阴极射线管(cathode ray tube,CRT)玻璃附加值极低,毒性浸出实验表明CRT玻璃为危险废物,是当前我国电子垃圾处理处置中首要的必须解决的难题。废弃CRT玻璃安全处理处置的关键在于其含铅锥玻璃的处理处置。文章从锥玻璃的组成出发,探讨...阴极射线管(cathode ray tube,CRT)玻璃附加值极低,毒性浸出实验表明CRT玻璃为危险废物,是当前我国电子垃圾处理处置中首要的必须解决的难题。废弃CRT玻璃安全处理处置的关键在于其含铅锥玻璃的处理处置。文章从锥玻璃的组成出发,探讨真空碳热还原除铅的可能性及可行性,计算表明真空碳热还原除铅完全可能,实验结果表明900℃,10 Pa下反应4 h铅的去除率可达93.53%,残余物中铅的质量分数仅为0.9%。该法为解决废弃危险电子垃圾CRT玻璃问题提供了新的思路,具有较强的应用价值。展开更多
磷矿粉被广泛用于固定污染土壤中的重金属,然而施用草酸活化磷矿粉后对土壤中铅形态的研究非常有限。该文采用Tessier连续提取法分析砖红壤中施加未活化和经草酸活化的磷矿粉后,砖红壤中外源铅形态的变化。结果表明:随着磷矿粉施加量的...磷矿粉被广泛用于固定污染土壤中的重金属,然而施用草酸活化磷矿粉后对土壤中铅形态的研究非常有限。该文采用Tessier连续提取法分析砖红壤中施加未活化和经草酸活化的磷矿粉后,砖红壤中外源铅形态的变化。结果表明:随着磷矿粉施加量的增加,各处理中交换态铅质量分数比对照(64.1mg/kg)显著下降,未活化磷矿粉处理(PR)的交换态铅质量分数为0.1mg/kg,而草酸活化磷矿粉处理(APR)中未检出;醋酸盐提取态铅质量分数除草酸活化磷矿粉2000mg/kg处理为24.5mg/kg(APR3)减少外,其他处理均高于对照(27.2mg/kg),在未活化磷矿粉500mg/kg(PR2)处理时达到最大值41.8mg/kg;铁锰氧化物结合态除未活化磷矿粉50mg/kg(PR1)处理为69.5mg/kg低于对照(74.2mg/kg)外,其余均高于对照,在APR3处理时达最大值117.2mg/kg;有机物结合态铅质量分数除PR1处理为20.7mg/kg,其余均高于对照处理(21.8mg/kg),在APR3处理时达到最大值46.5mg/kg;PR处理残渣态铅与对照相比(44.2mg/kg)显著增加至60.6mg/kg,对APR处理其变化范围为42.7～43.5mg/kg,各处理稍低于对照,但差异不显著(p<0.05)。显然,磷矿粉的施加可有效降低砖红壤中交换态铅质量分数,增加稳定态铅质量分数,且草酸活化磷矿粉的效果更佳。同时,草酸活化后磷矿粉的释磷能力增加,除草酸活化磷矿粉最高施磷量处理外(5000mg/kg),施入磷矿粉和草酸活化磷矿粉后释放的磷对环境构成风险可能性极小。X-射线衍射光谱(X-ray diffraction,XRD)和扫描电镜(scaning electron microscope,SEM)结果分析也表明草酸活化磷矿粉的释磷能力增加,更有利于固定土壤中的铅。该研究可为草酸活化磷矿粉固定土壤中的铅提供参考依据。展开更多
The capability of carbon nanotubes （CNTs） to adsorb lead （Pb） in aqueous solution was investigated. Batch mode adsorption experiment was conducted to determine the effects of pH, agitation speed, CNTs dosage and c...The capability of carbon nanotubes （CNTs） to adsorb lead （Pb） in aqueous solution was investigated. Batch mode adsorption experiment was conducted to determine the effects of pH, agitation speed, CNTs dosage and contact time. The removal of Pb（II） reached maximum value 85% or 83% at pH 5 or 40 mg/L of CNTs, respectively. Higher correlation coefficients from Langmuir isotherm model indicates the strong adsorptions of Pb（II） on the surface of CNTs （adsorption capacity Xm = 102.04 mg/g）. The results indicates that the highest percentage removal of Pb （96.03%） can be achieved at pH 5, 40 mg/L of CNTs, contact time 80 min, and agitation speed 50 r/min.展开更多
Carbon nanotubes (CNT) were modified bynitric acid oxidation. Infrared spectroscopy (IR) demon-strated that hydroxyl (—OH) and carbonyl (—C== O) func-tional groups were introduced to the surface of modifiedCNT. Micr...Carbon nanotubes (CNT) were modified bynitric acid oxidation. Infrared spectroscopy (IR) demon-strated that hydroxyl (—OH) and carbonyl (—C== O) func-tional groups were introduced to the surface of modifiedCNT. Micrometrics ASAP 2000 measurement showed that the surface area of modified CNT was slightly increased.Furthermore, the Pb2+ adsorption behavior on the surface of modified CNT has been investigated. The results indicate that the modified CNT has an exceptional adsorption capa-bility for Pb2+ removal. The adsorption isotherms are well described by the Langmuir equation under test temperatures and the kinetics level is three.展开更多
