scholarly journals A comparison of different pilot constructed clarifiers with the purpose of achieving the optimum condition in turbidity removal at water treatment plants in Tehran

2017 ◽  
Vol 12 (3) ◽  
pp. 576-588 ◽  
Author(s):  
Seyed Ahmad Mirbagheri ◽  
Sima Malekmohamadi ◽  
Sheida Sohrabi Nasrabadi
Keyword(s):  
Water Treatment ◽  
Optimum Condition ◽  
Removal Efficiency ◽  
Ferric Chloride ◽  
Flow Rate ◽  
Superior Performance ◽  
Turbidity Removal ◽  
Flow Rates ◽  
Water Treatment Plants

Clarifying is one of the most crucial stages in water treatment at water treatment plants. Determining the type of the clarifier in water treatment plants and using it efficiently is necessary. In this study, a pilot is designed and constructed in which the pulsator, the superpulsator and the accelerator are simulated. For each system, turbidity removal efficiency for different influent turbidities and flow rates were studied and the optimum condition was obtained. The results showed that the superpulsator has a superior performance compared to the pulsator, and the pulsator has a superior performance compared to the accelerator and these differences are more sensible at higher flow rates. Also, the best condition for achieving the highest efficiency for the pulsator and the superpulsator is determined to be at flow rate 3 lit/min for an initial turbidity of 2,500 NTU with alum as the coagulant and the highest efficiency for the accelerator is determined to be at flow rate 3 lit/min for an initial turbidity of 2,500 NTU with ferric chloride as the coagulant. Comparing the turbidity removal efficiency shows that for 67% of the cases, ferric chloride has a better performance as the coagulant compared to alum and increasing the influent turbidity leads to an increase in the removal efficiency. Furthermore, three water treatment plants located in Tehran were studied and their characteristics were compared and suggestions were made to enhance their qualities.

scholarly journals Critical parameters in the production of ceramic pot filters for household water treatment in developing countries

2014 ◽  
Vol 13 (2) ◽  
pp. 587-599 ◽  
Author(s):  
A. I. A. Soppe ◽  
S. G. J. Heijman ◽  
I. Gensburger ◽  
A. Shantz ◽  
D. van Halem ◽  
...  
Keyword(s):  
Developing Countries ◽  
Water Treatment ◽  
Removal Efficiency ◽  
Rice Husk ◽  
Flow Rate ◽  
Critical Parameters ◽  
Small Scale ◽  
Material Strength ◽  
Flow Rates ◽  
Pore Sizes

The need to improve the access to safe water is generally recognized for the benefit of public health in developing countries. This study's objective was to identify critical parameters which are essential for improving the performance of ceramic pot filters (CPFs) as a point-of-use water treatment system. Defining critical production parameters was also relevant to confirm that CPFs with high-flow rates may have the same disinfection capacity as pots with normal flow rates. A pilot unit was built in Cambodia to produce CPFs under controlled and constant conditions. Pots were manufactured from a mixture of clay, laterite and rice husk in a small-scale, gas-fired, temperature-controlled kiln and tested for flow rate, removal efficiency of bacteria and material strength. Flow rate can be increased by increasing pore sizes and by increasing porosity. Pore sizes were increased by using larger rice husk particles and porosity was increased with larger proportions of rice husk in the clay mixture. The main conclusions: larger pore size decreases the removal efficiency of bacteria; higher porosity does not affect the removal efficiency of bacteria, but does influence the strength of pots; flow rates of CPFs can be raised to 10–20 L/hour without a significant decrease in bacterial removal efficiency.

Rehabilitation of water treatment plants with operational constrains: a study on turbidity removal

2013 ◽  
Vol 3 (4) ◽  
pp. 549-556 ◽  
Author(s):  
Kaveh Sookhak Lari ◽  
Morteza Kargar
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Term Effect ◽  
High Rate ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Water Treatment Plants ◽  
Long Term Effect

High-rate lamella settlers in clarifiers and triple media filters have been implemented in Isfahan water treatment plant (known as ‘Baba-Sheikh-Ali’) in Iran to upgrade existing clarification/filtration processes during the recent years. The applied technologies are mainly used to reduce finished water turbidity as the primary regional criterion on water quality. However, application of both technologies faced some operational limitations since they began to work. These problems are due to the existing layout of the process units and available materials. The current study focuses on performance of restricted application of the two technologies with respect to turbidity removal. Online measured turbidity data from a two-year field observation (since March 2010) are used. In particular, results show a more promising and long-term effect on turbidity removal due to tripling filter media rather than application of the lamella settlers in clarifiers. The reasons for these observations are discussed.

scholarly journals Natural agents as auxiliaries in water clarification: literature review and experimental evaluation

