Performance analysis and life cycle greenhouse gas emission assessment of an integrated gravitational-flow wastewater treatment system for rural areas

Environmental Science and Pollution Research - Due to the lack of appropriate wastewater treatment facility in rural areas, the discharging of wastewater without sufficient treatment results in...     

Two comparative approaches to identify the conservation priority areas impacted by heavy metals on Yellow Sea coasts

This study aimed to develop a practical approach to identify the priority areas with ecological significance along highly human disturbed coastal areas. Field surveys were used to assess and complement to the results of the remote sensing (RS)-based analysis. The RS-based biodiversity hotspot (BH) identification process was accomplished in three steps. The lands with native vegetation cover, including the national natural reserve lands, were first selected as the baseline BHs (BBHs). Then, after assigning resistance coefficients to each land use, the least accumulative cost (LAC) of the BBHs was calculated by distance analysis, while the normalized differential vegetation index (NDVI) from the Landsat Thematic Mapper was reclassified into 20 grades based on the Euclidean distance to the main anthropogenic sources. Finally, the RS-based BH identification was realized through the logistic calculation of LAC less than a series of thresholds and NDVI more than 10. While the field survey-based BH identification was through the logistic calculation between HM potential ecological risks of low to moderate and BHs acquired by NDVI-based integrated assessments. The results proved that RS-based analysis could be an important surrogate for necessary field surveys to manage BHs along coasts.     

Selenium for the mitigation of toxicity induced by lead in chicken testes through regulating mRNA expressions of HSPs and selenoproteins

Lead (Pb) is a toxic element and environmental pollutant. Pb toxicity and antagonistic effect of selenium (Se) on Pb have been deeply studied in mammals. The testis is one of the target organs of Pb in birds. The aim of this study was to investigate the mitigating effect of Se on Pb toxicity in chicken testes by determining messenger RNA (mRNA) expressions of 5 heat shock proteins (HSPs) and 25 selenoproteins. Sixty male chickens (7-day-old) were randomly divided into the control group, the Se group, the Pb group, and the Pb + Se group, and were fed for 90 days. The feeding methods of chickens were as follows: The control group was fed drinking water and commercial diet (0.49 mg/kg Se). Lead acetate was added into the drinking water (350 mg/L Pb). Sodium selenite was added into the commercial diet (1 mg/kg Se). Multivariate correlation analysis and principal component analysis (PCA) were used to define the relationships among all the measured factors and the most important parameters that could be used as key factors, respectively. The results indicated that Se decreased the increase of mRNA expressions of all the HSPs and increased the decrease of mRNA expressions of all the selenoproteins induced by Pb in the chicken testes. HSP70 may be a biomarker of Pb poisoning in the chicken testes. Se alleviated Pb-induced toxicity in the chicken testes through regulating mRNA expressions of HSPs and selenoproteins.

     

重金属暴露铜锈环棱螺全组织均一化cDNA文库构建及表达序列标签特征分析

构建cDNA文库是寻找生物新功能基因的有效手段.采用SM ART技术构建了重金属铜和镉暴露铜锈环棱螺全组织均一化cDNA文库,文库库容为1.78×106克隆,重组率大于99%.从初始文库中随机挑取6000个克隆进行测序,获得5 473个高质量表达序列标签(ESTs)序列.经聚类分析得到3 961个Unigene(平均长...     

Polycyclic aromatic hydrocarbons and ecotoxicological characterization of sediments from the Huaihe River, China

The distribution, source, ecological risk and ecotoxicity of polycyclic aromatic hydrocarbons (PAHs) of sediments from 7 sampling sites, named as Xinyang (XY), Huainan (HN), Bengbu (BB), Xuyi (XuY), Fuyang (FY), Mengcheng (MC) and Zhengzhou (ZZ), in the Huaihe River basin, China, have been investigated. The total concentrations of 16 USEPA priority PAHs ranged from 62.9 to 2232.4 ng g?1 dry weight (d.w.) with a mean concentration of 1056.8 ng g?1 d.w. Through the assessment of ecological risk, we found that the levels of PAHs in the Huaihe River should not exert adverse biological effects. The total benzo[a]pyrene toxicity equivalent (TEQ) values calculated for samples varied from 0.01 to 194.1 ng g?1 d.w., with an average of 65.9 ng g?1. The toxicity data were accordant with the chemical analysis results in this study. HN, BB and ZZ showed the greatest pollution extent both in the chemical analysis and the study of ecotoxicological effects.     

