The role of microparticles in dead-end ultrafiltration of wwtp-effluent

Abstract

Ultrafiltration is considered as an interesting polishing technique for effluent of wastewater treatment plants (wwtp-effluent). Results in pilot-scale experiments indicated that microparticles might dominate the filtration characteristics. In this article the results of investigations on the role of microparticles on the filterability of effluent is described. Calculation effects on particle size distributions of effluent showed that particles smaller than 2.0 microm predominantly influence the filterability of the wwtp-effluent. Additionally, experiments were performed on the filterability of size fractions of effluent. Effluent was fractionated with laboratory filters (pore diameter 5.0, 1.2, 0.45, 0.2 and 0.1 microm). The filterability of this pre-filtered effluent in applying ultrafiltration was evaluated by measurement of the SUR, a new parameter for measurement of the filterability of effluent. The results showed that filterability of the effluent was mainly influenced by 40% to 57% by the fraction larger than 0.1 microm and smaller than 0.2 microm, which is five to twenty times larger than the ultrafiltration membrane pores. Pre-treatment of the effluent by coagulation or sand filtration showed only minor influence on these results.

New process for treatment of organically fouled water: experiences with WWTP effluent

“…Most of these studies aimed at improving the water quality for use as household or process water [6][7][8][9]. In these projects the main treatment process was membrane filtration.…”

“…WWTP effluent is characterised by foulants with an organic background, which interact with colloids [12]. Next, WWTP effluent consists of high concentrations of micro-and nanoparticles that tend to foul MF and UF membranes [13,14]. Most of the foulants have a biological background and are related to EPS, which can be determined as polysaccharides and amino sugars [15,16].…”

“…Roorda [8] concludes that pre-treatment of WWTP effluent with only in-line coagulation and/or deep-bed filtration is not enough to remove these foulants. Cost-effective possibilities for preventing the foulants from entering the membrane might be found by applying a pre-coat that acts as a secondary membrane [17], or by pre-treatment of the WWTP effluent with activated carbon filtration or the addition of powdered activated carbon that preferentially adsorbs the foulants [ 18].…”

“…The installation was equipped with capillary NF membranes of X-flow. In previous research on NF of WWTP effluent these membranes were tested at the Driebergen [6] and Tilburg-Noord WWTPs [8].…”

SUR test used for optimisation of membrane filtration plants treating wastewater effluents

“…Although in the Netherlands WWTP effluent contains low but still decreasing pollutant concentrations, here also only a few reuse facilities exist. Improvement of advanced treatment schemes for effluent may promote water reclamation in many cases [ 1 ].…”