Harnessing carboxymethyl cellulose and Moringa oleifera seed husks for sustainable treatment of a multi-metal real waste.

This study aimed to evaluate effective treatment strategies for laboratory waste with an initial pH of 1.0, containing Cr6+, Mn2+, Co2+, Fe3+, Ni2+, Cu2+, Zn2+, Sr2+, Hg2+, and Pb2+ ions, focusing on flocculation, precipitation, and adsorption techniques. The study utilized microparticles derived from Moringa oleifera seed husks (MS), cryogels of carboxymethyl cellulose (CMC), and hybrid cryogels combining CMC and MS (CMC-MS25 and CMC-MS50) as adsorbents. The optimal strategy involved raising the pH to 7 using NH4OH, leading to the partial precipitation of metal ions. The remaining supernatant was then passed through columns packed with the aforementioned adsorbents. Utilizing CMC-MS25 and CMC-MS50 adsorbents resulted in the simultaneous removal of over 90% of the targeted metal ions. The adsorption of Cu2+ ions onto the adsorbents was facilitated by electrostatic interactions between Cu2+ ions and carboxylate groups, as well as Cu-OH chelation, as confirmed by X-ray photoelectron spectroscopy. Under optimized conditions, the fixed-bed column adsorption capacity was determined as 88.2 mg g-1. The CMC-MS25 adsorbents proved reusable at least 5 times, with the recovered Cu2+ ions potentially suitable for other processes. The scalability and feasibility of producing these novel adsorbents suggest a promising, cost-effective solution for treating complex matrices and recovering high-value metals, as copper.

Moringa oleifera oil influence on biodegradation behaviour of polymers.

Vegetable oils (VOs) can be used as plasticizers or as biodegrading additives for commercial polymers. According to the literature, the use of concentrations higher than 5% of oils added to polymers or their mixtures indicated loss of mechanical properties on the final product. However, VOs can be used as a compatibilizer for the mixture of synthetic polymers with biopolymers (PM) under concentrations higher than 5%. Moringa oleifera oil (MO) was used as a compatibilizer to PM mixtures using oil concentrations higher than 5%, 10% and 15% in mass. PMs were analysed at first based on mechanical properties which indicated a better concentration at 15% of MO. This article presents a study of MO influence on biodegradation behaviour of PM, which was composed of low-density polyethylene obtained from food bags and biopolymers (PB) obtained in market plastic bags. PM doped with different concentrations of MO was submitted to studies of mechanical, chemical, morphological and thermal properties and their biodegradation behaviour was evaluated. The concentration of 15% of MO increased the thermal resistance of PM, improved the biodegradation behaviour according to controlled and free tests and reduced its stiffness without a loss of important mechanical properties. The results of this work showed that MO influenced positively the biodegradation of the PM mixture by improving 30% of the degrading speed.