Inorganic pollution in water—the analyst's viewpoint†

Inorganic pollution comprises both major and minor constituents, although only 12 chemical elements may be considered major components. Twenty‐eight elements constitute a group of common minor elements and an additional 13 elements comprise a group of less common minor constituents. Reliable quantitative data are required on the occurrence of these substances in a wide variety of water types, usually at extremely low concentrations. The analysis of standard reference water samples provides information on the overall reliability of water‐quality data. Although most major constituents may be determined with acceptable reliability, determinations of certain minor constituents lack comparable precision; for example, determinations of boron, nickel, and chromium. Few precision data are available on the determination of the less common trace elements. Several comparatively new analytical techniques, such as flameless atomic absorption spectrophotometry, voltammetry, and emission spectroscopy with plasma excitation, appear capable of providing improved sensitivity.     

无机离子对光催化水处理过程影响的研究进展

无机离子在自然水体和生产废水中广泛存在。在不同的反应体系,无机离子对光催化反应的影响不同。深入了解无机离子对光催化水处理过程的影响有助于研究光催化反应的机制,增强金属离子与有机污染物光催化反应的协同作用,提高光催化反应的效率。     

超临界二氧化碳萃取环境样品中金属离子的研究进展

原位络合的超临界萃取技术开辟了超临界二氧化碳（ＳＣ－ＣＯ２）萃取金属离子的新途径。本文综述国外有关ＳＣ－ＣＯ２萃取环境样品中金属离子的原理、流程、应用及影响因素等方面的研究进展,并相信随着研究工作的不断深入,更加理想的络合剂和ＳＣ－ＣＯ２携带剂的发现,必将使ＳＣ－ＣＯ２萃取金属离子的技术在环境样品中痕量金属离子的前处理和分析以及有害金属离子的处理等方面的应用前景更为广阔     

Removal of heavy metals using waste eggshell

The removal capacity of toxic heavy metals by the reused eggshell was studied.As a pretreatment process for the preparation of reused material from waste eggshell,calcination was performed in the furnace at 800℃for 2 h after crushing the dried waste eggshell.Calcination behavior,qualitative and quantitative elemental information,mineral type and surface characteristics before and after calcination of eggshell were examined by thermal gravimetric analysis(TGA),X-ray fluorescence (XRF),X-ray diffraction(XRD) and scanning electron microscopy(SEM),respectively.After calcination,the major inorganic composition was identified as Ca(lime, 99.63%)and K,P and Sr were identified as minor components.When calcined eggshell was applied in the treatment of synthetic wastewater containing heavy metals,a complete removal of Cd as well as above 99% removal of Cr was observed after 10 min. Although the natural eggshell had some removal capacity of Cd and Cr,a complete removal was not accomplished even after 60 min due to quite slower removal rate.However,in contrast to Cd and Cr,an efficient removal of Pb was observed with the natural eggshell rather than the calcined eggshell.From the application of the calcined eggshell in the treatment of real electroplating wastewater, the calcined eggshell showed a promising removal capacity of heavy metal ions as well as had a good neutralization capacity in the treatment of strong acidic wastewater.     

赤泥对电解锰渣中可溶性锰离子固化效果研究

为了探讨赤泥固化电解锰渣中可溶性锰离子的固化效果和可行性,本文采用X射线衍射(XRD)、电子扫描显微镜(SEM)和X射线荧光光谱(XRF)等分析手段,对比评估了新鲜赤泥、陈旧赤泥(堆放1年以上)、生石灰以及陈旧赤泥复合生石灰等固化剂在不同添加剂量下对电解锰渣中可溶性锰离子的固化效果,并初步阐释了赤泥固化电解锰渣中可溶性...     

Impact of Post-Methanation Distillery Effluent Irrigation on Groundwater Quality

Molasses-based distilleries generate large quantities of effluent, which is used for irrigation in many countries including India. The effluent is rich in organic and inorganic ions, which may leach down and pollute the groundwater. An on-farm experiment was conducted to assess the impact of long-term irrigation with post-methanation distillery effluent (PMDE) on nitrate, sulphate, chloride, sodium, potassium, and magnesium contents in the groundwater of two sites in northwest India. Electrical conductivity (EC), pH, total dissolved solids (TDS), sodium adsorption ratio (SAR) and colour were also determined to assess the chemical load in the groundwater. Nitrate content in the groundwater samples ranged from 16.95 mg L⁻¹ in the unamended fields to 59.81 mg L⁻¹ in the PMDE-amended fields during the 2-year study (2001–2002). Concentrations of TDS in water samples from tubewell of the amended field was higher by 40.4% over the tubewell water of the unamended field. Colour of the water samples of the amended fields was also darker than that of the unamended fields. The study indicated that the organic and inorganic ions added through the effluent could pose a serious threat to the groundwater quality if applied without proper monitoring.     

