Spectrometric study of crystal violet in presence of polyacrylic acid and polyethylenimine and its removal by polyelectrolyte enhanced ultrafiltration

Response surface-optimized removal of Reactive Red 120 dye from its aqueous solutions using polyethyleneimine enhanced ultrafiltration

“…Milli-Q RO water (Millipore, USA) was mainly employed for feed preparation and dilution of test solutions, in accordance with the experimental requirements. The analytical grade polyethyleneimine (PEI) polymeric binding solution, supplied by Sigma Aldrich., USA, yielded satisfactory performance as a chelating agent on direct usage (Cojocaru et al, 2009;Ouni and Dhahbi, 2010). Hence, the claims made by the manufacturer/supplier to its quality were justified, which thereby explained the exclusion of diafiltration process with regard to the pre-treatment of the as-purchased PEI solutions (Chakraborty et al, 2014).…”

“…As such, the inclusion of temperature as a process factor would have involved unnecessarily large number of experimental trials involving five process parameters, in the central composite design (CCD) prescribed by RSM. Also the selection of the process variables, namely, pH, polymer to dye ratio, transmembrane pressure and cross-flow rate, for experimental analyses was based on the fact that these factors were considered as the principal process parameters in similar PEUF based investigations documented in archival literature (Fradj et al, 2014;Ouni and Dhahbi, 2010). Hence, temperature was not included as a process factor in the present study and the experiments were carried out at the unperturbed room temperature of 35°C (Chakraborty et al, 2014).…”

“…Despite being immensely successful in handling a wide spectrum of industrial effluents, its application, as a treatment technique for effecting dye removal from highly colored effluents, is rather limited. This is primarily due to the fact that the molecular weights of the spent dyes are considerably lower than the molecular weight cut-off (MWCO) of the ultrafiltration membranes (Dasgupta et al, 2014a;Ouni and Dhahbi, 2010). Consequently, the reclaimed permeate quality usually fails to satisfy the stipulations mandated in regard to innocuous disposal of treated effluents or effective process water reuse in principal industrial processes.…”

“…This trade-off between operation cost and dye retention efficiency can be substantially resolved by employing a hybrid process involving complexation and ultrafiltration, wherein the target contaminants are bound by water-soluble polymers or polymeric macroligands to form macromolecular complexes, which can be effectively retained by the subsequent ultrafiltration process. This process has been termed as polymer enhanced ultrafiltration (PEUF) and its applicability in removing contaminants such as heavy metal ions from industrial wastewaters has been explicitly reconnoitered in the recent scientific investigations (Chakraborty et al, 2014;Shao et al, 2013;Zamariotto et al, 2010), although studies on the usage of PEUF in dye contaminated wastewater remediation is still relatively limited, as revealed in the appraisal of archival literature (Fradj et al, 2014;Mondal et al, 2012;Ouni and Dhahbi, 2010). A meticulous survey of the PEUF based scientific investigations available in archival literature has, moreover, revealed the fact that most of these have employed classical methods to appraise the effects of various process parameters, such as pH, polyelectrolyte concentration, and transmembrane pressure, on the retention of the target solutes from their respective aqueous solutions (Fradj et al, 2014;Ouni and Dhahbi, 2010).…”

“…This process has been termed as polymer enhanced ultrafiltration (PEUF) and its applicability in removing contaminants such as heavy metal ions from industrial wastewaters has been explicitly reconnoitered in the recent scientific investigations (Chakraborty et al, 2014;Shao et al, 2013;Zamariotto et al, 2010), although studies on the usage of PEUF in dye contaminated wastewater remediation is still relatively limited, as revealed in the appraisal of archival literature (Fradj et al, 2014;Mondal et al, 2012;Ouni and Dhahbi, 2010). A meticulous survey of the PEUF based scientific investigations available in archival literature has, moreover, revealed the fact that most of these have employed classical methods to appraise the effects of various process parameters, such as pH, polyelectrolyte concentration, and transmembrane pressure, on the retention of the target solutes from their respective aqueous solutions (Fradj et al, 2014;Ouni and Dhahbi, 2010). The application of a flexibile statistical tool, such as response surface methodology (RSM) in such cases, reduces the time expended on the required analyses by resorting to the formulation of a robust design matrix, that is engineered to yield precisely configured experimental trials within the dictated ranges of variables.…”