A dynamic contaminant fate model of organic compound: a case study of Nitrobenzene pollution in Songhua River, China

A one-dimensional dynamic contaminant fate model, coupling kinematic wave flow option with advection-dispersion-reaction equation, has been applied to predict Nitrobenzene pollution emergency in Songhua River, China that occurred on November 13, 2005. The model includes kinetic processes including volatilization, photolysis and biodegradation, and diffusive mass exchange between water column and sediment layer as a function of particles settling and resuspension. Four kinds of quantitative statistical tests, namely Nash-Sutcliffe efficiency, percent bias, ratio of root-mean-square to the standard deviation of monitoring data and Theil’s inequality coefficient, are adopted to evaluate model performance. The results generally show that the modeled and detected concentrations exhibit good consistency. Flow velocity in the river is most sensitive parameter to Nitrobenzene concentration in water column based on sensitivity analysis of input parameters. It indicates flow velocity has important impact on both distribution and variance of contaminant concentration. The model performs satisfactory for prediction of organic pollutant fate in Songhua River, with the ability to supply necessary information for pollution event control and early warning, which could be applied to similar long natural rivers.     

Perfluoroalkyl acids in blood serum samples from children in Taiwan

Severe perfluoroalkyl acid (PFAA) contamination resulting from the fast-growing semiconductor, electrochemical, and optoelectronic industries has been determined in the river water in the vicinity of the Taipei area, Taiwan, during recent years. However, little is known about body burdens of the PFAA contaminations in local residents, especially children living in the Taipei area recently. In this study, ten target PFAA analytes consisted of three perfluorosulfonates (PFSAs) and seven perfluorocarboxylates (PFCAs) in the blood serum samples, collected from 225 healthy children with an average age of 13.6 years in the Taipei area from 2009 to 2010, were analyzed via high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). As the dominant PFAA contaminant in the blood serum samples from Taiwanese children, perfluorooctane sulfonate (PFOS) contributed 86 % of all the target PFAA analytes, while the other nine analytes contributed less than 5 % individually. PFOS showed the highest median up to 29 ng/mL, ranging from 0.03 to 148 ng/mL, which was higher than that observed in the serum samples collected from Taiwanese children between 2006 and 2008. Statistically, serum concentrations of perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), and perfluorooctanoic acid (PFOA) had significantly positive correlations with ages of children (p?<?0.05). Furthermore, serum PFBS, PFHxS, and PFOA concentrations in the male children were considerably higher than those in the female children (p?=?0.049, p?=?0.000, p?=?0.000).     

广西综合环境质量结构与功能属性构建及其关系耦合优化

用主分量分类分析方法对广西2001—2015年各要素环境质量监测指标与自然、经济、人口、能源和污染物排放等年鉴统计指标构成的综合环境质量结构与功能属性关系进行耦合。结果表明:广西综合环境质量在省域层次上呈现明显的年、季、月等时间尺度变化规律。在市域层次上,年际时空交互变化规律分异明显;月份的时空交互变化规律在城市空间格局上有明显分异,但时间序列的分异规律不明显;季度的时空交互变化规律在空间与时间上均无明显分异。研究可为经济发展、国土空间优化、能源利用、环境保护等决策管理与判别提供参考。     

Spatial effect of environmental regulation measures on industrial structure upgrading from the empirical analysis of Beijing-Tianjin-Hebei region and its surrounding areas

ABSTRACT

This paper investigates the spatial effect of environmental regulation measures on the upgrading of industrial structure in the integrated development strategy of Beijing-Tianjin-Hebei region and its surrounding areas. In order to reflect the effect of the environmental regulation and different regulation measures more truly, this paper constructs indices of the environmental regulation measures through the results of policy texts quantification. On the basis of the previous research, this paper divides environmental regulation into the following types: personnel and administrative measures of command and control; market-oriented fiscal, taxation, financial and other economic measures; guidance measures. Spatial panel regression results show that administrative measures of command control and market-oriented fiscal measures have a significant role in promoting regional industrial structure upgrading, but not conducive to the advancement of the industrial structure of adjacent areas. Their roles in promoting and inhibition are counteracted, which causes the total effect of industrial structure upgrading of Beijing-Tianjin-Hebei and the surrounding areas are not significant. Personnel measures, financial measures, other economic measures and guidance measures do not have the short-term effect and spatial effect on the upgrading of industrial structure.     

N-methylcarbamate pesticides and their phenolic degradation products: hydrolytic decay,sequestration and metal complexation studies

We report on the rates of decomposition of a group of N-methylcarbamate (NMC) pesticides (carbaryl, carbofuran and propoxur) under pre-determined tropical field conditions. Rates of decomposition for three NMCs were determined at pH 7.08 and T?=?20?°C and pH 7.70 and T = 33?°C respectively, as follows: carbaryl (78?days and 69?days); carbofuran (143?days and 83?days) and propoxur (116?days and 79?days). Investigation on methods for removal of NMCs and their phenolic decomposition products shows that activated charcoal outperforms zeolite, alumina, diatomaceous earth, cellulose and montmorillonite clay in the removal of both NMCs and phenols from aqueous solution. Furthermore, metal complexation studies on the NMCs and phenols showed that Fe (III) forms a complex with isopropoxyphenol (IPP) within which the Fe:IPP ratio is 1:3, indicative of the formation of a metal chelate complex with the formula Fe(IPP)₃.     

