Feb 2014, Volume 8 Issue 1

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    Michael Patrick WALSH

    It is well established that ambient particles in the size range of 2.5 microns or less case a wide variety of adverse health effects. According to a recent study from the World Health Organization, in 2010 these effects resulted in approximately 3.2 million premature deaths with vehicles being one of the significant contributors. Diesel vehicle particulate emissions which are virtually all smaller than 2.5 microns raise additional special concerns due to their carcinogenicity and high ratio of black carbon (BC) to organic carbon; black carbon has recently been found to be the second most important contributor to climate change after carbon dioxide. Other pollutants emitted by diesels and other vehicles such as the oxides of nitrogen and volatile organic compounds also contribute to ambient particulate matter smaller than 2.5 microns in size (PM2.5) after undergoing secondary transformations in the atmosphere. Technologies have been developed that can dramatically reduce vehicle emissions when clean, low sulfur fuels are available and these technologies are being phased in throughout the industrialized world resulting in a global decrease in particulate matter (PM) and BC emissions from vehicles. However the vehicle population is growing rapidly in the developing world, leading to increases in emissions in many countries. Unless these rapidly industrializing countries move to state of the art vehicles and clean fuels, global PM, BC and NOx emissions from road vehicles will start to turn up over the next 10 to 15 years.

    Yan SUN, Huang HUANG, Ying SUN, Chao WANG, Xiaolei SHI, Hongying HU, Takashi KAMEYA, Koichi FUJIE

    The purpose of this study was to give a worldwide overview of the concentrations of typical estrogenic endocrine disrupting chemicals (EDCs) in the effluent of sewage plants and then compare the concentration distribution of the estrogenic EDCs in ten countries based on the survey data of the estrogenic EDCs research. The concentrations of three main categories (totally eight kinds) of estrogenic EDCs including steroidal estrogens (estrone (E1), estradiol (E2), estriol (E3) and 17α-ethynylestradiol (EE2)), phenolic compounds (nonylphenol (NP) and bisphenol A (BPA)) and phthalate esters (dibutyl phthalate (DBP) and dibutyl phthalate (2-ethylhexyl) phthalate (DEHP)) in the effluents of sewage plants reported in major international journals over the past decade were collected. The statistics showed that the concentration distributions of eight kinds of EDCs were in the range of ng·L-1 to μg·L-1. The concentrations of steroidal estrogens mainly ranged within 50.00 ng·L-1, and the median concentrations of E1, E2, E3 and EE2 were 11.00, 3.68, 4.90 and 1.00 ng·L-1, respectively. Phenolic compounds and phthalate esters were found at μg·L-1 level (some individual values were at the high level of 40.00 μg·L-1). The median concentrations of BPA, NP, DBP and DEHP were 0.06, 0.55, 0.07 and 0.88 μg·L-1, respectively. The concentrations of phenolic compounds and phthalate esters in the effluents were higher than that of steroids estrogens. The analysis of the concentration in various ten countries showed that steroids estrogens, phenolic compounds and phthalate esters in sewage plant effluents were detected with high concentration in Canada, Spain and China, respectively.

    Wei WEI, Shuxiao WANG, Jiming HAO, Shuiyuan CHENG

    This study estimates the detailed chemical profiles of China’s anthropogenic volatile organic compounds (VOCs) emissions for the period of 2005–2020. The chemical profiles of VOCs for seven activity sectors are calculated, based on which the Photochemical Ozone Creation Potential (POCP) of VOCs for these sectors is evaluated. At the national level, the VOCs species emitted in 2005 include alkanes, alkenes and alkynes, aromatic compounds, alcohols, ketones, aldehydes, esters, ethers and halocarbons, accounting for 26.4 wt.%, 29.2 wt.%, 21.3 wt.%, 4.7 wt.%, 5.4 wt.%, 1.7 wt.%, 2.1 wt.%, 0.7 wt.% and 2.2 wt.% of total emissions, respectively. And during 2005-2020, their mass proportions would respectively grow or decrease by -6.9%, -32.7%, 7.3%, 65.3%, 34.7%, -48.6%, 108.5%, 100.5%, and 55.4%. This change would bring about a 13% reduction of POCP for national VOCs emissions in the future. Thus, although the national VOCs emissions are expected to increase by 33% over the whole period, its ozone formation potential is estimated to rise only by 14%. Large discrepancies are found in VOCs speciation emissions among provinces. Compared to western provinces, the eastern provinces with a more developed economy would emit unsaturated hydrocarbons and benzene with lower mix ratios, and aromatic compounds except benzene, oxidized hydrocarbons and halocarbons with higher mix ratios. Such differences lead to lower POCP of VOCs emitted in eastern provinces, and higher POCP of VOCs emitted in western provinces. However, due to the large VOCs emissions from Chinese eastern region, the ozone formation potential of VOCs emission in eastern provinces would be much higher than those in western provinces by about 156%–235%.

