scholarly journals The performance of sludge blanket clarifier against conventional settler under high water turbidity conditions

2018 ◽  
Vol 13 (3) ◽  
pp. 642-653 ◽  
Author(s):  
Moharram Fouad ◽  
Shaban Hassan
Keyword(s):  
Removal Efficiency ◽  
Field Data ◽  
High Water ◽  
Ease Of Use ◽  
Turbid Water ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Accumulation Pattern ◽  
Algae Removal ◽  
Sludge Accumulation

Abstract The performance of a sludge blanket clarifier was evaluated and compared to conventional settlers under high levels of turbidity and algae in the field and experimentally. Field data of sludge blanket and conventional clarifier operation were observed simultaneously for the treatment of highly turbid water. In addition, a comparison was carried out on turbidity removal efficiency, algae removal, and sludge accumulation pattern. Finally, these systems were simulated in the laboratory and operated to treat turbid water with high levels of turbidity and algae up to 80 NTU and 109cells/l respectively. Field data confirmed that the sludge blanket clarifier equipped with upper sludge cones has a high removal efficiency of turbidity and algae, ease of use and has insignificant sludge accumulation compared to the conventional settler. Further, laboratory experiments have confirmed that sludge blanket clarifier is also very effective for the treatment of high algae concentrations up to 109cells/l, with a short retention time, compared to a conventional settler, which was not effective under these conditions.

scholarly journals Enhanced Coagulation Efficiency of Moringa Oleifera Seeds Through Selective Oil Extraction

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Suleyman A. Muyibi ◽  
Saad A. Abbas Megat Johari M. M. Noor Fakrul Razi Ahmadun
Keyword(s):  
River Water ◽  
Moringa Oleifera ◽  
Oil Extraction ◽  
Kernel Weight ◽  
Turbid Water ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Kaolin Suspension ◽  
High Turbidity ◽  
Moringa Oleifera Seed

In this laboratory based study, varying quantities of oil, corresponding to 20 % w/w, 25 % w/w and 30 % w/w kernel weight extracted from Moringa oleifera seeds ( S1, S2, S3) respectively  were applied in the coagulation of model turbid water (kaolin suspension) and turbid river water samples from River Batang Kali and River Selangor in Malaysia to determine the percentage oil removed which gave the best coagulation efficiency. For model turbid water (kaolin suspension) coagulation of low turbidity of 35 NTU, medium turbidity of 100 NTU and high turbidity of 300 NTU, sample S2  gave the best turbidity removal corresponding to 91.7%, 95.5% and 99% respectively. Application of sample S2 to River Batang Kali with low initial turbidity of 32 NTU and high initial turbidity of 502 NTU gave a highest turbidity removal of 69% and 99% respectively. Application to River Selangor with medium initial turbidity- of 87 NTU and high initial turbidity of 466 NTU gave a highest residual turbidity' of 94% and 98.9%,  respectively.Key words: Moringa oleifera seed, selective oil extraction, coagulation, model turbid water (kaolin suspension), river water, turbidity removal.

The Effect of Variation in Cone Position Heigth on Raw Water Turbidity Removal in Sedimentation Unit Continuous Discharge Flow (CDF) Method as a New Method

2021 ◽  
Vol 20 (1) ◽  
pp. 58-64
Author(s):  
Ridwan Ridwan ◽  
Reri Afrianita ◽  
Yar Gustina
Keyword(s):  
Removal Efficiency ◽  
Rank Correlation ◽  
New Method ◽  
Raw Water ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Spearman’S Rank Correlation ◽  
Optimum Position ◽  
Exhaust Stream ◽  
Laboratory Scale Reactor

