亚硝酸对聚磷菌好氧吸磷抑制作用研究

为确定亚硝酸对聚磷菌好氧吸磷的抑制作用,利用批量实验研究了在不同pH下不同浓度的亚硝态氮对聚磷菌好氧吸磷过程的影响.实验结果表明,亚硝酸对聚磷菌好氧吸磷具有更直接的影响;亚硝酸质量浓度达到0.001 00 mg/L时,聚磷菌好氧吸磷即会受到50％的抑制.聚磷菌受到较低浓度的亚硝酸抑制时,其在无亚硝酸存在的环境中好氧吸磷能力基本能恢复.     

DBO模式在污水处理行业的应用研究

DBO模式是PPP模式之一,在国家大力推进PPP模式之际,尝试开展DBO模式在污水处理行业的应用研究,分析污水处理行业发展趋势与问题,DBO模式在污水处理行业应用的适用领域与适用条件、优点,提出DBO模式在污水处理行业的推行路径,希望通过DBO模式解决污水处理行业的问题,促进行业健康发展。本文认为,城镇、乡镇与村庄生活污水处理、工业企业废水治理等领域具有项目设计与建设非标准化、项目需求明确、责任边界清晰、项目运营服务质量和成本容易监测等特点,应用DBO模式具有可行性。这些领域内的项目若有可靠的建设资金来源、稳定的运行费用保障机制、急于改善的区域水环境质量及严格的环保设施运行需求,适合采用DBO模式。DBO模式可以提高这些项目的建设质量和运营质量,节约成本,缩短建设周期,提高抗风险能力。同时,在行业层面,能够解决这些领域面临的项目设计不合理、建设质量不高、运行费用高、运行管理不善、闲置等诸多问题,可以促进先进实用技术和管理经验的应用,提高行业技术和运营管理水平的整体进步。因此,建议政府从开展实施试点、制定行业规范、加大宣传和推广、颁布政策文件等方面大力推进DBO模式在污水处理行业的应用。     

Evaluation of spatial-temporal variations and trends in surface water quality across a rural-suburban-urban interface

Water quality degradation is often a severe consequence of rapid economic expansion in developing countries. Methods to assess spatial-temporal patterns and trends in water quality are essential for guiding adaptive management efforts aimed at water quality remediation. Temporal and spatial patterns of surface water quality were investigated for 54 monitoring sites in the Wen-Rui Tang River watershed of eastern China to identify such patterns in water quality occurring across a rural-suburban-urban interface. Twenty physical and chemical water quality parameters were analyzed in surface waters collected once every 4–8 weeks from 2000 to 2010. Temporal and spatial variations among water quality parameters were assessed between seasons (wet/dry) and among major land use zones (urban/suburban/rural). Factor analysis was used to identify parameters that were important in assessing seasonal and spatial variations in water quality. Results revealed that parameters related to organic pollutants (dissolved oxygen (DO), chemical oxygen demand (manganese) (COD_Mn), and 5-day biochemical oxygen demand (BOD₅)), nutrients (ammonia nitrogen (NH₄ ⁺-N), total nitrogen (TN), total phosphorus (TP)), and salt concentration (electrical conductivity (EC)) were the most important parameters contributing to water quality variation. Collectively, they explained 70.9 % of the total variance. A trend study using the seasonal Kendall test revealed reductions in COD_Mn, BOD₅, NH₄ ⁺-N, petrol, V-phen, and EC concentrations over the 11-year study period. Cluster analysis was employed to evaluate variation among 14 sampling sites representative of dominant land use categories and indicated three, three, and four clusters based on organic, nutrient, and salt water quality characteristics, respectively. Factors that are typically responsible for water quality degradation (including population, topography, and land use) showed no strong correlation with water quality trends implying considerable point source inputs in the watershed. The results of this study help inform ongoing water quality remediation efforts by documenting trends in water quality across various land use zones.     

Spatial and temporal variations of nitrous oxide flux between coastal marsh and the atmosphere in the Yellow River estuary of China

To investigate the spatial and seasonal variations of nitrous oxide (N₂O) fluxes and understand the key controlling factors, we explored N₂O fluxes and environmental variables in high marsh (HM), middle marsh (MM), low marsh (LM), and mudflat (MF) in the Yellow River estuary throughout a year. Fluxes of N₂O differed significantly between sampling periods as well as between sampling positions. During all times of day and the seasons measured, N₂O fluxes ranged from ?0.0051 to 0.0805 mg N₂O m^?2 h^?1, and high N₂O emissions occurred during spring (0.0278 mg N₂O m^?2 h^?1) and winter (0.0139 mg N₂O m^?2 h^?1) while low fluxes were observed during summer (0.0065 mg N₂O m^?2 h^?1) and autumn (0.0060 mg N₂O m^?2 h^?1). The annual average N₂O flux from the intertidal zone was 0.0117 mg N₂O m^?2 h^?1, and the cumulative N₂O emission throughout a year was 113.03 mg N₂O m^?2, indicating that coastal marsh acted as N₂O source. Over all seasons, N₂O fluxes from the four marshes were significantly different (p?<?0.05), in the order of HM (0.0256?±?0.0040 mg N₂O m^?2 h^?1)?>?MF (0.0107?±?0.0027 mg N₂O m^?2 h^?1)?>?LM (0.0073?±?0.0020 mg N₂O m^?2 h^?1)?>?MM (0.0026?±?0.0011 mg N₂O m^?2 h^?1). Temporal variations of N₂O emissions were related to the vegetations (Suaeda salsa, Phragmites australis, and Tamarix chinensis) and the limited C and mineral N in soils during summer and autumn and the frequent freeze/thaw cycles in soils during spring and winter, while spatial variations were mainly affected by tidal fluctuation and plant composition at spatial scale. This study indicated the importance of seasonal N₂O contributions (particularly during non-growing season) to the estimation of local N₂O inventory, and highlighted both the large spatial variation of N₂O fluxes across the coastal marsh (CV?=?158.31 %) and the potential effect of exogenous nitrogen loading to the Yellow River estuary on N₂O emission should be considered before the annual or local N₂O inventory was evaluated accurately.     

