Predictability of fouling-potential of raw water for ultrafiltration membranes

2011 ◽  
Vol 11 (4) ◽  
pp. 481-489
Author(s):  
S. Krause ◽  
A. Obermayer
Keyword(s):  
Water Quality ◽  
Membrane Fouling ◽  
Large Scale ◽  
High Capacity ◽  
Raw Water ◽  
Ultrafiltration Membranes ◽  
Small Water ◽  
Lab Experiments ◽  
Flux Decline ◽  
Public Drinking Water

The public drinking water supply of southern Germany is characterized by a rather decentralized network. Due to the hydrogeological setting in these parts of Germany many of the small water works with an average capacity of 50 m3/h have to treat raw water extracted from karstic or cliffy aquifers. These raw waters tend to be contaminated with particles and pathogens acquired during snowmelt or after strong rainfalls. In the last decade ultrafiltration has become the technology of choice for the removal of the aforementioned contaminants. Flux decline caused by unanticipated membrane fouling is the main limitation for the application of ultrafiltration membranes. This paper describes how membrane fouling phenomena can be predicted by using a statistical approach based on data from large scale filtration systems in combination with field and lab experiments on raw water quality and membrane performance. The data defines water quality and respective fouling phenomena both in technical scale filtration plants and in lab experiments of eleven different raw waters. The method described here is more economically feasible for small water works when compared to typical pilot experiments that are used for high capacity water works.

Effects of flocculent aggregates on microfiltration with coagulation pretreatment of high turbidity waters

2006 ◽  
Vol 53 (7) ◽  
pp. 191-197 ◽  
Author(s):  
S. Lee ◽  
J. H. Kweon ◽  
Y. H. Choi ◽  
K.-H. Ahn
Keyword(s):  
Drinking Water ◽  
Membrane Fouling ◽  
Raw Water ◽  
Cleaning Efficiency ◽  
Membrane Cleaning ◽  
Han River ◽  
Turbid Waters ◽  
Flux Decline ◽  
Negative Effect ◽  
High Turbidity

Immersed membrane systems, and those with in-line coagulation, have been extensively applied in drinking water systems. Sedimentation is usually replaced by membrane processes in both systems. In these systems, voluminous flocculent aggregates formed during coagulation could be potential foulants. When raw waters with high turbidity are introduced, particle loadings to membrane due to coagulation pretreatment are enormous and thus could increase fouling. In general, during the rainy season, the turbidity of the Han River water, which supplies drinking water for the City of Seoul, Korea, is more than a hundred times higher than usual. Therefore, effects of floc on membrane fouling were investigated with highly turbid waters. Two turbidity concentrations, 40 and 200 NTU, were formulated by the addition of kaolin (used as a natural particle surrogate) to the Han River raw water. The results showed that the flux decline behaviours of the highly turbid waters were different from those of natural raw water. Coagulation pretreatment was very effective at reducing membrane fouling. Flocculent aggregates showed a negative effect on the flux decline, but a positive effect on the membrane cleaning efficiency.

A decade of large scale experience in dissolved air flotation

2001 ◽  
Vol 43 (8) ◽  
pp. 27-34 ◽  
Author(s):  
S. Kempeneers ◽  
F. Van Menxel ◽  
L. Gille
Keyword(s):  
Water Quality ◽  
Large Scale ◽  
Mechanical Design ◽  
Operational Experience ◽  
Raw Water ◽  
Dissolved Air Flotation ◽  
The Past ◽  
Air Flotation ◽  
Entire Treatment ◽  
Dissolved Air

In April 1990 Antwerpse Waterwerken brought a new DAF-plant into operation at the production centre Notmeir-Walem. The flotation unit, which has a capacity of 200,000 m3/d, was integrated in one of the two existing treatment lines. Its main objective was to eliminate the important raw water quality fluctuations caused by increasing algal growths. During the past ten years several optimisation studies were carried out which resulted in a further simplification of operation and mechanical design. This paper will focus mainly on the integration of dissolved air flotation in the entire treatment line, the consequences on the dual layer filtration and the operational experience and information gathered during the past decade.

