UV-Fenton氧化法降解有机氟废水

针对有机氟废水中有机氟化合物C-F键稳定性强、难于降解的特点,采用UV-Fenton氧化法对五氟丙烷(F245)产品样品废水进行氧化降解处理,目的在于建立一种有机氟废水降解的有效方法。通过在波长185 nm紫外灯照射下,对温度、pH、催化剂以及催化剂与H2O2的比例4个因素进行正交实验设计,确定了反应的最佳条件:温度49℃、pH为4、催化剂Fe2+浓度1 mmol/L、Fe2+/H2O2比例1:50、反应时间24 h。实验结果表明,五氟丙烷(F245)产品样品废水经UV-Fenton氧化法降解处理后,有机氟被完全降解。     

活性染料K-2BP、KN-B和KN-R在椰壳活性炭上的脱色性能

开展椰壳活性炭对活性染料K-2BP、KN-B和KN-R的吸附脱色研究。发现K-2BP、KN-B和KN-R在该型活性炭上的吸附脱色率均随初始pH值的降低、温度的升高、染料初始浓度的降低、活性炭用量的增加以及NaCl盐度的增加而增加。在pH=7和T=25℃下,K-2BP、KN-B和KN-R在活性炭上的等温吸附规律符合Langmuir模型方程,最大饱和吸附量Qmax分别为263.15、256.41和250 mg/g,吸附自由能△G298 K分别为-10.632、-3.783和-2.805 kJ/mol;该条件下K-2BP、KN-B和KN-R的动力学吸附规律均符合准一级动力学吸附方程。等温吸附研究和吸附动力学研究均表明,相同条件下3种活性染料在该型活性炭上的吸附效果由高到低的顺序为:K-2BP>KN-B>KN-R。     

我国高效节水型可持续农业发展模式选择

通过发展高效节水农业的背景和技术基础分析,根据我国区域光热、水土资源特点,以提高大气水、地表水、土壤水和地下水等水资源的利用效率为目的,以提高土地的生物学产量和经济效益为目标,研究提出了抗旱型、立体型、设施型、 复合型、免耕型和集水型等高效节水型农业发展模式,为今后建立我国不同特色的集约高效节水型农业提供可供借鉴的模式。     

Temporal dimension and water quality control in an emission trading scheme based on water environmental functional zone

Emission trading is one of the most effective alternatives to controlling water pollution. Water environmental functional zone (WEFZ) is used to determine the water quality standard and identify the zone boundary for each river or reach. In this study, a new emission trading scheme was addressed based on WEFZ, accounting for both the temporal dimension and water quality control. A temporal factor of emission trading was proposed based on variations in the environmental capacity within a year by dividing the year into three periods, including high, normal, and low periods of environmental capacity. During each period, emission trading was implemented exclusively. A water quality-control scheme was suggested based on the water quality requirement in the water functional zone, in which the water quality at the downstream boundary of the zone was required to meet the water standard following auto-purification in the stream. Two methods of calculating water quality control are addressed for point-source pollution and non-point-source pollution. The calculated temporal dimension and water quality control were located in Dongxi River of the Daning Watershed in the Three Gorges Watershed. The high period was during June, July, and August, the normal period was during April, May, September, and October, and the low period was during January, February, March, November, and December. The results from the water quality calculation demonstrated that the discharge of point-source and non-point-source pollutions led to an excess of common contaminants at the downstream boundary of WEFZ. The temporal and spatial factors above should be incorporated into the emission trading scheme based on WEFZ.     

