Potential application of 2-(6-ethylamino-3-ethylimino-2,7-dimethyl-3H-xanthen-9-yl) benzoic acid phenyl thiourea for mercury determination

Heavy metal contamination of the environment is a public health problem and research to develop new tools for monitoring the environmental impact of these elements is necessary. This study describes the preparation of a rhodamine-based probe 1 and its potential applications for detecting mercuric ion [Hg(II)] in samples from a nutrition media containing Salvinia auriculata. It was observed that an excess of probe 1 led to quenching in the fluorescence/absorption response, which was evidenced by a decrease in the signal when the stoichiometry differed from 1:1. Consequently, this probe is not suitable for quantitative analysis of Hg(II). Also, probe 1 reacts with methylmercury (MeHg) with different stoichiometry than that observed for Hg(II). These results indicate the potential application of probe 1 for qualitative detection of Hg(II) and MeHg in environmental samples.     

低能离子诱变产表面活性剂的烃降解菌研究

为有效治理石油污染土壤,从长期遭受石油污染的土壤中筛选出一株烃降解菌8-11作为出发菌,利用低能N+注入烃降解菌进行诱变,在能量为20 keV、剂量为90×2.6×1013ions/cm2条件下筛选出一株高效烃降解菌——诱变菌23。原油摇瓶发酵实验表明诱变菌对原油的降解率达到74%;降解后原油的全烃气相色谱图显示,经过7 d的作用,原油中的正构烷烃完全降解。诱变菌23能够产生大量的生物表面活性物质,傅里叶红外光谱分析表明其产生的生物活性物质为糖脂类化合物,该糖脂类生物表面活性剂能使发酵液的表面张力从空白对照的56.1 mN/m降低为29.3 mN/m。研究表明诱变菌23具有较高的烃降解能力,能有效降低表面张力,具有较大的应用潜力。     

Biosorption effects of copper ions on Candida utilis under negative pressure cavitation

Under the optimal condition of copper ions adsorption on yeast,we found some different effects among static adsorption, shaking adsorption and negative pressure cavitation adsorption, and the methods of yeast with different pretreatments also affect adsorption of copper ions. At the same time, the change of intercellular pH before and after adsorption of copper with BCECF was studied. The copper distribution was located by using PhenGreen （dipotassium salt and diacetate）, and the surface of yeast was observed by an atomic force microscope. The results showed that negative pressure cavitation can improve bioadsorption capacity of copper ions on yeast. However, the yeasts＇ pretreatment has a higher effect on bioadsorption. It indicates that heavy metal bioadsorption on yeast has much relation with its cellular molecule basis. With the adsorping, the intercellular pH of yeast increased gradually and changed from acidity to alkalescence. These results may suggest that negative pressure cavitation can compel heavy metals to transfer from the cell surface into inside cell and make the surface of yeast coarse.     

The formation of dithionate during the iron(III)-catalysed autoxidation of sulfur(IV)-oxides

The iron(III)-catalyzed autoxidation of sulfur(IV)-oxides results in the formation of two different oxidation products of sulfur(IV): dithionate, S₂O₆²⁻, and sulfate, SO₄²⁻. The yield of these reaction products depends on the experimental conditions. Under the studied conditions ([Fe(III)] : [SIV)] = 1:10, pH = 2–4) dithionate is the minor reaction product. The formation of dithionate is influenced by the initial pH but not by the initial O₂ concentration. The presence of CO²⁺, Mn²⁺, and Ni²⁺ have no influence on the yield of dithionate, whereas in the presence of Cr³⁺ less and, in the presence of Cu²⁺, no dithionate is formed.     

离子色谱法测定水中无机阴离子水样的预处理

本文介绍了用离子色谱法测定无机阴离子，对污染严重的水样通常采用预处理柱法。论述了预处理柱的制备、再生，测定了预处理柱对重金属及有机物的去除率及无机阴离子的回收率。     

