Spent Coffee Bioelastomeric Composite Foams for the Removal of Pb²⁺ and Hg²⁺ from Water

Abstract

Herein we present an interesting approach for the reutilization of coffee waste in water remediation. This is achieved by the development of bioelastomeric foams composed of 60 wt % of spent coffee powder and 40 wt % of silicone elastomer using the sugar leaching technique. In this study, we present the necessary characteristics of the developed “green” foams for the successful removal of Pb2+ and Hg2+ ions from water, and we identify the involved mechanisms. The capability of the bioelastomeric foams to interact with Pb2+ and Hg2+ is not affected by the presence of other metal ions in water as tests in real wastewater demonstrate. The incorporation of the spent coffee powder in a solid porous support, without compromising its functionality, facilitates the handling and allows the accumulation of the pollutants into the foams enabling their safe disposal. The fabricated foams can be used for the continuous filtration and removal of metal ions from water, demonstrating their versatility, in contrast to the sole coffee powder utilized so far, opening the way for the reutilization and valorization of this particular waste.

Silk Fibroin/Orange Peel Foam: An Efficient Biocomposite for Water Remediation

“…The theoretical maximum adsorption capacity ( Q max theor ) values obtained by the Langmuir isotherm fitting are quite similar to the Q max experimental values (Table S3, Supporting Information) confirming the validity of the model. The dimensionless constant ( R L ) calculated from the parameters obtained with the Langmuir isotherm is an equilibrium parameter called separation factor, which can be used to define whether a process is favorable . For all the adsorbents, the R L values are 0 < R L < 1, confirming that the MB adsorption on the adsorbent materials is favorable (0.014, 0.009, and 0.144 for SFOP foam, SF foam, and OP powder, respectively).…”

“…Nevertheless, its wide use in large‐scale water treatment could be considerably difficult, due to the time‐consuming and complicated processes required for the recovery of the powder after the remediation process. A strategy to improve the handling of OP for water remediation applications may be the fixing of the powder in a solid porous system . The polluted water can permeate the porous solid, where aqueous pollutants can selectively interact and concentrate on the OP active component.…”

An Environmentally Benign Approach for As (V) Absorption from Wastewater Using Untreated Coffee Grounds—Preliminary Results

“…However, the reason that relatively low concentrations of arsenic were observed is due to the small surface area and volume of untreated coffee grounds. Therefore, pretreating the untreated coffee wastes such as calcination to eliminate the impurities and modification with other cation reagents would be necessary to improve the adsorption capacity of the coffee waste [30].…”

“…For example, Azouaou et al demonstrated that the adsorption of cadmium was observed in aqueous solutions by using untreated coffee grounds [29]. In addition, lead and mercury from wastewater were removed using spent coffee bioelastomeric composite forms in a study by Fragouli et al [30]. However, to the best of our knowledge, no study to remove arsenic from the wastewater by using untreated coffee grounds has been reported.…”

Sustainable Exploitation of Coffee Silverskin in Water Remediation

“…The amount of solids used for all experiments was 0.12 g and the volume of aqueous solution was 20 mL, with a metal concentration ranging between 20 and 100 ppm, as previously reported [27].…”