    Qingwei BU, Donghong WANG, Zijian WANG, Junnong GU

    The Danjiangkou reservoir was selected to provide the source water for the middle routes of the South to North Water Transfer Project, which has provoked many environmental concerns. To date, investigations of water contamination of the source water of the Danjiangkou reservoir with organic micro-pollutants have been limited. This study was conducted to identify and rank organic contaminants that pose risks in the Danjiangkou reservoir. To this end, the Chemical Hazard Evaluation and Management Strategies (CHEMS-1) approach was adapted to integrate the deconvolution technology of qualitative identifying contaminants for site-specific environmental matrices. The samples were screened for the presence of 1093 contaminants using deconvolution technologies and the hazard values of the identified contaminants were calculated using the adapted CHEMS-1 approach according to their hazardous properties and occurrence in source water. The results showed that 46 contaminants from 1093 targets were present in Danjiangkou water, 23 of which appeared at frequencies higher than 50%, and 15 of which were identified as priorities. Over half (53%) of the high-ranked contaminants were polycyclic aromatic hydrocarbons (PAHs), with chrysene ranked highest on the list. Health risk assessment of the top-ranked PAHs was conducted and revealed that cancer risks of PAHs detected in the source water of Danjiangkou to different populations ranged from 10-7 to 10-6, indicating a low cancer risk to consumers. The results of this study indicated that the adapted CHEMS-1 approach was feasible for site-specific screening of organic contaminants to identify and rank potential priority pollutants.

    Yanqing YU, Xiaoliang LI, Xiaolan ZOU, Xiaobin ZHU

    A novel method for the synthesis of zeolite was developed in this paper. The synthesis was carried out by hydrothermal activation after alkali fusion and coal fly ash (CFA) was used as raw material with seawater of different salinities. Seawater salinity was varied from 32 to 88 for zeolite crystallization during the hydrothermal process. The results show that seawater salinity plays an important role in zeolite synthesis with CFA during hydrothermal treatment. The products were a mixture of NaX zeolite and hydroxysodalite; seawater salinity more strongly affected the crystallization than the type and chemical composition of the zeolites. The yield of CFA transformed into zeolite gradually rose with the increase in salinity, reaching a transformation rate of 48%–62% as the salinity increased from 32 to 88, respectively. The proposed method allows for the efficient disposal of by-products; therefore, the application of seawater in zeolite synthesis presents promising economic and ecological benefits.

    Qian SUI, Jun HUANG, Shuguang LU, Shubo DENG, Bin WANG, Wentao ZHAO, Zhaofu QIU, Gang YU

    The application of appropriate advanced treatment process in the municipal wastewater treatment plants (WWTPs) has become an important issue considering the elimination of emerging contaminants, such as pharmaceutical and personal care products (PPCPs). In the present study, the removal of 13 PPCPs belonging to different therapeutic classes by the sequential ultraviolet (UV) and ozonation process in a full-scale WWTP in Beijing was investigated over the course of ten months. Most of the target PPCPs were effectively removed, and the median removal efficiencies of individual PPCPs, ranging from -13% to 89%, were dependent on their reaction rate constants with molecular ozone. Noticeable fluctuation in the removal efficiencies of the same PPCPs was observed in different sampling campaigns. Nevertheless, the sequential UV and ozonation process still made a significant contribution to the total elimination of most PPCPs in the full-scale WWTP, by compensating for the poor or fluctuant removal performance of PPCPs by biologic treatment process.

