Sorption of ammonium and phosphate from aqueous solution by biochar derived from phytoremediation plants

Abstract

Abstract:The study on biochar derived from plant biomass for environmental applications is attracting more and more attention. Twelve sets of biochar were obtained by treating four phytoremediation plants, Salix rosthornii Seemen, Thalia dealbata, Vetiveria zizanioides, and Phragmites sp., sequentially through pyrolysis at 500 °C in a N 2 environment, and under different temperatures (500, 600, and 700 °C) in a CO 2 environment. The cation exchange capacity and specific surface area of biochar varied with both plant species and pyrolysis temperature. The magnesium (Mg) content of biochar derived from T. dealbata (TC) was obviously higher than that of the other plant biochars. This biochar also had the highest sorption capacity for phosphate and ammonium. In terms of biomass yields, adsorption capacity, and energy cost, T. dealbata biochar produced at 600 °C (TC600) is the most promising sorbent for removing contaminants (N and P) from aqueous solution. Therefore, T. dealbata appears to be the best candidate for phytoremediation application as its biomass can make a good biochar for environmental cleaning.

Recovery of nutrients from biogas digestate with biochar and clinoptilolite

“…There was a strong negative correlation between initial loading ratio and PO4-P removal efficiency (r=-0.72, p=0.008). Our results for orthophosphate removal efficiency were in line with other studies which reported removal efficiencies of between 38 % and 95 % (Sarkhot et al, 2013;Zeng et al, 2013). We did not investigate the mechanisms involved in orthophosphate removal by biochar, but potential mechanisms suggested for orthophosphate removal from liquid solutions include phosphate adsorption to MgO on the biochar surface (Yao et al, 2011), precipitation reactions between phosphate and Ca + and Mg + ions (Wang et al, 2015c), anion exchange with surface hydroxyl groups (Sarkhot et al, 2013) and electrostatic interaction of phosphate anions with charged hydroxide surfaces (Chen et al, 2011).…”

“…Effect of the initial loading ratio on nutrient and organic matter removal Several potential mechanisms for ammonium removal by biochar from liquid solutions have been proposed: cation exchange with cations such as Ca 2+ , Mg 2+ , K + , Na + in biochar (Hale et al, 2013;Sarkhot et al, 2013;Zeng et al, 2013;Cui et al, 2016), chemical reactions with (oxygen-containing) surface functional groups (Kizito et al, 2015;Wang et al, 2015aWang et al, , 2015cCui et al, 2016), surface areadependent physical diffusion and physical entrapment of NH4 + in biochar pores (Clough et al, 2013;Kizito et al, 2015), co-adsorption with soluble organic matter (Lehmann et al, 2002;Sarkhot et al, 2013) and struvite (MgNH4PO4.6H2O) precipitation on biochar (Cui et al, 2016). Lehmann et al (2002) attribute ammonium adsorption to the coadsorption with soluble organic matter.…”

“…cation exchange with cations such as Ca 2+ , Mg 2+ , K + , Na + in biochar (Hale et al, 2013;Sarkhot et al, 2013;Zeng et al, 2013;Cui et al, 2016), chemical reactions with (oxygen-containing) surface functional groups (Kizito et al, 2015;Wang et al, 2015aWang et al, , 2015cCui et al, 2016), surface area-dependent physical diffusion and physical entrapment of NH4 + in biochar pores (Clough et al, 2013;Kizito et al, 2015), co-adsorption with soluble organic matter (Lehmann et al, 2002;Sarkhot et al, 2013) and struvite (MgNH4PO4.6H2O) precipitation on biochar (Cui et al, 2016). Orthophosphate removal has been explained by phosphate adsorption to MgO on the biochar surface (Yao et al, 2011), precipitation reactions between phosphate and Ca + and Mg + ions (Wang et al, 2015c), anion exchange with surface hydroxyl groups (Sarkhot et al, 2013) and electrostatic interaction of phosphate anions with charged hydroxide surfaces (Chen et al, 2011 …”

“…Sorbent materials enriched in nutrients can be considered to be nutrient carriers, which can subsequently be used as a fertiliser in agricultural fields. Biochar has been suggested as a sorbent for the removal of ammonium (Mukherjee et al, 2011;Hale et al, 2013;Hollister et al, 2013;Sarkhot et al, 2013;Hina et al, 2014;Wang et al, 2015a) and phosphate (Yao et al, 2013;Zeng et al, 2013;Wang et al, 2015c) from various wastewaters. Biochar has also attracted growing interest as an effective sorbent for removing organic contaminants due to its porous structure and large surface area (Chen et al, 2011;Ahmad et al, 2014;Mohan et al, 2014;Oh & Seo, 2015;Wang et al, 2015b).…”

Development of a Biochar-Plant-Extract-Based Nitrification Inhibitor and Its Application in Field Conditions

“…These authors concluded that BC from pine bark pyrolyzed at 650 °C adsorbed a higher quantity of phenols, coinciding with our study. These physical characteristics promote an effective adsorption of molecules because of the increased surface area and rougher texture of biochar, which improves the adsorption capacity of BC with organic molecules [41][42][43][44].…”