Unit sedimentasi metode continuous discharges flow (CDF) adalah metode baru dalam menyisihkan kekeruhan yang menggunakan prinsip tangki bocor secara kontinu dan terkendali. Perubahan ketinggian posisi cone dari dasar zona pengendapan ke bagian atas, dapat memperkecil jarak antara sumber aliran buang akibat bocor yang berasal dari cone sebagai sumber gaya baru yang bekerja terhadap flok, dan pada akhirnya meningkatkan efisiensi penyisihan kekeruhan. Penelitian ini bertujuan untuk menganalisis efisiensi penyisihan kekeruhan air baku pada 3 variasi ketinggian posisi cone di zona pengendapan. Penelitian menggunakan reaktor skala laboratorium kapasitas 240 L/jam yang terdiri dari unit koagulasi terjunan, flokulasi baffle channel dan sedimentasi metode CDF. Unit sedimentasi metode CDF yang digunakan adalah CDF 6% dengan variasi ketinggian posisi cone 0 m, 0,33 m dan 0,66 m dari dasar zona pengendapan. Air baku yang digunakan adalah Sungai Batang Kuranji Kota Padang dengan kekeruhan 25,876 – 26,012 NTU dan tawas sebagai koagulan dalam proses koagulasi. Hasil penelitian menunjukkan efisiensi penyisihan kekeruhan pada ketinggian posisi cone 0 m, 0,33 m dan 0,66 m secara berurutan adalah sebesar 82,88%, 83,86% dan 84,60%. Ketinggian posisi cone 0,66 m dari dasar zona pengendapan adalah posisi optimum dengan efisiensi penyisihan kekeruhan 1,72% lebih besar dari posisi cone di dasar zona pengendapan, yaitu 0 m. Analisis pengaruh ketinggian posisi cone terhadap penyisihan kekeruhan menggunakan korelasi Rank Spearman, menunjukkan pengaruh yang sangat kuat, semakin tinggi posisi cone semakin besar efisiensi penyisihan. Bilangan Reynolds (NRe)dan bilangan Froude (NFr) pada aliran buang ini secara berurutan adalah 23,83 dan 9,33x10-4. ABSTRACTThe continuous discharges flow (CDF) sedimentation unit is a new method for removing turbidity using the principle of a continuous and controlled leaking tank. Changes in the height of the cone position from the bottom of the settling zone to the top, can reduce the distance between the exhaust flow sources due to leakage from the cone as a new force source acting on the floc, and ultimately increase the efficiency of turbidity removal. This study aims to analyze the efficiency of raw water turbidity removal at 3 variations in the height of the cone position in the settling zone. The study used a laboratory-scale reactor with a capacity of 240 L/hour consisting of a plunge coagulation unit, baffle channel flocculation, and CDF sedimentation method. The sedimentation unit for the CDF method used is 6% CDF with variations in the height of the cone position 0 m, 0.33 m, and 0.66 m from the bottom of the settling zone. The raw water used is Sungai Batang Kuranji, Padang City with a turbidity of 25.875 – 26.012 NTU and alum as a coagulant in the coagulation process. The results showed that the efficiency of removal of turbidity at the height of the cone 0 m, 0.33 m, and 0.66 m respectively was 82.88%, 83.86%, and 84.60%. The height of the cone position 0.66 m from the bottom of the settling zone is the optimum position with a turbidity removal efficiency of 1.72% greater than the cone position at the bottom of the settling zone, which is 0 m. Analysis of the effect of the height of the cone position on the removal of turbidity using Spearman's Rank correlation showed a very strong influence, the higher the cone position the greater the removal efficiency. Reynolds number (NRe) and Froude number (NFr) in this exhaust stream are 23.83 and 9.33x10-4, respectively.

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.

scholarly journals A Comparative Study of Water Turbidity Removal Efficiency of Anthracite and Gravel in Roughing Filter

2020 ◽  
Vol 3 (1) ◽  
pp. 42-49
Author(s):  
Bhesh Kumar Karki ◽  
Iswar Man Amatya
Keyword(s):  
Grain Size ◽  
Removal Efficiency ◽  
Filtration Rate ◽  
Cost Effective ◽  
Head Loss ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Flow Rates ◽  
Cost Effective Method ◽  
Flow Rate Change

This research was carried out to compare turbidity removal efficiency of anthracite up flow roughing filter (RF) model to gravel RF model at different flow rates. Two identical filter columns with (230*230*1570) mm3 in internal dimensions were operated at same time. Same grain size (2 - 4.75) and (4.75 - 9.5) mm were used in gravel model and anthracite model. All the sizes were achieved by properly sieving through standard sieve sizes (2, 4.75, 9.5, 12.5 and 25 mm). The study involved measuring turbidity every 2 hours and head loss once a day. Filter models were operated around 200 NTU influent turbidity until maximum allowable head loss was reached. Three sets of experiments were carried at filtration rate of .0.5 to 1.5 m/h. Anthracite model was 2.07% more efficient in terms of turbidity removal. Increasing filtration rate from 0.5 to 1.5 m/h, the effluent turbidity in gravel model increased from 24.44 to 33.52 NTU whereas that in anthracite model increased from 21.48 to 28.02 NTU and removal efficiency in anthracite model decreased from 89 to 86% while in gravel model decreased from 88 to 84%. Thus, it can be concluded that anthracite model was highly significant to removal turbidity and less affected by the flow rate change in case of efficiency. Thus, this cost-effective method can be used in context of Nepal as well.

