Municipal solid waste management in Pudong New Area, China

The increase in population, the rapid economic growth and the rise in community living standards accelerate municipal solid waste (MSW) generation in developing cities. This problem is especially serious in Pudong New Area, Shanghai, China. The daily amount of MSW generated in Pudong was about 1.11 kg per person in 2006. According to the current population growth trend, the solid waste quantity generated will continue to increase with the city's development. In this paper, we describe a waste generation and composition analysis and provide a comprehensive review of municipal solid waste management (MSWM) in Pudong. Some of the important aspects of waste management, such as the current status of waste collection, transport and disposal in Pudong, will be illustrated. Also, the current situation will be evaluated, and its problems will be identified.     

混凝沉淀法处理磷矿浮选废水试验研究

对于质量浓度高达268.5mg/L的磷矿浮选废水,在实验确定的最佳工艺条件下,出水磷酸盐质量浓度小于0.5mg/L,达到国家综合污水排放一级标准,磷的去除率高达99.85%;同时,磷矿浮选废水中CODcr和SS的去除率也达到了75.3%和81.2%.处理成本低,具有明显的经济效益和环境效益.     

超声波处理剩余污泥有机物、氮和磷的释放特性研究

以生活污水处理厂污泥为研究对象.采用超声波技术研究了污泥破解过程中有机物、氮和磷的释放规律.结果表明,在声能密度为0.167、0.330、0.500 W/mL的条件下,污泥中的有机物、氮和磷的释放均随超声时间而增加;破解后污泥释放出的有机物以分子量(MW)≤2 000的物质为主,且上清液BOD5/COD>0.33;所释放的氮以有机氮为主,其次是氨氮,污泥破解液COD/凯氏氮平均值为11,适合于生物法脱氮;污泥破解所释放的正磷酸盐约占污泥总磷质量的6.0%～18.2%.利用沉淀结晶法将其回收,可减轻原污水处理工艺的磷负荷.     

基于实测光谱的叶绿素a估测模型

为了有效地监测太湖湖区的富营养化程度,建立一种最佳的估测模型。对太湖水体进行了连续监测,获得了从2004年10月20～29日的实测光谱数据和水质数据。通过实测光谱反射率和叶绿素a浓度的相关分析,得到了叶绿素a反演的最佳波段,并通过比值法、反射峰位置法、峰谷距离法、峰高法和一阶微分法建立了基于实测光谱的叶绿素a浓度的估测模型。通过14个检验点,分别对5种模型进行了对比分析,结果发现,通过比值法建立的估测模型总体误差最小,估测精度最高,其695 nm附近反射峰与677 nm反射谷的比值与叶绿素a浓度之间具有良好的相关性,可决系数R²可达0.7433,可以作为整个湖区叶绿素a浓度的最佳估测模型。最后,应用该模型对该季节湖区的营养化程度做出了总体评价。     

Aerosol chemistry and the effect of aerosol water content on visibility impairment and radiative forcing in Guangzhou during the 2006 Pearl River Delta campaign

Optical and chemical aerosol measurements were obtained from 2 to 31 July 2006 at an urban site in the metropolitan area of Guangzhou (China) as part of the Program of Regional Integrated Experiment of Air Quality over Pearl River Delta (PRIDE-PRD2006) to investigate aerosol chemistry and the effect of aerosol water content on visibility impairment and radiative forcing. During the PRIDE-PRD2006 campaign, the average contributions of ammonium sulfate, organic mass by carbon (OMC), elemental carbon (EC), and sea salt (SS) to total PM_2.5 mass were measured to be 36.5%, 5.7%, 27.1%, 7.8%, and 3.7%, respectively. Compared with the clean marine period, (NH₄)₂SO₄, NH₄NO₃, and OMC were all greatly enhanced (by up to 430%) during local haze periods via the accumulation of a secondary aerosol component. The OMC dominance increased when high levels of biomass burning influenced the measurement site while (NH₄)₂SO₄ and OMC did when both biomass burning and industrial emissions influenced it. The effect of aerosol water content on the total light-extinction coefficient was estimated to be 34.2%, of which 25.8% was due to aerosol water in (NH₄)₂SO₄, 5.1% that in NH₄NO₃, and 3.3% that in SS. The average mass-scattering efficiency (MSE) of PM₁₀ particles was determined to be 2.2 ± 0.6 and 4.6 ± 1.7 m² g⁻¹ under dry (RH < 40%) and ambient conditions, respectively. The average single-scattering albedo (SSA) was 0.80 ± 0.08 and 0.90 ± 0.04 under dry and ambient conditions, respectively. Not only are the extinction and scattering coefficients greatly enhanced by aerosol water content, but MSE and SSA are also highly sensitive. It can be concluded that sulfate and carbonaceous aerosol, as well as aerosol water content, play important roles in the processes that determine visibility impairment and radiative forcing in the ambient atmosphere of the Guangzhou urban area.     

