Effects of pre-treatment with magnetic ion exchange resins on coagulation/flocculation process

2008 ◽  
Vol 57 (1) ◽  
pp. 57-64 ◽  
Author(s):  
B. Sani ◽  
E. Basile ◽  
C. Lubello ◽  
L. Rossi
Keyword(s):  
Ion Exchange ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Ion Exchange Resin ◽  
Test Procedures ◽  
Aggregation State ◽  
Jar Test ◽  
Pre Treatment ◽  
Magnetic Ion

A new Magnetic Ion EXchange resin for DOC (Dissolved Organic Carbon) removal (MIEX®DOC Resin) has been evaluated as water pre-treatment at the Drinking Water Treatment Plant (DWTP) of Florence in order to reduce the oxidant demand and disinfection by-products (DBPs) formation potential. This pre-treatment leads to several effects on downstream treatment processes. In this experimental study the effects of MIEX® pre-treatment on clariflocculation process were evaluated with respect to coagulant demand reduction and characteristics of flocs formed. The analysis was conducted using traditional jar test procedures and a Photometric Dispersion Analyser (PDA2000) which provided continuous information about the aggregation state of particles during the jar tests. For a fixed turbidity goal in clarified water, ion exchange pre-treatment led to coagulant dosage reduction up to 60% and PDA results shown that flocs formed in pre-treated water were bigger and more resistant to shearing effects than those formed by conventional clariflocculation.

Analysis of a clariflocculation process with a photometric dispersion analyser (PDA2000)

2002 ◽  
Vol 2 (5-6) ◽  
pp. 57-63
Author(s):  
L. Rossi ◽  
C. Lubello ◽  
E. Poggiali ◽  
O. Griffini
Keyword(s):  
Test Procedure ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Process Efficiency ◽  
Aggregation State ◽  
Maximum Slope ◽  
Jar Test ◽  
Photometric Dispersion

In this experimental study the clarification process of the drinking water treatment plant (WTP) of Florence (Italy) has been evaluated. At present, the most common way to optimise the clariflocculation process (best type and dosage of coagulants and mixing conditions) is the jar-test procedure which can give information about the final turbidity, and consequently the process efficiency, after a settling period in a batch procedure at laboratory-scale. An alternative method with a Photometric Dispersion Analyser (PDA2000) was recently introduced at the WTP to provide quick and continuous information (flocculation index, correlated with the flocs size) about the aggregation state of particles during a modified jar-test procedure. The PDA2000 was applied to a real suspension (namely Arno river water) providing useful data for the determination of best type and optimum dosage of coagulants. Furthermore a strong correlation between the removal efficiency of the turbidity and PDA a parameter derived from the PDA 2000 data (defined as the rate of the square root of the flocs size index and the maximum slope of the growing curve) was observed.

Improving the biological stability of drinking water by ion exchange

2011 ◽  
Vol 11 (1) ◽  
pp. 107-112 ◽  
Author(s):  
A. Grefte ◽  
M. Dignum ◽  
S. A. Baghoth ◽  
E. R. Cornelissen ◽  
L. C. Rietveld
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Ion Exchange ◽  
Biofilm Formation ◽  
Formation Rate ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Biological Stability ◽  
Biological Activated Carbon ◽  
Pre Treatment

To guarantee a good water quality at the consumer’s tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research is to measure the effect of NOM removal by ion exchange on the biological stability of drinking water. Experiments were performed in two lanes of the pilot plant of Weesperkarspel in the Netherlands. The lanes consisted of ozonation, softening, biological activated carbon filtration and slow sand filtration. Ion exchange in fluidized form was used as pre-treatment in one lane and removed 50% of the dissolved organic carbon (DOC); the other lane was used as reference. Compared to the reference lane, the assimilable organic carbon (AOC) concentration of the finished water in the lane pretreated by ion exchange was 61% lower. The biofilm formation rate of the finished water was decreased with 70% to 2.0 pg ATP/cm2.day. The achieved concentration of AOC and the values of the biofilm formation rate with ion exchange pre-treatment showed that the biological stability of drinking water can be improved by extending a treatment plant with ion exchange, especially when ozonation is involved as disinfection and oxidation step.

scholarly journals Treatment of Severely-Deteriorated Post-Fire Runoff: A Comparison of Conventional and High-Rate Clarification to Demonstrate Key Drinking Water Treatment Capabilities and Challenges

