Performance evaluation of a simultaneous electrocoagulation and electrofiltration module for the treatment of Cu-CMP and oxide-CMP wastewaters

Preparation of carbon fibers/carbon/alumina tubular composite membranes and their applications in treating Cu-CMP wastewater by a novel electrochemical process

“…Further, it would explain the dilute milky appearance of wastewater. Similar findings were also obtained by other studies using SEM-EDS analysis for suspended solids in various CMP wastewaters [34,45]. Fig.…”

“…According to Table 3, the suspended solids in raw Cu-CMP wastewater was associated with a high negative zeta potential (i.e., −43.80 mV) and low isoelectric points (i.e., pH 0.8) resulting in their good stability in the solution. As shown in Table 3, similar results were also obtained in a separate study with a different Cu-CMP wastewater for zeta potential and isoelectric point determinations [34]. The tested Cu-CMP wastewater in this study also had a high total solids content of 1084 mg/L and a conductivity of 483 S/cm.…”

“…6, the particle size of suspended solids in Cu-CMP wastewater ranged from 40 to 615 nm with a mean particle size of 153 nm. As compared with the previous study [34], which had a broader particle size distribution ranging from 60 to 1100 nm and a larger mean particle size of 215 nm. Therefore, the prepared CCATCMs with a nominal pore size of 3 nm as indicated above would be suitable for electrofiltration of Cu-CMP wastewater studied in this investigation.…”

“…Results of previous studies [7,30,31,33,34] revealed that a higher applied electric field strength would result in a greater filtration rate (or permeate flux). In this work, the CEFS determined in the preliminary experiments was selected as the lower level for the electric field strength in Table 1 (i.e., 10 V/cm).…”

“…Therefore, a simultaneously electrocoagulation/electrofiltration (EC/EF) method was developed by the principal investigator of the present study [32]. Based on the principle of this novel method, a few earlier studies [33,34] employing the flat-type polymeric membranes had been carried out for treating several CMP wastewaters. Permeate with low turbidity, total solids content and sludge yield was obtained in comparison with that of using the chemical coagulation and precipitation method.…”