Photodegradation of perfluorooctanoic acid by synthesized TiO2-MWCNT composites under 365nm UV irradiation

Degradation of perfluorooctanoic acid (PFOA) is of great importance due to its global distribution, persistence and toxicity to bioorganisms. In present study, a composite TiO₂ with multiple wall carbon nano-tubes (MWCNTs) was synthesized using sol-gel method and it was used as photocatalyst to degrade PFOA in water. The prepared composite catalyst displayed significant absorption in UV to visible light region. The loading content of TiO₂ on MWCNTs could be adjusted by changing the ratio of precursor to MWCNTs. Due to the combined effect of the adsorption ability and e⁻ transport capacity of MWCNT, the composites displayed much higher photocatalytic ability to PFOA as compared to pure TiO₂ under UV irradiation. The photocatalyst prepared with 10:1 of tetrabutyl titanate/MWCNT was the most effective. With the optimal dosage at 1.6 g L⁻¹, almost 100% of PFOA was degraded in acid medium after irradiation for 8 h. It was proposed that PFOA were mainly degraded by stepwise losing a moiety of CF₂.     

Phytoplankton toxicity of the antibiotic chlortetracycline and its UV light degradation products

Two common freshwater phytoplankton species Microcystis aeruginosa and Scenedesmus obliquus were employed as test organisms to investigate the toxic effects of chlortetracycline widely used in human medicine and veterinary as antibiotic. Toxicity assays were performed into two parts: antibiotic toxicity test and antibiotic degraded products toxicity test. In general, chlortetracycline had significantly toxic effect on population growth and chlorophyll-a accumulation of two phytoplankton. Although M. aeruginosa had ability to grow after exposed to chlortetracycline at 0.5 mg L⁻¹, its photosynthesis function was also disrupted. Compared with the data in two phytoplankton species, the chlorophyceae was more sensitive than the cyanophyceae. The adverse effect on S. obliquus was stronger than that on M. aeruginosa with increasing concentrations. In addition, for M. aeruginosa, regardless of the UV light degradation time, the treated chlortetracycline also had adverse effect on population growth and chlorophyll-a accumulated. The degraded chlortetracycline under any treatment time was more toxic for S. obliquus than chlortetracycline itself excluding under 24 h. However, the correlation between the toxicity and degradation time was not clear and toxicity enhanced in fact did not follow the increase or decrease in degradation time. Our study showed that the antibiotic chlortetracycline and its degraded products had adverse effect on freshwater phytoplankton, the former has not been reported before and the latter has been overlooked in other research in the past.     

新型生物絮凝剂的研究

本文对近两年来新型生物絮凝剂的研究报道进行了综述。这些新型生物絮凝剂的研究领域包括复合型生物絮凝剂的研制,微生物絮凝剂与其它絮凝剂的复配,微生物絮凝剂的生物学研究,以及微生物絮凝剂培养条件的优化等。并对今后生物絮凝刺的研发方向进行了展望。     

江苏省环境监测现代化中的人才建设

人才是环境监测现代化建设的决定性因素,培养和造就一批高素质的环境监测人才队伍是环境监测现代化的前提。相对环境监测现代化的要求,江苏省环境监测人才队伍学存在结构不合理、高层次人才短缺等问题。提出要树立“人才资源整体开发观念”,并从选才、聚才、育才、用才等方面阐述了江苏省环境监测现代化人才队伍建设的对策。     

The future of water in Australia: The potential effects of climate change and ozone depletion on Australian water quality,quantity and treatability

Water is a resource that is essential for all life on Earth. An exponentially growing human population, in addition to unprecedented industrial and technological development, threaten the availability and quality of this resource. Climate change and ozone depletion are two major environmental problems facing mankind today. These problems have the potential to further strain currently available freshwater resources. Recent research has shown that climate change and ozone depletion are linked phenomena and their interaction exacerbates their impact. Changes in precipitation, surface runoff, solar UV radiation, temperatures, and evaporation are some of the predicted outcomes of climate change and ozone depletion. They influence the biogeochemical cycles and aquatic ecosystems in lakes and rivers, and alter the character of natural organic matter (NOM) and, consequently, they have the potential to affect the quality, quantity and treatability of our water resources. Given these uncertainties, and the need to mitigate the consequences of climate change and ozone depletion, the issues of changing water quality, quantity and treatability cannot be ignored by Australian governments and water utilities.     

