Removal of tetracycline from wastewater using pumice stone: equilibrium, kinetic and thermodynamic studies.

Ulker Asli Guler,Meltem Sarioglu

doi:10.1186/2052-336x-12-79

Abstract

In this study, pumice stone was used for the removal of tetracyline (TC) from aqueous solutions. It was characterized by XRD, FT-IR, SEM and BET analyses. Cation exchange capacity of pumice stone was found to be 9.9 meq/100 g. Effect of various parameters such as solution pH (2–11), adsorbent dosage (0.5-10 g/L), contact time (2.5-120 min), initial TC concentration (5–300 mg/L) and temperature (20–50°C) on TC adsorption onto pumice was investigated. Also the adsorption of TC on pumice stone was studied as a function of Na+ and Cu2+ cations changing pH from 2 to 11 using batch experiments. The best removal efficiency performance was exhibited at adsorbent dosage 10 g/L, pH 3, contact time 120 min. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models were applied to the equilibrium data. The result has shown that the adsorption was favorable, physicochemical in nature and agrees well with Langmuir and Freundlich models. The maximum Langmuir adsorption capacity was found to be 20.02 mg/g. The adsorption behavior of TC on pumices stone was fitted well in the pseudo-second order kinetics model. Thermodynamic parameters calculated from the adsorption data at different temperature showed that the adsorption reaction was feasible, spontaneous and exothermic.

Highlights

Antibiotics are used the worldwide in human and veterinary medicine for about 70 years [1,2,3]
The presence of residual antibiotics in soil and water is potentially hazardous for the bacteria and non-target organisms and these can promote the selection of genetic variants of microorganisms resulting in the occurrence of antibiotic resistant pathogens [13,14,15,16,17]
The experimental results were combined with XRD, FT-IR and SEM analyses in order to identify in the interaction between pumice stone and TC and the specific surface area and components of pumice stone were determined by BET and XRF analyses, respectively

Summary

Introduction

Antibiotics are used the worldwide in human and veterinary medicine for about 70 years [1,2,3]. Many adsorbent has been used for TC removal from wastewaters; in this study the pumice stone was used for TC removal from wastewaters with comprehensive research. TCs are highly adsorbed by several materials such as clay, montmorillonite, rectorite, palygorskite, chitosan particles, oxide minerals, humic substances, soil, activated carbon and sediments [3,7,15,17,20,22,23,24,25,26,27,28,29]. Porous and volcanic stone with a large surface area. It is generally pale in color, ranging from white, cream, blue or grey, to green-brown or black [30] and used as an adsorbent, filter bed and support material in water and wastewater treatment [31,32,33]. The experimental results were combined with XRD, FT-IR and SEM analyses in order to identify in the interaction between pumice stone and TC and the specific surface area and components of pumice stone were determined by BET and XRF analyses, respectively

Materials and methods

Results and discussion

Conclusions