Enhanced PCBs sorption on biochars as affected by environmental factors: Humic acid and metal cations

• Published in: Environmental pollution (1987) Vol. 172; pp. 86 - 93
• Main Authors: Wang, Yu, Wang, Lei, Fang, Guodong, Herath, H.M.S.K., Wang, Yujun, Cang, Long, Xie, Zubin, Zhou, Dongmei
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2013; Elsevier
• Subjects: Adsorption; analysis; Applied sciences; Biochar; cations; Cations - chemistry; Charcoal; Charcoal - chemistry; chemistry; conifer needles; Decontamination. Miscellaneous; Earth sciences; Earth, ocean, space; edaphic factors; Engineering and environment geology. Geothermics; Environmental Restoration and Remediation; Environmental Restoration and Remediation - methods; Exact sciences and technology; Humic acid; humic acids; Humic Substances; Metal cations; Metals; Metals - chemistry; methods; Pollution; Pollution, environment geology; Polychlorinated biphenyls; Polychlorinated Biphenyls - analysis; Polychlorinated Biphenyls - chemistry; soil; Soil - chemistry; Soil and sediments pollution; Soil Pollutants; Soil Pollutants - analysis; Soil Pollutants - chemistry; soil pollution; wheat straw; Asia; China; Polychlorinated biphenyls; Metal cations; Adsorption; Biochar; Humic acid; Organic waste; Combustion residue; Adsorption capacity; Environmental factor; Soil pollution; Organic halogen compounds; Persistent organic pollutant; Decontamination; Upgrading; Chlorocarbon; Aromatic compound; Agricultural waste; Organic compounds; Polychlorobiphenyls; Cation effect; Organic chlorine compounds; Vegetal waste; Waste management; Halogenated hydrocarbon; Waste reuse; Charcoal
• ISSN: 0269-7491; 1873-6424; 1873-6424
• DOI: 10.1016/j.envpol.2012.08.007

Biochar plays an important role in the behaviors of organic pollutants in the soil environment. The role of humic acid (HA) and metal cations on the adsorption affinity of polychlorinated biphenyls (PCBs) to the biochars in an aqueous medium and an extracted solution from a PCBs-contaminated soil was studied using batch experiments. Biochars were produced with pine needles and wheat straw at 350 °C and 550 °C under anaerobic condition. The results showed that the biochars had high adsorption affinity for PCBs. Pine needle chars adsorbed less nonplanar PCBs than planar ones due to dispersive interactions and separation. Coexistence of HA and metal cations increased PCBs sorption on the biochars accounted for HA adsorption and cation complexation. The results will aid in a better understanding of biochar sorption mechanism of contaminants in the environment. ► Application of the biochars for PCBs sorption was a new and effective way. ► The biochars had higher adsorption affinity for PCBs in the soil extracted solution. ► Pine needle chars adsorbed less nonplanar PCBs than planar ones. ► Coexisting humic acid or metal cations increased PCBs sorption on the biochars. The biochars had higher adsorption affinity for PCBs in the extracted soil solution because coexisting humic acid and metal cations increased their sorption.