    Kaifeng RAO, Na LI, Mei MA, Zijian WANG

    Effluents from wastewater treatment plant (WWTP) have been reported to have a broad spectrum of endocrine disrupting compounds (EDCs). The majority of studies have focused on the occurrence of estrogenic activity, while ignoring nuclear hormone receptors (NRs) pathways. In the present study, a battery of in vitro yeast bioassays and a cell bioassay, including antagonistic and agonistic effects on estrogen receptor (ER), androgen receptor (AR), progesterone receptor (PR), estrogen-related receptor (ERR) and aryl hydrocarbon receptor (AHR), were conducted to evaluate the removal efficiencies of EDCs by different treatment processes of a WWTP located in Beijing. Estrogenic, anti-estrogenic, anti- androgenic, anti-progesteronic, anti-ERR and the activation of AHR activities were detected in samples from all treatment processes and the receiving water. The concentration of estrogenic contaminants with estradiol (E2) equivalent concentrations ranged from 0.82 × 10-9 to 3.54 × 10-9 g E2-EQ·L-1. The concentration of anti-estrogenic contaminants with 4-hydroxytamoxifen (4-OHT) equivalent concentrations ranged from 1.24 × 10-6 to 2.36 × 10-6 g 4-OHT-EQ·L-1. The concentration of anti-androgenic contaminants ranged from 2.21 × 10-8 to 3.52 × 10-6 g flutamide-EQ·L-1. The concentration of anti-progesteronic contaminants ranged from 3.15 × 10-5 to 2.71 × 10-4 g RU486-EQ·L-1. The concentration of anti-ERR contaminants ranged from 7.09 × 10-5 to 6.50 × 10-4 g 4-OHT-EQ·L-1. The concentration of AHR activators ranged from 1.7 × 10-10 to 3.4 × 10-10 g TCDD-EQ·L-1. These processes including secondary clarifier, coagulation, as well as coal and sand filtration could eliminated 67.2% of estrogenic contaminants, 47.0% of anti-estrogenic contaminants, 98.3% of anti-androgenic contaminants, 88.4% of anti-progesteronic contaminants, 65.4% of anti-ERR contaminants and 46.9% of AHR activators. WWTP effluents contain multiple receptor disruptors may have very complex adverse effects on exposed organisms.

    Jiaxing GUO, Huan LIU, Yang JIANG, Dongquan HE, Qidong WANG, Fei MENG, Kebin HE

    To understand the household CO2 emission level in China, as well as how much the neighborhoods’ socio-economic or design factors could influence the CO2 emission, 23 neighborhoods in Jinan were investigated in 2009 and 2010. These neighborhoods fall into four different types: superblock, enclave, grid and traditional. The household CO2 emission includes sources of both in-home energy use and passenger transportation. The average CO2 emission per household is 7.66 t·a-1, including 6.87 t in-home operational emission and 792 kg transportation emission. The household CO2 emission by neighborhood categories is 10.97, 5.65, 6.49, 5.40 t·household-1·a-1 for superblock, enclave, grid and traditional respectively. Superblock has the highest average emission and also the highest percent (more than 25%) of transportation emission among four different types of neighborhoods. The residential CO2 emission of superblock neighborhoods in Jinan has already reached the level in developed countries nearly ten years ago. It is predictable that more superblock neighborhoods would be built in China with the fast urbanization. How to avoid the rapid household CO2 emission growth in the future would be a systematic issue. The study also found that in addition to income and apartment area, household density, land use mix and accessibility to public transportation are three primary factors which have significant impacts on CO2 emission. High density, mixed land use and convenient accessibility to public transportation tend to reduce household CO2 emission.

