Spatial scale and seasonal dependence of land use impacts on riverine water quality in the Huai River basin,China

Land use pattern is an effective reflection of anthropic activities, which are primarily responsible for water quality deterioration. A detailed understanding of relationship between water quality and land use is critical for effective land use management to improve water quality. Linear mixed effects and multiple regression models were applied to water quality data collected from 2003 to 2010 from 36 stations in the Huai River basin together with topography and climate data, to characterize the land use impacts on water quality and their spatial scale and seasonal dependence. The results indicated that the influence of land use categories on specific water quality parameter was multiple and varied with spatial scales and seasons. Land use exhibited strongest association with dissolved oxygen (DO) and ammonia nitrogen (NH₃-N) concentrations at entire watershed scale and with total phosphorus (TP) and fluoride concentrations at finer scales. However, the spatial scale, at which land use exerted strongest influence on instream chemical oxygen demand (COD) and biochemical oxygen demand (BOD) levels, varied with seasons. In addition, land use composition was responsible for the seasonal pattern observed in contaminant concentrations. COD, NH₃-N, and fluoride generally peaked during dry seasons in highly urbanized regions and during rainy seasons in less urbanized regions. High proportion of agricultural and rural areas was associated with high nutrient contamination risk during spring. The results highlight the spatial scale and seasonal dependence of land use impacts on water quality and can provide scientific basis for scale-specific land management and seasonal contamination control.     

Molecular characterization of microbial communities and quantification of <Emphasis Type="Italic">Mycobacterium immunogenum</Emphasis> in metal removal fluids and their associated biofilms

A number of human health effects have been associated with exposure to metal removal fluids (MRFs). Multiple lines of research suggest that a newly identified organism, Mycobacterium immunogenum (MI), appears to have an etiologic role in hypersensitivity pneumonitis (HP) in case of MRFs exposed workers. However, our knowledge of this organism, other possible causative agents (e.g., Pseudomonads), and the microbial ecology of MRFs in general, is limited. In this study, culture-based methods and small subunit ribosomal RNA gene clone library approach were used to characterize microbial communities in MRF bulk fluid and associated biofilm samples collected from fluid systems in an automobile engine plant. PCR amplification data using universal primers indicate that all samples had bacterial and fungal contaminated. Five among 15 samples formed colonies on the Mycobacteria agar 7H9 suggesting the likely presence of Mycobacteria in these five samples. This observation was confirmed with PCR amplification of 16S rRNA gene fragment using Mycobacteria specific primers. Two additional samples, Biofilm-1 and Biofilm-3, were positive in PCR amplification for Mycobacteria, yet no colonies formed on the 7H9 cultivation agar plates. Real-time PCR was used to quantify the abundance of M. immunogenum in these samples, and the data showed that the copies of M. immunogenum 16S rRNA gene in the samples ranges from 4.33?×?10⁴ copy/ml to 4.61?×?10⁷ copy/ml. Clone library analysis revealed that Paecilomyces sp. and Acremonium sp. and Acremonium-like were dominant fungi in MRF samples. Various bacterial species from the major phylum of proteobacteria were found and Pseudomonas is the dominant bacterial genus in these samples. Mycobacteria (more specifically MI) were found in all biofilm samples, including biofilms collected from inside the MRF systems and from adjacent environmental surfaces, suggesting that biofilms may play an important role in microbial ecology in MRFs. Biofilms may provide a shield or sheltered microenvironment for the growth and/or colonization of Mycobacteria in MRFs.     

电解锰渣的综合利用进展与研究展望

电解锰渣是电解金属锰时产生的酸性滤渣,含有大量有害物质。随着电解锰行业的快速发展,大量堆放填埋的电解锰渣引发了严重的水土、生态环境污染问题,对锰渣的无害化处理与资源化利用已成为电解锰行业和环保领域的研究热点。在电解锰渣特性的分析基础上,对国内外电解锰渣的综合利用进展(如锰离子回收、肥料制作和建筑材料应用)进行了回顾,分析了锰渣各种资源化利用方法的优缺点。最后,展望了电解锰渣的研究与应用前景,旨在为锰矿资源的可持续性开发与电解锰渣的综合回收利用提供参考。     

地下油罐泄漏区污染源的自动识别

地下油罐泄漏隐蔽性大,不易被及时发现,而且泄漏出的烃类化合物毒性强,对地下水会造成严重污染.为了对某一地下油罐污染源位置和强度进行准确识别,本研究结合现场调查结果,建立了该地下油罐泄漏区的石油污染物反应运移模型.在基本确定污染源泄漏区范围的前提下,进一步建立地下油罐泄漏区污染源的识别模型,并利用遗传算法对泄漏区污染源的位置和泄漏强度进行了自动识别,进而通过参数敏感性分析来评价和比较不同参数对污染物运移结果的影响.结果表明,运移模型中与地下水流场变化相关的特征参数（如开采量、水力坡度、渗透系数等）对污染物运移结果的影响相对比较明显.对于污染源来说,研究不同污染组分在含水层中的化学和生物化学变化显得尤为重要.     

