Effect of adsorptive fouling on membrane performance: Case study with a pulp mill effluent

The compatibility of a wide range of membrane materials with a pulp mill effluent was evaluated with respect to adsorptive fouling. Membranes were initially evaluated by their pure water permeability and separation characteristics with a polyethylene glycol test solute. These membrane coupons were contacted with a pulp mill effluent sample at 50°C in the absence of a transmembrane pressure for 3 h and then recharacterized. The change in the separation and permeation was interpreted as changes in the average pore size and the ratio of the number of pores to the effective pore length ( n/ ΔxA) of the membrane. A decreasing pore size indicated the formation of an adsorbed fouling layer. An increased n/ δxA ratio suggested that adsorption occurred on the membrane surface rather than in the pores.