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 Use of Aloe vera as an Organic Coagulant for Improving Drinking Water Quality

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2024
Author(s):  
Abderrezzaq Benalia ◽  
Kerroum Derbal ◽  
Amel Khalfaoui ◽  
Raouf Bouchareb ◽  
Antonio Panico ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Suspended Solids ◽  
Aluminum Sulfate ◽  
Aloe Vera ◽  
Drinking Water Treatment ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Maximum Turbidity ◽  
Optimal Ph

The coagulation–flocculation–sedimentation process is widely used for removal of suspended solids and water turbidity reduction. The most common coagulants used to conduct this process are aluminum sulfate and ferric sulfate. In this paper, the use of Aloe vera as a natural-based coagulant for drinking water treatment was tested. The bio-coagulant was used in two different forms: powder as well as liquid; the latter was extracted with distilled water used as a solvent. The obtained results showed that the use of the natural coagulant (Aloe vera) in both powder (AV-Powder) and liquid (AV-H2O) forms reduced the water turbidity at natural pH by 28.23% and 87.84%, respectively. Moreover, it was found that the use of the two previous forms of bio-coagulant for drinking water treatment had no significant influence on the following three parameters: pH, alkalinity, and hardness. The study of the effect of pH on the process performance using Aloe vera as a bio-coagulant demonstrated that the maximum turbidity removal efficiency accounted for 53.53% and 88.23% using AV-Powder and AV-H2O, respectively, at optimal pH 6.

scholarly journals Effect of Cone-Plate Clarifier Structure Parameters on Flocculation Efficiency

Separations ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 6
Author(s):  
Yulong Zhang ◽  
Peikun Liu ◽  
Linjing Xiao ◽  
Long Chang ◽  
Fangping Yan ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Coal Mine ◽  
Mine Water ◽  
Regression Models ◽  
Structural Parameters ◽  
Insertion Depth ◽  
Turbidity Removal ◽  
Plate Spacing ◽  
Coal Mine Water ◽  
Flocculation Effect

In this study, a coal mine water flocculation system was established. A series of flocculation tests were carried out at different structural parameters (cylinder height, cone-plate insertion depth and cone-plate spacing) to better investigate the effect of the cone-plate clarifier on coal mine water treatment performance. Sixteen sampling points were set up in the system for data monitoring to generate the required data. The cone-plate clarifier was divided into five zones for flocculation analysis. The increased cylinder height facilitated the flocculation of particles in the micro flocculation zone and the settling of particles in the settlement zone. The chemicals used are polyaluminum chloride (PACl), Fe3O4 and polyacrylamide (PAM), corresponding to doses of 60 mg/L, 40 mg/L and 6 mg/L, respectively. Insufficient insertion depth of the cone-plate will cause the small flocs that have not been fully flocculated to enter the exit pipe zone directly through the cone-plate, while too much insertion depth will cause the large floc in the settlement zone to re-enter the exit pipe zone. The flocculation effect of small flocs increased as the cone-plate spacing decreased, which is consistent with the shallow pool theory. When the cone plate spacing was too narrow, the amount of fluid was reduced and the increase in fluid velocity reduced the flocculation effect. Curve fitting was conducted for Suspended solids(SS) and turbidity removal efficiency under each structural parameter to derive the variation of SS and turbidity removal efficiency under different structural parameters. The regression models of SS and turbidity removal efficiency on the cylinder height, cone-plate insertion depth and cone-plate spacing were established based on the curve fitting results, and the regression models were verified to be well fitted based on the comparison of experimental results. Finally, the optimal values of SS and turbidity removal efficiency were found based on the regression model. The flow rate of the cone-plate clarifier is 0.6 m3/h. The SS removal efficiency reached 96.82% when the cylinder height was 708 mm, the cone-plate insertion depth was 367 mm and the cone-plate spacing was 26 mm. The turbidity removal efficiency reached 86.75% when the cylinder height was 709 mm, the cone-plate insertion depth was 369 mm and the cone-plate spacing was 26 mm.

