Assessing and maintaining membrane performance in a post-sedimentation ultrafiltration process

2012 ◽  
Vol 7 (2) ◽  
Author(s):  
Christopher C. Boyd ◽  
Steven J. Duranceau
Keyword(s):  
Water Quality ◽  
Citric Acid ◽  
Sodium Hydroxide ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Feed Water ◽  
Membrane Performance ◽  
Surface Water Treatment ◽  
Cleaning Agents ◽  
The Impact

A pilot test program was conducted to evaluate methods for maintaining the productivity of a hollow fiber ultrafiltration membrane operating at constant flux values of 49.2 and 62.3 gallons/ft2-day. The ultrafiltration pilot filtered settled water from a conventional surface water treatment plant in Florida. The testing assessed the impact of different chemical maintenance protocols on UF membrane performance. Seasonal variations in water quality necessitated changes in the type and combination of cleaning agents used to maintain membrane performance. Sodium hypochlorite, citric acid and sodium hydroxide were used during pilot testing as the fouling characteristics of the water changed with time. Pilot results were used to develop alternative chemically enhanced backwash strategies that varied with seasonally-impacted changes in feed water quality. Citric acid, with a target pH of <3, was found to be effective in August and September; whereas, a combination of citric acid and high pH sodium hydroxide chemically enhanced backwashes successfully maintained performance between November, 2010 and May, 2011.

scholarly journals Treatment Method Assessment of the Impact on the Corrosivity and Aggressiveness for the Boiler Feed Water

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1965 ◽  
Author(s):  
Skoczko ◽  
Szatyłowicz
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Saturation Index ◽  
Treatment Plant ◽  
High Water ◽  
Feed Water ◽  
Exchange Cation ◽  
Boiler Water ◽  
The Impact ◽  
Boiler Feed Water

The aim of the study was the assessment of corrosivity and aggressiveness for boiler feed water. The negative effects of water corrosivity and aggressiveness may include silting up of the steel water supply system and the destruction of boiler equipment touched or washed by such water. They may cause the whole industrial production system to fail or be destroyed. That is why it was important to reach a high water purification level, including the calculation of water aggressiveness and corrosivity indicators. The carried out test showed that the simple system used before the modernization of the industrial water treatment plant is not sufficient to reach clean and stable water. The authors proposed modernization, including additional processes to improve boiler water quality, and designed new devices for water treatment. As a result of the new idea, groundwater taken as raw water was treated in individual and complex processes, such as pre-aeration, filtration, ion exchange (cation and anion exchange resigns), extra aeration, and extra degassing. The conducted research included chemical analyses of raw and treated water. In the conducted studies, the indirect method of water aggressiveness and corrosivity assessment was applied using mathematical calculation of the Langelier Saturation Index (LSI), the Ryznar Stability Index (RI), the Larson–Skold Index (LI), and the Singley Index (SI). The results proved that the new proposed processes for the boiler feed water treatment station allow reaching a high water quality and low level of water aggressiveness and corrosion.

The impact of algogenic organic matter on water treatment plant operation and water quality: A review

2015 ◽  
Vol 46 (4) ◽  
pp. 291-335 ◽  
Author(s):  
M. Pivokonsky ◽  
J. Naceradska ◽  
I. Kopecka ◽  
M. Baresova ◽  
B. Jefferson ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Plant Operation ◽  
The Impact

Development of a predictive model to determine the temporal variability in mine feed water quality towards informing and forecasting plant operating strategy – a South African coal mine water treatment plant case study

2016 ◽  
Vol 11 (3) ◽  
pp. 621-633
Author(s):  
J. Nathoo ◽  
E. Hong Gay ◽  
N. Hussain
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Coal Mine ◽  
Mine Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Feed Water ◽  
Unsteady State ◽  
Mine Water Treatment ◽  
Brine Treatment

