Experimental analysis, modeling and optimization of chromium (VI) removal from aqueous solutions by polymer-enhanced ultrafiltration

EFFICIENT REMOVAL OF Cr(VI) BY POLYELECTROLYTE-ASSISTED ULTRAFILTRATION AND SUBSEQUENT ELECTROCHEMICAL REDUCTION TO Cr(III)

“…This method separates ionic species from aqueous solution and is called polymer-enhanced ultrafiltration (PEUF), polymer-assisted ultrafiltration or liquid-phase polymer-based retention. [11][12][13][14][15] PEUF is a hybrid method that involves interaction of the functional polymer with the chromate ion, forming a new polymer-metal macromolecule whose molecular weight is above the ultrafiltration membrane molar mass cut off; therefore, it is retained by size exclusion. 11,2 The advantage of the PEUF method is that it is performed in homogeneous media, preventing the phenomenon of diffusion or mass transfer that occurs with heterogeneous media.…”

Heavy Metal Removal from Liquid Wastes by Using Micellar-Enhanced Ultrafiltration

“…Nickel is a precious element which favors biological functions, but, in case of large amounts, it is carcinogen besides to provoke skin dermatitis, gastrointestinal distress, and pulmonary fibrosis (Borba et al 2006). Even chromium has a positive influence on human metabolism, but, if assumed in excess, it causes lots of health problems, whose the most dangerous is carcinoma (Khezami and Capart 2005;Chakraborty et al 2014). Cobalt in traces favors red blood cell production, but it is a toxic metal if ingested in high concentrations (Karate and Marathe 2008).…”

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

“…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).…”

“…a constant of protonation using the RSM toolkit explicitly take into account the linear, quadratic and interaction effects of various process factors, thereby resulting in better and pragmatic predictions for near optimal process factor levels in the prescribed region of operability (Chakraborty et al, 2014;Cojocaru et al, 2009). The present study deals with the application of PEUF in the removal of Reactive Red 120 dye from its aqueous solution using a popular water soluble polymeric amine, polyethyleneimine (PEI) known for its excellent chelating abilities due to the presence of donor electron pair on the nitrogen atom, rich content of surface functional groups and commendable chemical stability (Shao et al, 2013).…”

“…Additionally, the paradigm performance demonstrated by PEUF technology, in terms of its dye retention efficiency, was statistically optimized by suitably indexing the linear, quadratic and interaction effects of governing process parameters, namely, cross-flow rate, transmembrane pressure, pH and polymer to dye ratio, so as to enhance the dye separation efficiency as well as the cost-effectiveness of the process. Response surface methodology (RSM) was selected as the appropriate mathematical/statistical tool for carrying out the optimization process in sequential steps, which are enumerated as (1) design of experiments (DoE), wherein the controllable process parameters are concurrently varied over the statistically dictated set of experimental trials and investigation of the obtained results so as to determine if the current levels of the independent input variables are likely to yield optimal response (2) suitable mathematical approximation of the true response function explicating the relationship between target response (Y) and input process factors (X i s), using appropriate predictive empirical models; (3) mathematical estimation of the coefficients characterizing the selected polynomial models, and (4) statistical validation of the adequacy of the polynomial model fit (Chakraborty et al, 2014;Kumar and Pal, 2012).…”