2020 ◽  
Author(s):  
Jesse Skwaruk ◽  
Monica Emelko ◽  
Uldis Silins ◽  
Micheal Stone
Keyword(s):  
Water Treatment ◽  
River Water ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
High Rate ◽  
Case Scenario ◽  
Worst Case ◽  
Jar Test ◽  
Doc Concentration

The ability to treat worst-case scenario, “black water” resulting from wildfire ash transport directly from hillslopes to source waters was investigated—this has not been reported previously. The treatment response capabilities of conventional chemical pre-treatment and high rate clarification processes were evaluated at bench scale; these included: sand-ballasted flocculation (SBF), SBF with enhanced coagulation, and SBF with powdered activated carbon (PAC).<div><br></div><div>Fresh ash was collected from the Thuya Lake Road (TLR) wildfire (+51.4098 latitude, -120.2435 longitude; burn area 556 ha), which was part of the Little Fort Fire Complex that burned in July 2017, near Little Fort, British Columbia, Canada. The ash was used to prepare a severely-deteriorated source water matrix. It was added to high quality river water (Elbow River, Calgary, Alberta) to reflect post-fire water quality conditions when ash is mobilized off the landscape to receiving waters during a major runoff event.</div><div><br></div><div><p>Prior to mixing, ash was sieved through a 1 mm screen to remove any large debris and conifer needles that typically would not be found in water treatment plant influent streams. Three concentrations of ash in river water were prepared (2.0, 10.0, and 20.0 g×L<sup>-1</sup> of ash; five replicates of each) by adding ash to 1000 mL of Elbow River water in 2-L plastic square beakers, and mixed using a jar test apparatus (Phipps & Bird, PB-900 Series Programmable 6-Paddle Jar Tester, Richmond, VA) at 120 RPM for 2 minutes. Turbidity and dissolved organic carbon (DOC) concentrations consistent with or slightly higher than the levels that have been reported following severe wildfire (i.e., >1000 NTU and >15mg×L<sup>-1</sup>, respectively) were targeted. These water matrices were black-colored, in a manner consistent with previous reports of severely-deteriorated water conditions after wildfire.<sup></sup></p><p> </p><p>Standard methods were used to evaluate turbidity (Method 2130B;<sup> </sup>Hach 2100 N turbidimeter, Loveland, CO), pH (4500-H<sup>+</sup>B Electrometric method; <sup> </sup>Orion 720A pH meter, Thermo Fisher Scientific, Waltham, MA), DOC concentration (filtration through pre-rinsed 0.45 µm Nylaflo membranes, Pall, Port Washington, NY; Method 5310C;<sup> </sup>Shimadzu TOC-V WP analyzer, Kyoto, Japan), and UVA<sub>254</sub> (Method 5910B;<sup> </sup>1 cm quartz cell; Hach DR 5000 Spectrophotometer, Loveland, CO). Specific ultraviolet absorbance at 254 nm (SUVA)<sub> </sub>was calculated by dividing UVA<sub>254</sub> absorbance by the DOC concentration.</p></div><div></div>

scholarly journals Optimum Coagulant Forecasting with Modeling the Jar Test Experiments Using ANN

2017 ◽  
Author(s):  
Sadaf Haghiri ◽  
Sina Moharramzadeh ◽  
Amin Daghighi
Keyword(s):  
Water Treatment ◽  
Mean Squared Error ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Dosage Level ◽  
Water Treatment Plant ◽  
Real Variable ◽  
Optimum Dose ◽  
High Dose ◽  
Jar Test

Abstract. Nowadays the proper utilization of water treatment plants and optimizing their use is of particular importance. Coagulation and flocculation in water treatment are among the common ways through which the use of coagulants leads to instability of particles and formation of larger and heavier particles, resulting in improvement of sedimentation and filtration processes. Determination of the optimum dose of such a coagulant is of particular significance. A high dose, in addition to adding costs, can cause the sediment to remain in the filtrate, a dangerous condition according to the standards, while a sub-adequate dose of coagulants can result in the reducing the required quality and acceptable performance of the coagulation process. While jar tests are used for testing coagulants, such experiments face many constraints with respect to evaluating the results produced by sudden changes in input water because of their significant costs, long time requirements, and complex relationships among the many factors (turbidity, temperature, pH, alkalinity, etc.) that can influence the efficiency of coagulant and test results. Modeling can be used to overcome these limitations, and in this research study, Artificial Neural Network (ANN) Multi-Layer Perceptron (MLP) with one hidden layer has been used for modeling the jar test to determine the dosage level of used coagulant in water treatment processes. The data contained in this research have been obtained from the drinking water treatment plant located in the Ardabil province. To evaluate the performance of the model, the parameters Mean Squared Error (MSE) and the Correlation Coefficient R2 have been used. The obtained values are within an acceptable range that demonstrates the high accuracy of the models with respect to the estimation of water quality characteristics and the optimal dosages of coagulants, so using these models will allow operators to not only reduce costs and time taken to perform experimental jar tests, but also to predict a proper dosage for coagulant amounts and to project the quality of the output water under real variable conditions.

