四川某中小城镇污水处理厂进水水质统计分析

生活污水水质对处理工艺的选择、设计参数的选取以及稳定运行十分重要。运用SPSS软件,对四川某中小城镇污水处理厂为期一年的进水指标(水量、COD、氨氮、总磷、pH、SS)进行方差和相关性分析。方差分析结果显示进水量、氨氮和SS在月份和季节之间存在显著性差异,而总磷和pH仅在月份之间存在显著差异,COD在季度和月份之间无显著性差异;指标相关性分析表明,进水量和氨氮之间呈负相关,氨氮和总磷、COD和总磷之间呈正相关,且相关性显著。在此分析的基础上对污水处理厂设计、工艺选择及运行管理提出了一些建议。     

燃煤电厂烟气氮氧化物排放控制技术发展现状

在广泛查阅文献的基础上,对近年来国内外已成功应用和正在研究开发的一些主要的燃煤烟气氮氧化物控制技术进行了介绍。结合我国目前脱硝行业整体水平和国家环保政策要求,对我国脱硝行业技术研发方向提出了建议。     

Beyond hypoxia：Occurrence and characteristics of black blooms due to the decomposition of the submerged plant Potamogeton crispus in a shallow lake

Organic matter-induced black blooms(hypoxia and an offensive odor) are a serious ecosystem disasters that have occurred in some large eutrophic shallow lakes in China. In this study, we investigated two separate black blooms that were induced by Potamogeton crispus in Lake Taihu, China. The main physical and chemical characteristics, including color- and odor-related substances, of the black blooms were analyzed. The black blooms were characterized by low dissolved oxygen concentration(close to 0 mg/L), low oxidation-reduction potential, and relatively low pH of overlying water. Notably higher Fe2+and∑S2-were found in the black-bloom waters than in waters not affected by black blooms. The black color of the water may be attributable to the high concentration of these elements, as black FeS was considered to be the main substance causing the black color of blooms in freshwater lakes. Volatile organic sulfur compounds, including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, were very abundant in the black-bloom waters. The massive anoxic degradation of dead Potamogeton crispus plants released dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, which were the main odor-causing compounds in the black blooms. The black blooms also induced an increase in ammonium nitrogen and soluble reactive phosphorus levels in the overlying waters. This extreme phenomenon not only heavily influenced the original lake ecosystem but also greatly changed the cycling of Fe, S, and nutrients in the water column.     

Removal of polycyclic aromatic hydrocarbons from aqueous solution by raw and modified plant residue materials as biosorbents

Removal of polycyclic aromatic hydrocarbons （PAHs）, e.g., naphthalene, acenaphthene, phenanthrene and pyrene, from aqueous solution by raw and modified plant residues was investigated to develop low cost biosorbents for organic pollutant abatement. Bamboo wood, pine wood, pine needles and pine bark were selected as plant residues, and acid hydrolysis was used as an easily modification method. The raw and modified biosorbents were characterized by elemental analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The sorption isotherms of PAHs to raw biosorbents were apparently linear, and were dominated by a partitioning process. In comparison, the isotherms of the hydrolyzed biosorbents displayed nonlinearity, which was controlled by partitioning and the specific interaction mechanism. The sorpfion kinetic curves of PAHs to the raw and modified plant residues fit well with the pseudo second-order kinetics model. The sorption rates were faster for the raw biosorbents than the corresponding hydrolyzed biosorbents, which was attributed to the latter having more condensed domains （i.e., exposed aromatic core）. By the consumption of the amorphous cellulose component under acid hydrolysis, the sorption capability of the hydrolyzed biosorbents was notably enhanced, i.e., 6-18 fold for phenanthrene, 6-8 fold for naphthalene and pyrene and 5-8 fold for acenaphthene. The sorpfion coefficients （Kd） were negatively correlated with the polarity index [（O＋N）/C], and positively correlated with the aromaticity of the biosorbents. For a given biosorbent, a positive linear correlation between logKoc and logKow for different PAHs was observed. Interestingly, the linear plots of logKoc-logKow were parallel for different biosorbents. These observations suggest that the raw and modified plant residues have great potential as biosorbents to remove PAHs from wastewater.     

