Hydrodynamic and kinetic study of a hybrid detoxification process with zero liquid discharge system in an industrial wastewater treatment

This work focused on the degradation of toxic organic compounds such as methyl violet dye (mv) in water, using acombined photocatalysis/low pressure reverse osmosis (lpro) system. the performance of the hybrid system wasinvestigated in terms of the degradation efficiency of mv, cod and membrane separation of tio2. the aim of the presentstudy was to design a novel solar reactor and analyze its performance for removal of mv from water with titaniumdioxide as the photocatalyst. various operating parameters were studied to investigate the behavior of the designedreactor like initial dye concentration (c = 10-50 mg/l), loading of catalyst (ctio2 = 200-800 mg/l), suspension flow rate(ql = 0.3-1.5 l/min), ph of suspension (5–10), and h2o2 concentration (ch2o2 = 200-1000 mg/l). the operating parameterswere optimized to give higher efficiency to the reactor performance. optimum parameters of the photocatalysis processwere loading of catalyst (400 mg/l), suspension flow rate (0.5 l/min), h2o2 concentration (400 mg/l), and ph = 5. thedesigned reactor when operating at optimum conditions offered a degradation of mv up to 0.9527 within one hours ofoperation time, while a conversion of 0.9995 was obtained in three hours. the effluent from the photocatalytic reactorwas fed to a lpro separation system which produced permeate of turbidity value of 0.09 ntu which is closed to that ofdrinking water (i.e., 0.08 ntu). the product water was analyzed using uv-spectrophotometer and ftir. the analysis resultsconfirmed that the water from the hybrid-system could be safely recycled and reuse. it was found that the kinetics of dyedegradation was first order with respect to dye concentration and could be well described by langmuir-hinshelwoodmodel. a power-law based empirical correlation was developed for the photocatalysis system, related the dyedegradation (r) with studied operating conditions.