The Trifinio Region: a case study of transboundary forest change in Central America

Strategic planning to increase forest cover in Central American transboundary areas of the Mesoamerican Biological Corridor requires understanding land-cover and land-use change trends and drivers. We estimated forest cover change from remotely sensed land-cover and land-use classifications from 1986, 2001, and 2010, in the tri-national Trifinio Region, bordering El Salvador, Guatemala, and Honduras. Our analysis spanned subnational, national, regional, and protected border areas. We determined correlations with direct drivers of deforestation, developing a multilevel linear regression model. Higher population density significantly correlated with deforestation; coffee, agroforestry, and pasture replaced forests. The tri-national park retained forests compared to neighboring areas, but additionality requires more research. The literature on drivers suggests similar processes and factors in other tropical regions. Forest cover governance efficacy is highly variable. Results indicate relationship between governance and forest cover though more comprehensive understanding of this complex region is needed to determine their causality.     

Kinetic, equilibrium isotherm and thermodynamic studies of Cr(VI) adsorption onto low-cost adsorbent developed from peanut shell activated with phosphoric acid

A particular agricultural waste, peanut shell, has been used as precursor for activated carbon production by chemical activation with H₃PO₄. Unoxidized activated carbon was prepared in nitrogen atmosphere which was then heated in air at a desired temperature to get oxidized activated carbon. The prepared carbons were characterized for surface area, surface morphology, and pore volume and utilized for the removal of Cr(VI) from aqueous solution. Batch mode experiments were conducted to study the effects of pH, contact time, particle size, adsorbent dose, initial concentration of adsorbate, and temperature on the adsorption of Cr(VI). Cr(VI) adsorption was significantly dependent on solution pH, and the optimum adsorption was observed at pH 2. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to analyze the kinetic data obtained at different initial Cr(VI) concentrations. The adsorption kinetic data were described very well by the pseudo-second-order model. Equilibrium isotherm data were analyzed by the Langmuir, Freundlich, and Temkin models. The results showed that the Langmuir adsorption isotherm model fitted the data better in the temperature range studied. The adsorption capacity which was found to increase with temperature showed the endothermic nature of Cr(VI) adsorption. The thermodynamic parameters, such as Gibb’s Free energy change (ΔG°), standard enthalpy change (ΔH°), and standard entropy change (ΔS°) were evaluated.     

A2/O+硫磺填料柱组合工艺脱氮除磷的效果

以某城市污水厂进水为研究对象,采用A2/O+硫磺填料反应柱组合工艺,考察其对COD、总氮、总磷以及溶解性磷处理效果的改善。组合工艺出水水质稳定后,连续运行55 d,并对工艺的出水进行常规指标分析。结果表明:组合工艺的脱氮除磷效果较单个A2/O工艺都得到了较大的改善,而COD去除效果变化不大。A2/O系统对COD有良好的去除效果,出水的COD平均去除率能达到94%;TN和TP去除效果相对较差,出水平均去除率分别为60%和57.4%。经硫磺填料反应柱的脱氮除磷作用,系统出水TN去除率提高到84%,TP去除率提高到69.8%,COD去除率变化不大,升高到95.3%。     

Ni／Fe／Al2O3·PVDF催化还原剂的表征及制备过程优化

在PVDF基体改性的基础上,采用浸渍法制备出Ni／Fe／Al2O3PVDF催化还原剂。通过对一氯乙酸的脱氯效果研究,对交联液配比及交联时间、不同浓度硫酸镍浸渍时间、镍铁比等因素进行优化,实验优化结果表明,Ni／Fe／Al2O3PVDF催化还原剂对一氯乙酸脱氯60min脱氯率达到64％。经SEM表征,制备出的双金属在膜载体表面及断面分布均匀,呈球状和片状结构且双金属未发生团聚。     

日本废弃小型电子产品循环要利用状况

日本政府自2013年4月1日开始实施《废弃小型电子产品循环再利用促进法》.基于此法的第三条第一款,日本环境省和经济产业省于2013年3月6日正式出台了基本方针,制定了再资源化目标,即至2015年止,每年回收14万t(相当于每人1 kg)废旧手机等小型电子产品,回收率达到20％左右,并介绍了其主要内容及目前的实施状况.     

Dechlorane plus and possible degradation products in white stork eggs from Spain

The occurrence of the emerging chlorinated flame retardant Dechlorane Plus (DP) and three of its possible degradation products was investigated in white stork eggs from two colonies in Spain. The average DP concentrations were 401 pg/g wet weight (w.w.) for the urban/industrial colony and 105 pg/g w.w. for the rural colony. One possible degradation product, anti-[DP-1Cl], was found in approximately 10% of the samples. No significant stereoisomer enrichments were detected in any colony based on the average anti-DP fractional abundances found which agrees with previous studies in herring gulls. The relationship between DP and PBDE contents in both colonies was explored leading to different scenarios, i.e. no correlation was found in the urban colony but they were statistically correlated in the rural colony. To the best of our knowledge, this is the first study to report DP in a species from a terrestrial food web, and also to report a DP degradation product in biota.     

