真菌黑色素由于其金属结合特性而被认为是潜在的生物吸附剂,稳定性,和可扩展性。以前的研究建立了可扩展的真菌黑色素生产方法与有前途的菌株,然而,它们对金属污染废水处理的适用性尚未得到充分报道。在这里,使用显微镜和光谱学技术生产并表征了源自非晶质的黑色素色素。对Cu(II)的吸附性能,Pb(II),Cd(II),和Zn(II)使用批量测试进行评估。黑色素颜料由具有吲哚基成分的纳米颗粒的聚集体组成。吸附容量随溶液pH值的增加而增加,尤其是在pH>4.0。Cu(II)的最大结合能力,Pb(II),Cd(II),黑色素上的Zn(II)分别为69.18、103.23、24.31和13.57mg/g,分别。竞争吸附实验表明,亲和力为Cu(II)>Pb(II)>Cd(II)>Zn(II)。吸附时间通常需要<2.5h才能达到平衡;伪二级动力学模型很好地描述了动力学。色素中自由基的螯合能力被认为是一种可能的吸附机制。即使在5个连续的吸附-解吸循环之后,初始吸附容量几乎保持完整。完全去除Cu(II),Pb(II),确认了金属污染废水中的Cd(II)。因此,衍生自A.resinae的黑色素色素可用作适用于处理金属污染的水溶液的生物吸附剂。
Fungal melanins have been considered as potential biosorbents due to their metal-binding properties, stability, and scalability. Previous studies established scalable fungal melanin production methods with promising strains, however, their applicability for metal-contaminated effluents treatment has not been sufficiently reported. Herein, melanin pigment derived from Amorphotheca resinae was produced and characterized using microscopy and spectroscopy techniques. Adsorptive properties towards Cu(II), Pb(II), Cd(II), and Zn(II) were evaluated using batch tests. Melanin pigment was composed of aggregates of nanosized particles with indole-based constituents. Adsorption capacities increased with the pH of solution, especially at pH > 4.0. Maximum binding capacities of Cu(II), Pb(II), Cd(II), and Zn(II) on melanin were 69.18, 103.23, 24.31, and 13.57 mg/g, respectively. The competitive adsorption experiments elucidated affinity as Cu(II)>Pb(II)≫Cd(II)>Zn(II). Adsorption time generally required <2.5 h to reach equilibrium; the pseudo-second-order kinetic model well described the kinetics. Chelating ability of free radicals in pigment was considered as a possible mechanism for adsorption. Initial adsorption capacities remained almost intact even after 5 consecutive adsorption-desorption cycles. Complete removal of Cu(II), Pb(II), and Cd(II) from metal-contaminated effluent was confirmed. Consequently, melanin pigment derived from A. resinae can be used as a biosorbent suitable for the treatment of metal-contaminated aqueous solutions.