Key Laboratory of Paper Science and Technology of Ministry of Education, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
Department of Chemical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada.
Molecules. 2018 Aug 11;23(8):2005. doi: 10.3390/molecules23082005.
The presence of dyes in wastewater effluents made from the textile industry is a major environmental problem due to their complex structure and poor biodegradability. In this study, a cationic lignin polymer was synthesized via the free radical polymerization of lignin with [2-(methacryloyloxy) ethyl] trimethyl ammonium chloride (METAC) and used to remove anionic azo-dyes (reactive black 5, RB5, and reactive orange 16, RO16) from simulated wastewater. The effects of pH, salt, and concentration of dyes, as well as the charge density and molecular weight of lignin-METAC polymer on dye removal were examined. Results demonstrated that lignin-METAC was an effective flocculant for the removal of dye via charge neutralization and bridging mechanisms. The dye removal efficiency of lignin-METAC polymer was independent of pH. The dosage of the lignin polymer required for reaching the maximum removal had a linear relationship with the dye concentration. The presence of inorganic salts including NaCl, NaNO₃, and Na₂SO₄ had a marginal effect on the dye removal. Under the optimized conditions, greater than 98% of RB5 and 94% of RO16 were removed at lignin-METAC concentrations of 120 mg/L and 105 mg/L in the dye solutions, respectively.
纺织工业废水排放中染料的存在是一个主要的环境问题，这是由于它们复杂的结构和较差的生物降解性。在这项研究中，通过木质素与[2-（甲基丙烯酰氧基）乙基]三甲基氯化铵（METAC）的自由基聚合合成了一种阳离子木质素聚合物，并将其用于从模拟废水中去除阴离子偶氮染料（活性黑 5，RB5 和活性橙 16，RO16）。考察了 pH 值、盐度、染料浓度以及木质素-METAC 聚合物的电荷密度和分子量对染料去除的影响。结果表明，木质素-METAC 是一种有效的絮凝剂，通过电荷中和和桥联机制去除染料。木质素-METAC 聚合物的染料去除效率与 pH 值无关。达到最大去除率所需的木质素聚合物用量与染料浓度呈线性关系。无机盐（包括 NaCl、NaNO₃ 和 Na₂SO₄）的存在对染料去除的影响很小。在优化条件下，在染料溶液中木质素-METAC 浓度分别为 120mg/L 和 105mg/L 时，RB5 和 RO16 的去除率均大于 98%和 94%。
