Community-Based Integrated Watershed Management

1 INTRODUCTIONIn the past, natural resources management initiatives havefocused on large but specific sector projects such as dams,reservoirs for water supply schemes, irrigation systems,crop production, at forestation, etc. Often these projectswere treated as technical and administrative issues ratherthan as a socio-economic and political one. However, thehigh social and environmental cost of such schemes haveled to a change of paradigm since the 1980s towards small-scale community projec…     

The Clean Development Mechanism and Sustainable Development in China''''s Electricity Sector

1 INTRODUCTIONEnergy and environmental issues in China have receivedsignificant attention in both the peer-reviewed literatureand in international energy and environmental policymaking in the last number of years. China's coal dominatedenergy consumption results in significant regional pollutionproblems, most notably acid rain that affects nearly 1/3rdof China's landmass and air pollution that plagues manyof its major cities. China now ranks as the top emitterof sulphur dioxide (SO2) pol…     

Evaluating the e ects of granular and membrane filtrations on chlorine demand in drinking water

In this study, chlorine decay experiments were conducted for the raw water from Nakdong River that is treated by Chilseo Water Treatment Plant (CWTP) situated in Haman, Korea as well as the e uents from sand and granular activated carbon (GAC) filters of CWTP and fitted using a chlorine decay model. The model estimated the fast and slow reacting nitrogenous as well as organic/inorganic compounds that were present in the water. It was found that the chlorine demand due to fast and slow reacting (FRA and SRA) organic/inorganic substances was not reduced significantly by sand as well as GAC filters. However, the treated e uents from those filters contained FRA and SRA that are less reactive and had small reaction rate constants. For the e uents from microfiltration, ultrafiltration, and nanofiltration the chlorine demand because FRA and SRA were further reduced but the reaction rate constants were larger compared to those of sand and GAC filter e uents. This has implications in the formation of disinfection by products (DBPs). If DBPs are assumed to form due to the interactions between chlorine and SRA, then it is possible that the DBP formation potential in the e uents from membrane filtrations could be higher than that in the e uents from granular media filters.     

Methane and nitrous oxide emissions from a subtropical coastal embayment (Moreton Bay, Australia)

Surface water methane (CH₄) and nitrous oxide (N₂O) concentrations and fluxes were investigated in two subtropical coastal embayments (Bramble Bay and Deception Bay, which are part of the greater Moreton Bay, Australia). Measurements were done at 23 stations in seven campaigns covering different seasons during 2010-2012. Water-air fluxes were estimated using the Thin Boundary Layer approach with a combination of wind and currents-based models for the estimation of the gas transfer velocities. The two bays were strong sources of both CH₄ and N₂O with no significant differences in the degree of saturation of both gases between them during all measurement campaigns. Both CH₄ and N₂O concentrations had strong temporal but minimal spatial variability in both bays. During the seven seasons, CH₄ varied between 500% and 4000% saturation while N₂O varied between 128 and 255% in the two bays. Average seasonal CH₄ fluxes for the two bays varied between 0.5 ± 0.2 and 6.0 ± 1.5 mg CH₄/(m²·day) while N₂O varied between 0.4 ± 0.1 and 1.6 ± 0.6 mg N₂O/(m²·day). Weighted emissions (t CO₂-e) were 63%-90% N₂O dominated implying that a reduction in N₂O inputs and/or nitrogen availability in the bays may significantly reduce the bays' greenhouse gas (GHG) budget. Emissions data for tropical and subtropical systems is still scarce. This work found subtropical bays to be significant aquatic sources of both CH₄ and N₂O and puts the estimated fluxes into the global context with measurements done from other climatic regions.     

模拟消落带水华暴发行为的数值沙堆模型

以长江最大支流汉江近年来水华污染的现场资料为例,通过氮磷浓度、水温、流速和光照等实测数据构建了消落带开放水域环境体系的数值沙堆模型,描述了藻类生长及水华暴发的动力学机制;利用数值沙堆系统崩塌行为反映出的频率-尺度幂律关系作为判断消落带水域是否暴发水华以及规模大小的依据,采用有限尺度标度分析从不同侧面验证了水华暴发系统的自组织临界性,并揭示出各种拟合参数与水华暴发规模之间的定量关系.研究表明,沙堆模型如果存在良好的幂律关系,相应的消落带水域将暴发水华,且幂律指数越大,水华污染程度越严重.     

