Removal of 4-chlorobenzoic acid from spiked hydroponic solution by willow trees (Salix viminalis)

• Published in: Environmental science and pollution research international Vol. 17; no. 7; pp. 1355 - 1361
• Main Authors: Deavers, Kamila, Macek, Tomas, Karlson, Ulrich G, Trapp, Stefan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.08.2010; Springer-Verlag; Springer Nature B.V
• Subjects: Acids; Adsorption; Ammonium; Ammonium Chloride - metabolism; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Biodegradation, Environmental; Biomass; Carcinogens; Cells, Cultured; Chlorobenzoates - analysis; Chlorobenzoates - metabolism; Chlorobenzoates - toxicity; Chlorobenzoic acid; degradation; Degradation products; Dose-Response Relationship, Drug; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental cleanup; Environmental Health; Herbicides; Hydrogen-Ion Concentration; Hydroponics; Liquid chromatography; Metabolism; Metabolites; Microbial degradation; Nitrates - metabolism; Nutrient concentrations; PCB; Pesticides; Plant tissues; Plant Transpiration; plants; Polychlorinated biphenyls; Polychlorinated Biphenyls - metabolism; Research Article; Salix - drug effects; Salix - metabolism; Salix viminalis; Soil Pollutants - analysis; Soil Pollutants - metabolism; Soil Pollutants - toxicity; Studies; Trees; Waste Water Technology; Water Management; Water Pollution Control; Willow trees; Willows; Europe; Degradation; Chlorobenzoic acid; Plants; Metabolism; Willows; PCB
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-010-0321-3

Background Chlorobenzoic acids (CBA) are intermediate products of the aerobic microbial degradation of PCB and several pesticides. This study explores the feasibility of using basket willows, Salix viminalis, to remove 4-CBA from polluted sites, which also might stimulate PCB degradation. Methods The removal of 4-CBA by willow trees was investigated with intact, septic willow trees growing in hydroponic solution and with sterile cell suspensions at concentrations of 5 mg/L and 50 mg/L 4-CBA. Nutrient solutions with different levels of ammonium and nitrate were prepared to achieve different pH levels. The concentration of 4-CBA was tracked over time and quantified by HPLC. Results and discussion At the low level of 4-CBA (5 mg/L), willows removed 70% (pH 4.2) to 90% (pH 6.8), while 48% (pH 4.2) to 52% (pH 6.8) of the water was transpired. At the high 4-CBA level (50 mg/L), the pH varied between 4.4 and 4.6, and 10% to 30% of 4-CBA was removed, but only 5% to 9% of the water. In sterile cell suspensions, removal of 4-CBA by fresh biomass was much higher than removal by dead biomass. Conclusions The results indicate that 4-CBA is toxic to willow trees at 50 mg/L. The removal of 4-CBA from solution is by both passive processes (uptake with water, sorption to plant tissue) and metabolic processes of the plants. Recommendations and outlook Plants, such as willow trees, might assist in the degradation of PCB and their degradation products CBA.