含添加剂细水雾抑制瓦斯爆炸有效性试验研究

为进一步提高细水雾的抑爆灭火效能,在建立细水雾抑爆系统试验平台的基础上,选用MgCl2、FeCl2和NaHCO3这3种添加剂,研究细水雾对瓦斯爆炸火焰的抑制效果.结果表明:使用含添加剂细水雾后,体积分数为9.5％的瓦斯的爆炸传播速度从13.8 m/s至少降到2.75 m/s;水雾区火焰长度最多缩短了242 mm;含0.8％FeCl2的细水雾有效性系数为6,有效性最高;从火焰图片剖面像素分布可以看出,火焰的辐射体温度均出现了不同程度的降低.不同添加剂不同程度地提高了细水雾的灭火效能,对瓦斯体积分数接近化学当量比的火焰传播有明显抑制效果.     

Synergistic impacts of anthropogenic and biogenic emissions on summer surface O3 in East Asia

A factor separation technique and an improved regional air quality model (RAQM) were applied to calculate synergistic contributions of anthropogenic volatile organic compounds (AVOCs),biogenic volatile organic compounds (BVOCs) and nitrogen oxides (NOx) to daily maximum surface O3(O3DM) concentrations in East Asia in summer (June to August 2000).The summer averaged synergistic impacts of AVOCs and NOx are dominant in most areas of North China,with a maximum of 60 ppbv,while those of BVOCs and NOx are notable only in some limited areas with high BVOC emissions in South China,with a maximum of 25 ppbv.This result implies that BVOCs contribute much less to summer averaged O3DM concentrations than AVOCs in most areas of East Asia at a coarse spatial resolution (1×1) although global emissions of BVOCs are much greater than those of AVOCs.Daily maximum total contributions of BVOCs can approach 20 ppbv in North China,but they can reach 40 ppbv in South China,approaching or exceeding those in some developed countries in Europe and North America.BVOC emissions in such special areas should be considered when O3 control measures are taken.Synergistic contributions among AVOCs,BVOCs and NOx significantly enhance O3 concentrations in the Beijing-Tianjin-Tangshan region and decrease them in some areas in South China.Thus,the total contributions of BVOCs to O3DM vary significantly from day to day and from location to location.This result suggests that O3 control measures obtained from episodic studies could be limited for long-term applications.     

Destruction of 4-phenolsulfonic acid in water by anodic contact glow discharge electrolysis

Destruction of 4-phenolsulfonic acid (4-PSA) in water was carried out using anodic contact glow discharge electrolysis. Accompanying the decay of 4-PSA, the amount of total organic carbon (TOC) in water correspondingly decreased, while the sulfonate group of 4- PSA was released as sulfate ion. Oxalate and formate were obtained as minor by-products. Additionally, phenol, 1,4-hydroquinone, hydroxyquinol and 1,4-benzoquinone were detected as primary intermediates in the initial stages of decomposition of 4-PSA. A reaction pathway involving successive attacks of hydroxyl and hydrogen radicals was assumed on the basis of the observed products and kinetics. It was revealed that the decay of both 4-PSA and TOC obeyed a first-order rate law. The effects of different Fe ions and initial concentrations of 4-PSA on the degradation rate were investigated. It was found that the presence of Fe ions could increase the degradation rate of 4-PSA, while initial concentrations lower than 80 mmol/L had no significant effect on kinetic behaviour. The disappearance rate of 4-PSA was significantly affected by pH.     

A fishy odor episode in a north China reservoir：Occurrence, origin, and possible odor causing compounds

A significant outbreak of fishy odor occurred in a reservoir located in Inner Mongolia, China, in the winter of 2011, and the odor rating, algal density and concentrations of some potential odorous compounds were monitored over a period of two months. The peak odor rating of the fishy odor was 7 according to flavor profile analysis. Among the dominant algal species （two diatom and one chrysophyte species） observed during the survey, the chrysophyte Dinobryon sp. was the most abundant species, with the peak density recorded at 88,520 cells/mL. Seven potential algal metabolites including heptanal, 2,4-heptadienal, 2,4-decadienal, nonanal, 2-octenal, 2,6- nonadienal and hexanal were detected. The principal component analysis result showed that n-hexanal, n-heptanal and 2,4-decadienal, possibly the metabolites of diatoms, and 2,4-heptadienal, possibly the metabolite of Dinobryon sp., might have contributed to the fishy odor episode. This study demonstrated that the fishy odor episode in this reservoir might be caused by the abnormal growth of chrysophytes and diatoms under the ice-cover.     

Supercritical Fluids-Assisted Processing Using CO2 Foaming to Enhance the Dispersion of Nanofillers in Poly(butylene succinate)-Based Nanocomposites and the Conductivity

Journal of Polymers and the Environment - With the rapid development of electronic information technology, traditional metal conductive materials can no longer satisfy the needs of a wider...