活性炭处理含铬废水的研究

活性炭具有优良的吸附性和还原性,已广泛用于废水处理工业.采用静态试验的方法,考察了活性炭加入量、吸附时间、pH值、温度等因素对含Cr(Ⅵ)废水去除率的影响.研究表明活性炭的投加量为0.6g/mL,pH为4,吸附时间为150min,温度为20时℃时铬的去除率为97％.在适宜的条件下,活性炭可以较好的去除废水中的Cr(Ⅵ).     

在线还原-流动注射化学发光法同时测定Cr(Ⅵ)和Cr(Ⅲ)

研究了以小颗粒氢醌氧化还原树脂为还原柱,在线还原Cr(Ⅵ)为Cr(Ⅲ),以鲁米诺-过氧化氢体系流动注射化学发光同时测定Cr(Ⅵ)和Cr(Ⅲ)的方法.方法简单,快速,Cr(Ⅲ)的检出限为4.0×10-10g·m L-1;Cr(Ⅵ)的检出限为6.2×10-10g·m L-1.Cr(Ⅲ)和Cr(Ⅵ)的线性范围为1.0×10-9~5.0×10-7g·m L-1.测定结果与标准方法无显著性差异.还原柱至少可供2000次测量.     

疏水型SiO_2气凝胶对Cr(Ⅵ)的吸附及动力学研究

以疏水型SiO2气凝胶为吸附剂,研究其对Cr(Ⅵ)的吸附性能。考查了pH、吸附时间、气凝胶用量对Cr(Ⅵ)吸附率的影响,探索了吸附Cr(Ⅵ)的动力学特性。实验结果表明,在pH=2、气凝胶的量m=0.4 g、反应时间t=75 min时,疏水型SiO2气凝胶对Cr(VI)的去除率较高;疏水型SiO2气凝胶对Cr(Ⅵ)吸附行为更符合准二级动力学模型;使用乙醇作为脱附剂,脱附效果较好。     

偶氮胂（Ⅲ）高灵敏度法测定痕量铬的研究

研究了偶氮胂（Ⅲ）与CrO7^2-的褪色反应,建立了一种新的光度法测定痕量Cr(Ⅵ)方法,发现其在硝酸介质中具有高灵敏的褪色反应,摩尔吸光系数达4．8&;#215;10^6,Cr(Ⅵ)量在0－0．8Mg/25ml范围内符合比耳定律。     

TiO2-葡萄糖体系光催化还原Cr(Ⅵ)研究

研究了葡萄糖存在下TiO2光催化还原Cr(Ⅵ)过程中葡萄糖浓度、Cr(Ⅵ)初始浓度及不同反应条件对Cr(Ⅵ)光降解速率的影响．TiO2催化剂悬浮体系能有效地光催化还原溶液中Cr(Ⅵ)离子；葡萄糖的存在对TiO2的光催化还原Cr(Ⅵ)的反应具有明显的促进作用，符合一级反应动力学规律．     

Science Letters:Remediation of Cr(Ⅵ) in solution using vitamin C

The effectiveness of vitamin C in treating Cr(Ⅵ)-contaminated water is being evaluated. Cr(Ⅵ) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(Ⅵ) to essentially nontoxic Cr(Ⅲ). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(Ⅵ) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration.The reaction mechanism of Cr(Ⅵ) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(Ⅵ)-contaminated soils and groundwater.     

Remediation of Cr（Ⅵ） in solution using vitamin C

The effectiveness of vitamin C in treating Cr(Ⅵ)-contaminated water is being evaluated. Cr(Ⅵ) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(Ⅵ) to essentially nontoxic Cr(Ⅲ). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(Ⅵ) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration.The reaction mechanism of Cr(Ⅵ) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(Ⅵ)-contaminated soils and groundwater.     

冰模板-微波法协同的用于吸附水中Cr(Ⅵ)的生物炭制备

该文采用新鲜含水的豆腐渣为原料,液氮冷冻后的冰为模板,利用微波加热快速制备功能性分级孔生物碳材料,用来吸附水中的重金属铬Cr(Ⅵ).文章探究了不同微波加热时间制备的生物炭的微观结构和化学组成差异,及其对Cr(Ⅵ)吸附的影响.该项研究为吸附水中的Cr(Ⅵ)提供了一种快速、绿色的方法,具有工业化应用的潜在价值.实验过程包括...     

Determination of Diffusion Coefficient and Analysis of Diffusion Factors of Cr(Ⅵ) Ion in Clay Soil

Some laboratory diffusion tests were conducted with diffusion device to determine the diffusion coefficient of Cr(Ⅵ) ion passing through Dalian red clay samples. The concentrations of Cr(Ⅵ) at different places of the samples were then measured spectrophotometrically after a standing time of 1 000 d. A one-dimensional solute transport equation was used to simulate the transport of Cr(Ⅵ) through clay samples. Back-calculation of diffusion coefficient of Cr(Ⅵ) was made with finite difference method. Parametric...     

Removal of hexavalent chromium from aqueous solution by iron nanoparticles

Groundwater remediation by nanoparticles has收稿日期increasing interest in recent years. This report presents a thorough evaluation of hexavalent chromium removal in aqueous solutions using iron (Fe0) nanoparticles. Cr(Ⅵ) is a major pollutant of groundwater. Zero-valent iron, an important natural reductant of Cr(Ⅵ), is an option in the remediation of contaminated sites, transforming Cr(Ⅵ) to essentially nontoxic Cr(Ⅲ). At a dose of 0.4 g/L, 100% of Cr(Ⅵ) (20 mg/L) was degraded. The Cr(Ⅵ) removal efficiency decreased significantly with increasing initial pH. Different Fe0 type was compared in the same conditions. The reactivity was in the order starch-stabilized Fe0 nanoparticles＞Fe0 nanoparticles＞Fe0 powder＞Fe0 filings. Electrochemical analysis of the reaction process led to the conclusion that Cr(OH)3 should be the final product of Cr(Ⅵ). Iron nanoparticles are good choice for the remediation of heavy metals in groundwater.