Improved land cover and emission factors for modeling biogenic volatile organic compounds emissions from Hong Kong

This paper describes a study of local biogenic volatile organic compounds (BVOC) emissions from the Hong Kong Special Administrative Region (HKSAR). An improved land cover and emission factor database was developed to estimate Hong Kong emissions using MEGAN, a BVOC emission model developed by Guenther et al. (2006). Field surveys of plant species composition and laboratory measurements of emission factors were combined with other data to improve existing land cover and emission factor data. The BVOC emissions from Hong Kong were calculated for 12 consecutive years from 1995 to 2006. For the year 2006, the total annual BVOC emissions were determined to be 12,400 metric tons or 9.82 × 10⁹ g C (BVOC carbon). Isoprene emission accounts for 72%, monoterpene emissions account for 8%, and other VOCs emissions account for the remaining 20%. As expected, seasonal variation results in a higher emission in the summer and a lower emission in the winter, with emission predominantly in day time. A high emission of isoprene occurs for regions, such as Lowest Forest-NT North, dominated by broadleaf trees. The spatial variation of total BVOC is similar to the isoprene spatial variation due to its high contribution. The year to year variability in emissions due to weather was small over the twelve-year period (?1.4%, 2006 to 1995 trendline), but an increasing trend in the annual variation due to an increase in forest land cover can be observed (+7%, 2006 to 1995 trendline). The results of this study demonstrate the importance of accurate land cover inputs for biogenic emission models and indicate that land cover change should be considered for these models.     

Resident Motivations and Willingness-to-Pay for Urban Biodiversity Conservation in Guangzhou (China)

The monetary assessment of biodiversity measures the welfare damages brought by biodiversity losses and the cost-benefit analysis of conservation projects in a socio-economic context. The contingent valuation method could include motivational factors to strengthen economic analysis of nature conservation. This study analyzed Guangzhou residents’ motivations and willingness-to-pay (WTP) for an urban biodiversity conservation program in the National Baiyun Mountain Scenic Area (BMSA). The peri-urban natural site, offering refuge to some endemic species, is under increasing development pressures for recreational and residential use. A questionnaire survey was conducted in the Guangzhou metropolitan area during June to October 2007. We interviewed face-to-face 720 stratified sampled households to probe residents’ attitudes towards the city’s environmental issues, motivations for urban nature conservation, and WTP for biodiversity conservation. Principal component analysis identified five motivational factors, including environmental benefit, ecological diversity, nature-culture interaction, landscape-recreation function, and intergenerational sustainability, which illustrated the general economic values of urban nature. Logistic regression was applied to predict the probability of people being willing to pay for the urban biodiversity conservation in BMSA. The significant predictors of WTP included household income and the factor nature-culture interaction. The median WTP estimated RMB149/household (about US$19.5/household) per year and an aggregate of RMB291 million (approximately US$19.5/household) per year and an aggregate of RMB291 million (approximately US38.2 million) annually to support the urban conservation project. Including public motivations into contingent valuation presents a promising approach to conduct cost-benefit analysis of public projects in China.     

油田作业废水高效处理技术中试研究

文章根据新疆油田作业废水特征及油田地处干旱区的地理特点,结合国内外含聚合物污水处理的技术现状,以及油田连续生产稳定运行的要求,在含油污水处理技术的基础上,开展了作业废水处理关键技术研究和工艺优化,采用了"隔油—絮凝气浮—深层过滤"技术。中试试验结果表明:处理后废水COD_(Cr)、石油类、SS可分别由680 mg/L、98.6 mg/L、56.2 mg/L降至98.8 mg/L、5.4 mg/L、4.5 mg/L,去除率分别为85.5%、94.5%、92.0%。     

稠油火驱开采技术节能减排效果分析

火驱作为稠油热采的有效接替技术,与注蒸汽开采技术相比,具有采收率高,能耗低,CO_2排放少的优势。文章从火驱驱油机理特征阐述了火驱与注蒸汽技术的不同点,从燃料开采能耗、热效率、注入剂资源、数据对比四个方面分析火驱比注蒸汽热效率高,无燃料开采成本,能耗是注蒸汽的50%;从CO_2气体排放方式和排放量对比可知,火驱能够减少温室气体排放,为油田节能减排、环保生产起到积极作用。     