Process analysis of PM2.5 pollution events in a coastal city of China using CMAQ

US EPA's Community Multiscale Air Quality modeling system(CMAQ) with Process Analysis tool was used to simulate and quantify the contribution of individual atmospheric processes to PM_(2.5) concentration in Qingdao during three representative PM_(2.5) pollution events in the winter of 2015 and 2016. Compared with the observed surface PM_(2.5) concentrations, CMAQ could reasonably reproduce the temporal and spatial variations of PM_(2.5) during these three events. Process analysis results show that primary emissions accounted for 72.7%–93.2% of the accumulation of surface PM_(2.5) before and after the events.When the events occurred, primary emissions were still the major contributor to the increase of PM_(2.5) in Qingdao, however the contribution percentage reduced significantly,which only account for 51.4%–71.8%. Net contribution from horizontal and vertical transport to the accumulation of PM_(2.5) was also positive and its percentage increased when events occurred. Only 1.1%–4.6% of aerosol accumulation was due to PM processes and aqueous chemical processes before and after events. When the events occurred,contribution from PM processes and aqueous chemistry increased to 6.0%–11.8%. Loss of PM_(2.5) was mainly through horizontal transport, vertical transport and dry deposition, no matter during or outside the events. Wet deposition would become the main removal pathway of PM_(2.5), when precipitation occurred.     

森林凋落物研究现状及我国西南喀斯特地区研究展望

近几十年来,我国西南喀斯特地区生态环境退化严重,石漠化面积迅速扩大,林地覆盖率急剧下降,成为制约我国西部大开发生态建设中不可回避的重要科学问题,严重影响了西南地区社会、经济的可持续发展。喀斯特地区土层薄且侵蚀严重,土壤中的有机碳和营养盐主要来自地表枯枝落叶层的分解及累积。在气候变暖、陆地生态系统土壤温度升高、土壤有机碳急速流失和土壤质量退化的背景下,分析不同林下凋落物量和降解动态以及土壤有机碳库积累差异,揭示西南喀斯特地区不同林地凋落物归还量及其对土壤碳库积累的贡献具有极其重要的意义,将为喀斯特地区林地恢复重建和石漠化遏制工作提供科研依据。     

Laboratory culture of the freshwater benthic gastropod Bellamya aeruginosa （Reeve） and its utility as a test species for sediment toxicity

This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa(Reeve),a new potential species for sediment toxicity testing.B.aeruginosa was successfully cultured with an effective culture system under proposed laboratory conditions.Optimal ad libitum feeding levels for larvae,juveniles,and adults were 2.0,6.0,and 16.0 mg fish food/(snail·day),respectively.Mean survival rates of juveniles were higher than 90%.The snails could be sexed at 9 weeks of age,and their generation time is approximately 4 months.Reproduction continued all year around;the mean fecundity was 0.55 newborn/(female·day).The utility of this species for bioassays was evaluated in both 10-day and 28-day case studies with artificial sediments.The 10-day LC50 of Cu for larvae was 480 μg/g dry weight(dw),and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 μg/g dw.Survival and growth are reliable indicators of acute toxicity.Larvae accumulated more Cu than adults.B.aeruginosa exhibited a higher sensitivity to Cu exposure than standard test species(Hyalella azteca and Chironomus tentans).The 28-day test of sediment toxicity with adults showed that fecundity was a robust endpoint indicator of reproductive toxicity,and the biochemical endpoints of superoxide dismutase,catalase,and glutathione could be used as sensitive biomarkers for Cu-induced oxidative damage.B.aeruginosa can be therefore recommended as a candidate for the standardization of the freshwater sediment toxicity test protocol.     

淀粉接枝阳离子絮凝剂的制备及性能研究

主要利用化学方法对环氧氯丙烷和胺类进行阳离子改性获得阳离子醚化剂,然后与碱化后的淀粉接枝制得一种絮凝性能良好的有机高分子阳离子絮凝荆,并对所得产品作了絮凝性能实验。由实验得知该絮凝剂对悬浮细小颗粒有很好的去除效果,如高岭土溶液（1g／L）产生矾花时间较短,加入絮凝剂后搅拌3min左右即可产生明显絮体,且絮体较大,静置后透光率达90％以上。     

生物法治理污水处理场恶臭废气技术探讨

介绍了生物法治理污水处理场恶臭废气的工艺流程、基本原理,分析了对恶臭废气中有机污染物的去除效果,提出了需改进的问题。     

Advances in air pollution control for vessels in China

Vessel emissions have contributed a great deal to air quality deterioration in China. Hence,the Chinese government has promulgated a series of stringent emission regulations. It is in this context that vessel emission control technology research is in full swing. In particular,during the 13th Five-Year Plan, the air pollution control technology of vessels has greatly improved. Vessel emission control has followed two main governance routes: source emission reduction and aftertreatment technology...