Effect of inorganic carbon on anaerobic ammonium oxidation enriched in sequencing batch reactor

The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon(sodium bicarbonate)on anaerobic ammonium oxidation.The enrichment of anammox bacteria was carried out in a 7.0-L sequencing batch reactor(SBR)and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR.Research results,especially the biomass,showed first signs of anammox activity after 54 d cultivation with synthetic w...     

Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants

Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditionalchlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaksin the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose.Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditionson the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration,liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9%was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically foundto be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammoniaremoval rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plantmembrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatmentplant, also paved the way towards a larger scale application.     

Effects of operational factors on soluble microbial products in a carrier anaerobic baffled reactor treating dilute wastewater

The effects of feed strength,hydraulic residence time(HRT),and operational temperatures on soluble microbial product(SMP) production were investigated,to gain insights into the production mechanism.A carrier anaerobic batfled reactor (CABR) treating dilute wastewater was operated under a wide range of operational conditions,namely,feed strengths of 300-600 mg/L,HRTs of 9-18 h,and temperatures of 10-28℃.Generally, SMP production increased with increasing feed strength and decreasing temperature.At high temperature (28℃),SMP production increased with decreasing HRT. As the temperature Was decreased to 18 and 10℃.the SMP production was at its peak for 12 h HRT Therefore,temperature could be an important determinant of SMP production along with HRT. A higher SMP to soluble chemical oxygen demand (SCOD) ratio Was found at high temperature and long HRT because of complete volatile fatty acid degradation.SMP accounted for 50%-75% of the SCOD in the last chamber of the CABR.As a secondary metabolite.some SMP could be consumed at lower feed strength.     

中国南方红壤丘陵区湖南水环境时空变化研究

以中国南方红壤丘陵区的典型区域-湖南省为例,利用1990～2000年湘、资、沅、澧四水和洞庭湖区重要断面的水质数据,采用综合污染指数方法和污染分担率方法,研究了湖南省水环境质量时空变化特征,并选取1990～2005年经济和废水排放数据,分析了经济因子与废水排放之间的相互关系,建立湖南省废水排放的库兹涅茨曲线模型。研究结果表明,从时间上看,湖南省的总体水环境污染有加重的趋势;从空间上看,水环境质量是从湖南省的西部向东部恶化。在流域和地区对比中,湘江和位于该流域的株洲市最为严重,总氮和汞是湖南省最主要的污染因子;通过环境库兹涅茨曲线模型模拟表明,湖南水环境与经济发展的关系位于环境库兹涅茨曲线上升段。本研究结果对于改善整个湖南省水环境污染状况,以便采取正确的防治策略具有一定的实践意义。     

柠檬酸废渣石膏综合利用研究进展及前景展望

柠檬酸废渣石膏主要由二水石膏组成,化学成分与天然石膏相近,只要工艺合理,就可以实现柠檬酸废渣石膏的资源化利用。综述了柠檬酸废渣石膏生产石膏粉、石膏砌块和石膏板材,用于硫铝酸盐水泥生产,用作水泥缓凝剂、制备晶须等方面的研究进展;提出了柠檬酸废渣石膏在生产粉笔、用于水泥矿化剂和与石英尾砂等工业废渣联合使用等方面的应用前景。     

白音锡勒牧场草原植物群落的数量分析

采用双向指示种分析（Two—Way Indicator Species Analysis,TWINSPAN）和无趋势对应分析（Detrended Correspondence Analysis,DCA）技术,对白音锡勒牧场2004年和2005年的48个样点的草原植物群落调查数据进行分析。结果表明：1．TWINSAN分类与DCA排序具有高度的一致性,吻合度达83％,输出结果准确可信;2．研究区域有草甸草原和典型草原两种草原类型,其中在典型草原内可划分为五个植物群落类型,即1）大针茅（Stipa grandis）＋羊草（Leymus chinensis）＋糙隐子草（Cleistogenes squarrosa）群落;2）克氏针茅（Stipa krylovii）＋糙隐子草（Cleistogenes squarrosa）＋冰草（Agropyron cirstatum）群落;3）冷蒿（Artemisia frigida）＋糙隐子草（Cleistogenes squarrosa）＋大针茅（Stipa grandis）群落;4）糙隐子草（Cleistogenes squarrosa）＋冷蒿（Artemisia frigida）＋一、二年生植物（annual—biennial）群落;5）星毛委陵菜（Potentilla tanacetifolia）＋糙隐子草（Cleistogenes squarrosa）＋一、二年生植物（annual-biennial）群落,这五个植物群落类型反映了典型草原植物群落退化演替序列;3．研究区不同植物群落类型的物种数量、生态种组类型等不同。冷蒿（Artemisia frigida）＋糙隐子草（Cleistogenes squarrosa）＋大针茅（Stipa grandis）群落为研究区植物群落退化演替中的中度退化阶段,物种数量最多,生态种组类型最多,样点间差异较大。     

钛基表面电沉积钌的工艺研究

说明了一种能在钛基上直接电镀金属钌的新工艺.该工艺在三氯化钌体系中进行,通过在电镀液中加入氨基磺酸、氯化铵和一些添加剂,提高了钌镀工艺的电流效率,且镀层光亮平整.试验还通过电化学测试、扫描电镜(SEM)和XRD等方法研究了电流密度、温度、pH值、主盐和添加剂浓度等参数对镀层性能的影响.结果表明:电镀钌工艺最佳电流密度范围是0.5～0.8 A/dm2,添加剂浓度的最佳范围是20～30g/L,微观电镜图也显示了钌镀层较为致密.最后,该镀钌工艺实现了在主盐浓度不高的情况下仍然镀出了致密的钌层.     

利用hypermesh和feko软件来仿真舰艇RCS

利用feko软件,结合hypermesh剖分的优化网格,对舰艇RCS进行了仿真计算。经过hy—permesh剖分得出的优化网格较feko自己剖分的网格质量更好,更符合MOM三角面元网格的需要,而且在计算时间以及内存需求方面均有明显的优势,有利于更好地对舰船RCS进行仿真。最后计算了某型舰艇的RCS,结果验证了这种方法的精度。     

电磁环境数据采集及实验室模拟技术研究

对电磁环境数据采集技术和实验室模拟技术进行了介绍和分析,并结合混响室技术对MIL-STD-464A给出的舰船甲板上工作的外部电磁环境(200 MHz～4.2 GHz)进行了实验室模拟.结果表明,现有的测试仪器能够模拟出MIL-STD-464A中的强射频环境.     

长三角大都市带人口容量与资源环境支撑能力建设

为推动长三角都市带人口稳定扩容,寻求提高长三角地区资源环境支撑能力的途径。基于国外已经成熟的大都市带,认为产业集聚规模、资源支撑条件、环境承受能力是影响大都市带人口容量的主要因素。根据预测,长三角都市带未来的人口规模为107亿~117亿。通过对支撑长三角都市带经济-人口容量的资源环境要素分析,认为扩大长三角地区的人口容量,关键在于提高长三角地区资源环境的支撑能力,认为未来经济发展所需各类用地保障程度的高低、战略性矿产资源供〖JP2〗给能力的强弱以及区域环境容量的大小是影响长三角都市带人口容量大小的关键因素。建议在国家层面通过土地政策的调整提高长三角大都市带各类功能用地的保障能力,通过建立国家石油储备制度等方式加强战略性矿产资源供给能力建设,同时在长三角大都市带地区率先实施循环经济战略。