scholarly journals Coagulant dose as an operating parameter in a solid contact clarifier

2018 ◽  
Vol 14 (1) ◽  
pp. 27-35
Author(s):  
W. Illangasinghe ◽  
N. Ratnayaka ◽  
J. Manatunge ◽  
N. Jayasuriya
Keyword(s):  
Laboratory Tests ◽  
Operating Parameter ◽  
Raw Water ◽  
Upward Flow ◽  
Solid Contact ◽  
Water Turbidity ◽  
Variable Parameters ◽  
Jar Test ◽  
Flocculation Test ◽  
Quadratic Relationship

Abstract The objective of this study was to determine the applicability of the laboratory flocculation test (Jar Test) for a solid contact clarifier. Cohesivity, a parameter characterizing the sludge blanket can be established by determining the Sludge Cohesion Coefficient (SCC) by conducting a Sludge Cohesion Test (SCT). A series of laboratory tests were performed using the Jar Test and SCT. Considering the large number of variable parameters involved with natural raw water, sludge samples were prepared using synthetic raw water with varying turbidity and coagulant dose combinations. A comparison was made between the optimum coagulant dose obtained using the two tests. Highest SCC observed at the optimum coagulant dose was within the range of 0.6–3.3 m/hr. Low SCC values indicate a light and fragile sludge blanket whereas high SCC values indicate a quick settling consistent blanket. With increasing raw water turbidity, the optimum coagulant dose given by SCT is lower than that of the Jar Test. Hence, at higher raw water turbidity occurrences, it may be possible to operate the upward flow solid contact clarifiers with lower coagulant dose. A significant quadratic relationship is observed between the optimum coagulation doses with R2 = 0.9 and α < 0.05.

Observations of blanket characteristics in full-scale floc blanket clarifiers

2003 ◽  
Vol 47 (1) ◽  
pp. 197-204 ◽  
Author(s):  
L.C. Chen ◽  
S.S. Sung ◽  
W.W. Lin ◽  
D.J. Lee ◽  
C. Huang ◽  
...  
Keyword(s):  
Treatment Process ◽  
Combined Treatment ◽  
The Other ◽  
Raw Water ◽  
Water Turbidity ◽  
Capillary Suction ◽  
Zeta Potentials ◽  
High Turbidity ◽  
Water Supply Company ◽  
Clarified Water

We monitored the changes in concentrations, zeta potentials, sizes and capillary suction times of the solids flocs in the clarified water from eight floc blanket clarifiers of PingTsan Water Works of Taiwan Water Supply Company with low (<10 NTU) and high (>100 NTU) turbidity raw water. For the former, one-stage coagulation-sedimentation treatment was adopted which yielded a rather unstable blanket. Complete washout was noticeable when the PACl dosage was insufficient. On the treatment of high-turbidity raw water, on the other hand, the Works adopted the combined treatment process, that is, the raw water was first coagulated and settled in a pre-sedimentation tank, afterwards, its effluent was coagulated again and clarified in the clarifiers. The resulting flocs could form a networked blanket that was relatively stable to the shock load in raw water turbidity.

Treatment of taste and odor material by oxidation and adsorption

2004 ◽  
Vol 49 (9) ◽  
pp. 289-295 ◽  
Author(s):  
S.-W. Jung ◽  
K.-H. Baek ◽  
M.-J. Yu
Keyword(s):  
Drinking Water ◽  
Raw Water ◽  
Initial Concentration ◽  
Blue Green Algae ◽  
Jar Test ◽  
Treatment Processes ◽  
Taste And Odor ◽  
Removal Efficiencies ◽  
Run Time ◽  
Lab Test

