苯并[a]芘降解菌SL-1的筛选、鉴定及其降解特性

从土壤中筛选出一株以苯并[a]芘为唯一碳源的高效降解菌SL-1,经形态观察、生理生化分析以及16SrDNA基因序列分析,该菌株鉴定为假单胞菌（Pseudomonassp．）。28℃震荡培养10d后,菌株SL-1对5mg·L^-1苯并[a]芘的降解率为35．7％;同时测定该降解菌的生长曲线、降解率变化曲线、最佳培养条件;土壤修复试验表明,42d时,降解菌SL-1对苯并芘的降解率达到76．3％。     

Rapid removal of bisphenol A on highly ordered mesoporous carbon

Bisphenol A (BPA) is of global concern due to its disruption of endocrine systems and ubiquity in the aquatic environment. It is important, therefore, that e orts are made to remove it from the aqueous phase. A novel adsorbent, mesoporous carbon CMK-3, prepared from hexagonal SBA-15 mesoporous silica was studied for BPA removal from aqueous phase, and compared with conventional powdered activated carbon (PAC). Characterization of CMK-3 by transmission electron microscopy (TEM), X-ray di raction, and nitrogen adsorption indicated that prepared CMK-3 had an ordered mesoporous structure with a high specific surface area of 920 m2/g and a pore-size of about 4.9 nm. The adsorption of BPA on CMK-3 followed a pseudo second-order kinetic model. The kinetic constant was 0.00049 g/(mg min), much higher than the adsorption of BPA on PAC. The adsorption isotherm fitted slightly better with the Freundlich model than the Langmuir model, and adsorption capacity decreased as temperature increased from 10 to 40°C. No significant influence of pH on adsorption was observed at pH 3 to 9; however, adsorption capacity decreased dramatically from pH 9 to 13.     

A review on completing arsenic biogeochemical cycle：Microbial volatilization of arsines in environment

Arsenic （As） is ubiquitous in the environment in the carcinogenic inorganic forms, posing risks to human health in many parts of the world. Many microorganisms have evolved a series of mechanisms to cope with inorganic arsenic in their growth media such as transforming As compounds into volatile derivatives. Bio-volatilization of As has been suggested to play an important role in global As biogeochemical cycling, and can also be explored as a potential method for arsenic bioremediation. This review aims to provide an overview of the quality and quantity of As volatilization by fungi, bacteria, microalga and protozoans. Arsenic bio-volatilization is influenced by both biotic and abiotic factors that can be manipulated/elucidated for the purpose of As bioremediation. Since As bio- volatilization is a resurgent topic for both biogeochemistry and environmental health, our review serves as a concept paper for future research directions.     

美洲商陆（Phytolacca Americana L.）对铀的富集特征及根际微生物群落功能多样性的响应

在模拟低(25 mg·kg-1)、中(50 mg·kg-1)、高(100 mg·kg-1)剂量铀污染的条件下,采用盆栽试验,研究了美洲商陆富集铀的特点及铀污染对根际微生物群落的影响.结果表明,铀污染对美洲商陆生长的影响可能存在一个阈值,该阈值介于25~50 mg·kg-1之间,低于该阈值时,铀污染能够促进美洲商陆的生长,反之,则会抑制美洲商陆的生长.美洲商陆成熟时,根、茎和叶的最大铀富集量分别为131.69、9.87和45.33μg,是一种较为理想的修复铀尾矿的植物.Biolog-Eco测试结果表明,土壤中铀会对美洲商陆根际微生物群落产生负效应,铀胁迫可使根际微生物代谢迟缓,对碳源的选择发生转移,对糖类、羧酸类和胺类碳源的利用显著减少,对酚酸类碳源的利用显著增加;同时,铀胁迫可导致根际微生物群落功能多样性指数、均匀度指数及优势微生物种类降低.最后,利用培养96 h的平均吸光值进行聚类和主成分分析.结果表明,铀胁迫下美洲商陆根际微生物群落异于对照,美洲商陆根际微生物对铀胁迫的适应是以降低对糖类、羧酸类和胺类等碳源的利用为代价的.     

郑州市碳素行业无组织VOCs排放特征分析及健康风险评价

选择郑州市3家典型碳素企业,研究了不同功能区的挥发性有机污染物(volatile organic compounds,VOCs)的排放特征及其臭氧生成潜势(ozone formation potential,OFP),并利用美国环保署(EPA)的健康风险评价模型对碳素行业排放的VOCs的健康风险进行了初步评价.结果表明,3家企业生产区VOCs质量浓度在89. 77～964. 60μg·m~(-3)之间,管理区在51. 46～121. 59μg·m~(-3)之间,萘和二硫化碳是碳素企业厂区内浓度最高的污染物;生产区VOCs的臭氧生成潜势在75. 42～1 416. 73μg·m~(-3)之间,管理区在65. 32～202. 42μg·m~(-3)之间,主要来自于芳香烃和烯烃的贡献.生产区VOCs致癌健康风险(Risk)为3. 5×10~(-5)～2. 8×10~(-3),管理区为2. 0×10~(-5)～9. 4×10~(-5),高于EPA推荐的最大可接受水平(10~(-6));生产区VOCs非致癌健康风险危害指数(hazard index,HI)为3. 2～1. 4×10~2,管理区为4. 3×10~(-1)～3. 8,除企业甲的管理区外均大于1,可能会对暴露人群的健康造成致癌和非致癌危害.     