白塔堡河不同粒级有机物的三维荧光特征解析

利用三维荧光扫描(3DEEM)和体积积分法(FRI),分析了辽河流域白塔堡河在春汛期水中溶解性有机物(DOM)、小粒径有机物(0.22~0.7μm)和大粒径有机物(>0.7μm)的分布。结果显示:白塔堡河中有机物以芳香类蛋白质和溶解性微生物代谢产物为主,腐植酸类物质含量极少;5类组分在不同粒径有机物中分布相似,在0.22μm以下的DOM中分布最多;溯源分析显示,DOM来源较单一,表现出较强的内源生物降解特性,而颗粒状有机物则表现出内源和陆源的双重特性;多元统计分析显示,白塔堡河点位有机物分布基本上呈现区域性分布特征。     

基于安全评价方法的HSE检查监督管理信息系统改进研究

以广州石化HSE检查监督管理信息系统为背景,分析了该系统的实施效果和不足之处,提出引入安全评价方法进行改进,建立一个具有安全评价和预测功能的HSE检查监督系统,并指出该系统的改进途径和具体操作方法,为石化企业开发和改进HSE检查监督管理信息系统提供参考.     

高效菌处理焦化废水试验研究

介绍了高效菌处理焦化废水的试验研究.试验针对焦化废水处理的流行工艺A/O法进行研究,投加高效菌后对好氧池和缺氧池的NH3-N和COD去除效果明显.结果表明,当进水COD质量浓度在2 000 mg/L以下时,出水COD可最低可降至120 mg/L以内,COD去除率最高可达到85％;进水NH3-N质量浓度在300 mg/L以下时,出水氨氮可稳定在15 mg/L以内,氨氮去除率仍可达到95％.     

岩溶槽谷区不同土地利用方式下土壤微生物特征研究

为探索岩溶山区农村不同用地类型土壤肥力及微生物活性状况,对青木关地区五种土地利用类型的土壤肥力、微生物数量及其相关性进行了分析.结果表明：（1）岩溶山区土壤微生物数量的变化受人为影响较大,在总体数量上均以细菌为主,且与一般土壤微生物数量分布情况相吻合;（2）不同用地类型土壤中微生物总量与土壤微生物多样性指数二者的变化趋势不一致,但玉米地例外;（3）通过Pearson相关性分析得出,土壤中有机质、全钾、有效钾和有效磷的含量与土壤微生物之间的相互关系显著。     

Fenton法处理中药废水的研究

采用Fenton氧化技术对中药废水进行实验处理,对主要操作条件及其对实验处理效果的影响进行了实验研究。主要考察了废水pH、H2O2投加量、Fe^2＋投加量及温度等对废水中CODcr去除率的影响。实验结果显示,在pH=3.0,H2O2投加量为4/5Qth,Fe^2＋浓度为7.9×10^-3mol.L-1,20℃的情况下反应80 m in后CODcr去除率可以达到71.40%,Fenton氧化反应对中药废水有比较好的处理效果,改善了废水的可生化性,有利于进一步进行生化处理。     

轮休措施对堵塞型垂直潜流人工湿地的影响

采用不可滤物质的定量化分析方法研究了采取轮休措施对人工湿地堵塞程度的改善效果,同时分析了轮休措施对垂直潜流人工湿地污染物去除效果的改变和植物生长的影响.结果表明,轮休措施对解决人工湿地的堵塞有明显地改善,采取轮休措施后单位基质中的不可滤物质含量较轮休前有所降低,其中不可滤有机物减少量十分明显,不可滤无机物量在短期和长时间轮休前后分别表现出基本稳定和较大幅度降低的特性;短期轮休后COD、TP和TN的去除率都较轮休前有所降低,氨氮的去除率在人工湿地轮休后较轮休前高;应结合人工湿地的基质、植物种类调整运行工况,进行不同时间长度和方式的轮休,以确保植物生长不受该措施的影响.