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Preparation Of Porous Beads And Adsorption Of Organic Solvents And Oils Polydimethylsiloxane

Posted on:2015-02-18Degree:MasterType:Thesis
Country:ChinaCandidate:X M LeiFull Text:PDF
GTID:2261330428970108Subject:Environmental Engineering
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Water pollution incidents in recent years, frequent accidents, water pollutioncaused by long-term accumulated contamination are a serious threat to socialeconomy and ecological environment.Organic solvent can bring about seriousdamage to human health because of its difficult degradation in theenvironment.Aiming at the problem of Organic solvent in water, conventionalphysical process will be treated as the water solvent completely, chemical methodswill cause secondary pollution.As environmentally friendly processing methods,biological treatment method only be use of organic which can be completelydecomposed by organisms in a long time. Adsorption treatment is an important andsophisticated technology to dispose aqueous solution, Adsorption resin is a new typeof organic adsorption materials developed in recent years,it’s adorption performanceis good and can be regeneration easily, will replace the activated carbon gradually.There are more and more insider study the synthesis and application of high oilabsorption resin, in order to recycle the organic solvent in the water by highefficiency and low cost. This subject adopts the polydimethylsiloxane (PDMS)prepolymers for component A, a mixture of n-butyl acetate and tin laurate ascomponent B. This resin’s advantages are strong lipophilicity and chemical, thermalstability, good mechanical strength, be easy to separate from water.It can be used asefficient oil absorption material processing waste water containing organic solvents.This subject makes PDMS porous spheres that can float on the surface of waterby adding carbon tetrachloride and octane mixture as actuators agent hole.Characterized by thermogravimetric, pore structure, scanning electron microscopy(SEM) method. Inspect the ball to the oil absorption characteristics of differentorganic solvents and the biggest oil absorption rate.The results show that:(1)The best synthetic conditions of PDMS porousspheres is Quality is better than A: B is about31, pore-foaming agent is4mL carbontetrachloride and octane1:1mixture, polymerization time is40min, reactiontemperature is70℃, stirring rate is80r/min, dispersing agent is gelatin solution whichconcentration is0.05g/mL.(2) Results of characterization: insoluble in common acid and alkali and organicsolvent, has thermal stability, basically stable below451℃; See from scanningelectron microscopy (SEM) analysis of PDMS porous ball,it has a large number ofpore structure inside, this kind of structure is advantageous to the adsorbate fast to the interior pore, improve oil absorption rate. The existence of the obturator increasedretention.(3)PDMS porous spheres choose to adorpt different solvents according to itssolubility parameters,largest oil absorption rate is n-heptane2.55g/g. Through thedynamics analysis, Adsorption kinetics accords with pseudo secondary dynamicsequation. By repeating the oil absorption tests showed that the material can berecycled many times, and shall not affect the oil absorption rate.(4) Aqueous organic solvent adsorption experiments,the remove rate of solventis about70%by PDMS porous spheres. Temperature, pH, adsorption dose of PDMSporous pellet oil absorption rate is less affected, influenced by the initial concentration(5) Through the experiment had a greater influence on the filling height of thecurve,the penetration time is130min when the height is11cm.
Keywords/Search Tags:PDMS porous spheres, organic solvent, adsorption
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