New parameter for monitoring fouling during ultrafiltration of WWTP effluent

2001 ◽  
Vol 43 (10) ◽  
pp. 241-248 ◽  
Author(s):  
J. H. Roorda ◽  
J. H.J.M. van der Graaf
Keyword(s):  
Water Quality ◽  
Membrane Fouling ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Waste Water Treatment Plant ◽  
Feed Water ◽  
Sufficient Information ◽  
Cake Filtration ◽  
Ultrafiltration Membranes ◽  
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.

scholarly journals Applicability of a Combined DAF-MF Process to Respond to Changes in Reservoir Water Quality through a Two-Year Pilot Plant Operation

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 964
Author(s):  
Joon-seok Kang ◽  
Jayeong Seong ◽  
Jewan Yoo ◽  
Pooreum Kim ◽  
Kitae Park ◽  
...  
Keyword(s):  
Water Quality ◽  
Membrane Fouling ◽  
Pilot Plant ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Raw Water ◽  
Reservoir Water ◽  
Particle Count ◽  
Raw Water Quality ◽  
Pre Treatment

The optimal operating conditions of a combined dissolved air flotation (DAF)-microfiltration (MF) process to respond to changes in raw water quality were investigated by operating a pilot plant for two years. Without DAF pre-treatment (i.e., MF alone), MF operated stably with a transmembrane pressure (TMP) increase of 0.24 kPa/d when the turbidity of raw water was low and stable (max. 13.4 NTU). However, as the raw water quality deteriorated (max. 76.9 NTU), the rate of TMP increase reached 43.5 kPa/d. When DAF pre-treatment was applied (i.e., the combined DAF-MF process), the MF process operated somewhat stably; however, the rate of TMP increase was relatively high (i.e., 0.64 kPa/d). Residual coagulants and small flocs were not efficiently separated by the DAF process, exacerbating membrane fouling. Based on the particle count analysis of the DAF effluent, the DAF process was optimised based on the coagulant dose and hydraulic loading rate. After optimisation, the rate of TMP increase for the MF process stabilised at 0.17 kPa/d. This study demonstrates that the combined DAF-MF process responded well to substantial changes in raw water quality. In addition, it was suggested that the DAF process must be optimised to avoid excessive membrane fouling.

Unintended consequences of biofuels production?The effects of large-scale crop conversion on water quality and quantity

2010 ◽  
Author(s):  
Heather L. Welch ◽  
Christopher T. Green ◽  
Richard A. Rebich ◽  
Jeannie R.B. Barlow ◽  
Matthew B. Hicks
Keyword(s):  
Water Quality ◽  
Large Scale ◽  
Unintended Consequences ◽  
Water Quality And Quantity

Applied Research in Membrane Fouling in the Membrane Bioreactor Systems with Large-scale Equipment

2019 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Kong Linghan ◽  
Zhao Weidian ◽  
Ran Deqin ◽  
Hui Bing ◽  
Lu Linguo ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Large Scale ◽  
Membrane Bioreactor ◽  
Applied Research

Leading the City of Baltimore into the 21st Century: Flexible Treatment Solutions and Integrated Raw Water Management

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
J. L. Manuszak ◽  
M. MacPhee ◽  
S. Liskovich ◽  
L. Feldsher
Keyword(s):  
Water Management ◽  
Water Quality ◽  
Water Supply ◽  
Conceptual Design ◽  
Membrane Filtration ◽  
Treatment Plant ◽  
Low Pressure ◽  
Management Tool ◽  
Raw Water ◽  
The City