制备条件对硅胶负载氧化锆吸附除氟的影响

应用浸渍法制备了硅胶负载氧化锆除氟吸附剂,研究了焙烧温度、硅胶粒度、浸渍时间、浸渍温度、浸渍液浓度、浸渍固液比和浸渍次数等制备参数对吸附剂吸附容量的影响.实验发现焙烧温度有较大影响,450℃焙烧有最大的吸附量,再升高温度吸附量迅速下降.浸渍可在2h内达到平衡.浸渍温度越高,浸渍液浓度越高,则吸附容量越大.采用较高浓度一次浸渍优于低浓度多次浸渍.硅胶粒度和浸渍固液比也影响吸附量,粒度越大吸附量越小,粒度小于0.25mm后吸附量趋于稳定.     

国内外雨水、污水和中水在城市绿地系统中的应用进展及发展现状

由于人口增加,城市化程度加快,水资源短缺日趋加剧,文章依据可持续发展理念,提出雨水、污水和中水在城市绿地系统中的应用,对指导城市供水、用水、节水、污水处理和水资源保护,促进城市水系统的良性循环有重要作用;指出它能充分发挥生产潜力,使资源最佳化,非常适合建设节约型城市,具有广阔的应用前景;并对国内外雨水、污水和中水在城市绿地系统中的应用方法及相关实例进行了综述,是环境保护中最具说服力的应用事例,旨在使人们形成节约资源、尊重自然的生态观念。     

Technical feasibility study of an onshore ballast water treatment system

To fulfill the requirements of Guidelines for approval of ballast water management system (G8), a set of onshore ballast water treatment equipment utilizing micro-pore ceramic filtration (MPCF) and UV radiation (MPCF&UV) system was designed and set up with a maximum flow rate of 80 m³·h⁻¹. Technical feasibilities of MPCF&UV system were evaluated in three areas: removal efficiencies of indicator organism and oceanic bacteria, perdurability of a ceramic filter, and application on native seawater. The results showed that no indicator organism (Dunaliella) or oceanic bacteria was detected after treatment of 20 L MPCF and UV radiation at 1.3×10⁴ μW·s·cm⁻². A 20 L ceramic filter can run continuously for 5.3 h at the flow rate of 15 m³·h⁻¹ before its pressure drop up to 0.195 MPa. The removal percentage of total plankton amounts were 91.9% at a flow rate of 70 m³·h⁻¹ by 80 L MPCF and UV radiation at 1.3×10⁴ μW·s·cm⁻².     

环境中十氯酮的研究进展

十氯酮(Chlordecone)是一种人工合成的有机氯杀虫剂,对人和动物有多种毒性作用,在环境中能够长期存在,已被列入《斯德哥尔摩公约》禁用名单.目前关于十氯酮的研究主要集中在美国James River和法国法属西印度群岛地区.本文综述了十氯酮的毒性研究结果,十氯酮的环境分析方法进展,及其在各种环境介质中的浓度水平,并对在我国进行相关研究提出了建议,以期推动十氯酮的研究工作.     

High-solids anaerobic co-digestion of sewage sludge and food waste in comparison with mono digestions: Stability and performance

System stability and performance of high-solids anaerobic co-digestion of dewatered sludge (DS) and food waste (FW) in comparison with mono digestions were investigated. System stability was improved in co-digestion systems with co-substrate acting as a diluting agent to toxic chemicals like ammonia or Na⁺. For high-solids digestion of DS, the addition of FW not only improved system stability but also greatly enhanced volumetric biogas production. For high-solids digestion of FW, the addition of DS could reduce Na⁺ concentration and help maintain satisfactory stability during the conversion of FW into biogas. System performances of co-digestion systems were mainly determined by the mixing ratios of DS and FW. Biogas production and volatile solids (VSs) reduction in digestion of the co-mixture of DS and FW increased linearly with higher ratios of FW. A kinetic model, which aimed to forecast the performance of co-digestion and to assist reactor design, was developed from long-term semi-continuous experiments. Maximum VS reduction for DS and FW was estimated to be 44.3% and 90.3%, respectively, and first order constant k was found to be 0.17 d^?1 and 0.50 d^?1, respectively. Experimental data of co-digestion were in good conformity to the predictions of the model.     

青岛某小区景观湖水水质年变化规律研究

为了获得青岛某住宅小区内景观湖水质全年变化规律,并确定最佳换水时间,采用国标法及行业标准法检测该小区景观湖及其水源的全年水质变化.结果表明:景观湖水各水质指标全年波动明显,均受季节和降水情况影响,在降水丰沛的8-10月份水质较好;除pH全年符合景观水质标准外,其余指标均有月份超标;除COD浓度较高外,其余指标9-11月均较低,水质较好;水源白沙河的水质多在降水丰沛的9、10月份水质较好,综合看来,9-10月份为每年的最佳换水时间.