Preparation of poly(lactic acid) (PLA)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV)/graphene oxide (GO) polymeric composites for the selective removal of lead ions (Pb(II)) in water

Abstract

AbstractLead pollution in water has risen globally, due to industrialization and globalization. In this study, this problem was addressed by preparing poly (lactic acid) (PLA)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV)/graphene oxide (GO) composites and addressing their effectiveness in absorbing water, and adsorbing Pb(II) ions in water. In water absorption studies, increasing the GO content to above 1 wt.% (3 and 5 wt.%) resulted in the degradation of the composites. All blends, and composites with 1 wt.% GO loading showed good water intake properties, with the composites having the highest. Pb (II) ion intake analyses showed that all the materials adsorb Pb(II) ions significantly in 24 h contact time, but the composites with 1 wt.% GO loadings adsorbed the greatest (81.3%–86.5%). For the effect of pH on adsorption, the adsorption of Pb(II) ions increased with an increase in pH from acidic to basic. This was attributed to the abundance of hydroxyl ions in basic media, that will not compete with Pb(II) ions for adsorption sites. Conclusions were that the 49.5/49.5/1 w/w PLA/PHBV/GO composite was the most optimal adsorbent of Pb(II). This composite could be used in industrial water purification processes like membranes, to remove lead ions from water while conserving the environment.Highlights Melt mixed PLA/PHBV/GO composites for removing lead ions from water. 1 wt.% GO contents in the composites sufficiently absorbed water. 3 and 5 wt.% GO contents resulted in the hydrolytic degradation of composites. Contact time is directly proportional to the degree of lead ion adsorption. Basic pH media resulted in the optimal adsorption of lead ions from water.