层燃螺旋炉排焚烧技术处理含油污泥研究

通过对几种含油污泥无害化处理技术的比选,分析不同处理技术物耗、能耗情况,优选出经济有效的含油污泥焚烧技术,结合新疆油田含油污泥的特点,采用层燃螺旋炉排焚烧技术,利用其燃烧热能生产蒸汽用于原油生产,采用余热吸收急冷与碱液半干法除酸技术,有效控制了二次污染;采用布袋除尘与烟尘固化技术确保了烟气达标排放。年节省成本支出3095.88万元。     

石油污染土壤原位生物修复的强化实验研究

为研究添加营养物质和高效降解石油微生物对油污土壤生物修复的作用,通过分层土柱的方法,连续监测了不同条件下不同土层的含水率、石油烃含量、细菌数量及脱氢酶活性。结果表明:添加营养物质同时接种高效微生物可使降解效果明显改善,降解率比在自然条件下提高近50%,而单纯添加营养物质不接种高效微生物可使降解率比在自然条件下提高约25%。降解初期,上层土壤降解效果较好,而到中后期,中下层降解效果好于上层。微生物数量和脱氢酶活性与石油降解率之间存在良好的相关性,脱氢酶活性比微生物数量更能反映修复过程中微生物的存活状态。添加营养物质和高效降解石油微生物对油污土壤原位生物修复具有强化作用。     

能源利用中烃类气体检测技术研究进展

烃类气体作为地表油气地球化学勘查地下油气藏的直接指标,以及钻井液检测中指导钻井作业的重要因素,在挥发性烃类污染控制中也发挥着重要作用。通过对各类烃类气体检测技术现状和应用情况进行分析与整理,为该类技术针对不同目标的选择与组合提供了依据。     

Immobilization of non-point phosphorus using stabilized magnetite nanoparticles with enhanced transportability and reactivity in soils

Laboratory batch and column experiments were conducted to investigate the immobilization of phosphorus (P) in soils using synthetic magnetite nanoparticles stabilized with sodium carboxymethyl cellulose (CMC-NP). Although CMC-stabilized magnetite particles were at the nanoscale, phosphorus removal by the nanoparticles was less than that of microparticles (MP) without the stabilizer due to the reduced P reactivity caused by the coating. The P reactivity of CMC-NP was effectively recovered when cellulase was added to degrade the coating. For subsurface non-point P pollution control for a water pond, it is possible to inject CMC-NP to form an enclosed protection wall in the surrounding soils. Non-stabilized “nanomagnetite” could not pass through the soil column under gravity because it quickly agglomerated into microparticles. The immobilized P was 30% in the control soil column, 33% when treated by non-stabilized MP, 45% when treated by CMC-NP, and 73% when treated by both CMC-NP and cellulase.     

Bioaccumulation and tissue distribution of organochlorine pesticides (OCPs) in freshwater fishes: a case study performed in Poyang Lake,China’s largest lake

Concentrations and tissue distribution of organochlorine pesticides (OCPs) in different tissues of freshwater fish, silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis), collected from Poyang Lake, China’s largest shallow lake, and were studied. OCPs were detected with the observed concentrations ranging from 280.67 to 1,006.58 ng/g wet weight (ww) for bighead carp and from 67.28 to 930.06 ng/g ww for silver carp. Composition analysis demonstrated OCPs in both fish were from the same polluted environment, and then, the species-specific bioaccumulation might be mainly due to the different fish age as well as the different feeding habits elucidating from the stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope analysis. Tissue distribution indicated that dietary intake was the major exposure route of OCPs for both fish and higher accumulation potency of OCPs by the hepatobiliary-related tissues (such as liver, kidney, bile, and heart). The higher metabolic activities of these tissues elucidating from the higher values of δ¹⁵N might be the potential-determined factor responsible for the tissue-specific accumulation.