Massive blooms of blue-green algae in reservoirs produce the musty-earthy taste and odor, which are caused by compounds such as 2-MIB and geosmin. 2-MIB and geosmin are rarely removed by conventional water treatment. Their presence in the drinking water, even at low levels (ng/L), can be detected and it creates consumer complaints. So those concentrations have to be controlled as low as possible in the drinking water. The removals by oxidation (O3, Cl2, ClO2) and adsorption (PAC, filter/adsorber) were studied at laboratory and pilot plant (50 m3/d) to select suitable 2-MIB and geosmin treatment processes. The following conclusions were derived from the study. Both of the threshold odor levels for 2-MIB and geosmin appeared to be 30 ng/L as a consequence of a lab test. For any given PAC dosage in a jar-test, removal efficiencies of 2-MIB and geosmin were increased in proportion to PAC dosage and were independent of their initial concentration in raw water for the tested PAC dosages. In comparison of geosmin with 2-MIB, the adsorption efficiency of geosmin by PAC was superior to that of 2-MIB. The required PAC dosages to control below the threshold odor level were 30 mg /L for geosmin and 50 mg/L for 2-MIB at 100 ng/L of initial concentration. Removal efficiencies of odor materials by Cl2, ClO2, and O3 were very weak under the limited dosage (1.5 mg/L), however increased ozone dosage (3.8 mg O3/L) showed high removal efficiency (84.8% for 2-MIB) at contact time 6.4 minutes. According to the initial concentrations of 2-MIB and geosmin, their removal efficiencies by filter/adsorber differed from 25.7% to 88.4%. For all those, however, remaining concentrations of target materials in finished waters were maintained below 30 ng/L. The longer run-time given for the filter/adsorber, the higher the effluent concentration generated. So it is necessary that the run-time of the filter/adsorber be decreased, when 2-MIB or geosmin occurs in raw water.

scholarly journals Effectiveness of caporite to reduce concentration of iron and mangan in Ciliwung river water as raw water PDAM

2021 ◽  
Vol 11 (1) ◽  
pp. 30
Author(s):  
Nadhila Aulia Dwiputri ◽  
Mia Azizah ◽  
Nurlela Nurlela
Keyword(s):  
River Water ◽  
Government Regulation ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Quality Standard ◽  
Raw Water ◽  
Jar Test ◽  
Iron Manganese ◽  
Manganese Level ◽  
Iron And Manganese

The water of the Ciliwung river used as raw water for PDAM Depok contains iron and manganese, which levels were quite high and exceeded the quality standard. The purposes of the research are to determine the effectiveness of caporite to reduce levels of iron and manganese to reach levels that meet the standards of Government Regulation Number 82 of 2001. The sample used in this study was the water of the Ciliwung river used as a source of raw water for PDAM Depok with two different water treatment plant (WTP) locations, location 1 in Legong WTP and location 2 in Citayam WTP. Raw water was taken using a submersible water pump located at the bottom of the Ciliwung river. The analytical method used as a reference for determining iron levels was based on the FerroZine Rapid Liquid Method 1970, and for manganese levels was based on 1- (2-Pyridylazo) -2-Naphthol PAN Method 1977, both methods using the Spectrophotometric method. The results showed that iron and manganese levels were quite high, exceeding the standards of Government Regulation No.82 of 2001 with a maximum standard of iron content is 0.3 mg/L, and a maximum standard of manganese level is 0.1 mg/L. After adding a certain dose of chlorine to Ciliwung river water in the Legong and Citayam WTPs, it was found that chlorine effectively reduced Fe and Mn levels because it was able to reduce levels up to 80% and meet the quality standards.Keywords: Caporite, Iron, Manganese, Ciliwung River, RegulationABSTRAKEfektivitas kaporit untuk menurunkan kadar besi dan mangan dalam air sungai Ciliwung sebagai air baku PDAMAir sungai Ciliwung yang digunakan sebagai air baku PDAM Depok terdapat zat besi dan mangan dengan kadarnya cukup tinggi serta melebihi ambang baku mutu. Tujuan penelitian ini untuk mengetahui efektivitas kaporit dalam menurunkan kadar besi dan mangan sehingga memenuhi standar baku mutu Peraturan Pemerintah Nomor 82 Tahun 2001 untuk kelas 1. Sampel air yang digunakan dalam penelitian ini diambil dari 2 titik lokasi Instalasi Pengolahan Air (IPA) yang berbeda, yaitu  dari IPA Legong dan  IPA Citayam. Sampel air baku diambil dengan menggunakan pompa air submersible (pompa celup) yang berada di dasar sungai Ciliwung. Penelitian dilakukan dengan eksperimen jar test di laboratorium. Metode analisis untuk menentukan kadar besi  mengacu pada FerroZine Rapid Liquid Method tahun 1970 dan mangan berdasarkan 1-(2-Pyridylazo)-2-Napthol PAN Method tahun 1977 dengan menggunakan metode Spektrofotometri. Hasil penelitian menunjukan kadar besi dan mangan yang cukup tinggi hingga melebihi standar yang telah ditetapkan dalam PP No.82 Tahun 2001 dengan kadar Fe maksimal 0,3 mg/L dan kadar Mn maksimal 0,1 mg/L. Setelah dilakukan penambahan bahan kimia kaporit ke dalam sampel air sungai Ciliwung  dari  IPA Legong dan Citayam, dengan dosis 10 mg/L untuk penurunan Fe dan 30 mg/L untuk penurunan Mn dapat efektif menurunkan konsentrasi Fe dan Mn  hingga 80%, dan memenuhi  standar baku mutu yang digunakan.Kata Kunci: Kaporit, Besi, Mangan, Sungai Ciliwung, Baku Mutu

scholarly journals Antibacterial activity of the white lily Moringa oleifera seed extract and its use in water treatment

