Abstract:

In order to improve the adsorption capacity of wheat stalk for heavy metal，the dithiocarboxyl wheat stalk （DTWS） was prepared by modifying wheat stalk（WS） with carbon disulfide（CS₂） under alkaline condition. The influencing factors on the preparation of DTWS were investigated by the single factor experimental method，and the preparation conditions of DTWS were also determined. The results showed that the optimal preparation conditions of DTWS were as follows：the particle size of WS 420 μm（40 meshes），m（WS）∶V（CS₂）∶m（NaOH） 1∶2∶2，pre-reaction temperature 35 ℃，pre-reaction times 45 min，main-reaction temperature 50 ℃ and main-reaction time was 1.5 h. The highest removal rate of Cd（Ⅱ） could reach 100% with DTWS. The specific surface area and pore volume of DTWS were 0.738 2 m²/g and 0.000 268 cm³/g，respectively. It is found that the modification reaction in the preparation of DTWS mainly occurs on the hydroxyl groups（—OH） of WS molecular structure，and DTWS had good adsorption performance for Cd（Ⅱ）.

Key words: adsorbent, wheat stalk, modification, wastewater containing cadmium

摘要：

为了提高小麦秸秆对重金属的吸附能力，采用二硫化碳（CS₂）在碱性条件下对小麦秸秆（WS）进行二硫代羧基改性，制备了二硫代羧基化小麦秸秆（DTWS）。通过单因素实验法考察了DTWS制备过程的影响因素，确定了DTWS的制备条件。结果表明，DTWS的最佳制备条件：WS粒径为420 μm（40目），m（WS）∶V（CS₂）∶m（NaOH）为1∶2∶2，预反应温度为35 ℃，预反应时间为45 min，主反应温度为50 ℃，主反应时间为1.5 h，该条件下制备的DTWS对水样中Cd（Ⅱ）的最高去除率可达100%。DTWS的比表面积为0.738 2 m²/g，孔容为0.000 268 cm³/g。研究表明，DTWS制备中的改性反应主要发生在WS分子结构的羟基（—OH）上，改性后的DTWS对重金属Cd（Ⅱ）具有良好的吸附性能。

关键词: 吸附剂, 小麦秸秆, 改性, 含镉废水

CLC Number: 

• X703.1