文摘阴极射线管(cathode ray tube,CRT)玻璃附加值极低,毒性浸出实验表明CRT玻璃为危险废物,是当前我国电子垃圾处理处置中首要的必须解决的难题。废弃CRT玻璃安全处理处置的关键在于其含铅锥玻璃的处理处置。文章从锥玻璃的组成出发,探讨真空碳热还原除铅的可能性及可行性,计算表明真空碳热还原除铅完全可能,实验结果表明900℃,10 Pa下反应4 h铅的去除率可达93.53%,残余物中铅的质量分数仅为0.9%。该法为解决废弃危险电子垃圾CRT玻璃问题提供了新的思路,具有较强的应用价值。
文摘磷矿粉被广泛用于固定污染土壤中的重金属,然而施用草酸活化磷矿粉后对土壤中铅形态的研究非常有限。该文采用Tessier连续提取法分析砖红壤中施加未活化和经草酸活化的磷矿粉后,砖红壤中外源铅形态的变化。结果表明:随着磷矿粉施加量的增加,各处理中交换态铅质量分数比对照(64.1mg/kg)显著下降,未活化磷矿粉处理(PR)的交换态铅质量分数为0.1mg/kg,而草酸活化磷矿粉处理(APR)中未检出;醋酸盐提取态铅质量分数除草酸活化磷矿粉2000mg/kg处理为24.5mg/kg(APR3)减少外,其他处理均高于对照(27.2mg/kg),在未活化磷矿粉500mg/kg(PR2)处理时达到最大值41.8mg/kg;铁锰氧化物结合态除未活化磷矿粉50mg/kg(PR1)处理为69.5mg/kg低于对照(74.2mg/kg)外,其余均高于对照,在APR3处理时达最大值117.2mg/kg;有机物结合态铅质量分数除PR1处理为20.7mg/kg,其余均高于对照处理(21.8mg/kg),在APR3处理时达到最大值46.5mg/kg;PR处理残渣态铅与对照相比(44.2mg/kg)显著增加至60.6mg/kg,对APR处理其变化范围为42.7～43.5mg/kg,各处理稍低于对照,但差异不显著(p<0.05)。显然,磷矿粉的施加可有效降低砖红壤中交换态铅质量分数,增加稳定态铅质量分数,且草酸活化磷矿粉的效果更佳。同时,草酸活化后磷矿粉的释磷能力增加,除草酸活化磷矿粉最高施磷量处理外(5000mg/kg),施入磷矿粉和草酸活化磷矿粉后释放的磷对环境构成风险可能性极小。X-射线衍射光谱(X-ray diffraction,XRD)和扫描电镜(scaning electron microscope,SEM)结果分析也表明草酸活化磷矿粉的释磷能力增加,更有利于固定土壤中的铅。该研究可为草酸活化磷矿粉固定土壤中的铅提供参考依据。
基金the Kulliyyah of Engineering(KOE) and Department of Biotechnology Engineering,IIUM for supporting and providing the laboratory facilities
文摘The capability of carbon nanotubes （CNTs） to adsorb lead （Pb） in aqueous solution was investigated. Batch mode adsorption experiment was conducted to determine the effects of pH, agitation speed, CNTs dosage and contact time. The removal of Pb（II） reached maximum value 85% or 83% at pH 5 or 40 mg/L of CNTs, respectively. Higher correlation coefficients from Langmuir isotherm model indicates the strong adsorptions of Pb（II） on the surface of CNTs （adsorption capacity Xm = 102.04 mg/g）. The results indicates that the highest percentage removal of Pb （96.03%） can be achieved at pH 5, 40 mg/L of CNTs, contact time 80 min, and agitation speed 50 r/min.
基金the National Natural Science Foundation of China (Grant No.50178067)
文摘Carbon nanotubes (CNT) were modified bynitric acid oxidation. Infrared spectroscopy (IR) demon-strated that hydroxyl (—OH) and carbonyl (—C== O) func-tional groups were introduced to the surface of modifiedCNT. Micrometrics ASAP 2000 measurement showed that the surface area of modified CNT was slightly increased.Furthermore, the Pb2+ adsorption behavior on the surface of modified CNT has been investigated. The results indicate that the modified CNT has an exceptional adsorption capa-bility for Pb2+ removal. The adsorption isotherms are well described by the Langmuir equation under test temperatures and the kinetics level is three.