Efectiveness of national air pollution control policies on the air quality in metropolitan areas of China

Understanding the efectiveness of national air pollution controls is important for control policy design to improve the future air quality in China. This study evaluated the efectiveness of major national control policies implemented recently in China through a modeling analysis. The sulfur dioxide(SO2) control policy during the 11th Five Year Plan period(2006–2010) had succeeded in reducing the national SO2emission in 2010 by 14% from its 2005 level, which correspondingly reduced ambient SO2and sulfate(SO4 2) concentrations by 13%–15% and 8%–10% respectively over east China. The nitrogen oxides(NOx) control policy during the 12th Five Year Plan period(2011–2015) targets the reduction of the national NOx emission in 2015 by 10% on the basis of 2010. The simulation results suggest that such a reduction in NOx emission will reduce the ambient nitrogen dioxide(NO2), nitrate(NO3), 1-hr maxima ozone(O3) concentrations and total nitrogen deposition by 8%, 3%–14%, 2% and 2%–4%, respectively over east China. The application of new emission standards for power plants will further reduce the NO2, NO3, 1-hr maxima O3concentrations and total nitrogen deposition by 2%–4%, 1%–6%, 0–2% and 1%–2%, respectively. Sensitivity analysis was conducted to evaluate the inter-provincial impacts of emission reduction in Beijing-Tianjin-Hebei and the Yangtze River Delta, which indicated the need to implement joint regional air pollution control.     

Nitrogen mass balance in a constructed wetland treating piggery wastewater effluent

The nitrogen changes and the nitrogen mass balance in a free water surface flow constructed wetland （CW） using the four-year monitoring data from 2008 to 2012 were estimated. The CW was composed of six cells in series that include the first settling basin （Cell 1）, aeration pond （Cell 2）, deep marsh （Cell 3）, shallow marsh （Cell 4）, deep marsh （Cell 5） and final settling basin （Cell 6）. Analysis revealed that the NH4＋-N concentration decreased because of ammonification which was then followed by nitrification. The NO4＋-N and NO4＋-N were also further reduced by means of microbial activities and plant uptake during photosynthesis. The average nitrogen concentration at the influent was 37,819 kg/year and approximately 45% of that amount exited the CW in the effluent. The denitrification amounted to 34% of the net nitrogen input, whereas the accretion of sediment was only 7%. The biomass uptake of plants was able to retain only 1% of total nitrogen load. In order to improve the nutrient removal by plant uptake, plant coverage in four cells （i.e., Cells 1, 3, 4 and 5） could be increased.     

江苏省300MW以上燃煤电厂汞排放现状分析

基于2012年江苏省10家典型燃煤电厂相关数据,分析了影响烟气中汞(Hg)排放浓度的因素。其中电厂负荷、烟气净化设施、燃烧炉类型等会直接影响烟气中Hg的排放浓度,而原煤中Hg的含量与烟气中Hg的浓度没有直接的关系。通过模型对江苏省现有300 MW以上燃煤电厂Hg排放量进行了估算,2012年Hg排放总量约为7.307 t。通过反距权重插值进行分析,发现在区域分布上江苏省整体呈现出南部高于北部的趋势。     

抽水蓄能电站工程建设中生态环境监理工作实践探讨

水利水电工程建设是促进国家经济发展的重要建设项目之一,抽水蓄能电站工程建设的重要性正在不断凸显。抽水蓄能电站工程的建设与生态环境有着密切的关系,由于抽水蓄能电站工程长期大规模的开发利用破坏了周边生态环境的稳定,加强工程建设中的环境监理工作是将生态破坏程度降到最低的必然要求。以抽水蓄能电站为实例,通过制定科学合理的环境监理方案,将生态环境监理要点落实到施工建设当中,以期最大限度地减少对生态环境的破坏。     

风力发电场施工期环境监理工作内容——以内蒙古阿拉善盟阿右旗风电场为例

本文以阿右旗风电场为例,综述了对风力发电场施工期的环境监理内容,旨在为以后的风力发电场施工期环境监理提供参考。     

城市污水处理厂控制系统现状及发展趋势

随着我国经济的发展和城市化进程的加快,城市规模不断扩大,城市的人口迅速增长,随之而来的是城市生活污水量不断增加。因此,未来我国应当加大对城市生活污水的处理力度,以改善不断恶化的水环境污染趋势。自动控制系统在城市污水处理系统中至关重要,目前已经逐步应用到污水处理工艺过程及出水水质监测过程当中,并且取得了很好的效果,这样不但节约了能源,而且有着广阔的发展前景。