AAS与ICP—AES间接测定天然水中硫酸盐

本文以ＳＯ４＾２－与过量Ｂａ＾２＋形成ＢａＳＯ４沉淀反应为基础，较详细地讨论了反应条件，从而拟定了用ＡＡＳ和ＩＣＰ－ＡＥＳ间接测定天然水中ＳＯ４＾２－的方法、确定了方法的精密度，ＡＡＳ法的ＲＳＤ％为１．５，ＩＣＰ－ＡＥＳ法为３．２， 两种方法对比分析的结果接近，误差为１．０％（相对）。用于天然水中ＳＯ４＾２－的测定，获得满意的结果。     

重金属离子对络合法（EDTA）测定Ca^2＋的干扰及其消除

用ＥＤＴＡ法测定Ｃａ＾２＋时，对Ｆｅ＾３＋，Ｃｕ＾２＋，Ｐｂ＾２＋，Ｍｎ＾２＋的干扰进行了试验，分别得出了最小干扰浓度，不同的干扰离子和浓度。采用不同的方法消除，效果良好。     

Fe^2＋,Mn^2＋在制革废水处理中的作用机理

本文介绍了制革废水混合处理工艺，对采用Ｆｅ＾２＋，Ｍｎ＾２＋，Ｏ２对Ｓ＾２－进行催化、氧化和沉淀预处理的方法进行了实验室试验和机理分析，证明，Ｆｅ＾２＋，Ｍｎ＾２＋，Ｏ２的协同催化，氧化，沉淀作用作为制革废水的一级处理是很有效的，并且在经济上也具有优势。     

都匀市降水pH值的变化趋势及特征分析

ｐＨ值是衡量降水酸性的重要指标。本文研究了都匀市降水ｐＨ值的变化趋势，并对其酸性降水的特征进行分析，提出了保护大气质量，降低酸雨频率的对策建议。     

西宁市区酸雨状况分析

用西宁市区１９９２～１９９４年１７８个酸雨观测降水样本，对降水的ｐＨ值和电导率做了统计，并结合气象条件进行了分析。经统计分析发现：西宁市区酸雨降水样本９个，酸性降水量达１０６．５ｍｍ，酸雨的频率为５．１％，占总降水量的８．６９％，降水的年平均ｐＨ值（ｐＨ）为６．４６属中性，酸雨多发生在暖季（５～９月）。     

TBP柱填料萃取回收铁钍渣浸出液中钍的研究

将ＴＢＰ固定于多孔载体上，用于萃取硝酸水溶液中的钍。实验表明，萃取分配比高，萃取容量大，能有效地防止乳化现象。将ＴＢＰ柱填料制备成填充柱，对含Ｔｈ＾４＋，Ｆｅ＾３＋和Ｃｅ＾３＋的铁钍渣浸出液进行萃取实验得出：当溶液硝酸浓度为４ｍｏｌ／ｌ，接触时间为１０ｍｉｎ时，萃余液中Ｔｈ＾４＋浓度粘于０．０１ｍｇ／ｌ。１ｇＴＢＰ柱填料可萃取的０．２５ｇ，反萃液中钍浓度为６２．５ｇ／ｌ，Ｆｅ＾３＋和Ｃｅ＾３＋的含     

微生物传感器技术原理及其在水环境监测中的应用

微生物传感器技术产生于７０年代，并且，已在水环境监测中得到应用，例如，ＢＯＤ、ＮＨ３、ＮＨ４＾＋、ＮＯ２＾－、ＮＯ３＾－等项目分析；毒物测定和毒性评价；致突变物的筛选等。实践证明，该项技术具有快速、灵敏、易于自动控制、成本低廉等优点；可以相信，它必定会越来越多的应用于环境监测。     

湿法处理工业废渣热力学分析

根据冶金，煤炭及无机化工工业类废渣的物理化学性质，通过Ｍ＾ｎ＋ ｅ－Ｈ２Ｏ系和Ｍ＾ｎ＋ｅ－Ｆ＾－Ｈ２Ｏ系热力学平衡图，对废渣中硅，铝，铁及钙镁等主要矿物的溶出热力学行为进行了分析。     

选择双波长光度法测定天然水中溶解氧

本文依据悬浮液对光的吸收行为研究ＤＯ与Ｍｎ＾２＋－Ｉ＾－－Ｈ＾＋反应液吸收光谱，发现在５２０－６００ｎｍ波长范围内其光谱与悬浊液光谱相平行，由此研究在此波长内任意选择双波长测定痕量锰的新方法，实验结果表明该方法灵敏度和精密度均较传统容量法高，计算曲线稳定性好，适合于天然水分析。     