不同氮磷浓度下2种无毒微藻的生长特性和脱氮除磷效能

根据城市二级出水水质特性,选择4种不同氮磷水平的二级出水作为培养基,研究纯培养与共培养下,椭圆小球藻(Chlorella ellipsoidea)和斜生栅藻(Scenedesmus obliquus)在不同初始氮磷浓度下的生长状况及脱氮除磷的能力。结果表明,纯培养条件下,椭圆小球藻在2#(TN=15.00 mg/L,TP=1.00 mg/L)实验组中生物量最高,斜生栅藻在4#(TN=10.00 mg/L,TP=0.20 mg/L)实验组中收获最大生物量,椭圆小球藻与斜生栅藻对TP均具有70%以上去除率。共培养下,3#(TN=15.00 mg/L,TP=0.50 mg/L)实验组收获最高生物量,斜生栅藻生物量均高于椭圆小球藻,表明斜生栅藻在共培养条件下更具有生长优势,培养基中TN、TP含量分别降至5.00 mg/L和0.05 mg/L以下。2种培养模式均可达到对二级出水的深度脱氮除磷。     

复合菌剂强化处理高盐废水脱氮效果

将耐盐脱氮复合菌剂投加到序批式生物反应器中,构建生物强化高盐废水处理系统(SBR1),以未投加复合菌剂系统(SBR2)作为对照,分析典型周期中氮素和溶解氧的变化趋势以及盐度冲击对脱氮效果的影响.实验表明,在曝气时间为6h时,生物强化系统脱氮率可稳定在96％以上,出水总氮浓度为3.8 mg/L左右.反应中始终无硝氮、亚硝氮积累,生物强化系统具有同步硝化好氧反硝化能力.当受到5％和7％较高盐度冲击时,生物强化系统表现出优于对照系统的抗盐度冲击能力,能够快速恢复原有活性,且出水总氮低于15 mg/L;当受到0％盐度的淡水冲击时,对照系统中耐盐污泥失活且无法恢复,而生物强化系统只需投加少量(3％)耐盐脱氮复合菌剂,即可快速恢复活性,出水总氮低于15 mg/L.本研究能够为生物强化高盐废水脱氮系统的构建和运行提供技术支持.     

pH对厌氧氨氧化反应脱氮效能的影响

采用具有恒定pH功能的SBR接种厌氧氨氧化颗粒污泥,研究了pH对厌氧氨氧化菌脱氮效能的影响。实验结果表明:在进水ρ(氨氮)和ρ(亚硝酸盐氮)分别为58.00 mg/L和79.28 mg/L、TN容积负荷为0.82 kg/(m3·d)、不控制反应pH的条件下,随着反应的进行,pH不断升高,当pH=8.02时,菌种的去除效能最高;在进水ρ(氨氮)和ρ(亚硝酸盐氮)分别为120.00 mg/L和159.33 mg/L、TN容积负荷为1.62 kg/(m3·d)、恒定反应pH为8.00的条件下,反应4.0 h时的容积基质氮去除速率(NRR)达到1.42 kg/(m3·d),氨氮去除率达98.39%,亚硝酸盐氮去除率达99.48%;拟合曲线推导的最适pH的理论值为7.85,反应4.0 h时的NRR理论最大值达1.52 kg/(m3·d)。     

固定污染源硝酸雾中硝酸根的检测

建立了固定污染源硝酸雾中硝酸根的检测方法。用硅胶管采集固定污染源硝酸雾中的硝酸,用碳酸钠溶液进行洗脱,最后使用离子色谱仪测定硝酸根质量浓度。对影响检测结果的加热时间和静置时间进行了研究。实验结果表明:最佳的加热时间为10 min,无需静置;方法的相对标准偏差为0.27%~0.62%,检出限为0.002 5μg/m L,加标回收率为99.7%~102.2%。该法线性关系良好,检出限低,精密度高,能满足固定污染源硝酸雾中硝酸根的测定要求。     

Development of a sensitive,competitive, indirect ELISA for the detection of fumonisin B1 in corn originating from Anhui province,China

Fumonisin B₁ (FB₁) is a secondary metabolite produced by Fusarium verticillioides or Fusarium proliferatum, which present in food and feed. It causes hazardous effects on human and animal health. A monoclonal antibody (mAb) against FB₁ was produced and a simple, reliable and sensitive, competitive, indirect enzyme-linked immunosorbent assay (ci-ELISA) for detection of FB₁ was developed and the experiment conditions were optimized. The coating concentration of FB₁-ovalbumin (FB₁-OVA) was 500 ng mL^?1, the action concentrations of anti-FB₁ mAb and goat anti-mouse IgG were 1.28 × 10⁴ and 1:5000, respectively. The 50% inhibitory concentration (IC₅₀) was 11 ng mL^?1, with a detectable range of 1.25–250 ng mL^?1, and a limit of determination (LOD) of 1.15 ng mL^?1. The cross-reactivity (CR) of the antibody against fumonisin B₂ (FB₂) was 60.4, and <1% against deoxynivalenol (DON), aflatoxin B₁ (AFB₁), ochratoxin A (OTA) or zearalenone (ZEN). In spiked samples (250 ng g^?1, 500 ng g^?1, 1000 ng g^?1), the mean recoveries ranged from 86.7 ± 5% to 102 ± 4%, and the coefficient of variation (CV) ranged from 3% to 10%. A survey of 96 corn samples from Bozhou, Fuyang, Bengbu, and Hefei, in Anhui province, China, was performed. Frequencies of FB₁ contamination were 83.3%, 95.8%, 20.8% and 91.7%, and the mean concentrations of positive samples were 0.702 μg kg^?1, 0.883 μg kg^?1, 0.074 μg kg^?1, and 0.276 μg kg^?1, respectively. The results of this study suggest that the ci-ELISA developed in this study can be used to identify FB₁ in corn, furthermore, further study is needed to investigate FB₁ contamination in food and feed to prevent its harmful health effects.