Experimental investigation of adsorption–flocculation–microfiltration hybrid system in wastewater reuse

Abstract

Membrane hybrid systems are becoming increasingly important as cost effective solutions in wastewater treatment and reuse. The effects of pretreatment namely floating medium flocculation (FMF) and powdered activated carbon (PAC) adsorption on organic and phosphorus removal was studied. The FMF was found to increase the phosphorus removal up to 97%. This preflocculation improved the dissolved organic removal only marginally (from 20% to 40%) whilst the pretreatment of adsorption increased the organic removal to more than 98%. The decline in filtration (permeate) flux of microfiltration was reduced by the incorporation of these pretreatment methods. Detailed studies on the effect of PAC dose indicated that a PAC dose of 1g/L was the optimum in terms of organic removal and filtration flux. PAC doses in excess of 1g/L contributed to a significant decrease in filtration flux.The critical flux was experimentally evaluated for crossflow microfiltration (CFMF) with and without the pretreatment. The pretreatment of adsorption led to six times higher critical flux than that without any pretreatment. The preflocculation 2 alone did not significantly increase the critical flux. There was only a 33% increase with preflocculation. However, the preflocculation combined with PAC adsorption resulted in nine times higher critical flux.The results showed that a pretreatment of flocculation and adsorption led to almost complete phosphorus and organic removal while reducing the membrane clogging.

Application of Magnetic Coconut Shell-derived Biocarbon for Methylene Blue Removal

“…Salts may have incorporated into the interior of the biocarbon and influenced development of internal porosity. Activation process also inhibits particle shrinkage and volume contraction (Guo et al, 2007). This result is in agreement with previous study where BET surface area of palm shells biocarbon (206 m 2 /g) is lower than activated palm shells biocarbon treated with H2SO4 (1014 m 2 /g) (Guo et al, 2005).…”

Flux and performance improvement in a submerged anaerobic membrane bioreactor (SAMBR) using powdered activated carbon (PAC)

“…The TMP stabilised at 0.1 bars at 10 LMH which indicated lower cake resistance and less membrane fouling with PAC addition, and showed that the SAMBR can be operated for some time at constant flux. Guo et al [29] have reported increases in filtration (permeate) flux of microfiltration by the incorporation of PAC as a pre-treatment method, where PAC adsorption led to a six times higher critical flux than without. The TMP increased to 0.25 bars only when the recycle flux was increased to 15 LMH, which shows that around 10 LMH was the critical flux in the presence of 1.67 g l -1 PAC under the given operating conditions, however, the TMP dropped back to a very low value when the flux was reduced to 10 LMH showing that the membrane fouling was reversible.…”

Submerged microfiltration coupled with physcio-chemical processes as pretreatment to sea water desalination

“…Thus, there is a need to establish an integrated hybrid system incorporating immersed membranes with adsorption and fl occulation. A long-term study with immersed membrane/adsorption hybrid system showed a consistent and superior organic removal with practically no membrane fouling [4].…”

“…The organic matter corresponding with the MW fraction of 1510 Da, 1180 Da, 530 and 130 Da represents biopolymers (polysaccharides and proteins), fulvic acid, low MW acids (hydrolysates of humic substances), and amphiphilics, respectively [4,8]. Figure 4 shows the MWD of SWOM with and without prereatment.…”

“…However, the use of MF without other processes led to fouling and unsustainable operation. Recent studies proved that hybrid membrane processes ( coupling fl occulation and/or adsorption with membranes) are effi cient in simultaneously reducing membrane fouling and improving water quality [3,4]. However, such results are not available for sea and brackish waters and are of paramount importance for the rational design of pretreatment.…”