Sun Yabo, Lu Tao, Pan Yali, Shi Menghan, Ding Dan, Ma Zhiwen, Liu Jiuyi, Yuan Yupeng, Fei Ling, Sun Yingqiang
School of Chemistry & Chemical Engineering, School of Material Science & Engineering, Anhui University, Jiulong Rd 111, Hefei, Anhui, 230039, PR China.
Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Hefei, Anhui, 230601, PR China.
Environ Sci Ecotechnol. 2022 Sep 3;12:100204. doi: 10.1016/j.ese.2022.100204. eCollection 2022 Oct.
Biotreatment of acidic rare earth mining wastewater via acidophilic living organisms is a promising approach owing to their high tolerance to high concentrations of rare earth elements (REEs); however, simultaneous removal of both REEs and ammonium is generally hindered since most acidophilic organisms are positively charged. Accordingly, immobilization of acidophilic () by calcium alginate to improve its affinity to positively charged REEs has been used for simultaneous bioremoval of REEs and ammonium. The results indicate that 97.19%, 96.19%, and 98.87% of La, Y, and Sm, respectively, are removed by beads (GS-BDs). The adsorption of REEs by calcium alginate beads (BDs) and GS-BDs is well fitted by both pseudo first-order (PFO) and pseudo second-order (PSO) kinetic models, implying that adsorption of REEs involves both physical adsorption caused by affinity of functional groups such as -COO- and -OH and chemical adsorption based on ion exchange of Ca with REEs. Notably, GS-BDs exhibit high tolerance to La, Y, and Sm with maximum removal efficiencies of 97.9%, 96.6%, and 99.1%, respectively. Furthermore, the ammonium removal efficiency of GS-BDs is higher than that of free cells at an initial ammonium concentration of 100 mg L, while the efficiency decreases when initial concentration of ammonium is higher than 150 mg L. Last, small size of GS-BDs favors ammonium removal because of their lower mass transfer resistance. This study achieves simultaneous removal of REEs and ammonium from acidic mining drainage, providing a potential strategy for biotreatment of REE tailing wastewater.
通过嗜酸生物对酸性稀土矿废水进行生物处理是一种很有前景的方法，因为它们对高浓度稀土元素（REEs）具有很高的耐受性；然而，由于大多数嗜酸生物带正电荷，同时去除稀土元素和铵通常会受到阻碍。因此，用海藻酸钙固定嗜酸（）以提高其对带正电荷稀土元素的亲和力，已被用于同时生物去除稀土元素和铵。结果表明，GS-BDs珠分别去除了97.19%、96.19%和98.87%的La、Y和Sm。海藻酸钙珠（BDs）和GS-BDs对稀土元素的吸附均能很好地拟合伪一级（PFO）和伪二级（PSO）动力学模型，这意味着稀土元素的吸附既涉及由-COO-和-OH等官能团亲和力引起的物理吸附，也涉及基于Ca与稀土元素离子交换的化学吸附。值得注意的是，GS-BDs对La、Y和Sm表现出高耐受性，最大去除效率分别为97.9%、96.6%和99.1%。此外，在初始铵浓度为100mg/L时，GS-BDs的铵去除效率高于游离细胞，而当铵初始浓度高于150mg/L时，效率会降低。最后，GS-BDs尺寸小有利于铵的去除，因为它们的传质阻力较低。本研究实现了从酸性采矿排水中同时去除稀土元素和铵，为稀土尾矿废水的生物处理提供了一种潜在策略。
