Phenol adsorption from wastewater using clarified sludge from basic oxygen furnace

• Published in: Journal of environmental chemical engineering 2019-08, Vol.7 (4), p.103259, Article 103259
• Main Authors: Mandal, Ashanendu, Das, Sudip Kumar
• Format: Article
• Language: English
• Subjects: Adsorption; Clarified sludge; D-R isotherm; Phenol; Pseudo-second-order; Wastewater
• ISSN: 2213-3437
• DOI: 10.1016/j.jece.2019.103259

[Display omitted] •Activated clarified sludge from basic oxygen furnace removes phenol from wastewater.•Removal (%) varies with phenol content, contact time, pH, temperature and dose.•The results strongly support the kinetic, isotherm and thermodynamic models.•The D–R isotherm is the best fit and facilitates the scale-up design.•Safe disposal of spent adsorbent is possible by incineration. Phenol (C6H5OH) found in wastewater is included in the list of priority pollutant. Amongst various ways, the effective way of phenol removal is the adsorption using various agricultural and industrial wastes. In this study, the clarified sludge produced from basic oxygen furnace in steel plant was taken as the adsorbent. The adsorbent characterizations were performed using SEM, XRD, and BET analysers. The adsorption percentage was studied with the variation of adsorbent dose (5–25 g/L), phenol concentration (10–40 mg/L), pH (3–9), adsorption time (50–300 min) and temperature (25–35 °C). The maximum phenol removal was observed at around 63% at the optimum conditions, i.e., with an adsorbent dose of 20 g/L, phenol concentration of 10 mg/L, pH of 7, adsorption time of 240 min and temperature of 35 °C respectively. The adsorption results were tested using several kinetic, isotherm, and thermodynamic models. The pseudo-second order (r2 = 0.98862) and the D–R isotherm (r2 = 0.99046) were the best supportive kinetic and isotherm models within the investigated experimental conditions. The thermodynamic study suggested for a non-spontaneous, endothermic, and random process. The novelty of this study is that besides elaborated experimental investigations and testing of models, the discussions on safe disposal of the used adsorbent and scale-up design of pilot data are included in this paper. The study established that the clarified sludge was an effective adsorbent for phenol removal from wastewater.