ClO2处理含铁,锰及细菌饮用水的应用研究

为了除去水中高含量的铁，锰及细菌，采用ＣｌＯ２氧化Ｆｅ＾２＋，Ｍｎ＾２＋和灭菌的方法。研究结果表明，处理后水平铁，锰都末检出，细菌指标符合国家饮用水标准。此法具有工艺简单，操作方便，反应速度快，去除率极高，不产生致癌物质ＴＨＭ、且能很好地除水中的异味及色度等优点。此法适用于各种生活给水系统。     

南充市近十年酸雨变化特征及降水化学组成研究

依据南充市2003~2012年城区降水环境监测统计资料,分析了酸雨变化特征及降水离子化学组成。研究表明:这十年,酸雨频率平均为50.4%,2007年降雨量为最高,呈波动递减趋势变化,降水年平均pH值为4.88,呈现"低—高—低"的变化特征,城区酸雨频率和降水pH值月均值变化呈现高低交替的波动趋势。城区降水中主要阳离子成分是Ca2+,主要阴离子成分是SO2-4和NO-3。(SO2-4/NO-3)比值逐年下降,平均比值为7.82,酸雨污染类型仍以硫酸型为主;降水(NH+4+Ca2+)/(SO2-4+NO-3)和Ca2+/NH+4比值呈波动性变化,2007年分别达到最高值为6.71和50.27,除2010年比值均较低小于1外,近年来均有增加趋势,表明碱性离子缓冲能力增强了,降水酸度降低,pH值增加,但2007年pH值较低,主要与降雨量有关。综合分析,降水酸度不仅是酸性离子和碱性离子中和作用,也受其他离子浓度和降雨量、风向等气候条件、距离传输以及地形等影响。     

Leaching from organic matter-rich soils by rain of different qualities: I. Concentrations

Soil monoliths from an area exposed to acid precipitation and from an unpolluted area were used in a lysimeter experiment to study effects of different rain qualities on the chemical composition of the leachate from shallow soils rich in organic matter. The vegetation was either dominated by moorgrass [Molinia caerulea (L.) Moench] or heather [Calluna vulgaris (L.) Hull]. The lysimeters received either "acid rain" (pH 4.3) or "normal rain" (pH 5.3). High concentrations of dissolved organic carbon (DOC) were characteristic of the leachate. The different "rain" qualities had no significant influence on the DOC concentration. More DOC was, however, leached from lysimeters with heather vegetation. Roughly 50% of the aluminum (Al) was in complex with organic material and the Al charge was calculated to be between +1.4 and +2.0. Sulfate (SO4(2-)) was the only component that was significantly influenced by the treatment, as more was leached from lysimeters receiving "acid rain." Sulfate was poorly correlated with pH, suggesting that reduced SO4(2-) input would not necessarily lead to reduced acidity. Differences in the pH of the leachate due to the treatments were less than 0.15 pH units. Nitrate (NO3-) was only leached in very low concentrations and of little consequence for the leachate acidity. Some observations do, however, suggest that NO3- may contribute to acidification in episodes with high precipitation. High concentrations of Cl- in the leachate and a significant positive correlation between Cl-, H+, and base cations indicate that sea salt episodes may be important for soil acidification and acidity of the leachate.     

The effects of throughfall manipulation on soil leaching in a deciduous forest

The effects of changing precipitation on soil leaching in a deciduous forest were examined by experimentally manipulating throughfall fluxes in the field. In addition to an ambient treatment (AMB), throughfall fluxes were reduced by 33% (DRY treatment) and increased by 33% (WET treatment) using a system of rain gutters and sprinklers on Walker Branch Watershed, Tennessee. Soil leaching was measured with resin lysimeters in the O horizons and with ceramic cup lysimeters in the E (25 cm) and Bt (70 cm) horizons. Large and statistically significant treatment effects on N fluxes were found in the O horizons (lower N fluxes in the DRY and higher N fluxes in the WET treatment). Together with the greater O horizon N content observed in the DRY treatment, this suggested that N was being immobilized at a greater rate in the DRY treatment than in the AMB or WET treatments. No statistically significant treatment effects on soil solution were found in the E horizons with the exception of (Ca2+ + Mg2+) to K+ ratio. Statistically significant treatment effects on electrical conductivity (EC), pH, Ca2+, Mg2+, K+, Na+, SO4(2-), and Cl- were found in the Bt horizons due to differences between the DRY and other treatments. Despite this, calculated fluxes of Ca2+, Mg2+, K+, Na+, SO4(2-), and Cl- were lowest in the DRY treatment. These results suggest that lower precipitation will cause temporary N immobilization in litter and long-term enrichment in soil base cations whereas increased precipitation will cause long-term depletion of soil base cations.     