The City of Baltimore, Maryland is one of many US cities faced with challenges related to increasing potable water demands, diminishing fresh water supplies, and aging infrastructure. To address these challenges, the City recently undertook a $7M study to evaluate water supply and treatment alternatives and develop the conceptual design for a new 120 million gallon per day (MGD) water treatment plant. As part of this study, an innovative raw water management tool was constructed to help model source water availability and predicted water quality based on integration of a new and more challenging surface water supply. A rigorous decision-making approach was then used to screen and select appropriate treatment processes. Short-listed treatment strategies were demonstrated through a year-long pilot study, and process design criteria were collected in order to assess capital and operational costs for the full-scale plant. Ultimately the City chose a treatment scheme that includes low-pressure membrane filtration and post-filter GAC adsorption, allowing for consistent finished water quality irrespective of which raw water supply is being used. The conceptual design includes several progressive concepts, which will: 1) alleviate treatment limitations at the City's existing plants by providing additional pre-clarification facilities at the new plant; and 2) take advantage of site conditions to design and operate the submerged membrane system by gravity-induced siphon, saving the City significant capital and operations and maintenance (O&M) costs. Once completed, the new Fullerton Water Filtration Plant (WFP) will be the largest low-pressure membrane plant in North America, and the largest gravity-siphon design in the world.

Optimisation of coagulation and chlorination in drinking water treatment: laboratory and full-scale studies

2002 ◽  
Vol 2 (2) ◽  
pp. 131-137
Author(s):  
N.D. Basson ◽  
C.F. Schutte
Keyword(s):  
Water Quality ◽  
Large Fraction ◽  
Drinking Water Treatment ◽  
Agricultural Runoff ◽  
Treatment Costs ◽  
Full Scale ◽  
Raw Water ◽  
Activated Carbon Adsorption ◽  
Treated Effluent ◽  
Quality Optimisation

The paper deals with laboratory and full-scale studies aimed at optimising treatment processes at the Balkfontein plant of Sedibeng Water in South Africa. The raw water is highly eutrophic and contains a large fraction of treated effluent from domestic and industrial sources as well as agricultural runoff. The eutrophic nature and changing raw water quality give rise to many operational difficulties and high treatment costs as well as problems with the final water quality. Optimisation of the coagulation and chlorination processes was seen as a cheaper solution to these problems than to install advanced processes such as ozonation and activated carbon adsorption that would add greatly to treatment costs. The laboratory studies indicated that through optimisation of coagulation-flocculation and by replacement of pre-chlorination by intermediate chlorination (after primary sedimentation) most of the treatment problems could be solved and final water of the required quality produced without a large increase in treatment costs.

Large-scale wetland-restoration of the Ronde Venen, The Netherlands

1995 ◽  
Vol 31 (8) ◽  
pp. 197-205 ◽  
Author(s):  
L. L. Bijlmakers ◽  
E. O. A. M. de Swart
Keyword(s):  
Water Quality ◽  
Wetland Restoration ◽  
Pollution Control ◽  
Large Scale ◽  
Major Elements ◽  
Control Mechanisms ◽  
Important Criterion ◽  
Spatial Strategy ◽  
Hydrological Characteristics ◽  
Spatial Composition

For the area of the Ronde Venen a plan for large-scale wetland-restoration and improvement of the water quality was developed. Major elements of the developed spatial strategy are the optimal use of the specific hydrological and ecological characteristics of the area. Based on regional hydrological characteristics within the study area hydrological sub-units were distinguished by connecting discharge and recharge areas. In this way the intake of polluted surface water from outside the area could be minimized, with an optimal use of specific local differences in water quality. Two scenarios were developed and evaluated using hydrological, hydrochemical and ecological models. The scenarios differed in spatial composition and the way the water level was manipulated. In order to optimize water quality, natural and artificial pollution control mechanisms were implemented as well. An important criterion for the evaluation was the extent to which the scenarios succeeded in optimizing conditions for the realization of the ecological goals. The most promising and acceptable scenario has been worked out in further detail.

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