Application of apricot stone waste from fruit processing industry in environmental cleanup: copper biosorption study

Abstract

-Introduction. Apricots (Prunus armeniaca L.) have an important role in Serbia's fruit production. Average annual production of 25,035 t generates approximately 1,577 t apricot stone (AS) waste and most of it ends up in landfill sites. In order to minimize the environmental impact, an investigation of the possible use of AS was done by developing a biosorbent for wastewater treatment. Materials and methods. AS waste from the fruit processing industry was used to remove Cu(II) ions from water solution by batch adsorption techniques. This solid waste residue was characterized by FTIR, SEM and EDX. The effects of pH, contact time, metal concentration and biosorbent dosage on the process of biosorption were studied. Results and discussion. Obtained FTIR results confirm that the uptake of Cu(II) ions from aqueous solution involves carboxylate moieties from lignin and fatty acids. Also, the presence of seeds in the AS blend significantly increased biosorption performance providing active sites important for the sorption process. The ion exchange mechanism was also confirmed. The best fitting adsorption model is the Langmuir model and the maximum biosorption capacity (q max ) is 4.45 mg L −1 at pH 5.0. Biosorption of the Cu(II) ions follows a pseudo secondorder kinetic model. According to thermodynamic parameters the biosorption process is endothermic and spontaneous. Conclusion. Numerous biosorbents were investigated for biosorption of Cu(II) ions from aqueous solution, but no report on application of untreated AS waste has been found in literature. This preliminary study confirmed that this material can successfully and rapidly remove dissolved copper ions from dilute solutions.Keywords: Serbia / apricot / Prunus armeniaca / waste management / biosorption / copper ions Résumé -Application des déchets de noyaux d'abricot issus de l'industrie agro-alimentaire à la dépollution : étude de la biosorption du cuivre. Introduction. L'abricot (Prunus armeniaca L.) tient une place importante dans l'économie de la Serbie. La production annuelle moyenne de 25 035 t génère environ 1 577 t de déchets de noyaux d'abricots (AS) dont la plus grande partie se retrouve dans des sites d'enfouissement. Afin de minimiser l'impact environnemental de ces déchets, une l'utilisation possible des AS a été envisagée, visant à développer un biosorbant pour le traitement des eaux usées. Matériel et méthodes. Les déchets AS provenant de l'industrie agro-alimentaire ont été utilisés pour éliminer les ions Cu (II) de solutions aqueuses par des techniques d'adsorption par lots. Le résidu des déchets solides a été caractérisé par spectroscopie infrarouge à transformation de Fourier (FTIR), microscopie électro-nique (SEM) et radioscopie à dispersion d'énergie (EDX). Les effets du pH, du temps de contact, de la concentration et du dosage du métal sur le biosorbant ont été étudiés au cours du processus de biosorption. Résultats et discussion. Les résultats obtenus par FTIR confirment que l'absorption des ions Cu (II) de la solution aqueuse met e...

Adsorption of Cu(II) ions from synthetic solution by sunflower seed husks

“…Peak at 1709 cm -1 is assigned to C=O stretching of carbonyl group. Peak at 1027 cm -1 could be assigned to -C-OH stretching vibration of alcohols and carboxylic acids (17).…”

Effect of chemical treatment on adsorption characteristics of apricot stone biosorbent

“…Ako je pH vrednost rastvora veća od pH vrednosti tačke nultog naelektrisanja, povećava se i broj negativno naelektrisanih grupa što favorizuje vezivanje katjona, u ovom slučaju jone dvovalentnog bakra, što su rezultati potvrdili u daljem toku ispitivanja. Suprotno, kada je pH vrednost niska, raste broj protonizovanih funkcionalnih grupa i smanjuje se mogućnost interakcija između površine i katjona u vodenom rastvoru [38,39,40]. Slika 5. pokazuje da se položaji platoa poklapaju za sve tri koncentracije KNO 3 , što ukazuje da je ovo indiferentan elektrolit, odnosno da ne postoji specifična sorpcija jona K + i NO 3 -na površini oba materijala.…”

“…U ranijim istraživanjima utvrđeno je da na sorpcioni kapacitet utiče početna pH vrednost rastvora i da je optimalna početna pH vrednost rastvora 5.0 [40]. Tokom procesa biosorpcije, menja se pH vrednost vodenog rastvora kao posledica kontakta različitih funkcionalnih grupa na površini biomaterijala sa sorbatom (slika 6).…”

Pb(II) biosorption by selected waste biomass

“…The chemical composition data of tested biosorbents are also shown in Figure 1 and their values are presented in papers [11,13,14]. Cellulose content ranged from 58% up to 16.5% and the highest percentages have stones and the lowest corn silk.…”

“…Apricot stones were air dried, milled (KHD Humbolt Wedag AG) and < 1 mm fraction was used. Samples were washed with deionized water to remove impurities, dried at 60 °C [11].…”