造纸污泥制备功能陶粒(GTL)及其对Cu²⁺吸附性能的研究

Study on Preparation of Functional Ceramsite (GTL) from Paper Sludge and Its Adsorption Properties for Cu²⁺

摘要: 以造纸污泥为主要原料，利用烧结法制备多孔陶粒(TL530)，然后用NaOH对TL530进行改性，得到对重金属具有良好吸附性能的功能陶粒(GTL)，并分析GTL对模拟废水中Cu²⁺的吸附效果与影响因素。以SEM、红外光谱等方式阐明GTL吸附Cu²⁺的机理。发现造纸污泥制备TL530适宜条件是：造纸污泥与膨润土、碳酸钙、硅酸钠的配比是5:3:1:1，陶粒预热温度是450℃、预热时间是25 min、陶粒烧结温度是1000℃、烧结时间为25 min；TL530改性制备GTL的适宜技术条件为：1 g TL530添加浓度为2.5 mol/L的NaOH 30 mL反应6 h，获得吸附重金属性能可靠的GTL；GTL对Cu²⁺具有良好的吸附作用，当GTL投加量是0.0025 g/mL模拟废水时，Cu²⁺去除率可达98.13%；GTL吸附铜离子的机理主要表现为化学吸附。

Abstract: Using paper sludge as the main raw material, the porous ceramsite (TL530) was prepared by sin-tering method. Subsequently, the TL530 was modified with NaOH to manufacture the functional ceramsite (GTL) with promising adsorption performance for heavy metals. In this work, the effi-ciency and influencing factors of the Cu²⁺ adsorption in simulated wastewater by the GTL was ex-plored. The mechanism of the Cu²⁺ adsorption by GTL was revealed through SEM and infrared spectroscopy. The results showed that the suitable conditions for the preparation of TL530 based on paper sludge were as follows: the ratio of paper sludge to bentonite, calcium carbonate, and sodium silicate was 5:3:1:1 under the preheating temperature of 450˚C with a preheating time of 25 min. The optimal ceramsite sintering temperature and duration were 1000˚C and 25 min, respectively. To manufacture the GTL from TL530, the desirable technical conditions can be summarized as 1 g of TL530 loaded with 30 mL NaOH (2.5 mol/L) for 6 h reaction time. The GTL exhibited strong adsorption capability for Cu²⁺. When the dosage of GTL was 0.0025 g/mL simulated wastewater, the Cu²⁺ removal efficiency reached up to 98.13%. The primary mechanism of Cu²⁺ removal by GTL is chemical adsorption.