    Haifeng ZHANG, Lu SU, Xiangyu LI, Jiane ZUO, Guangli LIU, Yujue WANG

    The relationship between the chemical contaminants and soil microbial toxicity of waste foundry sand (WFS) was investigated. Five different types of WFS from typical ferrous, aluminum, and steel foundries in China were examined for total metals, leachable metals, and organic contaminants. The soil microbial toxicity of each WFS was evaluated by measuring the dehydrogenase activity (DHA) of a blended soil and WFS mixture and then comparing it to that of unblended soil. The results show that the five WFSs had very different compositions of metal and organic contaminants and thus exhibited very different levels of soil microbial inhibition when blended with soil. For a given WFS blended with soil in the range of 10 wt.%–50 wt.% WFS, the DHA decreased almost linearly with increased blending ratio. Furthermore, for a given blending ratio, the WFSs with higher concentrations of metal and organic contaminants exhibited greater microbial toxicity. Correlation analysis shows that the relationship between ecotoxicity and metal and organic contaminants of WFSs can be described by an empirical logarithmic linear model. This model may be used to control WFS blending ratios in soil-related applications based on chemical analysis results to prevent significant inhibition of soil microbial activity.

    Lingyan HOU, Yun LU, Ying LI, Li LI

    The uterotrophic assay has been commonly used to test environmental estrogens in vivo, however, it is often not sensitive enough sometimes. An alternative way is to evaluate estrogenicity through biomarker genes. MicroRNA (miRNA) is a class of regulatory gene, which has been shown to be a good biomarker for many diseases and toxicological effects in recent years, and some evidences showed that estrogen induced response was partially mediated by miRNAs. In this study, two types of microarrays were used to test the 17β-estradiol (E2) induced miRNA expression profile at different time points in the immature mouse uterus. Statistical analysis showed the aldehyde slide based array had less variation than the amino slide based array, and 11 dysregulated miRNAs were screened out for significant fold change. Real-time PCR was performed to further confirm that 4 out of 7 selected miRNAs, namely miR-451, miR-155, miR-335-5p, and miR-365, are E2 regulated miRNAs in the uterus. The function of the predicted targets of these miRNAs is involved in cell grow control, which is consistent with the main E2 function in the uterus. MiR-451 had similar strong responses to E2 in the uterus of both immature and overiectomized mice, and could be a potential biomarker for estrogenicity in the uterus.

    Yufen REN, Zhiwei XU, Xinyu ZHANG, Xiaoke WANG, Xiaomin SUN, D. J. BALLANTINE, Shengzhong WANG

    Nitrogen contamination of surface water is a worldwide environmental problem with intensive agriculture and high population densities. We assessed the spatial and seasonal variation in concentrations of total nitrogen and different nitrogen species present in surface-water in Beijing, China. Also, chemical (NO3--N/C1-) and isotopic (δ15Nnitrate) indicators were used to identify nitrate sources. The results showed that, during 2009 and 2010, nitrate nitrogen concentrations ranged from 0.7 to 7.6 mg·L-1, ammonium nitrogen from 0.1 to 3.4 mg·L-1, and total nitrogen from 2.4 to 17.0 mg·L-1. Inorganic nitrogen accounted for between 60 and 100% of total nitrogen at the ten monitoring sites. Nitrate nitrogen, ammonium nitrogen, and total nitrogen concentrations at the 2 downstream monitoring sites in south-eastern Beijing were significantly higher than those at the other eight upstream monitoring sites (P<0.01). Examination of seasonal variation showed that there was a significant inverse relationship between nitrate nitrogen concentrations and precipitation, and that nitrate nitrogen concentrations peaked in the dry seasons. The information given by the δ15Nnitrate values and nitrate nitrogen concentrations, combined with the NO3--N/C1- ratio distribution, showed that domestic sewage was the major source of nitrate in Beijing. Methods to control and reduce sewage pollution are urgently needed to help manage surface water quality in Beijing.

