Elemental sulfur effects on Pb and Zn uptake by Indian mustard and winter wheat

A pot experiment was conducted to investigate the influence of elemental sulfur to contaminated soil on plant uptake by a heavy metal hyperaccumulator, Indian mustard( Brassica juncea ) and a field crop, winter wheat( Triticum. aestivum). Elemental sulfur(S) with different rates was carried out, they were 0(S0 ), 20(S20 ), 40(S40 ), 80(S80 ), and 160(S160 ) mmol/kg respectively. Extra pots with the same rates of S but without plants were used for soil sampling to monitor pH and CaCl2-extractable heavy metal changes. The results showed that S enhanced phytoextraction of Pb and Zn from contaminated soil. Application S effectively decreased soil pH down to 1.1 as the most at the rate of Sl60. The concentrations of CaCl2-extractable Pb and Zn in soil and uptake of Pb and Zn by the plants were increased with soil pH decreased. A good correlation between CaCl2-extractable Pb/Zn and soil pH was found( Rpb^2 = 0.847 and RZn^2 = 0,991, n = 25). With S application, soil CaCl2-extractable Pb and Zn concentrations, concentration of Pb and Zn in plants and the amount of removal by plant uptake were significanfly higher than those without S. Under the treatment of S160, the highest CaCl2-extmctable Pb and Zn were observed, they were 4.23 mg/kg and 0.40 mg/kg, 2.7 and 2.0 times as that of the control(So ) respectively. At the highest rates of S( Sl~0 ), both Indian mustard and winter wheat reached the highest uptake of Pb and Zn. The highest Pb concentrations in wheat and Indian mustard were 32.8 mg/kg and 537.0 mg/kg, all 1.8 times as that of the control, and the highest Zn concentrations in wheat and Indian mustard were 215.5 mg/kg and 404.0 mg/kg, 2.4 and 2.0 times as that of the control respectively. The highest removals of Pb and Zn from the contaminated soil were 0.41 rag/pot and 0.31 nag/pot by Indian mustard in the treatment of S160 through 50 days growth.     

降低总氮测定空白的方法改进

根据GB11894—89《水和废水监测分析方法》中水质总氮测定方法，发现空白值有增高现象，通过研究证明，氧化时间的长短、蒸馏水纯度的高低、碱性过硫酸钾存储时间的长短以及实验室环境等都会对总氮空白测定值有影响，文章对以上因素进行逐一分析和实验对比，明确了影响因素，提出了改进建议。     

测定空气SO2校准曲线斜率,试剂空白值影响因素的探讨

空气ＳＯ２的测定对实验测定条件比较敏感。通过实验，显色时间、显色温度、ＰＲＡ纯度、蒸馏水质量等试验条件均对其校准曲线有影响，所以在实验分析过程中，必须严格把握操作条件，严格遵循操作步骤。     

玉溪市中心城区酸雨变化趋势分析

以1991年至2000年实测数据为依据，揭示了玉溪市中心城区10年来酸雨的变化规律及其发展趋势。     

抚顺市降水污染现状分析

在抚顺市区设置5个监测点位，监测抚顺1998年6月～1999年5月的降水状况。结果表明，抚顺市区降水pH值基本呈中性，酸雨出现频率为6.9%，酸雨主要出现在雨量大的降水中。降水中主要的阴离子是SO4^2-，阳离子是Ca^2 、NH4^ ，抚顺市区的降水酸度是由这三种离子的相互关系决定的。     

土壤中水溶氟与总氟和土壤PH值的相关分析

使用实测资料，利用数理统计方法分析了土壤中水溶氟与总氟和土壤ＰＨ值三者间的相关关系，提出了在背景地区，土壤水溶氟与总氟、土壤ＰＨ值间无相关性；与土壤ＰＨ值间无相关性的结论。     

宜春市酸雨污染加剧

宜春市１９８３～１９９３年降水酸度ｐＨ年日均值由６．１３降至５．４６，最低ｐＨ值达３．１５，酸雨频率由３５．５％上升至５６．６％，酸雨污染加剧。     

总量控制下的大气环境影响评价与技术支持系统

基于浓度控制的大气环境影响评价内容与大气污染物总量控制管理办法的不协调性，探讨了大气总量控制技术支持系统，提出总量控制前提下的大气环评思路，在总量控制区依据A－P值法和窄烟云稀释矩阵反演模型制定城市大气总量控制发展规划；应用多源扩散模型计算总允许排放量。在进行各源允许排放量削减并优化调整的基础上，根据建设项目所在区域大气环境容量，给出了允许排放量和排放源强。     

密切值法在企业环境经济效益评价中的应用

本文将多目标决策中的密切值法应用于企业环境经济效益的评价，通过实例分析，并与灰色综合评判法、多级模糊层次综合评价法比较。认为该方法简便、适用、分辨率也高；不须加“权”，评价结果与实际情形相符合。     

吸光度比值一导数光谱法的应用研究

根据吸光度比值一导数光谱法兼具导数光谱法可消除低频背景干扰，以及MLRA法光谱分辨能力强的特点，研究了用该方法测定苯酚和间苯二酚二元混合物的有效性。结果表明，吸光度比值一导数光谱法对模拟样品的测定分析达到了检测要求；该方法具有良好的精密度与准确度，用于吸收峰严重重叠的二元混合物时，毋须对干扰组分分离而可直接测定，方法简便快速，利于推广。