Treatment of a mining water effluent for the sorption of heavy metal ions using polymer composite beads in a continuous column

Abstract

The performance of novel chitosan-poly(vinyl alcohol) gel beads was evaluated removing lead, cadmium and chromium from mining-influenced groundwater (MIGW) under hydrodynamic conditions employing column sorption experiments. To elicit the efficiency of the synthesized materials, the sorbent bed height within the packed column and volumetric flow were varied; the column configuration was changed using packed and fluidized arrangements. The fluidized bed configuration presented higher sorption efficiency for Pb, Cd and Cr ions than the fixed bed configuration: 78%, 52% and 62% against 60%, 35% and 37%. The packed bed data were processed using the Clark, Dose-Response, Yoon-Nelson and Woldborska models. The best fitting was obtained with the Dose-Response model. The experimental output confirmed the effective reduction of the harmful metals in MIGW at a very short breakthrough time from 3 to 15 min, which is strategic due to the global effects on both human health and environment.

Versatile Zwitterionic Beads for Heavy Metal Ion Removal from Aqueous Media and Soils by Sorption and Catalysis Processes

“…A growing global demand for water is occurring at the same time as an alarming rate of environmental degradation and industrial waste discharge. – Due to their high toxicity and lack of biodegradability, heavy metal ions (HMIs) present in the environment cause enormous issues; hence, it is imperative that industrial manufacturing and processing activities remove them using inexpensive environmentally acceptable sorbents. ,– Mining activities generate aqueous effluents with high metal content, and if these water resources are to be reutilized, contaminants such as HMIs and anions must be removed, getting pH values near neutrality. , These activities generate two types of aqueous solutions: the first involves a hydrometallurgical process aimed at refining precious metal ores using cyanide and mercury, both of which are highly toxic, even at low concentrations. The second type is mining-influenced groundwater or surrounding surface water, which can be produced by the lixiviation of some components from active mining sites of abandoned or inactive mines .…”

“…Column laboratory studies, which are considered preliminary to implementing a larger scale solution, are recommended for improving HMI sorption efficiency under real application conditions. Furthermore, it is widely known that a continuous process has a substantially greater sorption efficiency than a batch system, ,– primarily as the mass-transfer constraints are reduced.…”

“…1,6−8 Mining activities generate aqueous effluents with high metal content, and if these water resources are to be reutilized, contaminants such as HMIs and anions must be removed, getting pH values near neutrality. 9,10 These activities generate two types of aqueous solutions: the first involves a hydrometallurgical process aimed at refining precious metal ores using cyanide and mercury, both of which are highly toxic, even at low concentrations. The second type is mininginfluenced groundwater or surrounding surface water, which can be produced by the lixiviation of some components from active mining sites of abandoned or inactive mines.…”