Predominance of BDE-209 and other higher brominated diphenyl ethers in eggs of white stork (Ciconia ciconia) colonies from Spain

Polybrominated diphenyl ethers (PBDEs) are ubiquitous pollutants for which there is still a lack of knowledge about the environmental behavior and fate of the higher brominated congeners (octa- to deca-BDEs). In this study, the PBDE content and congener profiles in failed eggs from two colonies of white stork (Ciconia ciconia) in Spain were studied. The average total PBDE concentration was 1.64ng/g (wet weight, w.w.) for the rural colony and 9.08ng/g (w.w.) for the urban colony. Higher brominated BDEs dominated the congener profiles of both colonies. Of particular interest was the determination of BDE-209 as the dominant congener accounting for 44.1% and 38.6% of the total PBDE content in the rural and urban colonies, respectively. BDE-202, considered an indicator of BDE 209 debromination, was detected in 83% and all of the samples from rural and urban colonies, respectively. The observed congener profile in which BDE-207>BDE-208>BDE-206 does not correspond to any known technical PBDE mixture and is evidence for possible BDE-209 degradation.     

A Proposed Methodology to Assess the Quality of Public Use Management in Protected Areas

In recent years, the goal of nature preservation has faced, almost worldwide, an increase in the number of visitors who are interested in experiencing protected areas resources, landscapes and stories. Spain is a good example of this process. The rapidly increasing numbers of visitors have prompted administrations and managers to offer and develop a broad network of facilities and programs in order to provide these visitors with information, knowledge and recreation. But, are we doing it the best way? This research focuses on developing and applying a new instrument for evaluating the quality of visitor management in parks. Different areas are analyzed with this instrument (78 semi-quantitative indicators): planning and management capacity (planning, funding, human resources), monitoring, reception, information, interpretation, environmental education, training, participation and volunteer's programs. Thus, we attempt to gain a general impression of the development of the existing management model, detecting strengths and weaknesses. Although Spain's National Parks constituted the specific context within which to develop the evaluation instrument, the design thereof is intended to provide a valid, robust and flexible method for application to any system, network or set of protected areas in other countries. This paper presents the instrument developed, some results obtained following its application to Spanish National parks, along with a discussion on the limits and validity thereof.     

Comparative Life Cycle Assessment of Lignocellulosic Ethanol Production: Biochemical Versus Thermochemical Conversion

Lignocellulosic biomass can be converted into ethanol through either biochemical or thermochemical conversion processes. Biochemical conversion involves hydrolysis and fermentation while thermochemical conversion involves gasification and catalytic synthesis. Even though these routes produce comparable amounts of ethanol and have similar energy efficiency at the plant level, little is known about their relative environmental performance from a life cycle perspective. Especially, the indirect impacts, i.e. emissions and resource consumption associated with the production of various process inputs, are largely neglected in previous studies. This article compiles material and energy flow data from process simulation models to develop life cycle inventory and compares the fossil fuel consumption, greenhouse gas emissions, and water consumption of both biomass-to-ethanol production processes. The results are presented in terms of contributions from feedstock, direct, indirect, and co-product credits for four representative biomass feedstocks i.e., wood chips, corn stover, waste paper, and wheat straw. To explore the potentials of the two conversion pathways, different technological scenarios are modeled, including current, 2012 and 2020 technology targets, as well as different production/co-production configurations. The modeling results suggest that biochemical conversion has slightly better performance on greenhouse gas emission and fossil fuel consumption, but that thermochemical conversion has significantly less direct, indirect, and life cycle water consumption. Also, if the thermochemical plant operates as a biorefinery with mixed alcohol co-products separated for chemicals, it has the potential to achieve better performance than biochemical pathway across all environmental impact categories considered due to higher co-product credits associated with chemicals being displaced. The results from this work serve as a starting point for developing full life cycle assessment model that facilitates effective decision-making regarding lignocellulosic ethanol production.     

Gas phase reactions of unsaturated esters with Cl atoms

Background, aim, and scope  

Acrylate and methacrylate esters are α,β-unsaturated esters that contain vinyl groups directly attached to the carbonyl carbon (CH₂=CHCOO– and CH₂=CCH₃COO–, respectively) and are widely used in the polymer plastic and resin production. Rate coefficients for Cl reactions for most of the unsaturated esters have not been previously determined, and a good understanding is needed of all the atmospheric oxidation processes of these compounds in order to determine lifetimes in the atmosphere and to evaluate the impact of these reactions on the formation of photo-oxidants and therefore on health and environment.