Treatment of 2,4-D, mecoprop, and dicamba using membrane bioreactor technology

• Published in: Environmental science and pollution research international 2013-08, Vol.20 (8), p.5188-5197
• Main Authors: Ghoshdastidar, Avik J., Tong, Anthony Z.
• Format: Article
• Language: English
• Subjects: 2,4-D; 2,4-Dichlorophenoxyacetic Acid - metabolism; 2-Methyl-4-chlorophenoxyacetic Acid - analogs & derivatives; 2-Methyl-4-chlorophenoxyacetic Acid - metabolism; Acids; Agrochemicals; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria - metabolism; Benzoic acid; Biodegradation; Bioreactors; Bioremediation; Carbon; Chemical oxygen demand; Chromatography; Contaminants; Dicamba - metabolism; Dissolved oxygen; Earth and Environmental Science; Ecotoxicology; Effluents; Environment; Environmental Chemistry; Environmental Health; Herbicides; Herbicides - metabolism; High-performance liquid chromatography; Liquid chromatography; Mass spectrometry; Mass spectroscopy; Mecoprop; Membrane reactors; Metabolites; Municipal wastewater; Oxygen; Oxygen demand; Pesticides; Research Article; Sludge; Studies; Surface water; Toxic; Toxicity; Trace levels; Waste Disposal, Fluid - methods; Waste water; Waste Water Technology; Wastewater treatment; Wastewater treatment plants; Water Management; Water Pollutants, Chemical; Water pollution; Water Pollution Control; Water quality
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-013-1498-z

Phenoxyacetic and benzoic acid herbicides are widely used agricultural, commercial, and domestic pesticides. As a result of high water solubility, mobility, and persistence, 2,4-dichlorophenoxyacetic acid (2,4-D), methylchlorophenoxypropionic acid (mecoprop), and 3,6-dichloro-2-methoxybenzoic acid (dicamba) have been detected in surface and waste waters across Canada. As current municipal wastewater treatment plants do not specifically address chronic, trace levels of contaminants like pesticides, an urgent need exists for an efficient, environmentally friendly means of breaking down these toxic herbicides. A commercially available herbicide mix, WeedEx, containing 2,4-D, mecoprop, and dicamba, was subjected to treatment using membrane bioreactor (MBR) technology. The three herbicides, in simulated wastewater with a chemical oxygen demand of 745 mg/L, were introduced to the MBR at concentrations ranging from 300 μg/L to 3.5 mg/L. Herbicides and biodegradation products were extracted from MBR effluent using solid-phase extraction followed by detection using high-performance liquid chromatography coupled with mass spectrometry. 2,4-D was reduced by more than 99.0 % within 12 days. Mecoprop and dicamba were more persistent and reduced by 69.0 and 75.4 %, respectively, after 112 days of treatment. Half-lives of 2,4-D, mecoprop and dicamba during the treatment were determined to be 1.9, 10.5, and 28.3 days, respectively. Important water quality parameters of the effluent such as dissolved oxygen, pH, ammonia, chemical oxygen demand, etc. were measured daily. MBR was demonstrated to be an environmentally friendly, compact, and efficient method for the treatment of toxic phenoxyacetic and benzoic acid herbicides.