ELECTROMEMBRANE PURIFICATION OF WASTE WATER OF CHEMICAL PRODUCTION FROM IONS Cr6+, Zn2+, SO42-, Сl

Data on the retention factor, and the specific solvent flow during nanofiltration and electron-nanofiltration purification of sewage of galvanic plants from Cr6 +, Zn2 +, SO42-, Cl- ions were obtained. The interpretation of the experimental data depending on the transmembrane pressure, the fixed value of the current density and the type of semipermeable membrane is presented. It was established that the retention factor increases with increasing in transmembrane pressure because of the sealing of membranes, and selective migration of cations Zn2+ and anions SO42-, Cl-, which are inside of wastewater, occurs at the fixed value of current density mainly to the membranes OPMN-P and AMN-P near the cathode and the anode, respectively. The value of the flow is increased in the range of P = (1.0 – 1.4) MPa with increasing pressure, because the driving force of the process increases and the solution is heated due to the action of the electrical potential difference, and slightly decreases at P = (1.4 – 1.6) MPa due to the accumulation of sediments on the membrane surface at the increased flow. The study notes that in the case of electron-nanofiltration, the solution heats up because it is a conductor of the second kind and the main electrical resistance is concentrated in it, in contrast to the metal electrodes (conductors of the 1st kind) made from platinized titanium. Differences in the specific flow of the OPMN-P and AMN-P membranes from the operating pressure at an additional electrolyte potential are related to the material from which their active layer (polyamide, cellulose ether, respectively) is prepared and their different porous structure, distribution of pores over the surface, shape and orientationForcitation:Lazarev S.I., Kovaleva О.А., Popov R.V., Кovalev S.V., Ignatov N.N. Electromembrane purification of waste water of chemical production from ions Cr6+, Zn2+, SO42-, Сl-. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 119-125