New parameter for monitoring fouling during ultrafiltration of WWTP effluent

Abstract

Variations in water quality of waste water treatment plant (WWTP) effluent complicate ultrafiltration of this feed water. Traditional parameters do not provide sufficient information to explain the fouling of membranes during ultrafiltration of WWTP effluent. New parameters for measuring and monitoring the fouling potential of feed water for ultrafiltration membranes need to be developed. The normalised membrane fouling index for ultrafiltration membranes (MFI-UFn) can be used as such and is according to the cake filtration theory calculated from the ratio of filtration time and filtration volume as a function of the filtration volume. MFI-UFn can be calculated from both experiments with constant Trans Membrane Pressure (TMP) and from experiments with constant flux. This parameter can also be calculated independent of the scale of the experiment. Results show that differences in fouling potential can be measured for various feed waters using the same membrane type and for various membrane types using the same feed water. Variation in feed water quality leads to a deviation of the MFI-UFn, as was found especially for WWTP effluent. The applied TMP influences the value of the MFI-UFn, indicating cake compression when applying a higher TMP. MFI-UFn can be used to identify the effect of pre-treatment methods, which is useful when using WWTP effluent as feed water for an ultrafiltration processes.

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

“…In a previous paper [11 ] a new parameter for fouling prediction (MFI-UF,) was introduced. This parameter was related to the Modified Fouling Index using UF membranes (MFI-UF) [9], but was measured for a shorter period (14-30 min instead of 6-24 h as in [9]).…”

“…Boerlage et al [9] used the same equation to calculate the MFI-UF using UF membranes by using the same conditions as Schippers and Verdouw [8]. Roorda and van der Graaf [11] presented the normalised MFI-UF, i.e., MFI-UF,, as a standardised measurement for the prediction of filtration behaviour (see Roorda [ 1 ]). …”

“…The composition of the WWTP effluent is subject to regular changes due to weather influences, discontinuous discharges in the raw wastewater and other aspects [ 11 ]. Other important aspects in the determination of the fouling properties of WWTP effluent are membrane-solute interactions, which are specific for each combination of membrane type and WWTP effluent.…”

Fruit Juice Processing and Membrane Technology Application

“…This equation is expressed in (L/m 2 h) [24] and is valid for dilute solutions. The relationship between viscosity and temperature is described by Roorda and van der Graaf [178] and is feed dependent, although dilute feeds can be described by water. Flux reduction (FR) with regard to clean water flux can be determined as a percentage of J Ob by comparing the J Oa before and after membrane operation as described by Mänttäri and Nyström [137]:…”

Membrane Fouling Managament in Wastewater Treatment: Myths Versus Lessons Learned from Operating Membrane Bioreactor and Tertiary Filtration Systems

“…Such fouling increases system operating costs through increased power and chemical requirements and in severe cases, increased membrane costs caused by premature membrane replacement. Roorda et al (2001) describe the membrane fouling and its five mechanisms occurring simultaneously during filtration in addition to the initial resistance of the membrane (Rm):…”