scholarly journals One-step removal of lead from water using an electricity-free and sustainable membrane filtration

2021 ◽  
Vol 27 (4) ◽  
pp. 166-172
Author(s):  
Junwei Zhang ◽  
Yan Tung Lo ◽  
Hao Guo ◽  
Chuyang Tang
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Membrane Filtration ◽  
High Water ◽  
Water Safety ◽  
Drinking Water Contamination ◽  
Emergency Situations ◽  
Drinking Water Safety ◽  
Effective Removal ◽  
Volumetric Loading

Lead (Pb) is a typical contaminant in water with adverse effects on human health. Hong Kong’s incident of drinking water contamination by Pb in 2015 caused severe public concerns regarding drinking water safety. Conventional treatment methods for Pb removal generally require electricity, chemical dosage, and considerable time and space, which significantly restrict their use for rapid water purification under emergency situations. In this study, a polyvinyl alcohol/polyacrylic acid (PVA/PAA) composite nanofibrous membrane was developed for the rapid and effective removal of Pb from water. The PVA/PAA membrane had a high water permeability of 550 L/m2/h/kPa - 710 L/m2/h/kPa, which allowed the filtration to be driven by gravity (e.g. with a water height of 10.0 cm). The membrane showed consistently high removal efficiency of Pb (> 95%) with a volumetric loading up to 3000 L/m2. This high removal efficiency was attributed to the combined effects of complexing and electrostatic attraction between Pb and PAA. An esculent citric acid was used to regenerate the exhausted PVA/PAA membrane. The regenerated membrane maintained its removal efficiency of Pb over a five-cycle filtration. These results imply that the PVA/PAA composite membrane can be repeatedly used in electricity-free filtration devices for rapid elimination of Pb under emergency situations.

Stormwater runoff treatment filtration system and backwashing system

2019 ◽  
Vol 79 (4) ◽  
pp. 771-778 ◽  
Author(s):  
Junho Lee ◽  
Myungjin Lee
Keyword(s):  
Particle Size ◽  
Removal Efficiency ◽  
Recovery Rate ◽  
Stormwater Runoff ◽  
Pilot Scale ◽  
Solid Loading ◽  
Filter Media ◽  
Turbidity Removal ◽  
Filtration System ◽  
Combined Sewer

Abstract This study has been carried out to evaluate the applicability of the pilot scale hybrid type of stormwater runoff treatment system for treatment of combined sewer overflow. Also, to determine the optimum operation parameter such as coagulation dosage concentration, effectiveness of coagulant usage, surface loading rate and backwashing conditions. The pilot scale stormwater filtration system (SFS) was installed at the municipal wastewater plant serving the city of Cheongju (CWTP), Korea. CWTP has a capacity of 280,000 m3/day. The SFS consists of a hydrocyclone coagulation/flocculation with polyaluminium chloride silicate (PACS) and an upflow filter to treat combined sewer overflows. There are two modes (without PACS use and with PACS use) of operation for the SFS. In case of no coagulant use, the range of suspended solids (SS) and turbidity removal efficiency were 72.0–86.6% (mean 80.0%) and 30.9–71.1% (mean 49.3%), respectively. And, the recovery rate of filter was 79.2–83.6% (mean 81.2%); the rate of remaining solid loading in filter media was 16.4–20.8% (mean 18.8%) after backwashing. The influent turbidity, SS concentrations were 59.0–90.7 NTU (mean 72.0 NTU), 194.0–320.0mg/L (mean 246.7mg/L), respectively. The range of PACS dosage concentration was 6.0–7.1mg/L (mean 6.7mg/L). The range of SS and turbidity removal efficiency was 84.9–98.2 (mean 91.4%) and 70.7–96.3 (mean 84.0%), respectively. It was found that removal efficiency was enhanced with PACS dosage. The recovery rate of filter was 92.0–92.5% (mean 92.3%) the rate of remaining solid loading in filter media was 6.1–8.2% (mean 7.2%) after backwashing. In the case of coagulant use, the particle size of the effluent is bigger than influent particle size. The results showed that SFS with PACS use more effective than without PACS use in SS and turbidity removal efficiency and recovery rate of filter.

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