    Weifang SHI, Weihua ZENG

    The homogeneous risk characteristics within a sub-area and the heterogeneous from one sub-area to another are unclear using existing environmental risk zoning methods. This study presents a new zoning method by determining and categorizing the risk characteristics using the k-means clustering data mining technology. The study constructs indices and develops index quantification models for environmental risk zoning by analyzing the mechanism of environmental risk occurrence. We calculate the source risk index, air risk field index, water risk field index, and target vulnerability of the study area with Nanjing Chemical Industrial Park using a 100 m × 100 m mesh grid as the basic zoning unit, and then use k-means clustering to analyze the environmental risk in the area. We obtain the optimal clustering number with the largest average silhouette coefficient by calculating the average silhouette coefficients of clustering at different k-values. The clustering result with the optimal clustering number is then used for the environmental risk zoning, and the zoning result is mapped using the geographic information system. The study area is divided into five sub-areas. The common environmental risk characteristics within the same sub-area, as well as the differences between sub-areas, are presented. The zoning is helpful in risk management and is convenient for decision makers to distribute limited resources to different sub-areas in the design of risk reducing intervention.

    Shuai MA, Siyu ZENG, Xin DONG, Jining CHEN, Gustaf OLSSON

    The prediction of the influent load is of great importance for the improvement of the control system to a large wastewater treatment plant. A systematic data analysis method is presented in this paper in order to estimate and predict the periodicity of the influent flow rate and ammonia (NH3) concentrations: 1) data filtering using wavelet decomposition and reconstruction; 2) typical cycle identification using power spectrum density analysis; 3) fitting and prediction model establishment based on an autoregressive model. To give meaningful information for feedforward control systems, predictions in different time scales are tested to compare the corresponding predicting accuracy. Considering the influence of the rainfalls, a linear fitting model is derived to estimate the relationship between flow rate trend and rain events. Measurements used to support coefficient fitting and model testing are acquired from two municipal wastewater treatment plants in China. The results show that 1) for both of the two plants, the periodicity affects the flow rate and NH3 concentrations in different cycles (especially cycles longer than 1 day); 2) when the flow rate and NH3 concentrations present an obvious periodicity, the decreasing of prediction accuracy is not distinct with increasing of the prediction time scales; 3) the periodicity influence is larger than rainfalls; 4) the rainfalls will make the periodicity of flow rate less obvious in intensive rainy periods.

    Yanping HOU, Kaiming LI, Haiping LUO, Guangli LIU, Renduo ZHANG, Bangyu QIN, Shanshan CHEN

    Separator between anode and cathode is an essential part of the microbial fuel cell (MFC) and its property could significantly influence the system performance. In this study we used polyvinyl alcohol (PVA) polymer membrane crosslinked with sulfosuccinic acid (SSA) as a new separator for the MFC. The highest power density of 759±4 mW·m-2 was obtained when MFC using the PVA membrane crosslinked with 15% of SSA due to its desirable proton conductivity (5.16 × 10-2 S·cm-1). The power density significantly increased to 1106±30?mW·m-2 with a separator-electrode-assembly configuration, which was comparable with glass fiber (1170±46?mW·m-2). The coulombic efficiencies of the MFCs with crosslinked PVA membranes ranged from 36.3% to 45.7% at a fix external resistance of 1000 ?. The crosslinked PVA membrane could be a promising alternative to separator materials for constructing practical MFC system.

    Lili GAN, Jiane ZUO, Yajiao WANG, Thong Soon LOW, Kaijun WANG

    A self-developed sewer health assessment system using the fuzzy comprehensive evaluation and analytical hierarchy process was applied to give a comprehensive health condition evaluation on part of the local sewers in a southern Chinese city based on the sewer video data collected by a sewer inspection closed circuit television (CCTV) robot. Aside from the overall condition evaluation, the structure, function, and stability status of the sewer were also analyzed using the method. A comprehensive index H was proposed to give the overall health condition of pipes with different defects, and Ht, Hs, and Hf were used to quantify the defects affecting the tightness, stability, and function of the pipe, respectively. Results show that 48% of the inspected pipes were in good condition (0<H<0.25), and about 33% of the sewer pipes analyzed were categorized to be at severe or urgent condition levels (H>0.5), although most of the pipes were installed only within five years. Frequent sedimentation affects the function of the sewer, and deformation and joint damage affect the structure of the sewer.