The feed water quality associated with mine water treatment is typically characterised by a dynamic variability resulting from the fact that the final feed water to the water treatment plant (WTP) can be an amalgamation of water streams emanating from a number of sources. Consequently, the ability to deal with the dynamic nature of the feed water quality towards successful and sustainable mine water treatment goes beyond a proactive approach and requires a systemic, predictive approach. This paper discusses the development of an unsteady state mass balance model on a surface dam located on a coal mine towards predicting the dynamic fluctuations in total dam volume and its total dissolved solids (TDS) concentration in the feed water to a NuWater 20 MLD mobile WTP, comprising chemical conditioning, ultrafiltration and reverse osmosis (RO). The unsteady state mass balance, incorporated water entering the dam via the opencast pits, underground compartments, seasonal rainfall and the RO brine return. Water leaving the dam comprised the feed water to the WTP, partial brine treatment, surface evaporation and seepage. Validation of the model using actual data over an 8-month period showed excellent results. The model showed that without water treatment, the dam would overflow in 218 days. Although the dam's volume could be sustained at the ideal volume by treating 14.2 MLD, its TDS would exceed the maximum environmental limit in 197 days. Consequently, the combination of a 13.2 MLD WTP with a 1 MLD brine treatment plant provided the optimal water treatment strategy to sustainably maintain the dam's TDS concentration and volume within acceptable limits over the 5-year investigation period. This paper demonstrates the importance of using a predictive methodology for forecasting feed water characteristics and as an early warning system for most water treatment systems that are subjected to dynamic conditions.

Removal of organic matter by the PAC-UF process: first two years of a full-scale application

2001 ◽  
Vol 1 (4) ◽  
pp. 253-263 ◽  
Author(s):  
I. Baudin ◽  
C. Campos ◽  
J.M. Laîne
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Distribution System ◽  
Positive Impact ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Organic Content ◽  
Uf Membranes ◽  
The Impact

At the end of 1997, an innovative membrane-adsorption process was integrated at the Vigneux-sur-Seine water treatment plant in the southeast suburbs of Paris, France. This hybrid process consisted of the application of powdered activated carbon (PAC) upstream of ultrafiltration (UF) membranes and recycled to a floc blanket reactor (FBR) after membrane backwashes (FBR-PAC/UF process). This process was designed to mitigate seasonal episodes of micropollutants (pesticides and taste and odors) and to reduce the content of natural organic matter responsible for disinfectant and disinfection by-products. An intensive monitoring campaign of the plant effluent and ten sites in the distribution system was conducted two years before (1996-1997) and two years after (1998-1999) the start up of the PAC/UF process to characterize the impact of this treatment on the water quality of the distributed water. The objective of this paper is to illustrate the positive impact of the PAC/UF process on the organic and biological water quality of the Vigneux-sur-Seine distribution system. Thus, the combination of coagulation and adsorption in the FBR-PAC/UF process resulted in a TOC concentration lower than 0.7 mg/l, BDOC values lower than the detection limit (<0.2 mg/l) and total trihalomethanes concentrations below 10 μg/l. This reduction in organic content results in a reduction of the chlorine consumption by the water produced, which translates in the maintenance of higher chlorine residuals throughout the distribution system while using the same chlorine doses at the plant (0.3 mg/l).

scholarly journals Impact of an Extreme Winter Storm Event on the Coagulation/Flocculation Processes in a Prototype Surface Water Treatment Plant: Causes and Mitigating Measures

2019 ◽  
Vol 16 (15) ◽  
pp. 2808 ◽  
Author(s):  
Fuguo Qiu ◽  
Huadong Lv ◽  
Xiao Zhao ◽  
Dongye Zhao
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Surface Water ◽  
Low Temperature ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Operating Conditions ◽  
Raw Water ◽  
Winter Storm ◽  
Surface Water Treatment