聊城市冬季PM2.5及水溶性离子污染特征及来源分析

为研究聊城市冬季PM_2.5污染特征,于2016年1月7-29日在聊城市区对PM_2.5样品进行了采集,并对其水溶性离子（包括F-、Cl-、NO₃-、SO₄2-、NH₄+、Ca2+、Na+、Mg2+、K+）进行了分析.结果显示:观测期间聊城市ρ（PM_2.5）平均值为（192.4±88.9）μg/m3,超过GB 3095-2012《环境空气质量标准》日均二级标准限值的1.6倍.水溶性离子质量浓度为（77.4±46.9）μg/m3,占ρ（PM_2.5）的40.2%,其中SNA（NO₃-、SO₄2-和NH₄+）为主要离子,占水溶性离子比例达82.5%.轻度、中度、重度及严重污染时PM_2.5中水溶性离子质量浓度分别为（32.49±3.67）（46.26±17.66）（77.11±11.64）和（139.21±51.71）μg/m3,SNA分别占ρ（PM_2.5）的24.4%、26.7%、30.4%和39.0%,随着污染程度加重,SNA比例升高.观测期间SOR（硫转化率）与NOR（氮转化率）的平均值分别为0.18和0.20,随着ρ（PM_2.5）升高,SOR及NOR明显上升,表明冬季PM_2.5污染越严重时SO₂与NO₂的转化速率越强,二次无机污染严重.主成分分析结果表明,二次转化、扬尘源及工业生产为水溶性离子的主要来源.后向气流轨迹结果显示,观测期间污染气团主要来源于西北方向,受内蒙古及河北城市影响较大,但当污染气团来源于周边城市且天气静稳时,颗粒物浓度最高.研究显示,聊城市冬季PM_2.5污染较为严重.      

Study on the simultaneous reduction of methylmercury by SnCl2 when analyzing inorganic Hg in aqueous samples

Mercury (Hg) is among the most concerned contaminants in the world. It has three major chemical forms in the environment, including Hg⁰, Hg^2 +, and methylmercury (MeHg). Due to their differences in toxicity, mobility, and bioavailability, speciation analysis is critical for understanding Hg cycling and fate in the environment. SnCl₂ reduction-atomic fluorescence spectrometry detection is the most commonly used method for analyzing inorganic Hg. However, it should be noted that MeHg may also be reduced by SnCl₂, which would result in the overestimation of inorganic Hg. In this study, the reduction of MeHg by SnCl₂ in both de-ionized (DI) water and four natural waters was investigated. The results showed that MeHg could be reduced by SnCl₂ in DI water whereas this reaction was hard to occur in tested natural waters. By investigating the effects of water chemical characteristics (dissolved organic matter, pH and common anions and cations) on this reaction, SO₄^2 ? was identified to be the dominant factor prohibiting SnCl₂ induced MeHg reduction in natural waters. SO₄^2 ? in natural waters was evidenced to be reduced to S^2 ? by SnCl₂ and the generated S^2 ? can complex with MeHg to form MeHgS^? which is hard to be reduced by SnCl₂. Findings of this study indicate that the effect of MeHg reduction by SnCl₂ on inorganic Hg analysis is negligible in natural waters; however, at simulated experimental systems without SO₄^2 ?, SO₄^2 ? should be added as protecting agents to prevent MeHg reduction when analyzing inorganic Hg if it would not cause any other unwanted effects.     

典型“组群式”城市夏季大气颗粒物中水溶性离子化学特征及来源

为探究典型“组群式”城市——淄博市夏季大气颗粒物中水溶性离子化学特征及来源,于2016年8月对淄博市6个城市点（桓台、张店、临淄、淄川、博山、周村）、2个郊区点（沂源、高青）及1个清洁对照点（鲁山）同步进行PM_2.5和PM₁₀采样,分析了大气颗粒物质量浓度及9种水溶性离子的空间分布特征,并利用主成分分析方法探讨了PM_2.5和PM₁₀中水溶性离子的主要来源.结果表明:①淄博夏季各点位（清洁对照点除外）PM_2.5和PM₁₀质量浓度日均值范围分别为57.2~112和77.4~163 μg/m3,空间分布特征表现为城市点>郊区点>清洁对照点;各点位PM_2.5/PM₁₀（质量浓度之比）在0.61~0.80之间,表明淄博夏季大气颗粒物污染以PM_2.5为主.②水溶性离子在PM_2.5和PM₁₀中占比分别为53.3%和48.5%,其中二次无机离子分别占总离子浓度的91.4%和83.7%,表明大气颗粒物主要以二次离子为主,并且主要富集在PM_2.5中;PM_2.5中∑阴离子/∑阳离子（摩尔浓度之比）为1.07,PM₁₀中该比值为0.87,说明PM_2.5接近中性,而PM₁₀呈弱碱性.③淄博夏季各点位离子来源具有一定的空间差异性,城市点、郊区点与清洁对照点间的CD（分歧系数）均高于0.2,而城市点间CD值低于0.2,说明城市点位间的水溶性离子的化学性质较为相似.④主成分分析表明,淄博夏季大气PM_2.5中的水溶性离子可能主要来源于工业源、生物质锅炉、燃煤、二次源、道路尘及建筑尘,而PM₁₀中的离子主要来源于道路尘、建筑尘、海盐及二次源.研究显示,淄博市颗粒物污染严重,具有明显的空间分布特征,水溶性离子来源复杂,应采取分区、多源控制的污染防治对策.