Abstract

Organic azo-dyes, including Congo Red, present a significant environmental concern due to their widespread industrial usage and resistance to biodegradation, leading to severe contamination of effluents. This study explores the efficacy of two basic perovskites (MSnO₃, where M = Ca and Sr) in removing Congo Red by adsorption, offering a potential solution for wastewater treatment. The synthesis of the adsorbents was performed by a coprecipitation technique, an effective and no-waste producing method. By adjusting reaction conditions, the physical-chemical characteristics of the perovskites, including crystallinity, morphological features, surface area and porosity, were controlled. Adsorption studies conducted across a range of Congo Red concentrations (10–100 mg L^− 1) at pH 10 revealed MSnO₃ to possess exceptional adsorption capacity exceeding 100 mg per gram. The results indicate irreversible adsorption and potential adsorbent regeneration by thermal treatment. Slow kinetics also suggest strong binding forces aligned with the fundamentals of pseudo-second-order adsorption kinetic model. Regarding the impact of the synthesis parameters, while the precipitation conditions may not significantly influence adsorption performance, perovskite samples synthesized at higher temperatures are considered more suitable for this application due to their enhanced stability and regenerative capabilities for repeated use. Estimated correlations between sample parameters and adsorption efficiency provide a valuable insight for the practical application of oxide perovskites in addressing dye contamination issues.

中文翻译：

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探索钙钛矿和锡酸锶钙钛矿作为刚果红去除吸附剂

摘要

包括刚果红在内的有机偶氮染料因其广泛的工业用途和耐生物降解性而引起严重的环境问题，导致废水严重污染。本研究探讨了两种碱性钙钛矿（MSnO ₃，其中M = Ca和Sr）通过吸附去除刚果红的功效，为废水处理提供了潜在的解决方案。吸附剂的合成是通过共沉淀技术进行的，这是一种有效且无废物产生的方法。通过调节反应条件，可以控制钙钛矿的物理化学特性，包括结晶度、形态特征、表面积和孔隙率。在 pH 10下对一系列刚果红浓度 (10–100 mg L ^{− 1} ) 进行的吸附研究表明，MSnO ₃具有超过 100 mg/g 的卓越吸附能力。结果表明，热处理可实现不可逆吸附和潜在的吸附剂再生。慢动力学还表明强结合力与伪二级吸附动力学模型的基本原理一致。关于合成参数的影响，虽然沉淀条件可能不会显着影响吸附性能，但在较高温度下合成的钙钛矿样品被认为更适合该应用，因为它们具有增强的稳定性和重复使用的再生能力。样品参数和吸附效率之间的估计相关性为氧化物钙钛矿在解决染料污染问题中的实际应用提供了宝贵的见解。