低温电炉法制备膨胀石墨及其在染料废水处理中的应用

采用低温电炉法对传统高温膨胀制备膨胀石墨的方法进行优化,并对其在染料废水处理中的应用进行了研究。考察了氧化剂、插层剂和氧化次数对膨胀体积的影响,并使用SEM、XRD、FT-IR对样品进行外观形貌和结构表征。研究结果表明:使用高锰酸钾-磷酸-硝酸氧化插层体系一次氧化下并使用低温电炉法进行膨化的效果最好,制备出的膨胀石墨样品膨胀体积为390 m L/g,比表面积252 m2/g。在对活性黄模拟染料废水处理的实验中,考察了膨胀石墨用量、活性黄浓度和温度3个因素对于活性黄模拟染料废水吸附效果的影响,结果表明:对于质量浓度为250 mg/L的活性黄废水,膨胀石墨的最大吸附量可达到180 mg/g;当膨胀石墨添加量为2.0 g/L时处理效果最佳,去除率达到65%;而温度对于吸附过程影响较小。

Synthesis of expanded graphite using a low temperature furnace and its application in dyeing wastewater treatment

Expanded graphite (EG) has been prepared by using a furnace in an attempt to improve the traditional chemical oxidation method, and its application in treating dyeing wastewater has been investigated. The influence of different oxidants, intercalating agents and oxidation numbers on the expanding volume were investigated. The structure and properties of the products were studied by means of SEM, XRD, and FT-IR. The KMnO4-H3PO4-HNO3 system was found to work best, when employing a single expansion in the furnace. The largest volume density was 390mL/g and the specific surface area was 252 m2/g. In the treatment of Reactive Yellow dyeing wastewater, the effects of varying different factors including the amount of expanded graphite, the concentration of Reactive Yellow, and the temperature were investigated. The results showed: for dyeing wastewater containing 250 mg/L of Reactive Yellow, the adsorption capacity can reach as high as 180 mg/g. Treatment with 2.0 g/L of expanded graphite was most effective, with a removal ratio as high as 65%, and the adsorption reaching equilibrium in 30 minutes. Varying the temperature had no obvious effects on the adsorption process.