2020 ◽  
Vol 42 ◽  
pp. e44800
Author(s):  
João Paulo Nascimento Armeloni ◽  
Danieli Soares de Oliveira ◽  
Clainer Bravin Donadel
Keyword(s):  
Water Treatment ◽  
Literature Review ◽  
Removal Efficiency ◽  
Process Efficiency ◽  
Human Consumption ◽  
Agricultural Activity ◽  
Water And Wastewater Treatment ◽  
Turbidity Removal ◽  
Water Treatment Process ◽  
Treatment Processes

The increasing demand for water resources (primarily for human consumption and industrial and agricultural activity) is driven by socio-economic development, and population growth. Recent research has been focusing on alternative coagulants based on natural elements, as opposed to the commonly used iron and aluminum salts, for use in water and wastewater treatment processes. In this context, a thorough literature review on alternative coagulants and their application to water treatment processes has been conducted in this work. In addition, three experiments have been conducted with a widely used natural organic coagulant (Moringa oleifera). The alternative clarification system used is the helically coiled tube flocculator (HCTF), with high turbidity removal efficiency and low processing times. A comparative analysis of the turbidity reduction over time was performed with samples collected after 600, 900, 1200, 1500, 1800, 2100, 2400, and 2700 s from the hydraulic circuit. The process efficiency using the proposed alternative coagulant reached 95.3% (after 1800 s). The turbidity removal efficiency remained almost constant after 1800 s, with variations below 1%. These results prove that natural alternative agents can be powerful tools in the water treatment process, with efficiency values exceeding those obtained using chemicals (e.g., aluminum sulphate) as coagulant/ flocculant agents.

Application of Models in Developing Control Strategies for Activated Sludge Waste Water Treatment Plants

1984 ◽  
Vol 16 (5-7) ◽  
pp. 587-594 ◽  
Author(s):  
A Holmberg ◽  
J Forsström
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Activated Sludge ◽  
Control Strategies ◽  
Waste Water Treatment ◽  
Control Algorithms ◽  
Flow Rates ◽  
Simulation Techniques ◽  
Water Treatment Plants ◽  
Sludge Waste

This paper studies control of activated sludge plants using recycle and wastage flow rates as control variables. The behaviour of the control algorithms was studied using simulation techniques. The results indicate that the process is not sensitive to the recycle flow rate. Wastage flow control with the objective to keep the sludge concentration constant turned out to be promising.

scholarly journals Turbidity removal by rapid sand filter using anthracite coal as capping media

2021 ◽  
Vol 4 (1) ◽  
pp. 69-73
Author(s):  
Gopal Tamakhu ◽  
Iswar Man Amatya
Keyword(s):  
Comparative Analysis ◽  
Water Treatment ◽  
Bituminous Coal ◽  
Pilot Scale ◽  
Sand Filters ◽  
Turbidity Removal ◽  
Sand Filter ◽  
Filter Materials ◽  
Water Treatment Plants ◽  
Anthracite Coal

Rapid sand filters are very common in all conventional water treatment plants. Capping of existing rapid sand filters can be the promising method of improving the performance of rapid sand filters. Capping is process in which upper sand bed layer of few cm is replaced with capping material. However, this technique is limited in India due to unavailability of filter materials apart from sand. Some materials suitable for capping are anthracite coal, PVC granules, bituminous coal, broken bricks, etc. The attempt is made to study the effect of capping of Rapid sand filters by the use of anthracite coal as a capping media by pilot scale study. A series of test runs and experiments using different influent turbidity were tried. The pilot scale study has shown very encouraging results. Comparative analysis shows that higher rate of filtration is possible along with higher filter run and less backwash requirement. In the present work, conventional rapid sand filter and capped rapid sand filter are compared.

Optimization of Magnetic Coagulation Process for River Water Treatment Using the Response Surface Method

2012 ◽  
Vol 518-523 ◽  
pp. 3717-3722
Author(s):  
Jia Wei Hu ◽  
Jun Li ◽  
Yu Chen ◽  
Chang Wen Wang ◽  
Yan Li ◽  
...  
Keyword(s):  
Water Treatment ◽  
Response Surface ◽  
River Water ◽  
Removal Efficiency ◽  
Magnetic Particle ◽  
Operating Conditions ◽  
Turbidity Removal ◽  
Polluted River ◽  
Single Factor Experiment ◽  
Validation Experiments

Response surface methodology (RSM) was applied to optimize the magnetic coagulation conditions for micro-polluted river water treatment. Based on single-factor experiment, Box-Behnken central composition experiment design was applied. The poly aluminum Chloride (PAC), magnetic particle, polyacrylamide (PAM), mixing stirring and flocculating stirring revolving speed were chosen as causal factors. RSM was employed to study the effects of these factors on the turbidity removal efficiency. Base on the target value (>95%), the results show that the optimum conditions were PAC 29.31mgL-1, magnetic particle 61.90mgL-1, PAM 0.48mgL-1, mixing stirring revolving speed 288rpm, flocculating stirring revolving speed 6 rpm. The average turbidity removal efficiency in three validation experiments was 95.36%, with the predicted value was 95.19%. The relative error between the measured data and the predicted value was 0.17%. It confirms that RSM was a useful tool to optimize the magnetic coagulation operating conditions for micro-polluted river water treatment.

