Morosanu Irina, Bucatariu Florin, Fighir Daniela, Paduraru Carmen, Mihai Marcela, Teodosiu Carmen
Department of Environmental Engineering and Management, Gheorghe Asachi Technical University of Iasi, 73 D. Mangeron Street, 700050 Iasi, Romania.
Petru Poni Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi, Romania.
Polymers (Basel). 2023 Apr 19;15(8):1948. doi: 10.3390/polym15081948.
The modification of inorganic surfaces with weak cationic polyelectrolytes by direct deposition through precipitation is a fast approach to generating composites with high numbers of functional groups. The core/shell composites present very good sorption capacity for heavy metal ions and negatively charged organic molecules from aqueous media. The sorbed amount of lead ions, used as a model for priority pollutants such as heavy metals, and diclofenac sodium salt, as an organic contaminant model for emerging pollutants, depended strongly on the organic content of the composite and less on the nature of contaminants, due to the different retention mechanisms (complexation vs. electrostatics/hydrophobics). Two experimental approaches were considered: (i) simultaneous adsorption of the two pollutants from a binary mixture and (ii) the sequential retention of each pollutant from monocomponent solutions. The simultaneous adsorption also considered process optimization by using the central composite design methodology to study the univariate effects of contact time and initial solution acidity with the purpose of enabling further practical applications in water/wastewater treatment. Sorbent regeneration after multiple sorption-desorption cycles was also investigated to assess its feasibility. Based on different non-linear regressions, the fitting of four isotherms (Langmuir, Freundlich, Hill, and Redlich-Peterson models) and three kinetics models (pseudo-first order (PFO), pseudo-second order (PSO), and two-compartment first order (TC)) has been carried out. The best agreement with experiments was found for the Langmuir isotherm and the PFO kinetic model. Silica/polyelectrolytes with a high number of functional groups may be considered efficient and versatile sorbents that can be used in wastewater treatment processes.
通过沉淀直接沉积用弱阳离子聚电解质对无机表面进行改性是一种快速生成具有大量官能团的复合材料的方法。核/壳复合材料对水介质中的重金属离子和带负电荷的有机分子具有非常好的吸附能力。作为重金属等优先污染物模型的铅离子以及作为新兴污染物有机污染物模型的双氯芬酸钠盐的吸附量，很大程度上取决于复合材料的有机含量，而较少取决于污染物的性质，这是由于不同的保留机制（络合与静电/疏水作用）。考虑了两种实验方法：（i）从二元混合物中同时吸附两种污染物，以及（ii）从单组分溶液中依次保留每种污染物。同时吸附还通过使用中心复合设计方法来研究接触时间和初始溶液酸度的单变量效应，以优化过程，目的是在水/废水处理中实现进一步的实际应用。还研究了多次吸附 - 解吸循环后的吸附剂再生以评估其可行性。基于不同的非线性回归，对四种等温线（朗缪尔、弗伦德利希、希尔和雷德利希 - 彼得森模型）和三种动力学模型（伪一级（PFO）、伪二级（PSO）和双室一级（TC））进行了拟合。发现朗缪尔等温线和PFO动力学模型与实验结果的一致性最佳。具有大量官能团的二氧化硅/聚电解质可被视为可用于废水处理过程的高效且通用的吸附剂。
