Low-cost Posidonia oceanica bio-adsorbent for efficient removal of antibiotic oxytetracycline from water

Abstract

The presence of antibiotics as micro-contaminants in the water and aqueous environments is a health concern to humans and the ecosystem. Therefore, their elimination by adsorption to available and cheap materials in water treatment plants is a research topic of high relevance. The present paper reports on the adsorption behavior of Oxytetracycline on a bio-adsorbent prepared from Posidonia Oceanica; an abundant Mediterranean biomass.Characterization of the pretreated Posidonia biomaterial was achieved using several analyses such as Boehm acidbase titration method, pHPZC determination and analysis techniques (FTIR, 13 C CP-MAS NMR, optical microscopy and TGA). The pHPZC occurred around pH 2.11. Posidonia biomaterial showed a fast and high uptake rate throughout the adsorption process, which is a definite advantage for analytical applications such as water decontamination. The experimental kinetic data fitted very rightly the pseudo-second-order kinetic model and the equilibrium uptake can adopt the bi-Langmuir isotherm model for all studied pH values which assumes adsorptions at the two localized sites. Maximum adsorption capacities of 11.8 mg•g −1 and 4.4 mg•g −1 for the two adsorption sites are reached at pH 6. The oxytetracycline adsorption process onto Posidonia bio-adsorbent is spontaneous (ΔadsG 0 < 0), exothermic (ΔadsH 0 < 0), and entropically favorable (ΔadsS 0 > 0). The effect of pH on adsorption behavior and the thermodynamic parameters of adsorption are consistent with a possible origin of adsorption of Oxytetracycline by means of hydrogen bonding interactions between surface hydroxyl and phenolic groups of the biomaterial and Oxytetracycline. The proposed green and environmentally friendly biomaterial offers potential benefits as a bio-adsorbent in the remediation of aquatic environments contaminated by various organic materials.

Subcritical water extraction for recovering cellulose fibres from Posidonia oceanica waste

“…The peak at 898 cm − 1 corresponding to the β-glucosidic bond of cellulose gained intensity and de nition while the intensity of the bands at 875 and 711 cm − 1 decreased due to the removal of sugars from the lignocellulosic matrix. Similar changes have been reported by other authors during cellulose puri cation from PO(Tarchoun et al (2019);Ferchichi et al (2022).…”

Self-Assembled Aminated and TEMPO Cellulose Nanofibers (Am/TEMPO-CNF) Aerogel for Adsorptive Removal of Oxytetracycline and Chloramphenicol Antibiotics from Water

“…When the solution pH passes 7.0, OTC's surface charge turns to negative (OTCH − and OTC 2− ) due to the presence of the phenoxide ion, which will bind strongly to the quaternary ammonium cation of Am/TEMPO-CNF through an electrostatic interaction in addition to hydrogen bonding. Based on that mechanism, an improved adsorption trend was observed at pH higher than 6 [34,35]. The improved adsorption trend at higher pH could be attributed to the electrostatic interaction and hydrogen bonding and decreased electrostatic repulsion.…”

Towards Sustainable Management of Beach-Cast Seagrass in Mediterranean Coastal Areas

“…Importantly, in sensitive areas (e.g., protection zones for fish, sea turtles, or other biological resources, and areas subjected to coastal erosion), the seagrass banquettes should not be removed and their possible uses within the beach system (temporary displacement, creating beach walkways, dune consolidation) can be favored after considering the benefits derived for the beach-dune ecosystem. On the other hand, the uses for beach cast outside the beach system (agricultural and farm solutions [35,36], compost, and bedding [37]) should be considered as possible alternative solutions for a circular economy [38][39][40][41][42], especially in cases of consistent biomass deposits along the shores.…”