亚青会期间南京污染气体与气溶胶中水溶性离子的分布特征

使用β射线测尘仪、EMS污染气体监测系统、安德森9级采样器和IC型离子色谱分析仪对2013年8月10~28日南京市亚青会期间PM2.5、污染气体和水溶性离子进行了观测分析.结果表明,在亚青会期间PM2.5、NO2、O3和CO的浓度分别为37.0、19.3、48.1和0.7×103μg·m-3,分别比亚青会前降低了26.0%、42.6%、36.1%和46.1%.亚青会期间,细粒子段主要水溶性离子为Na+、NH+4、Ca2+和SO2-4,占80.6%;粗粒子段主要水溶性离子为Na+、Ca2+、NO-3和SO2-4,占77.9%.Ca2+、Mg2+和NO-3在亚青会期间为双峰型分布,其余离子为三峰型分布;亚青会前和后水溶性离子均为三峰型分布.由NO-3/SO2-4的值判断亚青会前和后南京市SO2和NOx主要来自于移动源,在亚青会期间主要来自固定源.     

接触过滤氧化法处理模拟含铁灰岩水的试验研究

为了解决煤矿灰岩水铁含量高,较难复用的问题,进行了接触过滤氧化法处理模拟含铁原水的试验研究。结果表明:采用石英砂滤料的接触过滤氧化工艺处理铁含量为2.0mg/L的模拟原水除铁效果明显,当气水比为2.0,pH值为7.5~8.0,停留时间小于2~3min,滤速为12.0m/h时,除铁率可达90%以上,滤后水满足铁含量0.3mg/L的井下复用水质要求,且过滤周期长达36h;同时分析得出最大平均催化氧化速率系数为KFe2+=1.50×1011L3mg-3s-1和除铁拟合曲线方程-Ln(Ct/Co)=-0.0011x2+0.0517x+1.748。     

赤水河中下游冬季河水化学空间分布特征分析

通过在枯水期对赤水河中下游干流及其支流共25个河水样品进行水化学采样,水化学分析结果表明:在阴阳离子组成中,Ca2+为主要阳离子,占总阳离子的64%以上;阴离子以HCO3-和SO42-为主,占总阴离子75%~91%,其中HCO3-占51%以上。Gibbs图研究区河水化学组成受岩石风化作用控制,阴阳离子三角图、水化学比值分析表明研究区河水化学组成主要受碳酸盐岩风化作用影响,在下游部分支流存在一定硅酸盐岩风化作用。水化学时空分布的对比分析表明,人为活动的对赤水河流域岩石风化速率和水化学组成产生了一定的影响。     

含溴水臭氧化过程阴离子对溴酸盐生成的影响

为研究常见无机阴离子对含溴水臭氧化过程溴酸盐(Br O-3)生成的影响,本研究通过小试分别考察了不同质量浓度氯离子(Cl-)、碳酸氢根离子(HCO-3)和硫酸根离子(SO2-4)对Br O-3生成的影响,并结合反应过程臭氧衰减、中间产物次溴酸/次溴酸根离子(HOBr/OBr-)生成及总溴浓度变化情况,进一步分析了这3种无机阴离子对Br O-3生成的影响机制.结果表明,以60 min为例,Cl-质量浓度为3~150 mg·L-1的水样Br O-3生成量相对于未投加Cl-条件降低了8.8%~25.7%;反应20min时,SO2-4质量浓度从0 mg·L-1增至30 mg·L-1时,Br O-3生成量减少了63.9%;而当HCO-3质量浓度由0 mg·L-1上升至30 mg·L-1时,Br O-3生成量增加了6.4倍,其质量浓度超过30 mg·L-1,继续投加HCO-3对Br O-3生成量的促进作用提高不大.研究表明,在相同的臭氧投加量和相同的反应时间下,投加Cl-和SO2-4均能抑制臭氧化过程Br O-3的生成,而投加HCO-3能极大地促进Br O-3的生成.     

离子色谱法测定环境空气中氯乙酸研究

建立了测定环境空气中氯乙酸的离子色谱法。采用碳酸钠和碳酸氢钠淋洗液作为吸收液采集大气中氯乙酸,氯乙酸吸收后转化成较稳定的氯乙酸钠,阴离子分离柱分离,过滤后直接进样分析,时间定性,峰高定量．对实际废气样品进行分析,氯乙酸的回收率94．O％-103．7％。当采样体积为30L时,氯乙酸方法最低检出浓度0．01mg/m^3。该方法分析速度快,所需样品量少,无需使用机试剂和有毒有害试剂,前处理简便,灵敏、可靠．适用于环境空气和工业废气中氯乙酸的测定。