CaCO3类吸收剂净化焚烧烟气中HCI气体的研究

通常烟气中的酸性气体采用Ca（OH）2净化，然而当烟气温度在300℃以上时，Ca（OH）2喷入到烟气中将快速生成CaCO3。研究了两种CaCO3的反应特性，比较了200-900℃内CaCO3类吸收剂和Ca（OH）2与烟气中HCl气体的反应率，发现在600℃左右和800℃及以上，CaCO3类吸收剂的反应率与Ca（OH）2相当或更高；CaCO3类吸收剂、特别是改性CaCO3可替代Ca（OH）2作为干式净化HCl气体的吸收剂，合适的反应温度在600℃左右。     

新常态下环境保护新形势研究

受工业化阶段转换、需求结构调整两个新常态本质因素的影响,我国经济增速、产业结构、重工业产能、能源需求及社会阶层正在发生结构性变化,经济增长新旧动力出现转换,由过去依靠劳动力成本、企业规模、资源环境低价的数量扩张型增长向依靠深化改革和创新驱动带来的效率质量提升型增长转变。经济发展阶段的新变化、新特点,使得环境压力有望高位舒缓,环境保护有望从临界点向转折点改变,生态文明建设和环境保护也呈现新问题、新要求和新特征。     

Biomineralization-based conversion of carbon dioxide to calcium carbonate using recombinant carbonic anhydrase

Recently, as a mimic of the natural biomineralization process, the use of carbonic anhydrase (CA), which is an enzyme catalyzing fast reversible hydration of carbon dioxide to bicarbonate, has been suggested for biological conversion of CO₂ to valuable chemicals. While purified bovine CA (BCA) has been used in previous studies, its practical utilization in CO₂ conversion has been limited due to the expense of BCA preparation. In the present work, we investigated conversion of CO₂ into calcium carbonate as a target carbonate mineral by using a more economical, recombinant CA. To our knowledge, this is the first report of the usage of recombinant CA for biological CO₂ conversion. Recombinant α-type CA originating in Neisseria gonorrhoeae (NCA) was highly expressed as a soluble form in Escherichia coli. We found that purified recombinant NCA which showed comparable CO₂ hydration activity to commercial BCA significantly promoted formation of solid CaCO₃ through the acceleration of CO₂ hydration rate, which is naturally slow. In addition, the rate of calcite crystal formation was also accelerated using recombinant NCA. Moreover, non-purified crude recombinant NCA also showed relatively significant ability. Therefore, recombinant CA could be an effective, economical biocatalyst in practical CO₂ conversion system.     

煤燃烧过程中影响NO_x转化的因素探讨

利用管式沉降炉对煤粉燃烧过程中的反应温度、初始氧浓度、反应时间、煤的挥发分及含氧量对燃料氮向NOx 转化的影响进行了试验研究 ,摸清了反应的规律 ,找出了影响转化的显著因素。     

攀西地区实施退耕和天保工程的问题及对策

攀西地处长江上游，在西南地区乃至全国的可持续发展战略中具有重要地位，目前生态退化严重。论述了攀植实施退耕还林还草和天然林保护工程的问题，如产业结构的单一性和脆弱性及地方财政的弱势地位造成对森林依赖性砍伐，法律法规等各项具体配套措施不到位，利益分享补偿机制等制度建设落后于实践，群众的落后思维方式和发展观念难以摒除等都使工程实施初期的经济效益不明显，当地群众脱贫又返贫，社会矛盾激化等。对此提出了相关对策，即区分当前和长远两个层次，在当前主要依靠国家加大财政转移支付和吸引民间投资，加强资金监督管理，强化普法执法，加强现有技术措施的推广应用等；远期内，完善基础设施，发展水电，旅游等资源商品型替代产品，重视农村科教文卫普及，摒除陈规陋习，控制人口增长，树立“环境容量／土承载力”的可持续发展意义.等     