宜宾市酸雨pH值预测的偏最小二乘回归分析

酸雨pH值受酸性离子(有机酸、无机酸)和碱性离子的影响。这些影响因素之间存在多重相关性。用一般最小二乘回归法建模预测pH值,估计参数存在着很大的误差,而且物理意义明显不足。本文以宜宾市区2002-2003年的27组降雨监测数据作为样本数据,应用偏最小二乘回归技术建立pH值预测模型,克服了自变量之间的多重相关性的问题。与最小二乘回归法相比更具有先进性,计算结果更为可靠;在确定了模型可行性后,分析比较了影响宜宾市区酸雨pH值的离子的重要性和离子来源。     

用灰色系统理论GM(1,1)建立大气降水中酸雨pH值的预测模型

本文用灰色系统理论GM(1,1)建立了大气降水中pH值的预测模型。经三种不同方法检验。对我市1990—1993年大气降水中酸雨pH值进行了预测,结果令人满意。     

STRATEGIES FOR SEPARATING METALS FROM ACID MINE WATERS1

ABSTRACT: Strategies for the precipitation and separation of the primary metal ions, Fe(II), Cu(II), Zn(II), Mn(II), and Cd(II) in acid waste waters such as those in tributaries of the upper Sacramento River in northern California, are discussed. The strategies exploit the: (1) differential oxygen and hydrogen peroxide oxidation and precipitation properties of the metal ions as a function of pH, (2) the addition of ions, such as Mg^{2 +} and Cl^-, to reduce unfavorable coprecipitation, and (3) the facilitation of oxidation-reduction reactions between metal ions and the stabilization of particular oxidation states. This may be accomplished with specific complexing agents such as thiocyanate, SCN^-, and thiourea (TU), S = C(NH₂)₂ in order to separate copper at low pH as Cu(I) using Fe(II) as a reducing agent.     

常用氧化剂性能研究

用四种常用的氧化剂:高锰酸钾、漂白粉、NaClO和H2O2/Fe2+对大港油田港深11井酸化废水进行了处理。考察了氧化剂的投加量、氧化时间和pH值对酸化废水色度和COD去除率的影响。实验结果表明,在最佳条件下,H2O2/Fe2+对酸化废水的色度和COD的去除率最高;用高锰酸钾处理废水,其COD去除率较高,但脱色效果差;而漂白粉和NaClO的脱色率较高,但其氧化能力有限。建议油田用氧化法处理废水时应采用H2O2/Fe2+催化氧化体系。     

四川盆地降水背景点及其降水化学组份的研究

本文对四川自然保护区降水化学组份的研究,作为四川盆地的酸雨背景值,并与国内其它降水背景值进行比较。研究结果表明四川降水背景值pH>5.6,pH值变化相对比较稳定,降水化学组份浓度较低,也说明盆地外来源的污染物对盆地内的贡献是不明显的。     

Adsorption-desorption behavior of copper at contaminated levels in red soils from China

Adsorption-desorption of copper (Cu2+) at contaminated levels in two red soils was investigated. The red soil derived from the Quaternary red earths (clayey, kaolinitic thermic plinthite Aquult) (REQ) adsorbed more Cu2+ than the red soil developed on the Arenaceous rock (clayey, mixed siliceous thermic typic Dystrochrept) (RAR). The maximum adsorption values (M(A)) that are obtained from the simple Langmuir model were 25.90 and 20.17 mmol Cu2+ kg(-1) soil, respectively, for REQ and RAR. Adsorption of Cu2+ decreased soil pH, by 0.8 unit for the REQ soil and 0.6 unit for the RAR soil at the highest loadings. The number of protons released per Cu2+ adsorbed increased sigmoidally with increasing initial Cu2+ concentration for the RAR soil, but the relationship was almost linear for the REQ soil. The RAR soil released about 2.57 moles of proton per mole of Cu2+ adsorbed at the highest Cu2+ loading and the corresponding value for the REQ soil was 1.12. The distribution coefficient (Kd) decreased exponentially with increasing Cu2+ loading. Most of the adsorbed Cu2+ in the soils was readily desorbed in the NH4Ac. After five successive extractions with 1 mol L(-1) NH4Ac (p 5.0), 61 to 95% of the total adsorbed Cu2+ in the RAR soil was desorbed and the corresponding value for the REQ soil was 85 to 92%, indicating that the RAR soil had a greater affinity for Cu2+ than the REQ soil at low levels of adsorbed Cu2+.