| Pertraction is the frontier technology in membrane baesd extraction,in which a dense non-porous membrane with high selectivity is applied to recovery of organic matter by extraction.Organic matter and salt ions can be effectively separated,increasing the efficiency of biochemical treatment for the organic wastewater.At present,main researches about pertraction technology used in waste organic treatment involve the process conditions and the mass transfer process,but have less the membrane selective extraction mechanism of organic matter and the study of film series combination is available.The ability of membrane selective extraction of for organic matter is closely related to the structural properties of the organic matter itself.Based on the molecular structure characterization method is applied convert the abstract structural properties of organics into structural parameters.Relationship between membrane permeation extraction technology and organic chemicals are investigated in this paper.Organic acid are selected as research subjects,which can be commonly found in organic wastewater.Ten kinds of structural parameters are selected to analysis the relationship between structural parameters and the extraction efficiency of organic matter in the membrane,mechanism of membrane extraction is investigated at the same time.The results show that:(1)PVMS and PPMS have excellent extraction rate for organic acid compared with PDMS.(2)Hydrophilic and hydrophobic properties of organic acids are the main factors in three kinds of membranes extraction behavior.The more hydrophobic is,the easy membrane extraction happen for organic acid.In specific,octanol-water partition coefficient(lgP)and solubility of organic matters are the main parameters affecting the extraction efficiency.With the increase of octanol-water coefficient or decrease of solubility,the extraction rate of organic acid in membranes is gradually increased.(3)With membrane extraction,n-valeric acid can be processed expediently,removal extent and recovery extent increase with n-valeric acid concentration increases,removal extent can reach 94% when n-valeric acid concentration was 7%;When the concentration of the n-valeric acid was 2%,the recovery extent of the membrane was 45.8%.Chemical reaction can improve the efficiency of membrane extraction.When flow rate is in the range of 1mL/min to 20mL/min,along with the increase of flow rate,n-valeric acid removal extent and recovery extent increase,improving the flow rate in practical engineering be able to enhance the separation effect of organic matter.(4)PDMS-PVMS-PPMS membrane extraction: The organics removal rate is best when organic matter concentration in 380.5mg/L for organic matter concentration of material liquid from 100.5 to 2171.50mg/L.When flow rate is in the range of 5mL/min to20mL/min,removal efficiency achieve maximum at 16mL/min.The effect of p H on the removal efficiency of organic acid is large,when pH changes from 10.5 to13.0,removal efficiency of organic acid increase 40%.Salt ion concentration affected the organic acid in the membrane phase-water distribution coefficient for removal efficiency of organic acid in a certain range to promote the diffusion process,when salt ion concentration is in the range of 1% to 20%,removal efficiency of organic matter increase 25%.Within a certain range,improving the temperature will promote the removal efficiency of organic matter and removal rate is best at 30 ?,but too high temperature will damage the membrane treatment its life,at room temperature in the practical engineering application is ok.(5)After the electrolysis respectively,PVMS and PPMS membrane are found has certain treatment effect for wastewater containing methyl orange wastewater,reactive brilliant blue wastewater directly and deep palm after electrolytic.It proves that coupling membrane and electrolysis technology can be coupled and applied in dyeing wastewater treatment. |
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