticals (VPs) in soil and groundwater through a series of migration processes. The sorption–desorption and transport of four commonly used VPs including trimethoprim (TMP), sulfapyridine, sulfameter, and sulfadimethoxine were investigated in three soil layers taken from an agricultural field in Chongming Island China and two types of aqueous solution (0.01 M CaCl₂ solution and wastewater treatment plant effluent). Results from sorption–desorption experiments showed that the sorption behavior of selected VPs conformed to the Freundlich isotherm equation. TMP exhibited higher distribution coefficients (K _d?=?6.73–9.21) than other sulfonamides (K _d?=?0.03–0.47), indicating a much stronger adsorption capacity of TMP. The percentage of desorption for TMP in a range of 8–12 % is not so high to be considered significant. Low pH (<pK _a of tested VPs) and rich soil organic matter (e.g., 0–20 cm soil sample) had a positive impact on sorption of VPs. Slightly lower distribution coefficients were obtained for VPs in wastewater treatment plant (WWTP) effluent, which suggested that dissolved organic matter might affect their sorption behavior. Column studies indicated that the transport of VPs in the soil column was mainly influenced by sorption capacity. The weakly adsorbed sulfonamides had a high recovery rate (63.6–98.0 %) in the leachate, while the recovery rate of TMP was only 4.2–10.4 %. The sulfonamides and TMP exhibited stronger retaining capacity in 20–80 cm and 0–20 cm soil samples, respectively. The transport of VPs was slightly higher in the columns leached by WWTP effluent than by CaCl₂ solution (0.01 M) due to their sorption interactions.     

Characterization of cadmium uptake,translocation, and distribution in young seedlings of two hot pepper cultivars that differ in fruit cadmium concentration

The reasons why some cultivars of hot pepper (Capsicum annuum L.) accumulate low levels of Cd are poorly understood. We aimed to compare the characteristics of Cd uptake and translocation in low-Cd and high-Cd hot pepper cultivars by determining the subcellular locations and chemical forms of Cd, and its distribution among different plant organs. We conducted a hydroponic experiment to investigate the subcellular distribution and chemical forms of Cd in roots, stems, and leaves of a low-Cd (Yeshengchaotianjiao, YCT) and a high-Cd cultivar (Jinfuzaohuangjiao, JFZ). The results showed that the concentrations of Cd in almost all subcellular fractions of roots, and in all chemical forms in roots, were higher in YCT than in JFZ. Compared with YCT, JFZ had higher Cd concentrations in almost all subcellular fractions of stems and leaves, and higher Cd concentrations in almost all chemical forms in stems and leaves. Additionally, YCT had significantly higher total Cd accumulation but a lower Cd translocation rate compared with JFZ. In general, the results presented in this study revealed that root-to-shoot Cd translocation via the xylem is the key physiological processes determining the Cd accumulation level in stems and leaves of hot pepper plants. Immobilization of Cd by the cell walls of different organs is important in Cd detoxification and limiting the symplastic movement of Cd.     

可降解餐盒去除地下水硝酸盐的砂槽模拟实验研究

采用室内砂槽实验装置,研究了以可降解餐盒(BMB)为反硝化碳源的生物反应器对于模拟污水中硝酸盐的去除效果及其影响因素。结果表明,以BMB为反硝化碳源的反应器启动时间短。当进水硝酸盐浓度为50 mg/L,水温为25℃,水力停留时间为1.15 d时,硝酸盐的去除率可达92.6%以上,实验过程中出现亚硝酸盐积累,出水TOC浓度上升,但反应稳定后亚硝酸盐浓度均低于0.1 mg/L,且TOC浓度有下降趋势;水力停留时间减小或者进水硝酸盐浓度增加均能使得脱氮效率降低,但当水力停留时间在0.57~1.15 d,进水硝酸盐浓度在50~80 mg/L范围变化时,反应器硝酸盐去除效率仍能达到80%以上;温度对反硝化作用影响较大,当温度为(20±1)℃时,硝酸盐的去除效率仅为62.0%、74.4%和97.5%。     

A review of polychlorinated biphenyls (PCBs) pollution in indoor air environment

Polychlorinated biphenyls (PCBs) were widely used in industrial production due to the unique physical and chemical properties. As a kind of persistent organic pollutants, the PCBs would lead to environment pollution and cause serious problems for human health. Thus, they have been banned since the 1980s due to the environment pollution in the past years. Indoor air is the most direct and important environment medium to human beings; thus, the PCBs pollution research in indoor air is important for the protection of human health. This paper introduces the industrial application and potential harm of PCBs, summarizes the sampling, extracting, and analytical methods of environment monitoring, and compares the indoor air levels of urban areas with those of industrial areas in different countries according to various reports. This paper can provide a basic summary for PCBs pollution control in the indoor air environment.

