水体中总氮检测的方法研究

使用碱性过硫酸钾氧化紫外分光光度法(GB 11894—1989)测定水中的总氮时,在严格按该方法分析步骤操作的情况下,依然会出现空白值偏高、检测结果不准确等问题。本文对水中总氮检测过程中的影响因素进行了总结、分析,对需要重点注意的环节进行了探讨,找出了问题的原因并提出了解决方法。     

内配燃料垃圾焚烧飞灰烧结无害化处理实验研究

研究了一种垃圾焚烧飞灰烧结无害化处理的工艺,该工艺是将飞灰与不同比例煤粉混合并添加助熔剂进行造粒烧结。通过对试样进行热流和热重测量,分析了飞灰试样在加热过程中热重变化的规律,并利用XRD、扫描电镜、氮吸附分析仪等仪器分析手段对烧结试样的物相、微观形态和孔隙特性等物理化学性质进行了研究。最后采用电感耦合等离子体发射光谱仪对烧结试样重金属浸出性进行了分析。实验结果为飞灰烧结炉的设计和内配燃料烧结工艺运行参数的制定提供了依据。     

原子荧光冷汞法测定地表水中的汞

建立原子荧光冷汞法测定地表水中的汞,通过实验及查阅相关资料对部分实验条件,如仪器的负高压和灯电流、屏蔽气和载气的流量、硼氢化钾和氢氧化钠的浓度、酸及其浓度等进行了优化。在最佳实验条件下汞的检出限为0.019μg/L,相关系数r>0.999,加标回收率为93.7%～106.4%,相对标准偏差0.79%～3.59%。实验结果表明:原子荧光冷汞法测定地表水中的汞具有简便、快速、清洁、高效、安全等优点,灵敏度高、精确度和准确度好、检出限低,是测定地表水中汞含量的有效方法。     

不同稳定剂对污染沉积物中重金属的稳定效果

采用壳聚糖、单宁酸和羟基磷灰石对沉积物中的重金属进行稳定化处理,并运用毒性浸出方法(TCLP)和重金属形态变化来评价其稳定效果.结果表明:壳聚糖、单宁酸及羟基磷灰石对于沉积物中重金属具有明显的稳定效果,羟基磷灰石对4种重金属Pb、Cu、Zn和Cd的稳定效率最高,分别达到90.03%、80.46%、60.40%和79.23%,单宁酸次之,壳聚糖对Zn的稳定效率随添加量增大而略有下降;羟基磷灰石使Pb、Cu、Zn和Cd的稳定态比例分别增加30.55%、16.83%、11.43%和15.39%,稳定态增加比例明显大于壳聚糖和单宁酸.      

沙尘天气过程对北京空气质量的影响

利用气象、沙尘暴特种观测以及环境监测等多种资料,对2010年3月19─22日沙尘天气过程的大气结构、沙尘源地和垂直水平输送条件以及北京近地层气象要素、空气质量的变化特征进行了分析. 结果表明:这次强沙尘暴天气过程是由冷空气短波槽快速东移南下、地面冷锋明显发展东移造成的;前期沙尘源地土壤湿度的减小为起沙提供了有利条件,同时低层存在的较强西北气流将从源地卷起的沙尘输送到下游地区;沙尘发生时,20 m气层内风速迅速增大,气层内垂直方向风速梯度也逐渐增大,相对湿度急剧降至20%～30%之间;受这次沙尘天气影响,北京地区ρ(TSP)以及10个区县的ρ(PM10)均迅速增加,空气质量达到重污染.      

加热炉炉管穿孔事故处理及原因分析

以一起直接式原油加热炉炉管穿孔事故为例,介绍了事故处理程序,分析了炉管穿孔的原因是由于漏点腐蚀、坑点腐蚀以及炉管管卡损坏导致的,并提出了类似事故防范对策.     

济源市平原区农田重金属污染特征及综合风险评估

铅锌冶炼区农田重金属污染问题受到广泛关注.本研究通过区域调查和空间分析明确济源市东部平原区农田土壤-小麦重金属污染特征,应用富集因子、潜在生态风险指数法和Monte Carlo模拟方法评估区域土壤重金属生态风险以及小麦Cd和Pb健康风险.结果表明：土壤Cd、Pb、Cu和Zn平均含量分别为1.51、97.1、29.0和79.5 mg·kg^-1,均高于河南省土壤元素背景值.其中74.2%和10.8%的样点Cd、Pb含量分别超过农田土壤风险筛选值,61.3%和40.9%的样点小麦Cd、Pb含量分别超过国家食品安全限量标准.富集因子研究结果表明土壤Cd污染程度最高.高风险区主要分布在西南部、西北部和中东部以铅锌冶炼为主的工业区.健康风险评估结果显示研究区小麦Cd非致癌风险和致癌风险高于国际推荐安全值的概率分别高达27.5%和100%.济源市小麦田Cd、Pb累积显著,需引起当地有关部门足够关注.空间分析与风险评价结果相结合,可以有效辨识高风险区域,进而为研究区污染防治和管控提供理论依据.     

Aerosol optical properties under different pollution levels in the Pearl River Delta (PRD) region of China

To clarify the aerosol hygroscopic growth and optical properties of the Pearl River Delta(PRD)region,integrated observations were conducted in Heshan City of Guangdong Province from October 19 to November 17,2014.The concentrations and chemical compositions of PM_2.5,aerosol optical properties and meteorological parameters were measured.The mean value of PM_2.5 increased from less than 35(excellent) to 35-75 μg/m³(good) and then to greater than 75 μg/m³(...     

Phosphate recovery with granular acid-activated neutralized red mud: Fixed-bed column performance and breakthrough curve modelling

Granular acid-activated neutralized red mud(AaN-RM) has been successfully prepared with good chemical stability and physical strength.However,its potential for industrial application remains unknown.Therefore,the performance of granular AaN-RM for phosphate recovery in a fixed-bed column was investigated.The results demonstrated that the phosphate adsorption performance of granular AaN-RM in a fixed-bed column was affected by various operational parameters,such as the bed depth,flow rate,initial...     

Performance of different macrophytes in the decontamination of and electricity generation from swine wastewater via an integrated constructed wetland-microbial fuel cell process

Plants constitute a major element of constructed wetlands(CWs).In this study,a coupled system comprising an integrated vertical flow CW(IVCW) and a microbial fuel cell(MFC) for swine wastewater tre atment was developed to research the effects of macrophytes commonly employed in CWs,Canna indica,Acorus calamus,and Ipomoea aquatica,on decontamination and electricity production in the system.Because of the different root types and amounts of oxygen released by the roots,the rates of chemical oxygen demand(COD) and ammonium nitrogen(NH_4~+-N) removal from the swine wastewater differed as well.In the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,the COD removal rates were 80.20%,88.07%,84.70%,and 82.20%,respectively,and the NH_4~+-N removal rates were 49.96%,75.02%,70.25%,and 68.47%,respectively.The decontamination capability of the Canna indica system was better than those of the other systems.The average output voltages were 520±42,715±20,660±27,and 752±26 mV for the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,respectively,and the maximum power densities were 0.2230,0.4136,0.3614,and0.4964 W/m~3,respectively.Ipomoea aquatica had the largest effect on bioelectricity generation promotion.In addition,electrochemically active bacteria,Geobacter and Desulfuromonas,were detected in the anodic biofilm by high-throughput sequencing analysis,and Comamonas(Proteobacteria),which is widely found in MFCs,was also detected in the anodic biofilm.These results confirmed the important role of plants in IVCW-MFCs.