Carbon dioxide adsorption and cycloaddition reaction of epoxides using chitosan–graphene oxide nanocomposite as a catalyst

One of today's major challenges is to provide green materials for a cleaner environment. We have conducted studies on carbon dioxide(CO2) adsorption and conversion to valuable products by an ecofriendly approach based in chitosan/graphene oxide(CSGO) nanocomposite film. Rheological behavior indicates that the CSGO has a better solvation property than the pure chitosan. An adsorption capacity of 1.0152 mmol CO_2/g of CSGO nanocomposite at4.6 bar was observed. The catalytic behavior of the CSGO nanocomposite in the presence of tetra-n-butylammonium iodide(n-Bu4 NI) as co-catalyst was evaluated for the cycloaddition of CO_2 to epoxides, to give cyclic carbonates, in the absence of any solvent. These results strongly suggest that the CSGO nanocomposite may open new vistas towards the development of ecofriendly material for catalytic conversion and adsorption of CO_2 on industrial scale.     

退耕还林工程费用有效性的影响因素分析

费用有效性评价是工程评价的重要方面。从政策制定和执行角度对退耕还林的费用有效性及其影响因素进行分析。具有重要的意义。利用实地调研数据和相关统计数据．从退耕地选择和造林入手对退耕还林工程实施的费用有效性殛其影响因素进行考察．并尝试对这些因素的作用机制进行了分析。研究指出由于缺乏长期的和有效的退耕还林规划以及相关政策措施的缺失．使得退耕还林费用有效性的损失在微观层面和宏观层面广泛存在。而各利益主体的利益不相害性是影响工程有效实施的基本矛盾。有必要在遇耕还林中确立明确的规划、清晰的退耕地选择标准。建立和完善管理信息系统和及时有效的反馈和控制机制。构建协调多方利益的长期稳定的生态补偿机制。从而改进退耕还林工程的费用有效性。     

影子价格─自然灾害经济评价中合理的价格

着重说明自然灾害经济评价中利用影子价格的原因，简要说明我国目前在投资项目评价中采用的影子价格及计算方法，以及在自然灾害经济评价中如何利用影子价格进行计算．     

Nonpoint Source Pollution Responses Simulation for Conversion Cropland to Forest in Mountains by SWAT in China

Several environmental protection policies have been implemented to prevent soil erosion and nonpoint source (NPS) pollutions in China. After severe Yangtze River floods, the “conversion cropland to forest policy” (CCFP) was carried out throughout China, especially in the middle and upper reaches of Yangtze River. The research area of the current study is located in Bazhong City, Sichuan Province in Yangtze River watershed, where soil erosion and NPS pollution are serious concerns. Major NPS pollutants include nitrogen (N) and phosphorus (P). The objective of this study is to evaluate the long-term impact of implementation of the CCFP on stream flow, sediment yields, and the main NPS pollutant loading at watershed level. The Soil and Water Assessment Tool (SWAT) is a watershed environmental model and is applied here to simulate and quantify the impacts. Four scenarios are constructed representing different patterns of conversion from cropland to forest under various conditions set by the CCFP. Scenario A represented the baseline, i.e., the cropland and forest area conditions before the implementation of CCFP. Scenario B represents the condition under which all hillside cropland with slope larger than 25° was converted into forest. In scenario C and D, hillside cropland with slope larger than 15° and 7.5° was substituted by forest, respectively. Under the various scenarios, the NPS pollution reduction due to CCFP implementation from 1996–2005 is estimated by SWAT. The results are presented as percentage change of water flow, sediment, organic N, and organic P at watershed level. Furthermore, a regression analysis is conducted between forest area ratio and ten years’ average NPS load estimations, which confirmed the benefits of implementing CCFP in reducing nonpoint source pollution by increasing forest area in mountainous areas. The reduction of organic N and organic P is significant (decrease 42.1% and 62.7%, respectively) at watershed level. In addition, this study also proves that SWAT modeling approach can be used to estimate NPS pollutants’ impacts of land use conversions in large watershed.