title: Sunlight mediated diesel degradation under saline conditions using ionic silver coated sand via nanoreduction: use of impregnated form of thiourea modified chitosan membranes for ex situ application.
abstract: The present research investigates the use of ionic silver coated sand dust (ISSD) for the sunlight mediated degradation of diesel under saline conditions. Sand dust was used as a template for reduction of silver ions by effective removal of chloride ions. Diesel degradation was estimated in terms of degradation (%), chloride removal, volume reduction and nanoparticle synthesis, respectively. The process was optimized using a 7-level Box-Behnken design. Among several factors, time (B), Tween 80 (C), ISSD dosage (D) and silver(I) concentration (F) were found to be most significant. Maximum diesel degradation 99.8% was obtained in a period of 14 h which was analyzed by gas chromatography. XPS analysis confirmed silver reduction as the underlying phenomena. TEM analysis and albeit first approximation method confirmed that enhanced degradation occurred due to physical contact between diesel components and ISSD. First order kinetic model exhibited the best fit. Light microscopy results showed the various stages in diesel degradation by a reduction in bubble size. Ex situ application was carried out using ISSD impregnated thiourea modified chitosan/PVA membranes by surface floatation technique for the remediation of diesel contaminated sea water. Complete diesel degradation was noted after 48 h of sunlight exposure.
authors.affiliation: School of Biosciences and Technology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Devlina
authors.initials: D
authors.lastname: Das
authors.affiliation: School of Biosciences and Technology, VIT University, Vellore, Tamil Nadu, India. Electronic address: nilanjana00@lycos.com.
authors.forename: Nilanjana
authors.initials: N
authors.lastname: Das
mesh_terms: D048271:Chitosan / Q000737:chemistry; D005742:Gasoline; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010782:Photolysis; D054712:Salinity; D012822:Silicon Dioxide / Q000737:chemistry; D012834:Silver / Q000737:chemistry* / Q000528:radiation effects*; D012965:Sodium Chloride / Q000737:chemistry; D013472:Sunlight; D013890:Thiourea / Q000737:chemistry
chemical_list: D005742:Gasoline; D008567:Membranes, Artificial; D012834:Silver; D012965:Sodium Chloride; D012822:Silicon Dioxide; D048271:Chitosan; D013890:Thiourea
keywords: Degradation; Diesel; Ex situ; Ionic silver coated sand dust (ISSD); Surface floatation technique