固定化混合菌修复油污染地表水的研究

从辽河油田受石油污染的河床底泥中筛选出一株芽孢杆菌(Bacillus sp.)和一株黄杆菌(Flavobacterium sp.),采用二次交联化学方法对2株细菌单独及混合固定,分别进行了不同接种量的固定化细菌对油的降解,以及固定化混合菌对环境的耐受性和在自然地表水中对油的降解进行研究,结果表明,在相同时间内固定化混合菌对油的降解效果明显优于固定化单株菌,而且都优于游离菌。固定化混合菌pH在6～10、温度在20～40℃范围内能保持较好的活性。在120 h时,固定化混合菌对自然地表水中油的降解率达94.5%,对地表水中COD的去除率达89.6%。扫描电子显微镜分析显示,固定化载体的微观结构适合细菌的生长,固定化混合菌在载体内部形成高密度的菌群。以上的研究为固定化微生物应用于油污染地表水的生物修复提供了一定的理论基础。     

Factors affecting the direct mineralization of CO2 with olivine

Olivine, one of the most abundant minerals existing in nature, is explored as a CO2 carbonation agent for direct carbonation of CO2 in flue gas. Olivine based CO2 capture is thermodynamically favorable and can form a stable carbonate for long-term storage. Experimental results have shown that water vapor plays an important role in improving CO2 carbonation rate and capacities. Other operation conditions including reaction temperature, initial CO2 concentration, residence time corresponding to the flow rate of CO2 gas stream, and water vapor concentration also considerably affect the performance of the technology.     

Treatability studies of naphthalene in soil,water and air with persulfate activated by iron(Ⅱ)

Chemical oxidation was applied to an artificially contaminated soil with naphthalene (NAP). Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. The importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction period. Design of Experiments method was applied to the following variables: sodium persulfate concentration [SP], ferrous sulfate concentration [FeSO₄], and pH. The system operated with a prefixed solid to liquid ratio of 1:2. The following conditions resulted in optimum NAP removal [SP] = 18.37 g/L, [FeSO₄] = 4.25 g/L and pH = 3.00. At the end of the 4 hr reaction, 62% of NAP was degraded. In the soil phase, the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental legislations. Besides the NAP partitioning view, the monitoring of each phase allowed the variabilities assessment over the process, refining the knowledge of mass reduction. Based on NAP distribution in the system, this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation, so that there is greater control of the system as to the distribution and presence of the contaminant in the environment. The results highlight the importance of treating the contaminant in all its phases at the contaminated site.     

Kitchen waste valorization through a mild-temperature pretreatment to enhance biogas production and fermentability: Kinetics study in mesophilic and thermophilic regimen

Biowaste valorization through anaerobic digestion is an attractive option to achieve both climate protection goals and renewable energy production.In this paper,a complete set of batch trials was carried out on kitchen waste to investigate the effects of mild thermal pretreatment,temperature regimen and substrate/inoculum ratio.Thermal pretreatment was effective in the solubilisation of macromolecular fractions,particularly carbohydrates.The ability of the theoretical methodologies in estimating...     

Characterization of atmospheric aerosol (PM10 and PM2.5) from a medium sized city in São Paulo state, Brazil

Air pollution causes deleterious effects on human health with aerosols being among the most polluting agents.The objective of this work is the characterization of the PM_(2.5) and PM_(10) aerosol mass in the atmosphere.The methods of analysis include WD-XRF and EDS.Data were correlated with meteorological information and air mass trajectories(model HYSPLIT)by multivariate analysis.A morphological structural analysis was also carried out to identify the probable sources of atmospheric aerosols in the city of Sao Jose do Rio Preto,Brazil.The mean mass concentration values obtained were 24.54 μg/m~3 for PM_(10),above the WHO annual standard value of 20 μg/m~3 and 10.88 μg/m~3 for PM_(2.5) whose WHO recommended limit is10 μg/m~3.WD-XRF analysis of the samples revealed Si and Al as major components of the coarse fraction.In the fine fraction,the major elements were Al and S.The SEM-FEG characterization allowed identifying the morphology of the particles in agglomerates,ellipsoids and filaments in the PM_(10),besides spherical in the PM_(2.5).The analysis by EDS corroborated WD-XRF results,identifying the crustal elements,aluminosilicates and elements of anthropogenic origin in the coarse fraction.For the fine fraction crustal elements were also identified;aluminosilicates,black carbon and spherical particles(C and O) originating from combustion processes were predominant.The use of multivariate analysis to correlate air mass trajectories with the results of the morpho-structural characterization of the particulate matter allowed confirmation of the complex composition of the particles resulting from the combination of both local and long-distance sources.