Predicting Contaminant Adsorption in Black Carbon (Biochar)-Amended Soil for the Veterinary Antimicrobial Sulfamethazine

Abstract

Commercial hardwood biochars ranging in N2 specific surface area of 0.1-427 m(2) · g(-1) were added to an agricultural soil at 0, 1, or 2% levels to determine whether they would predictably reduce the pore water concentration of sulfamethazine (SMT). The soil and biochar-soil mixtures were preweathered under mild (2 d, 20 °C) or more severe (28 d, 40 °C) conditions before spiking. The carbon-normalized biochar-water distribution coefficient (KBC) of the biochars varied by a factor of up to 10(4), depending on biochar properties and SMT concentration. Except for the fast-pyrolysis biochar, KBC greatly exceeded the soil organic carbon-water distribution coefficient KOC. Sorption in the mixtures increased as expected with biochar and dose. However, sorption was dramatically overpredicted (by up to 10(2.5)) by the sum of sorption to the individual components, indicating a strong weathering effect even under the mild conditions. The soil-subtracted weathered biochar-water isotherms were more linear, and the KBC values approached or lay within the range of KOC values reported for SMT in 19 soils. Biochars both in intimate contact with soil and placed in a membrane bag suspended in the solution showed reduced N2-B.E.T. surface area after weathering, implicating fouling of the biochar surface by humic substances transferred through water. The results indicate that only highly surfaceous, carbonaceous biochars would be useful for stabilizing soil contaminated with compounds such as SMT. They also suggest that weathering may attenuate the contribution of native (environmental) black carbon to sorption of such compounds in soils and sediments.

Recent advances in clean-up strategies of waters polluted with sulfonamide antibiotics: a review of sorbents and related properties

“…Only a few studies dealing with the adsorption of sulfa drugs on biochars have been published recently (Ji et al, 2011;Teixidó et al, 2013;Zheng et al, 2013). Biochar, also known as black carbon or charcoal, refers to carbonaceous materials obtained by plant biomass pyrolysis and are present naturally in soils (Schmidt and Noack, 2000).…”

Endogenous minerals have influences on surface electrochemistry and ion exchange properties of biochar

“…Interest in biochars has kept rising over the last few years because of their multi-functional environmental properties (Spokas et al, 2009;Teixido et al, 2013). People have produced biochars from different types of biomass waste because biochar can increase carbon sequestration when they are incorporated into soil (Ibarrola et al, 2012;Lu et al, 2012b).…”

Laboratory Tests of Biochars as Absorbents for Use in Recovery or Containment of Marine Crude Oil Spills

“…Increasing HTT leads to increasing degree of carbonization and micropore development of the produced char. Other properties of the biochars are given in Teixido et al (2013).…”