湖北省召开大气环境监测网站工作会议

会议对全省网络建设基本情况、网站设置内容落实情况、监测质量保证及网站建设中存在的问题等作了全面总结,讨论和修订了《湖北省大气环境例行监测技术规定》.省中心站还表扬了多年来不间断监测、上报数据齐全、报表清晰和规矩的网站,同时对今后网站工作提出了要求.     

Analysis of pollutant levels in central Hong Kong applying neural network method with particle swarm optimization

Air pollution has emerged as an imminent issue in modernsociety. Prediction of pollutant levels is an importantresearch topic in atmospheric environment today. For fulfillingsuch prediction, the use of neural network (NN), and inparticular the multi-layer perceptrons, has presented to be acost-effective technique superior to traditional statisticalmethods. But their training, usually with back-propagation (BP)algorithm or other gradient algorithms, is often with certaindrawbacks, such as: 1) very slow convergence, and 2) easilygetting stuck in a local minimum. In this paper, a newlydeveloped method, particle swarm optimization (PSO) model, isadopted to train perceptrons, to predict pollutant levels, andas a result, a PSO-based neural network approach is presented. The approach is demonstrated to be feasible and effective bypredicting some real air-quality problems.     

绘制氯气校准曲线的方法

甲基橙分光光度法测定氯气[1 ] 的机理是利用氯气氧化溴化钾 ,生成的溴能破坏甲基橙分子结构 ,使在酸性溶液中的甲基橙红色褪去 ,氯气含量越高 ,减色越明显。在用分光光度法测定时 ,吸光值是递减的 ,不同于一般的显色反应。因此 ,在绘制校准曲线时 ,标准系列的吸光值 ,不是通常的Ａ-Ａ0 ,而应采用Ａ0 -Ａ ,由此进行回归方程计算。同理 ,在样品测定时 ,也应以吸收液的吸光值Ａ吸-Ａ所得到的样品吸光值查出相应的含量。绘制氯气校准曲线的方法@丁建刚$泰兴市环境监测站!江苏泰兴225400 @殷红兰$泰兴市环境监测站!江苏泰兴225400 @屈红梅…     

Speciation of arsenic using solid phase extraction cartridges

Various solid phase extraction (SPE) cartridges were investigated for speciation of arsenite [As(III)], arsenate [As(v)], monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Cartridges containing different types of sorbent materials were tested for arsenic retention and elution characteristics. Alumina cartridges were found to completely retain all the four target arsenic species, and are suitable for removal and preconcentration purposes. For speciation analysis, different arsenic species were separated on the basis of their selective retention on and elution from specific cartridges. DMA was retained on a resin-based strong cation exchange cartridge and eluted with 1.0 M HCl. MMA and As(v) were both retained on a silica-based strong anion exchange cartridge and sequentially eluted with 60 mM acetic acid (for MMA) and 1.0 M HCl [for As(v)]. As(III) was not retained on either cartridge and remained in solution. Arsenic species in solution and those eluted from the cartridges were subsequently quantified by using flow injection with hydride generation atomic fluorescence spectrometry (FI-HGAFS) and hydride generation atomic absorption spectrometry (FI-HGAAS). A detection limit of 0.05 microg L(-1) arsenic in water sample was achieved using HGAFS. An application of the method was demonstrated at a drinking water treatment facility. As(III) and As(v) species were determined in water at various stages of treatment. The method is suitable for routine determination of trace levels of arsenic in drinking water to comply with more stringent environmental regulations.     

