Polyurethane Loaded with Vegetable Activated Carbon for Heavy Metals Removal from Water

Abstract

The heavy metals pollutants resulting from industrial wastewater are a major environmental problem due to their toxicity and non-biodegradability. Their removal became a trending environmental subject. The preparation of low-cost and eco-friendly adsorbents for industrial wastewater treatment has been widely investigated. Furthermore, the use of polymeric material for this purpose is highly increasing. In this study, banana stem agro-waste was valorized by preparing and characterizing its derived activated carbon used as a filler to improve the adsorption performance of polyurethane foams. The loaded polyurethane was synthesized in the shape of pellets, characterized by SEM, and tested in removing Pb 2 + and Cu 2 + from aqueous solutions. The effects of activated carbon filler concentration, number of filtering passes, and pH were examined. The loaded polyurethane demonstrated a good adsorption capacity that was enormously improved compared to the unloaded polymer. 77% Pb 2 + and 40% Cu 2 + removal were reached after one filtering pass only. The optimum pH was determined to be 4. After the 10th pass, and at any pH, almost 100% of the studied metals were eliminated. Rapid and straightforward selectivity and seawater deionization tests were carried out and confirmed the capacity performance of the prepared pellets in removing different aqueous ions.

Cr(VI) removal performance from wastewater by microflora isolated from tannery effluents in a semi-arid environment: a SEM, EDX, FTIR and zeta potential study

“…The attachment of chromium anion to cell surfaces leads to an accumulation of negative charges (Larson et al, 2023 ). The negative values of the zeta potentials confirm the accumulation of negative charges on the cell surfaces (Al-Jubory et al, 2020 ; El Malti et al, 2021 ). This observation suggests that electrostatic interactions play a role in metal adsorption.…”

Coconut power: a sustainable approach for the removal of Cr6+ ions using a new coconut-based polyurethane foam/activated carbon composite in a fixed-bed column

“…This observation might be attributed to the higher ratio of HCrO 4 − and Cr 2 O 7 2− present in the adsorbate at pH = 4, 21 which could significantly induce the uptake capacity of the PUAC. In contrast, the excessive protonation of the adsorbent surface at pH = 2 disrupted the interaction between Cr 6+ and the adsorbent, 1,44 leading to a decreased breakthrough time. Moreover, when pH was further increased from 4 to 6, there is an increased formation of CrO 4 2− and Cr 2 O 7 2− precipitates 3,21 which cannot be adsorbed by the PUAC, resulting in a decrease in the breakthrough time from 300 to 240 min.…”

“…42 Further, the low-intensity occurrence of these peaks suggests a low degree of graphitization, 43 and possesses a crystalline carbonaceous structure. 42,44…”

“…42 Further, the low-intensity occurrence of these peaks suggests a low degree of graphitization, 43 and possesses a crystalline carbonaceous structure. 42,44 Fig. 2 FTIR spectra of a blank polyurethane foam against the composite foam.…”

Experimental Design and Breakthrough Curve Modeling of Fixed-Bed Columns Utilizing a Novel 3D Coconut-Based Polyurethane-Activated Carbon Composite Adsorbent for Lead Sequestration

“…These angles correspond to the distinctive diffraction patterns associated with the amorphous carbon structure aligned with the (0 0 2) and (1 0 0) crystallographic planes, respectively [38]. Furthermore, the presence of these peaks at a subdued intensity implies a limited extent of graphitization, therefore implying the presence of a carbonaceous structure with relatively low crystallinity [39].…”