Climate change has often caused failure in water treatment operations. In this study, we report a real case study at a major surface water treatment plant in Alabama, USA. Following a severe winter storm, the effluent water turbidity surged to >15.00 Nephelometric Turbidity Units (NTU), far exceeding the 0.30 NTU standard. As a result, the plant operation had to be shut down for three days, causing millions of dollars of losses and affecting tens of thousands of people. Systematic jar tests were carried out with sediment samples from 22 upstream locations. The coagulation and settleability of sediment particles were tested under simulated storm weather conditions, i.e., low temperature (7 °C) and in the presence of various types and concentrations of natural organic matter (NOM) that was extracted from the local sediments. Experimental results proved that elevated NOM (6.14 mg·L−1 as Total Organic Carbon, TOC) in raw water was the root cause for the failure of the plant while the low temperature played a minor but significant role. Pre-oxidation with permanganate and/or elevated coagulant dosage were found effective to remove TOC in raw water and to prevent similar treatment failure. Moreover, we recommend that chemical dosages should be adjusted based on the TOC level in raw water, and a reference dosage of 0.29 kg-NaMnO4/kg-TOC and 19 kg- polyaluminum chloride (PACl) /kg-TOC would be appropriate to cope with future storm water impacts. To facilitate timely adjustment of the chemical dosages, the real time key water quality parameters should be monitored, such as turbidity, TOC, Ultraviolet (UV) absorbance, pH, and color. The findings can guide other treatment operators to deal with shock changes in the raw water quality resulting from severe weather or other operating conditions.

Improving water quality by reducing coagulant dose? A case study at the Sidi Said Maachou Water Treatment Plant (Morocco)

2004 ◽  
Vol 4 (5-6) ◽  
pp. 271-276
Author(s):  
D. Codiasse ◽  
Ch. Caudron ◽  
I. Baudin ◽  
M. Chouhou ◽  
C. Campos
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Operating Costs ◽  
Double Step ◽  
Organic Matter Removal ◽  
Bench Scale ◽  
The Impact

Many water treatment plants are currently facing the challenge of removing both turbidity and organic matter at a reasonable cost. This double objective often requires high coagulant doses, resulting in high operating costs due to the increase in both reagents use and sludge production. An attractive approach to reducing operating costs while maintaining the finished water quality is to add the coagulant in a double step sequence, which is referred to as double step coagulation. In this article, bench-scale experiments were conducted to assess the impact of a double step addition of coagulant on both turbidity and organic matter removal in clarification processes. The results showed that coagulant dose required for a given turbidity target can be significantly reduced. For example, for a final turbidity of 1 NTU, the coagulant dose can be reduced by 20% with respect to the Coagulant Reference Dose (CRD), which represents 200,000 Euros per year without any additional investment on infrastructure. Following these bench scale demonstrative tests, the double step coagulation strategy was adopted at full scale by the Sidi Said Maachou Water Treatment Plant in Morocco. Operated by the Société des Eaux de l'Oum Er-rbia, this plant treats 200,000 m3/day to supply the city of Casablanca. The double step coagulation was implemented to achieve a double objective: turbidity and organic matter removal at the lowest chemical cost.

scholarly journals Changes to Water Quality in the Water Supply Network of Zielona Góra

2019 ◽  
Vol 29 (1) ◽  
pp. 92-101 ◽  
Author(s):  
Anita Jakubaszek ◽  
Justyna Mossetty
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Water Distribution ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Supply Network ◽  
Test Results ◽  
Water Supply Network ◽  
Prolonged Retention ◽  
The Impact

Abstract The article presents physiochemical parameter changes in water supply network of Zielona Góra. On the basis of the obtained test results, the impact of prolonged retention of water in the network on its quality was determined, at the measuring points located on the territory of Zielona Góra. It was shown that together with an increase in distance of measuring points from Water Treatment Plant, content of mainly iron, turbidity and colour increased too. In the results analysis, it was determined that retention time and water distribution are the most significant factors in the network contributing to deterioration of water quality at measuring points.

Optimum location of an ultraviolet step in a surface water treatment plant

2002 ◽  
Vol 2 (5-6) ◽  
pp. 381-386
Author(s):  
C. Lemoine ◽  
D. Gatel ◽  
J. Cavard
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Quality Parameters ◽  
Current Level ◽  
Surface Water Treatment ◽  
Filtration Unit ◽  
The Impact ◽  
Treatment Step

To meet the new DBP rules, ozone doses will have to be minimized to control bromate formation. In some surface water treatment plants, this situation may become of concern, since disinfection will have to be maintained at the current level. Alternative disinfection means such as UV have therefore to be evaluated, and this study was designed to evaluate the impact of MP-UV on water quality parameters such as atrazine, BDOC or nitrites, to determine whether such a treatment step should be inserted before or after the current GAC filtration unit. According to the results shown here, this question is not an issue under conditions needed for Cryptosporidium inactivation.

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