scholarly journals Investigating the feasibility of removing the rapid mixing unit in conventional surface water treatment and its effect on turbidity removal

2021 ◽  
Author(s):  
Abolfazl Hessam ◽  
Mohammad Hadi Mehdinejad
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Removal Efficiency ◽  
Treatment Plant ◽  
Test Method ◽  
Turbid Water ◽  
Turbidity Removal ◽  
Rapid Mixing ◽  
Surface Water Treatment ◽  
Significant Difference

Abstract Coagulation and Flocculation processes play a major role in surface water treatment. The aim of this study was to eliminate the rapid mixing unit in the water treatment plant. This experimental study was conducted on turbid water. Turbid water was synthesized by kaolin powder. The conventional Jar Test method was used. The flocculation and sedimentation processes were performed on the turbid water without rapid mixing unit for getting the new optimal condition. When the PACl coagulant was used alone and in conjunction with chitosan, the percentages of turbidity removal in low, medium and high turbidities were obtained 86.7%, 95.8%, 97.8% and 86.67%, 95.73%, 98.26%, respectively. When the rapid mixing unit was emitted, the efficiency of turbidity removal in the low turbidity was reduced from 5.26% to 21.73%. But, in higher turbidity in two states (presence and absence of the rapid mixing units) did not have a significant difference. This study showed that the removal of the rapid mix unit on the removal efficiency of turbidity in the low turbidity is effective, but does not effect on higher turbid water. Also, to use PACl in conjunction with chitosan were effective on the removal efficiency and to reduce of residual aluminum.

Simultaneous Absorption of SO2 and NO Using Sodium Chlorate/Urea Absorbent in a Rotating Packed Bed

2014 ◽  
Vol 908 ◽  
pp. 187-190
Author(s):  
Mei Jin ◽  
Guo Xian Yu ◽  
Fang Wang ◽  
Ping Lu
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Flue Gas ◽  
Gas Flow ◽  
Packed Bed ◽  
Sodium Chlorate ◽  
Experimental Conditions ◽  
Flow Rates ◽  
Simultaneous Absorption ◽  
Rotating Packed Bed

In this work, simultaneous absorption of SO2and NO from N2-NO-SO2simulated flue gas using sodium chlorate as the additive and urea as the reductant was investigated experimentally in a rotating packed bed. In RPB, various rotational speeds, gas flow rates and liquid flow rates were studied by means of the removal efficiency of SO2and NO. The experimental results showed that the removal efficiency of SO2was higher than 99.00% under various experimental conditions and, at the same time, the removal efficiency of NO exhibited different results under various experimental conditions. The simultaneous NO removal efficiency of 82.45% and the SO2removal efficiency of 99.49% could be obtained under the N2flow rate of 0.5 m3/h, SO2flow rate of 6 mL/min, the NO flow rate of 4 mL/min, the rotational speed of 460 rpm and the absorbent flow rate of 40 L/h.

DEVELOPMENT OF A COAGULATION/FLOCCULATION PREDICTIVE MODEL FOR TURBIDITY REMOVAL FROM TEHRAN WATER TREATMENT PLANTS

2008 ◽  
Vol 7 (1) ◽  
pp. 13-16
Author(s):  
Mohammad Reza Alavi Moghadam ◽  
Avid Banihashemi ◽  
Reza Maknoon ◽  
Manouchehr Nikazar
Keyword(s):  
Water Treatment ◽  
Predictive Model ◽  
Turbidity Removal ◽  
Water Treatment Plants

Performance of Sodium Chlorite/Urea on Simultaneous Desulfurization and Denitrification in a Rotating Packed Bed

2014 ◽  
Vol 908 ◽  
pp. 183-186 ◽  
Author(s):  
Hong Guan Wu ◽  
Mei Jin ◽  
Fang Wang ◽  
Guo Xian Yu ◽  
Ping Lu
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Flue Gas ◽  
Packed Bed ◽  
Sodium Chlorite ◽  
Experimental Conditions ◽  
Flow Rates ◽  
Rotating Packed Bed ◽  
Removal Efficiencies ◽  
Simultaneous Desulfurization And Denitrification

Performance of simultaneous desulfurization and denitrification from N2-NO-SO2simulated flue gas using sodium chlorite as the additive and urea as the reductant in a rotating packed bed was investigated. In RPB, various rotational speeds, the flow rates of SO2, the flow rates of NO and the liquid flow rates were studied by means of the calculation of the removal efficiencies of SO2and NO. The experimental results showed that the removal efficiency of SO2was higher than 99.00% under various experimental conditions, while the removal efficiency of NO exhibited different results. A better simultaneous desulfurization and denitrification behavior could be obtained under the conditions of a SO2-NO-N2simulated flue gas with the ratio of SO2/NO/ N2=6:4:8.33(v), a rotational speed of 460 rpm and an absorbent flow rate of 120 L/h.

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