稀硫酸亚铁铵溶液标定对COD分析结果影响探讨

"快速密闭催化消解法"因具有快速经济的优点而在日常监测中被广泛采用.但在标定稀硫酸亚铁铵溶液时,各站存在着使用不同标定方法的现象.本文通过实验讨论了稀硫酸亚铁铵溶液标定对水样COD分析的影响.     

碱性过硫酸钾测定水中总氮的实验条件探讨

利用碱性过硫酸钾消解紫外分光光度法测定对水中总氮,虽然步骤较为简单,但实验条件要求很严苛,准确度不宜把握本实验通过对空白值、域性过硫酸钾溶液配制、消解时间、冷却时间等关键性问题,提出一些改进措施,从而优化实验条件和参数,得到更准确的标准曲线和测定值.     

Effect of functional groups on sludge for biosorption of reactive dyes

The sludge, which was collected from a biological coke wastewater treatment plant, was used as a low-cost adsorbent in the removal of reactive dyes (methylene blue (MB) and reactive red 4 (RR4)) from aqueous solution. The pH of dye solution played an important role on the dye uptake. As the solution pH increase, the MB uptake increased, while the RR4 uptake decreased. The maximum uptake of RR4 by protonated sludge was 73.7 mg/g at pH 1, and the maximum uptake of MB by sludge was 235.3 mg/g at pH 9. Three functional groups, including carboxyl, phosphonate, and amine group, were identified by potentiometric titration, fourier transform infrared (FT-IR) spectrometry, and X-ray photoelectron spectroscopy (XPS). The anionic functional groups, phosphonate and carboxyl group, were identified as the binding sites for the cationic MB. Amine groups were identified to bind RR4. The main mechanism of the reactive dyestuffs adsorption is electrostatic interaction.     

热爆炸理论在硝酸铵水溶液热安全性研究中的应用

本文概述了均温系统热爆炸非稳定理论,将其应用于含不同量杂质的硝酸铵水溶液体系中,并将临界爆炸温度和爆炸延滞期的试验值与计算值进行比较,结果表明应用热爆炸理论预先估算硝酸铵水溶液体系中达到任意升温的时间和预先计算达到预先选择的对应于爆炸的升温所需要的时间是可行的。     

Solubilization and degradation of perchloroethylene （PCE） in cationic and nonionic surfactant solutions

Solubilization of perchloroethylene (PCE) in a nonionic (Triton X-100) and a cationic (cetyltrimethylammonium bromide (CTAB)) surfactant solutions and the degradation of surfactant solubilized PCE using fine to nanosize Fe and bi-metallic Fe-Ni particles were investigated. Micelle partition coefficients (Km) and molar solubility ratio (MSR) for PCE in 10 g/L of surfactant solutions have been quantified and the solubility of PCE (100 mg/L in water) in the surfactant solutions increased by about ten fold. Of the two surfactants studied, Triton X-100 solubilized the higher amount of PCE per gram of surfactant. To degrade solubilized PCE, both iron and bimetallic Fe-Ni particles were used in continuously stirred batch reactors. The iron and bi-metallic particles were synthesized using the solution method and the particles were characterized using the SEM, EDS, TEM and XRD. The PCE solubilized up to 500 mg/L in both surfactant solutions were totally degraded at various rates by 200 g/L of bi-metallic Fe-Ni particles in less than 20 hr, which is the highest concentration of PCE degraded in the shortest time compared to data in the literature. The degradations of PCE solubilized in surfactant solutions were represented by nonlinear kinetic relationships which depended on the type of surfactant used for solubilizing the PCE.     

水泥窑SNCR烟气脱硝技术

由西安西矿环保科技有限公司开发的水泥窑SNCR烟气脱硝技术,适用于水泥、玻璃、化工等行业烟气脱硝。主要技术内容一、基本原理以尿素溶液或氨水为还原剂,在水泥熟料生产线上分解炉的适当位置喷入脱硝还原剂,在850℃~1000℃时,还原剂会优先与氮氧化物进行反应。一般来说,在保证合理的还原剂使用成本,氨逃逸量不超过5×10-6的     

Degradation of 4-CP in an internal electrolysis system

The characteristic and mechanism of parachlorophenol (4-CP) degradation in an internal electrolysis system were investigated. The degradation rate of 4-CP was higher in acid solution than that of in neutral or alkaline solution. Addition of activated carbon could make 4-CP easier be degraded by the surface contact catalysis. The dissolved oxygen in solution could take part in the electrode reaction and intensify the degradation of 4-CP. By the analysis of intermediates of degradation of 4-CP, it could be conferred that 4-CP was broken through the bond beside hydroxy firstly, then the bond beside chloride was broken and the chloride was dechlorinated simultaneously. Most intermediate products were glycerine, ethane diacid and acetic acid, while very few 1, 4-butanedial and alcohols were found.     

悬浮酵母菌对重金属Hg(Ⅱ)的吸附机理

通过扫描电子显微镜、能量分析谱、红外光谱和悬浮酵母菌的动电电位等分析手段,研究了悬浮酵母菌对Hg(Ⅱ)的吸附机理.由扫描电镜图像及能量分析谱可以看出,悬浮酵母菌吸附Hg(Ⅱ)后形态发生变化,悬浮酵母菌对Hg(Ⅱ)的吸附存在离子交换吸附;动电电位及pH曲线分析表明,悬浮酵母菌的零电点为pH=3.7,pH值是影响吸附效果的重要因素,溶液pH值为4.33时,吸附效果最好,去除率为99.95%;溶液pH＜4.0时,静电作用为主要的吸附机理;从吸附等温线可以得出,在溶液中Hg(Ⅱ)的初始质量浓度为601.8 mg/L,菌质量浓度为20g/L时,吸附达到饱和,此时的负载量为10.24 mg/g;红外光谱分析表明,悬浮酵母菌对Hg(Ⅱ)的主要吸附位点为-OH、-NH2、C=O、P=O和S=O.     

庞庄煤矿煤矸石淋溶液对周边水体影响分析

为研究庞庄煤矿张小楼煤矸石堆场淋溶液对其场地和周边地表水、地下水水质影响情况,围绕煤矸石堆场及周边采集13组水样做分析比对。结果表明,煤矸石堆场淋溶液对周边地表水体形成普遍污染,且污染物浓度随着污染距离增加逐步降低,一般化学污染指标主要包括溶解性总固体、硫酸盐、铁、锰、氨氮等,毒理学污染指标包括亚硝酸盐、氟化物、砷,超标倍率约为0.02~5.36。受距离及成井深度等因素影响,地下水体未遭受淋溶液明显的污染和影响。     

对氨基苯磺酸-N,N-二甲基苯胺光度法测定痕量亚硝酸盐的研究

亚硝酸盐有毒性,是致癌物质,所以在水质监测中它常列为重点分析项目之一。亚硝酸盐的测定方法,在国内外应用最广的是重氮偶联比色法。这些方法虽有较好的选择性,但其试剂溶液一般毒性大,稳定性差,且方法灵敏度不高。在研究苯胺类的偶氮化反应中,发现亚硝酸盐在较强酸性