闽江河口潮汐沼泽湿地天然低盐度梯度土壤胞外酶活性特征

为了揭示河口潮汐沼泽湿地天然低盐度梯度下土壤胞外酶活性的时空变化差异,对闽江河口淡水潮汐沼泽湿地和半咸水潮汐沼泽湿地短叶茳芏(Cyperus malaccensis)植被下不同季节的土壤胞外酶活性、土壤容重和含水率、植物生物量、以及有机碳特征值(SOC、POXC、DOC和C∶N比)进行测定与分析.研究结果表明在闽江河口天然盐度梯度上,当土壤盐度从0‰增加至4.2‰,土壤β-葡萄糖苷酶(BG)、纤维素水解酶(CBH)、酚氧化酶(PHO)和过氧化物酶(PEO)活性均显著增加,增幅分别为201%、305%、493%和252%.沿着闽江河口天然盐度梯度,土壤容重和含水率以及孔隙水DOC浓度没有显著变化,但土壤易氧化有机碳(POXC)含量、有机碳(SOC)含量和土壤C∶N比逐渐减少.半咸水潮汐沼泽湿地站点短叶茳芏的地上生物量低于淡水潮汐沼泽湿地站点,但地下生物量则显著高于淡水潮汐沼泽湿地站点.4种土壤胞外酶活性均与土壤C∶N比呈现显著的负相关,酚氧化酶(PHO)和过氧化物酶(PEO)与土壤SOC含量呈负相关.土壤β-葡萄糖苷酶(BG)活性最高值出现在春季,而纤维素水解酶(CBH)活性最高值出现在夏季.以上研究结果表明,土壤盐度是影响闽江河口潮汐沼泽湿地生态系统土壤胞外酶活性和碳库演变的重要环境因子.从河口淡水潮汐沼泽湿地至低盐的半咸水潮汐沼泽湿地,沼泽植物地下生物量增加,与碳分解相关的土壤胞外酶活性增加,并抑制土壤的有机碳积累.     

Effect of wet flue gas desulfurization (WFGD) on fine particle (PM2.5) emission from coal-fired boilers

In this study, the characteristics of fine particles before and after wet flue gas desulfurization(WFGD) in three coal-fired heating boilers in northern China were investigated by using a dilution-based emission sampling experimental system. The influences of the WFGD process on the mass and number concentrations as well as the chemical composition of fine particles were analyzed. The removal efficiency of desulfurization processes on particulate matter mass was 30.06%–56.25% for the three study units. The WFGD had a great influence on the size distributions of particle mass concentration and number concentration. A significant increase in the number and mass concentration of particles in the size range of 0.094–0.946 μm was observed. The watersoluble ion content accounted for a very large proportion of PM_(2.5) mass, and its proportion in PM_(2.5) increased from 28.39%–41.08% to 48.96%–61.21% after the WFGD process for the three units. The desulfurizing process also drastically increased the proportion of cation component(Ca~(2+) for unit A, Mg~(2+) for unit B, and Na+for unit C) and the proportion of SO_4~(2-) in PM_(2.5), and it increased the CE/AE values of PM_(2.5) from 0.82–0.98 to 0.93–1.27 for the three study units.     

通辽市森林、草原、沙地、湿地碳汇产业规划研究

全球和区域碳汇是全球变化研究和生态学研究的核心内容之一。为应对气候变化,世界各国各组织都在积极行动。本研究深入剖析了通辽市的植物资源、宜林区域及发展碳汇工程的基础条件,提出碳汇产业的发展思路及原则,确定碳汇产业的建设目标、碳汇工程的技术路线及技术指标,最后对发展的综合效益进行评价,制定产业发展的保障措施,进而形成完整的碳汇产业发展规划思路,为生态脆弱的欠发达民族地区的碳汇产业发展提供借鉴。     

微藻生物柴油研究现状

本文介绍了微藻生物柴油的优势及技术进展,以及国内外培养微藻制备生物柴油的研究现状,探讨了微藻生物柴油生产关键技术环节及存在的主要问题,展望了微藻生物柴油的未来发展趋势和潜在的应用前景。     

Immobilization of self-assembled pre-dispersed nano-TiO2 onto montmorillonite and its photocatalytic activity

The immobilization of pre-dispersed Ti O_2 colloids onto the external surface of the clay mineral montmorillonite(Mt) was accomplished and regulated via a self-assembly method employing the cationic surfactant cetyltrimethylammonium bromide(CTAB). The role of CTAB in the synthesis process was investigated by preparing a series of Ti O_2-CTAB-Mt composites(TCM) with various CTAB doses. The results indicated that a uniform and continuous Ti O_2 film was deposited on the external surface of montmorillonite in the composite synthesized with 0.1 wt.% of CTAB, and the TCM nano-composites showed much higher values for specific surface area, average pore size and pore volume than the raw montmorillonite clay. Then, the formed TCM materials were applied in photocatalytic degradation of 2,4-dichlorophenol(2,4-DCP) in aqueous solution. The degradation efficiency reached as high as 94.7%. Based on the degradation intermediates benezoquinone, fumaric acid and oxalic acid identified by LC–MS analysis, a mechanism for the photocatalytic oxidation of 2,4-DCP on Ti O_2/Mt nano-composites is proposed.