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⁺

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。
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.