水中Mg~(2+)的测试管快速测定

研制了一种测定水中Mg2 + 的测试管 ,测定范围为 0 .5mg/L～ 2 .0mg/L。该测试管适用于现场应急监测 ,具有快速、简便、抗干扰能力强和价格低廉等特点     

Development of a diffusive sampling method for determination of methyl isocyanate in air

A diffusive sampling method for determination of methyl isocyanate in air has been developed. A glass fibre filter impregnated with 1-(2-methoxyphenyl)piperazine in a commercially available diffusive sampling device was used to collect methyl isocyanate and the derivative formed was analysed with LC-MS/MS. The sampling rate was determined to be 15.6 ml min(-1), with a relative standard deviation of 7.3%. The sampler was validated for sampling periods from 15 min to 8 h, for relative humidities from 20% to 80% and for concentrations from I to 46 microg m(-3). A field validation was also made and the diffusive sampling results showed no difference compared to a pumped reference method. The impregnated filters have to be stored apart from the diffusive sampler housing and loaded into the sampler prior to each sampling.     

Multi-objective, decision-based assessment of a water quality monitoring network in a river system

Water quality monitoring network design has historically tended to use experience, intuition and subjective judgement in locating monitoring stations. Better design procedures to optimize monitoring systems need to simultaneously identify significant planning objectives and consider a number of social, economic and environmental constraints. The consideration of multiple objectives may require further decision analysis to determine the preference weights associated with the objectives to aid in the decision-making process. This may require the application of an optimization study to extract such information from decision makers or experts and to evaluate the overall effectiveness of locating strategies. This paper assesses the optimal expansion and relocation strategies of a water quality monitoring network using a two-stage analysis. The first stage focuses on the information retrieval of preference weights with respect to the designated planning objectives. With the aid of a pre-emptive goal programming model, data analysis is applied to obtain the essential information from the questionnaire outputs. The second stage then utilizes a weighted multi-objective optimization approach to search for the optimal locating strategies of the monitoring stations in the river basin. Practical implementation is illustrated by a case study in the Kao-Ping River Basin, south Taiwan.     

用新制蒸馏水代替重蒸蒸馏水配制测定亚硝酸盐氮、氨氮、酚的试液

用新制蒸馏水代替重蒸蒸馏水配制测定亚硝酸盐氮、氨氮、酚的试液ＣｏｍｐｏｕｎｄｅｄＴｈｅＳｏｌｕｔｉｏｎＮｉｔｒｉｔｅ－Ｎ，Ａｍｍｏｎｉａ－ＮａｎｄＰｈｅｎｏｌＷｉｔｈＮｅｗ－ｍａｄｅＤｉｓｔｉｌｅｄＷａｔｅｒｉｎｓｔｅａｄｏｆＡｆｒｅｓｈＤｉｓｔｉｌ...     

山东省首家县级环境监测网在博山成立

为提高博山地区的整体环境监测能力,准确、及时、全面地掌握环境质量和污染源变化动态,根据《中华人民共和国环境保护法》、《全国环境监测网络管理规定》、《全国环境监测管理条例》等法律、法规的要求,山东省淄博市博山区于1996年1月19日率先在省内成立首家地区性环境监测网,即博山地区环境监测网(以下简称博山网)。     

微量铊~(Ⅲ)的螯合滴定

本文比较了4-(2-吡啶偶氮)间苯二酚(PAR)、1-(2-吡啶偶氮)-2-萘酚(PAN)、2-(2-噻唑偶氮)-5-二乙氨基苯酚(TAF)、二甲酚橙(XO)、2-(2-苯骈噻唑偶氮)-5-二乙氨基苯酚(BAE)、1-(2-噻唑偶氮)-2-萘酚(TAN)、4-(2-噻唑偶氮)间苯二酚(TAR)、甲基百里酚兰(MTB)等八种金属指示剂于直接螫合滴定微量铊(Ⅲ)的适宜酸度范围、适宜温度范围和可测范围。其中以PAR、PAN XO和TAE更适宜于微量铊(Ⅲ)的滴定,其测定最低限可达4微克铊(Ⅲ),且酸度范围也较广,终点变色敏锐。本文还讨论了以PAR、XO、TAE为指示剂滴定铊(Ⅲ)时,其它离子干扰情况以及部分干扰离子的消除方法。最后还以PAR为指示剂螫合滴定测定天然水和工厂废水中微量铊,以及铊(Ⅲ)和铊(Ⅰ)共存时的连续测定。