2018 ◽  
Vol 5 (11) ◽  
pp. 699-707 ◽  
Author(s):  
Tânia Maria de Andrade ◽  
Krystyna Gorlach-Lira
Keyword(s):  
Water Treatment ◽  
Aqueous Extract ◽  
Water Samples ◽  
Moringa Oleifera ◽  
Heterotrophic Bacteria ◽  
Fecal Coliforms ◽  
Water Turbidity ◽  
Jar Test ◽  
Agar Diffusion Test ◽  
Moringa Oleifera Seed

White lily Moringa oleifera seed powder acts as a natural coagulant promoting the reduction of water turbidity by the coagulation and sedimentation of the suspended particles, also eliminating the microorganisms by sedimentation. The aqueous extract of M. oleifera presented an inhibitory capacity for the growth of Staphylococcus aureus, whereas the hydroalcoholic extract inhibited S. aureus, Salmonella typhimurium and Vibrio cholerae, using the agar diffusion test. Standard strains of Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis were resistant to the extracts. The water treatment through the aqueous extract of M. oleifera seeds at 0.02% and 0.01% concentrations was evaluated with the water samples collected in the Sinibu River, Paraíba State, Brazil, using the jar test. The water samples analyzed in this work were characterized by low turbidity (2.8-3.0 NTU), and pH and alkalinity between 5.8-7.3 and 10-30 mg CaCO3/L, respectively. After water treatment with M. oleifera aqueous extract, it was observed that pH, turbidity and alkalinity did not change significantly. Total heterotrophic bacteria counts in the crude water samples were between 1.9 x 10^5 UFC/100 mL and 1.1 x 10^6 CFU/100 mL, while the number of fecal coliforms was between 2.3 x 10^2 NMP/100 mL and 2.4 x 10^3 NMP/100 mL. The counts of total bacteria and fecal coliforms in the water samples treated with aqueous white lily extract at both concentrations tested (0.02% and 0.01%) during the 1.5-hour period did not differ significantly when compared to the untreated water. The results obtained in this work indicate that low turbidity of water influenced the efficacy of M. oleifera extract in the removal of bacteria in the treated water, since the level of coagulation depends on water turbidity.

scholarly journals Optimization of ACH Coagulant, Settling Time and Powdered Activated Carbon as Coagulant Aid with Economic Analysis

2021 ◽  
Keyword(s):  
Activated Carbon ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Settling Time ◽  
Raw Water ◽  
Economic Study ◽  
Optimal Process ◽  
Water Turbidity ◽  
Aluminum Sulphate ◽  
Actived Carbon

<p>Regular water treatment-plant (WTP) comprises of a number of units. Of course, problems exist throughout design and operation of the WTP units. Consequently, the current re-search aimed to minimize the shortcomings of the coagulation, sedimentation, and the adsorption methods through applying optimal process for these units. Additionally, eco-nomic analysis and the derivation mathematical models for the new coagulant (Aluminum Chlorohydrate (ACH)) and the traditional aluminum sulphate coagulant (Alum) were an-other objective of this work. Optimum coagulants for alum and ACH were obtained and presented for different raw water turbidities. The optimum settling time of 30 minutes and 40 minutes have been found for the settling of 1000 and 2000 NTU raw water sam-ples. Best dosages of 0.1 and 0.25 g/L of powdered actived carbon (PAC) were obtained for raw water turbidity of 419, and 1000 NTU which increased the removal efficiency of 28.95%, and 25.71%, respectively. Furthermore, the economic study for alum and ACH revealed that using ACH instead of alum led to reduction of cost by 32%. Commonly, it can be concluded that using ACH instead of alum is better because it is cheaper and more efficient. The predicted equations for the optimum dosages (Y) for alum (mg/L) and ACH (µl/L) dosages (X) were Y= 0.04 X + 14.42, and Y = 0.01 X + 0.72, respectively.</p>

scholarly journals OPTIMIZATION OF THE DRINKING WATER TREATMENT PROCESS OF A SUGAR PLANT STATION IN COTE DIVOIRE

2021 ◽  
Vol 9 (01) ◽  
pp. 512-524
Author(s):  
Konan Lopez Kouame ◽  
◽  
Nogbou Emmanuel Assidjo ◽  
Andre Kone Ariban ◽  
◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Process ◽  
Polynomial Regression ◽  
Drinking Water Treatment ◽  
Optimal Dose ◽  
Raw Water ◽  
Water Treatment Process ◽  
Jar Test ◽  
Coagulation And Flocculation

