title: Biodegradation of p-nitrophenol sorbed onto crystal violet-modified organoclay by Arthrobacter sp. 4Hβ.
abstract: Organoclays are effective sorbents for removal of organic contaminants from water, but their regeneration capacity limits their practical use as a biotechnological process for bioremediation. Here, the sorption of p-nitrophenol (PNP) to crystal violet (CV)-modified montmorillonite and its biodegradation by the bacterium Arthrobacter sp. 4Hβ were studied in a batch aqueous system. The degree of PNP sorption was dependent on the degree of CV modification (loaded at 80 % or 100 % of the clay's cation-exchange capacity-CVM80 and CVM100, respectively). CV sorption to the clay reduced its toxicity to bacteria. PNP at an initial concentration of 0.72 mM was degraded at rates of 65 % and 42 % in CVM80 and CVM100 suspensions, respectively. Both free and CV-clay-adsorbed PNP concentrations were reduced by the bacteria at rates proportional to the degree of CV modification. Three successive cycles of PNP reloading-degradation in the organoclay suspension demonstrated the potential of this matrix's regeneration and reuse toward maximal removal efficiency of organic pollutants.
authors.affiliation: MIGAL-Galilee Research Center, P.O. Box 831, Kiryat Shmona, 11016, Israel, segula@migal.org.il.
authors.forename: Segula
authors.initials: S
authors.lastname: Masaphy
authors.forename: Shay
authors.initials: S
authors.lastname: Zohar
authors.forename: Gurinaz
authors.initials: G
authors.lastname: Jander-Shagug
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D001173:Arthrobacter / Q000378:metabolism*; D000077215:Clay; D005840:Gentian Violet; D009596:Nitrophenols / Q000378:metabolism*; D018508:Water Purification / Q000379:methods
chemical_list: D000538:Aluminum Silicates; D009596:Nitrophenols; D005840:Gentian Violet; D000077215:Clay; C024836:4-nitrophenol