AWWA MTC95017

The objective of this work was to evaluate the biological stability of water produced by membrane filtration. This particular objective was included among other objectives of a large scale pilot project involving treatment of highly colored groundwater. The part of the project discussed in this paper was conducted at the Irvine Ranch Water District pilot facility during a period of almost nine months. Groundwater with an average color of approximately 160 units and TOC between 10 and 12 mg/L was fed to a multi-stage membrane filtration system. Spiral-wound sulfonated polyether sulfone membranes with a nominal molecular weight cut-off of 1000 daltons were used. The installation operated at an average water recovery of 89% and specific productivity between 0.23 and 0.36 gpd/sq.ft./psi. Average TDS rejection was 15%. Membrane permeate quality was consistently very good with color below 5 units, average TOC of 0.63 mg/L and average turbidity of 0.17 NTU. Biological stability of raw groundwater, membrane permeate and membrane reject was monitored generally every two to three weeks for over eight months. The following methods were used for this purpose: Assimilable Organic Carbon (AOC) using both Pseudomonas fluorescence P17 and Spirillum strain NOX; Biodegradable Dissolved Organic Carbon (BDOC) using a mixed bacterial population; Growth Rate (GR) of autochthonous microorganisms determined through direct observations of bacterial cells attached to test coupons. The results indicate that the effects of membrane filtration on the ability of water to support microbial growth are complex and indicate that microbial transformations may play an important role in membrane filtration.

Product Details

Published:

01/01/1995

ISBN(s):

0898678153

Number of Pages:

11

File Size:

1 file , 490 KB