Degradation of 2,4-D in soils by Fe3O4 nanoparticles combined with stimulating indigenous microbes

• Published in: Environmental science and pollution research international Vol. 19; no. 3; pp. 784 - 793
• Main Authors: Fang, Guodong, Si, Youbin, Tian, Chao, Zhang, Gangya, Zhou, Dongmei
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.03.2012; Springer Nature B.V
• Subjects: 2,4-D; 2,4-Dichlorophenoxyacetic Acid - analysis; 2,4-Dichlorophenoxyacetic Acid - chemistry; 2,4-Dichlorophenoxyacetic Acid - metabolism; Acid phosphatase; Acid Phosphatase - metabolism; Acidic soils; Amylases - metabolism; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacterial Proteins - metabolism; Biodegradation; Catalase - metabolism; Chemical Phenomena; Chromatography; Degradation; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Restoration and Remediation - methods; Enzymatic activity; Enzymes; Fungal Proteins - metabolism; Fungi - drug effects; Fungi - enzymology; Fungi - growth & development; Gram-Negative Bacteria - drug effects; Gram-Negative Bacteria - enzymology; Gram-Negative Bacteria - growth & development; Gram-Positive Bacteria - drug effects; Gram-Positive Bacteria - enzymology; Gram-Positive Bacteria - growth & development; Groundwater; Half-Life; Herbicides; Herbicides - analysis; Herbicides - chemistry; Herbicides - metabolism; High-performance liquid chromatography; Hydrogen-Ion Concentration; Iron oxides; Kinetics; Liquid chromatography; Magnetite Nanoparticles - chemistry; Magnetite Nanoparticles - ultrastructure; Microbial contamination; Microorganisms; Nanoparticles; Nanotechnology; Pollutants; Population studies; Research Article; Scanning electron microscopy; Soil - chemistry; Soil contaminants; Soil contamination; Soil degradation; Soil Microbiology; Soil microorganisms; Soil Pollutants - analysis; Soil Pollutants - chemistry; Soil Pollutants - metabolism; Soil pollution; Soil remediation; Soil sciences; Studies; Urease; Urease - metabolism; Waste Water Technology; Water Management; Water Pollution Control; China; Enzyme activities; nanoparticles; 2,4-D; Combined degradation; Microbial populations; Fe; O
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-011-0597-y

Purpose Degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in soils by Fe 3 O 4 nanoparticles combined with soil indigenous microbes was investigated, and the effects of Fe 3 O 4 nanoparticles on soil microbial populations and enzyme activities were also studied. Methods The soils contaminated with 2,4-D were treated with Fe 3 O 4 nanoparticles. The microbial populations and enzyme activities were analyzed by dilution plate method and chemical assay, respectively, and the concentration of 2,4-D in soil was determined by high-performance liquid chromatography (HPLC). Results The results indicated that Fe 3 O 4 nanoparticles combined with soil indigenous microbes led to a higher degradation efficiency of 2,4-D than the treatments with Fe 3 O 4 nanoparticles or indigenous microbes alone. The degradation of 2,4-D in soils followed the pseudo first-order kinetic. The half-lives of 2,4-D degradation (DT 50 ) of the combined treatments were 0.9, 1.9 and 3.1 days in a Red soil, Vertisol and Alfisol, respectively, which implied that the DT 50 of the combination treatments were significantly shorter than that of the treatments Fe 3 O 4 nanoparticles or indigenous microbes alone. The effects of Fe 3 O 4 nanoparticles on soil microbial populations and enzyme activities were also investigated and compared with the α-Fe 2 O 3 nanoparticles. The results suggested that the α-Fe 2 O 3 nanoparticles had only comparatively small effects on degradation of 2,4-D in soils, while the Fe 3 O 4 nanoparticles not only degraded 2,4-D in soils but also increased the soil microbial populations and enzyme activities; the maximum increase in enzyme activities were 67.8% (amylase), 53.8% (acid phosphatase), 26.5% (catalase) and 38.0% (urease), compared with the untreated soil. Moreover, the introduction of Fe 3 O 4 nanoparticles at the different dosage resulted in a variable degradation efficiency of 2,4-D in soil. Conclusion The method of combining Fe 3 O 4 nanoparticles with indigenous soil microbes may offer great benefits for the application of nanotechnology in remediation of herbicide contaminated soil.