Low Cost Activated Carbon for Removal of NOM and DBPs: Optimization and Comparison

Hoda Tafvizi,Tahir Husain,Shakhawat Chowdhury

doi:10.3390/w13162244

Abstract

Higher concentrations of disinfection byproducts (DBPs) in small water systems have been a challenge. Adsorption by tailored activated carbon (AC), developed from waste materials of a pulp and paper company using optimization of chemical activation by nitric acid followed by physical activation and metal coating, was tested for the removal of natural organic matter from water using synthetic and natural water. AC was coated with aluminum and iron salts in a ratio of 0.25 to 10.0% of metal: AC (wt:wt%). The optimization of dosage, pH, and time was performed to achieve the highest adsorption capacity. The modified AC of 0.75% Fe-AC and 1.0% Al-AC showed 35–44% improvement in DOC removal from natural water. An enhancement of 40.7% in THMs removal and 77.1% in HAAs removal, compared to non-modified, AC were achieved. The pseudo-second order was the best fitted kinetic model for DOC removal, representing a physiochemical mechanism of adsorption.

Highlights

Introduction and Triantafyllos KaloudisChronic exposure to disinfection byproducts (e.g., trihalomethanes (THMs) and halo acetic acids (HAAs)) in drinking water through ingestion, inhalation, and dermal contact increases the risk of adverse health effects
The objectives of this study are to: enhance the pore structure of activated carbon (AC) produced from pulp and paper waste materials for natural organic matter (NOM) removal; maximize adsorption capacity by a central composite statistical design of experiment and consider the factors of pH, time, and dosage; optimize metal (i.e., Al and Fe) coating on AC considering the levels of metal leaching, dye removal, iodine number, and surface area; and increase the removal of humic acids (HA) as the main precursor of
Optimization of adsorption capacity showed that a dosage of 0.15 g/L of AC for 24 h would result in the maximized adsorption of dissolved organic carbon (DOC)

Summary

Introduction

Chronic exposure to disinfection byproducts (e.g., trihalomethanes (THMs) and halo acetic acids (HAAs)) in drinking water through ingestion, inhalation, and dermal contact increases the risk of adverse health effects. The International Agency for Research on Cancer (IARC) categorizes certain types of THMs and HAAs in Group 2B with the possible increase of the risk for liver cancers [1,2]. The formation of disinfection byproducts (DBPs) occurs continuously in the municipal water as long as natural organic matter (NOM) is in contact with chlorine-based disinfectants [2]. An increased level of NOM in the last two decades [4,5,6,7].

Objectives

Methods

Results

Conclusion