scholarly journals Treatment of Severely-Deteriorated Post-Fire Runoff: A Comparison of Conventional and High-Rate Clarification to Demonstrate Key Drinking Water Treatment Capabilities and Challenges

2020 ◽  
Author(s):  
Jesse Skwaruk ◽  
Monica Emelko ◽  
Uldis Silins ◽  
Micheal Stone
Keyword(s):  
Water Treatment ◽  
River Water ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
High Rate ◽  
Case Scenario ◽  
Worst Case ◽  
Jar Test ◽  
Doc Concentration

The ability to treat worst-case scenario, “black water” resulting from wildfire ash transport directly from hillslopes to source waters was investigated—this has not been reported previously. The treatment response capabilities of conventional chemical pre-treatment and high rate clarification processes were evaluated at bench scale; these included: sand-ballasted flocculation (SBF), SBF with enhanced coagulation, and SBF with powdered activated carbon (PAC).<div><br></div><div>Fresh ash was collected from the Thuya Lake Road (TLR) wildfire (+51.4098 latitude, -120.2435 longitude; burn area 556 ha), which was part of the Little Fort Fire Complex that burned in July 2017, near Little Fort, British Columbia, Canada. The ash was used to prepare a severely-deteriorated source water matrix. It was added to high quality river water (Elbow River, Calgary, Alberta) to reflect post-fire water quality conditions when ash is mobilized off the landscape to receiving waters during a major runoff event.</div><div><br></div><div><p>Prior to mixing, ash was sieved through a 1 mm screen to remove any large debris and conifer needles that typically would not be found in water treatment plant influent streams. Three concentrations of ash in river water were prepared (2.0, 10.0, and 20.0 g×L<sup>-1</sup> of ash; five replicates of each) by adding ash to 1000 mL of Elbow River water in 2-L plastic square beakers, and mixed using a jar test apparatus (Phipps & Bird, PB-900 Series Programmable 6-Paddle Jar Tester, Richmond, VA) at 120 RPM for 2 minutes. Turbidity and dissolved organic carbon (DOC) concentrations consistent with or slightly higher than the levels that have been reported following severe wildfire (i.e., >1000 NTU and >15mg×L<sup>-1</sup>, respectively) were targeted. These water matrices were black-colored, in a manner consistent with previous reports of severely-deteriorated water conditions after wildfire.<sup></sup></p><p> </p><p>Standard methods were used to evaluate turbidity (Method 2130B;<sup> </sup>Hach 2100 N turbidimeter, Loveland, CO), pH (4500-H<sup>+</sup>B Electrometric method; <sup> </sup>Orion 720A pH meter, Thermo Fisher Scientific, Waltham, MA), DOC concentration (filtration through pre-rinsed 0.45 µm Nylaflo membranes, Pall, Port Washington, NY; Method 5310C;<sup> </sup>Shimadzu TOC-V WP analyzer, Kyoto, Japan), and UVA<sub>254</sub> (Method 5910B;<sup> </sup>1 cm quartz cell; Hach DR 5000 Spectrophotometer, Loveland, CO). Specific ultraviolet absorbance at 254 nm (SUVA)<sub> </sub>was calculated by dividing UVA<sub>254</sub> absorbance by the DOC concentration.</p></div><div></div>

Removal of algogenic organic matter by magnetic ion exchange resin pre-treatment and its effect on fouling in ultrafiltration

2011 ◽  
Vol 11 (1) ◽  
pp. 15-22 ◽  
Author(s):  
C. Liu ◽  
W. Chen ◽  
V. M. Robert ◽  
Z. G. Han
Keyword(s):  
Organic Matter ◽  
Ion Exchange ◽  
Membrane Fouling ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Major Barrier ◽  
Treated Water ◽  
Fouling Control ◽  
Pre Treatment ◽  
Magnetic Ion

