新型生物质果胶吸附材料的制备及水溶液中铜离子(Ⅱ)吸附性能研究

Preparation of Novel Biomass Pectin Adsorbing Material and Its Adsorption Performance for Copper(Ⅱ)Ion in Aqueous Solution

为了评价生物质果胶碱化改性在重金属离子废水处理方面的吸附性能,利用水提-醇沉法提取纯化豆腐柴叶中天然果胶,并通过碱化作用,制备新型生物质果胶吸附材料,同时对水溶液中重金属铜离子进行吸附试验,考察其吸附率和单位吸附量。然后,通过分析新型生物质果胶吸附材料组分半乳糖醛酸含量及酯化度,探讨其吸附机制。实验结果表明,天然果胶在pH 9的环境中碱化作用30 min时,可获得具有高效吸附水体中铜离子的新型生物质果胶吸附材料,其吸附率和单位吸附量分别达到89.6%(0.10 g)和105 mg/g(0.02 g)。另外,在果胶组分半乳糖醛酸含量和酯化度分析方面,果胶碱化作用未造成半乳糖醛酸分子的丢失,但可促使果胶中羧酸酯的水解,形成对应的羧酸钠盐,提升对水体铜离子的吸附性能。

To evaluate the adsorption performance of biomass pectin modified via alkalization in the treatment of heavy-metal ion wastewater,natural pectin was isolated from Premna microphylla leaves and purified by water-alcohol precipitation,and the subsequent alkalization afforded novel biomass pectin-based adsorbing materials,which was then tested to adsorb copper ions in aqueous solution to investigate adsorption efficiency and unit adsorption quantity.Subsequently,based on determination of galacturonic acid content and esterification degree of novel biomass pectin-based adsorbing materials,the adsorption mechanism was studied.The results demonstrated that alkalization of natural pectin at pH 9 for 30 min led to a new biomass pectin-based adsorption material with high efficiency for adsorbing copper ions in water the adsorption efficiency and unit adsorption quantity reaching 89.6%(0.10 g)and 105 mg/g(0.02 g),respectively.Furthermore,the determined galacturonic acid content and esterification degree indicated that alkalization of pectin couse no loss of galacturonic acid content,but can promote the hydrolysis of carboxylic ester to the correspondent sodium salt for enhancing adsorption performance of copper ion.