Modeling the atmospheric transport and deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans in North America

The atmospheric fate of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) was simulated for the year 2000 in North America using a SMOKE/CMAQ-based chemical transport model that was modified for this purpose. The 1999 USEPA emission inventories of PCDD/Fs and criteria pollutants were used. The 1995 Canadian emission inventory of criteria pollutants and the 1995 Canadian area source emissions for PCDD/Fs were used with the 2000 Canadian point source emissions. Modifications to CMAQ involved coupling it with dual organic matter (OM) absorption and black carbon (BC) adsorption models to calculate PCDD/F gas–particle partitioning. The model satisfactorily reproduced the particle bound fractions at all rural sites for which there were measured data and across the whole domain, the modeled vs. measured differences in particle bound fractions were less than 20% for nearly all congeners. The model predicted ambient air PCDD/F concentrations were also consistent with measurements. Simulated deposition fluxes were within 58% of direct measurements. PCDD/F atmospheric depositions to each of the Great Lakes were estimated for the year 2000. The results indicate that approximately 76% of the total deposition of PCDD/Fs to the Great Lakes (in W-TEQ, or toxic equivalent units as defined by the World Health Organization) is attributed to PCDD/Fs absorbed into OM in aerosol. For all of the lakes, more than 92% of all deposition is particle phase wet deposition and only 5–8% is particle phase dry deposition. Wet deposition from the gas phase is negligible. Of the 17 toxic PCDD/F congeners, the Cl_4–5DD/F compounds contribute approximately 70% to the total atmospheric deposition to the Great Lakes. The seasonal changes in the PCDD/F deposition flux track variations in ambient temperature.     

Spatial distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in soils from typical oil-sewage irrigation area, Northeast China

Air pollution is one of the major environmental problems in India, affecting health of thousands of 'urban' residents residing in mega cities. The need of the day is to evolve an 'effective' and 'efficient' air quality management plan (AQMP) encompassing the essential 'key players' and 'stakeholders.' This paper describes the formulation of an AQMP for mega cities like Delhi in India taking into account the aforementioned key 'inputs.' The AQMP formulation methodology is based on past studies of Longhurst et al., (Atmospheric Environment, 30, 3975-3985, 1996); Longhurst & Elsom, ((1997). Air Pollution-II, Vol. 2 (pp. 525-532)) and Beatti et al., (Atmospheric Environment, 35, 1479-1490, 2001). Further, the vulnerability analysis (VA) has been carried out to evaluate the stresses due to air pollution in the study area. The VA has given the vulnerability index (VI) of 'medium to high' and 'low' at urban roadways/intersections and residential areas, respectively.     

潮汐循环影响下上覆水环境因子和氮营养盐的变化及其相关关系

潮汐循环对水体理化特征的短期影响是潮汐河口各种理化参数变化的一个重要原因。通过崇明东旺沙堤外低潮滩和东海农场低潮滩采样及环境因子分析，发现崇明东滩各环境因子之间（除浊度外）相关性较好，均呈宽 “U”型变化；东海农场各环境因子之间相关性较差，变化不一致，且盐度、电导率变化与崇明东滩变化相反；受潮汐循环影响，崇明东滩涨潮初期各形态氮有明显释放过程，而东海农场的近底层水体在涨潮初期NH4+ N急剧下降，NOX- N缓慢下降；无论是在崇明东滩还是在东海农场，营养盐浓度受环境因子的共同影响，整个潮汐循环过程中总无机氮（TIN）与盐度呈显著线性负相关，这与整个长江口近岸水体的营养盐负荷相一致，长江上游淡水带来的高负荷营养盐流经河口进入海洋。     

固定化海带生物吸附剂的制备及其吸附Ni~(2+)的动力学特性

以海藻酸钠、明胶和海带粉为原料制备了固定化海带生物吸附剂。固定化海带生物吸附剂对Ni2+的吸附过程可分为3个阶段:快速吸附阶段、缓慢吸附阶段和吸附平衡阶段。动力学过程可用Lagergren准二级反应动力学方程描述,限速步骤为化学吸附。随Ni2+初始质量浓度的增加,固定化海带生物吸附剂的Ni2+吸附量逐渐增大,Ni2+去除率逐渐降低。吸附过程符合Langmuir和Freundlich吸附等温方程,说明该吸附体系既有物理吸附又有化学吸附,从吸附状态看属于多层吸附,由Langmuir吸附等温方程得出固定化海带生物吸附剂对Ni2+的最大吸附量为39.43mg/g,说明固定化海带生物吸附剂对Ni2+有较好的吸附性能。