Advanced oxidation treatment of pulp mill effluent for TOC and toxicity removals

Pulp mill effluent was treated by different advanced oxidation processes (AOPs) consisting of UV, UV/H2O2, TiO2-assisted photo-catalysis (UV/TiO2) and UV/H2O2/TiO2 in lab-scale reactors for total organic carbon (TOC) and toxicity removals. Effects of some operating parameters such as the initial pH, oxidant and catalyst concentrations on TOC and toxicity removals were investigated. Almost every method resulted in some degree of TOC and toxicity removal from the pulp mill effluent. However, the TiO2-assisted photo-catalysis (UV/TiO2) resulted in the highest TOC and toxicity removals under alkaline conditions when compared with the other AOPs tested. Approximately, 79.6% TOC and 94% toxicity removals were obtained by the TiO2-assisted photo-catalysis (UV/TiO2) with a titanium dioxide concentration of 0.75gl(-1) at pH 11 within 60min.     

污泥和垃圾堆肥用作林木育苗基质的研究

通过容器栽培试验,用出苗率、苗木生长指标、形态质量指数、叶片叶绿素含量等4指标对污泥和垃圾堆肥替代泥炭用作林木育苗容器基质的可行性进行了研究。结果显示,污泥和垃圾堆肥可以部分替代泥炭,能明显促进苗木生长,苗木叶片中的叶绿素含量明显高于对照,且叶片的生长期较对照长。基质最佳配方为污泥堆肥∶泥炭=1∶1和垃圾堆肥∶泥炭=1∶1。基质含盐量是影响种子出苗率的因素之一,盐分含量对针叶树种的影响大于阔叶树种。含盐量高的基质在播种前应考虑淋洗脱盐。     

试论土壤的生态肥力及其培育

探讨了“土壤生态肥力”的概念。所谓土壤生态肥力是指在一定的环境条件下,土壤及其生物群落（包括动物和微生物）之间长期协同进化、相互适应、相互作用而表现出来的一种和谐共融特性,以及在该特性状态下土壤保证植物生长所需物质与能量的可获得性和可持续性的一种功能与能力。在此基础上,提出了表征土壤生态肥力的一套诊断指标和有关土壤生态肥力的培育措施。     

基于Landsat 7的武汉市热岛效应研究

城市化使得城市数量和规模不断增加,城市作为人类对自然环境改造最为剧烈的部分,具有独特的区域环境,其中城市内部温度显著高于周边郊区的热岛效应是一个突出的城市环境问题,受到了普遍关注和研究。武汉市是长江中游特大城市,城市热岛效应明显,但对其研究很少。利用Landsat TM6波段数据,生成武汉市城市亮温场,分析了武汉市热场的分布、大小,利用亮温场均值、方差和相对温度评价城市热岛强度,并对城市热场的范围及强度变化与城市发展规模及方向进行了分析,取得了较好的效果。     

挥发酚和总氰化物在三种水质中测定方法的比对

本文采用连续流动注射法[1]和紫外分光光度法[2-3],分别对地表水、生活污水、工业废水三种水质中的挥发酚和总氰化物进行测定。实验结果表明:两种分析方法测定三种水质中的挥发酚和总氰化物结果基本一致,检出限、精密度、准确度、加标回收率均符合质量控制要求。连续流动注射法的自动化程度更高,操作更简便,可适用于多种水质挥发酚和总氰化物的分析。