Influence of water matrix and hydrochar properties on removal of organic and inorganic contaminants

Mirva Niinipuu,Stina Jansson,Erik Rosenbaum,Jean-François Boily,Magnus Bergknut

doi:10.1007/s11356-020-09164-7

Mirva Niinipuu, Stina Jansson + Show 3 more

Open Access

https://doi.org/10.1007/s11356-020-09164-7

Copy DOI

Abstract

The removal of contaminants from water using low-cost adsorbents has been widely studied, yet studies employing a realistic water matrix are still lacking. This study investigated the removal of organic compounds (trimethoprim, fluconazole, and perfluorooctanoic acid (PFOA)) and metals (As, Zn, and Cu) from landfill leachate. Additionally, tests in pure water, humic acid, and ion matrices were carried out to better understand how the water matrix affects adsorption. The hydrochars were produced from four feedstocks at three carbonization temperatures. The results show that the removal efficiencies for organic pollutants were low and metal removal by hydrochars was comparable with commercial activated carbon. The removal of all compounds from pure water was substantially lower. Tests with humic acid and ion-containing matrices could not fully explain the increased removal in the landfill leachate, which may be due to the combination of the water matrix and presence of soluble species from the hydrochars.

Highlights

Sustainable feedstock materials for the production of low-cost adsorbents have been studied extensively
The removal efficiency was substantially decreased in hydrochars produced at the highest temperature, while the hydrochars produced at 180 °C and 220 °C showed similar removal efficiencies
These results suggest that both treatment temperature and choice of feedstock affect the adsorption efficiencies of hydrochars for a given contaminant

Summary

Introduction

Sustainable feedstock materials for the production of low-cost adsorbents have been studied extensively. Studies on the adsorption of environmental contaminants are conducted in the mg L−1 range, which is orders of magnitude higher than actual concentrations in influents and unrealistic (Östman et al 2017; Silva et al 2018). This caveat is important to consider when assessing the suitability of various materials to real-life scenarios, and the limitations of previous contaminant adsorption studies have been highlighted in recent publications (Sedlak 2018; Silva et al 2018)

Objectives

Methods

Results

Conclusion