Implications: The review of PCBs pollution in indoor air in China is still limited. In this paper, we introduce the industrial application and potential harm of PCBs, summarize the sampling, extracting, and analytical methods of environment monitoring, and compare the indoor air levels of urban areas with industrial areas in different countries according to various reports.     

Response of sediment calcium and magnesium species to the regional acid deposition in eutrophic Taihu Lake,China

Acid deposition causes carbonate dissolution in watersheds and leads to profound impacts on water chemistry of lakes. Here, we presented a detailed study on the seasonal, spatial, and vertical variations of calcium and magnesium species in the overlying water, interstitial water, and sediment profiles in eutrophic Taihu Lake under the circumstance of regional acid deposition. The result showed that both the acid deposition and biomineralization in Taihu Lake had effects on Ca and Mg species. In the lake water, calcium carbonate was saturated or over-saturated based on long-term statistical calculation of the saturation index (SI). On the sediment profiles, significant difference in Ca and Mg species existed between the surface sediment (0–10 cm) and deeper sediments (>10 cm). The interstitial water Ca²⁺ and Mg²⁺, ion-exchangeable Ca and Mg in the surface sediment were higher than those in the deeper sediment. In the spring, when the acid deposition is more intensive, the acid-extracted Ca and Mg in the surface sediment were lower than that in the deeper sediment in the northwest lake, due to carbonate dissolution caused by the regional acid deposition. Spatially, the higher concentration of acid-extracted Ca and Mg in the northwest surface sediment than that in the east lake was observed, indicating the pronounced carbonate biomineralization by algae bloom in the northwest lake. Statistical analysis showed that acid deposition exerted a stronger impact on the variation of acid-extracted Ca and Mg in the surface sediment than the biomineralization in Taihu Lake. For the total Ca and Mg concentration in the spring, however, no significant change between the surface and deeper sediment in the northwest lake was observed, indicating that the carbonate precipitation via biomineralization and the carbonate dissolution due to acidic deposition were in a dynamic balance. These features are of major importance for the understanding of combined effects of acid deposition and eutrophication on freshwater lakes.

     

五氯酚(PCP)对鸡肝癌细胞(LMH)毒性效应的机制研究

五氯酚(pentachlorophenol,PCP)是一种持久性有机污染物,广泛用于灭钉螺、木材防腐、除草剂等方面,由于PCP在环境中的持久性和生物累积性,其对生态环境和人类健康造成潜在危害。本文以鸡肝癌细胞系(chicken hepatoma cells,LMH)为受试对象,探讨了PCP对细胞色素P450(CYP450)和抗氧化系统的影响。MTT结果显示LMH细胞经不同浓度PCP暴露后,呈现出先促进细胞增殖后抑制的J-型曲线,PCP对LMH细胞24 h的半数效应浓度(24 h-EC50)为427.52μmol·L~(-1)。LMH细胞在1.56、6.25、25、100μmol·L~(-1)PCP染毒条件下可增加细胞EROD、MROD、PROD和BFC活性,并可使CYP1A、1B、1C、2H及3A家族基因mRNA表达水平升高。LMH细胞在0.4~100μmol·L~(-1)PCP染毒下可显著降低硫酸基转移酶(SULT1B1和SULT 1C1)基因mRNA水平。此外,LMH细胞在6.25、25、100μmol·L~(-1)PCP染毒下可引起细胞内ROS升高,同时PCP(1.56~100μmol·L~(-1))可显著增加细胞内MDA含量和降低GSH/GSSH比值。这些结果表明细胞色素P450(CYP450)基因及酶活性的变化、细胞内ROS和MDA含量及GSH/GSSH可作为评价LMH细胞PCP毒性效应的敏感性生物标志物。此研究在细胞水平上利用多个评价指标研究PCP对细胞的毒性效应,为PCP环境风险评价提供依据。