Synthesis of magnetically-separable porous bone char as an effective adsorbent for disinfection by-products precursor removal from surface water

Abstract

This research was aims to synthesis pig bone char and apply to adsorb dissolved organic carbon (DOC) and trihalomethane formation potential (THMs) from Ping river water, Chiang Mai on October 2016. In addition, the magnetically-separable porous bone char was synthesized by adding ferrous nitrate at ratio 1:1. Pig bone char was pyrolysis at 650 and 900 degree Celsius for 2 hour. The synthesized bone char including magnetically-separable porous bone char (FPBC) and porous bone char (PBC) was investigated their physical and chemical characteristics including Point of Zero Charge (PZC), Surface charge density, Surface area (BET), Scanning electron microscope (SEM), Fe mapping and Energy-dispersive X-ray spectroscopy (EDXThe result showed that pig bone char that pyrolysis at 900 °c was the optimal adsorbent.

The adsorption kinetics and adsorption isotherms were examined under batch condition. Along with the kinetic study, the adsorption adsorbents reached to the equilibrium after 1 hour of contact time by varied concentration at 0.2, 0.4, 0.6 and 0.8 g/L. The pseudo-second order model was found to fit well with the adsorption kinetic of all adsorbents. From the adsorption isotherm results, the F-PBC-900 °C adsorbent was best fitted with Langmuir isotherm model and the PBC-900 °C adsorbent was best fitted with Freundlich isotherm model.

The DBPs precursor removal experiment were analyzed various parameters including dissolved organic carbon (DOC), UV Absorbance at wavelength 254 nm (UV-254), Fluorescence Excitation-Emission Matrices (FEEM), trihalomethane formation potentials (THMFPs) and Specific Trihalomethanes formation potential (STHMFPs). The results indicated that the pig bone char with adding iron (III) nitrate as magnetically-separable porous bone char at 0.4 g/L concentration can be utilized as low cost absorbent.