Natural organic matter (NOM) fouling continues to be the major barrier to efficient application of ultrafiltration (UF) in drinking water treatment. Algogenic organic matter (AOM), the main contributor to total NOM levels in raw waters characterised by elevated algae levels, is currently the subject of much investigation. In this study, the effect of AOM on fouling of ultrafiltration and the effectiveness of magnetic ion exchange resin (MIEX®) pre-treatment for AOM removal and membrane fouling control was evaluated. The results showed that, the main species of algae in raw water were Chlorella vulgaris, which accounted for 80% of total algae. AOM was predominantly hydrophilic (50% or more) with a low SUVA (1.7 Lm−1 mg−1). Coagulation alone could not remove AOM effectively (less than 20%), however, when combined with magnetic ion exchange resin pre-treatment, more than 60% of AOM was be removed; pre-treatment followed by coagulation was observed to be very effective in controlling membrane fouling by AOM. The application of magnetic ion exchange resin technology at a bed volume treatment rate (BVTR) of 800 was observed to effectively eliminate fouling of UF membrane. Careful analyses of the molecular weight (MW) distribution of AOM and UV absorbance of treated water revealed that the effectiveness in membrane fouling control was the result of the changes in AOM molecular characteristics in treated water, namely a change in MW due to the preferential removal of high molecular proteins by coagulation and magnetic ion exchange resin pre-treatment. The results demonstrate that magnetic ion exchange resin followed by coagulation might be a new membrane pre-treatment option for UF membrane fouling control.

Removal of natural organic material by a magnetic ion exchange resin

2008 ◽  
Vol 8 (2) ◽  
pp. 167-172 ◽  
Author(s):  
T. H. Boyer ◽  
P. C. Singer
Keyword(s):  
Ion Exchange ◽  
Fulvic Acid ◽  
Drinking Water Treatment ◽  
Fulvic Acids ◽  
Ion Exchange Resin ◽  
Charge Balance ◽  
Exchange Reactions ◽  
Suwannee River Fulvic Acid ◽  
Magnetic Ion ◽  
Natural Organic Material

The aim of this research was to elucidate the interactions among dissolved organic carbon (DOC), inorganic anions and a magnetic ion exchange (MIEX) resin. Model waters containing well characterised natural organic matter (NOM) extracts in addition to DOC-free model waters containing sulphate and bicarbonate were used in all experiments. The NOM extracts used in this work included two reference fulvic acids supplied by the International Humic Substances Society (IHSS): Suwannee River Fulvic Acid (SRFA) and Pony Lake Fulvic Acid (PLFA). These reference fulvic acids possess unique chemical characteristics that are representative of their distinct end-member environments. The charge density of the NOM extracts, obtained by potentiometric titration, was used to perform charge balance analyses for ion exchange reactions involving DOC, sulphate, bicarbonate and chloride. For SRFA, the results clearly show the stoichiometric exchange of DOC and bicarbonate for chloride. This work provides an improved understanding of the interactions between NOM, MIEX resin and the background solution matrix, and should result in more effective applications of ion exchange treatment for the removal of DOC during drinking water treatment.

Assessment of water treatment processes: detailed organic matter characterisation and membrane fouling indices at the Loddon Water Treatment Plant, Victoria, Australia

2011 ◽  
Vol 11 (3) ◽  
pp. 274-280 ◽  
Author(s):  
C. Khorshed ◽  
S. Vigneswaran ◽  
J. Kandasamy ◽  
R. Aryal ◽  
D. Dharmapalan
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Ion Exchange ◽  
Membrane Fouling ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Treatment Methods ◽  
Wide Range ◽  
Exchange Adsorption ◽  
Pre Treatment

Recent advances in membrane technology have led to its broad application, and reverse osmosis (RO) systems now represent the fastest growing segment of the desalination market. Its performance is hindered by membrane fouling. In this study pre-treatment methods to reduce RO fouling were investigated including flocculation, adsorption and ion exchange. Detailed organic characterisations were made in terms of florescence spectroscopy excitation emission matrix (EEM), UV254 absorbance and liquid chromatography-organic carbon detection (LCOCD). The different pre-treatment methods were assessed in terms of the fouling potential. This was quantified in terms of the modified fouling index measured using a dead-end cell micro-filtration (MF) unit. The existing pre-treatment of granular activated carbon (GAC) filter led to a good organic removal. Among the pre-treatment methods tested in the laboratory, purolite ion exchange/adsorption was found to be better than FeCl3 flocculation in terms of the amount as well as the wide range of organics removal. A pre-treatment of flocculation with Poly-ferric-silicate (PFSi) as flocculent gave a higher removal of organic matter compared to other pre-treatments tested. DOC was reduced from 11.5 to 4.25 mg/L, and it removed mostly the humic type substances.

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