This article presents an optimization of the drinking water treatment process at the SUCRIVOIRE treatment station. The objective is to optimize the coagulation and flocculation process (fundamental process of the treatment of said plant)by determining the optimal dosages of the products injected and then proposes a program for calculating the optimal dose of coagulant in order to automatically determine the optimal dose of the latter according to the raw water quality. This contribution has the advantage of saving the user from any calculations the latter simply enters the characteristics of the raw effluent using the physical interface of the program in order to obtain the optimum corresponding coagulant concentration. For the determination of the optimal coagulant doses, we performed Jar-Test flocculation tests in the laboratory over a period of three months. The results made it possible to set up a polynomial regression model of the optimal dose of alumina sulfate as a function of the raw water parameters. A program for calculating the optimal dose of coagulant was carried out on Visual Basic. The optimal doses of coagulant obtained vary from 25, 35, 40 and 45 mg/l depending on the characteristics of the raw effluent. The model obtained is: . Finally, verification tests were carried out using this model on the process. The results obtained meet the WHO drinkability standards for all parameters for a settling time of two hours.

Development of automatic coagulant dosage control technology for rapid change of raw water quality parameters

2012 ◽  
Vol 12 (6) ◽  
pp. 918-925 ◽  
Author(s):  
Y. Sangu ◽  
H. Yokoi ◽  
H. Tadokoro ◽  
T. Tachi
Keyword(s):  
Water Quality ◽  
Pilot Scale ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Control Technology ◽  
Raw Water ◽  
Control Logic ◽  
Water Turbidity ◽  
Coagulant Dosage ◽  
Raw Water Quality

An automatic coagulant dosage control technology for water purification plants was developed to deal with rapid changes of raw water quality parameters. Control logic was developed to decide coagulant dosage based on aluminum concentration in rapid mixing tank water based on results of semi-pilot scale experiments. This logic enabled quick feedback on the excess or lack of coagulant. It was found that the aluminum residual rate, which was proposed as an indicator of coagulation reactions, could be given as a function of coagulant dosage and turbidity. The effectiveness of the control logic was verified in semi-pilot scale experiments. Settled water turbidity was within ±0.5 NTU of target value even when raw water turbidity increased rapidly up to 100 NTU.

Removal of particulates, natural organic matters, and microorganisms in a surface amended slow sand filter

2002 ◽  
Vol 2 (5-6) ◽  
pp. 387-394
Author(s):  
H.-B. Jun ◽  
Y.-J. Lee ◽  
S.-S. Shin
Keyword(s):  
Surface Treatment ◽  
Raw Water ◽  
Sand Filters ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Sand Filter ◽  
Organic Matters ◽  
Slow Sand Filter ◽  
Natural Organic Matters ◽  
Filter Bed

Removal characteristics of particulates, natural organic matters, and microorganisms with six slow sand filter units were measured with a diameter of 50 mm and packed with sand to a depth of 50, 150, 300, 600, and two 700 mm, respectively. One of the 700 mm depth filters was amended by covering the surface of the filter bed with a prefilter. The raw water turbidity and pH was in the range of 1.5-2.0 NTU, and 7.0-7.7, respectively. Turbidity in each filter effluent was decreased as the depth of filter medium increased. However, a greater part of influent turbidity was removed within the top layer of the slow sand filters. Turbidity removal in the 700 mm depth filter with prefilter was similar to that without the prefilter, however, the removal of particles smaller than 2 mm was improved with the prefilter. The particles greater than 10 mm could be removed within the upper 50 mm depth in the slow sand filter. A greater fraction of the particles smaller than 2 mm was removed within the upper 50 mm, however, they were also removed in the deeper sand bed. The removal efficiency of DBP precursors represented by DOC and UV-254 absorbance was 9.2-31% and 2-31%, respectively. pH drop in the 50 mm depth filter was 0.12, while that in the 700 mm depth filter was 0.19. The effects of surface treatment with prefilter on UVA and DOC were not apparent.

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