Preparation Of The Organomontorillonite Modified With Quaternary Ammonium And The Investigations On Its Performence Of Adsorbing Organic Pollutant

With the development of society, industrial and domestic waste emissions incerasing,resulted in soil and water pollution, seriously affect the ecsoystem security. Clay mineralmaterials have environmental purification, environmental remediation and environmentalalternative (alternative large environmental load materials) functions, and one of the mosteffective method to purify organic pollutants in aqueous environment is using organic clay.Recently, a great many of research on organoclay adsorption, but the mechanism is unclear.This paper synthesized gemini quaternary ammonium surfactant Dimeric(1,2-bis(cetyldi-methylammonio)ethanedibromide(16-2-16) and trimeric surfactant methylcetylbis[2-(dimetyl-cetylammonio)ethyl]amoniumtribromide(16-2-16-2-16), and prepared the organoclays with16-2-16-montmorillonites and16-2-16-2-16-montmorillonites, compared them withtraditional surfactant cetyltrimethylammonium bromide(CTAB). We also studied adsorptionoforgan montmorillonites and original clay on phenol. The adsorption influence such as CEC,concentration and pH were investigated. Adsoption propieties and mechanism were alsodissused. The main conclusions are as follows:(1) Using adsorption isotherms to contrast the performance on CTAB-montmorillonite,16-2-16-montmorillonite and16-2-16-2-16-montmorillonite, and result showed that theadsorption amount of CTAB,16-2-16and16-2-16-2-16on montmorillonite were alomst thesame, suggested only one ion of the16-2-16and16-2-16-2-16adsorbed in the surface ofmontmorillonite. However,16-2-16and16-2-16-2-16were more efficient than CTAB.(2) The organic montmorillonites with different ion Exchange Capacity(CationicExchange Capacity, CEC) were confirmed by Fourier transform infrared spectroscopy (FTIR),X-ray diffraction(XRD), thermogravimetric analyzer(TGA), scanning electron microscope(SEM) and total organic carbon analyzer(TOC). Result showed that surfactants had beensuccessfully intercalated into the montmorillonite; organ-montmorillonite’s interlayspace andorganic carbon content increased with surfactant adsorption. The arrangement of CTAB-MMT,16-2-16-MMT and16-2-16-2-16-MMT were monolayer, bilayer and pseudotrimoleculour.What’s more,16-2-16-MMT and16-2-16-2-16-MMT were formed pseudotrimoleculour andparaffin complexes. The unmodified montorillonite showed neat structure, smooth strethmorphology, while organoclays showed loose layer chip, irregular and stripping layerstructure, and along with the increasing in hydropobic chain, slice layer stripping was moreobvuous.(3) The adsorption quatity of organic montmorillonites increased with CEC, and theadsorption ability were as follows:16-2-16-2-16-montorillonite>16-2-16-montorillonite>CTAB-montorillonite. The sorption of phenol onto CTAB-MMT was dominated byadsorption and adsorption isotherm was described with Langmuir; The sorption16-2-16-MMT and16-2-16-2-16-MMT were almost by partition.(4)Changing pH of phenol solution with2,6,10, found that organic montorillonitesadsorption quantity were highest in pH=10, lowest in pH=2. This because under the conditionof alkaline ionized, phenol can easily transit into anion, while acidic condition inhibit its ionization. Phenol anion not only can form with surfactant N positive ions with electrostaticattraction, but also form hydrogen bond with Si-O in the surface of montorillonite, so with theincreasing of ion surfactant N end heads and alkaline solution, adsorption of phenol increase.