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 Modification of the Sedimentation Unit with Continuous Discharges Flow (CDF) as a New Method to Increase Turbidity Removal in Raw Water

2021 ◽  
Vol 1 (1) ◽  
pp. 1-9
Author(s):  
Ridwan Ridwan ◽  
Reri Afrianita ◽  
Yogi Kurniawan
Keyword(s):  
Reynolds Number ◽  
Reynolds Numbers ◽  
New Method ◽  
Design Criteria ◽  
Raw Water ◽  
Turbidity Removal ◽  
Detention Time ◽  
Working Principle ◽  
Laboratory Scale Reactor ◽  
Scale Reactor

This study applies a new method to remove the turbidity of raw water in the sedimentation unit called CDF sedimentation using the working principle of a leaky tank at the bottom of the tank. The test was carried out on a laboratory scale reactor of 240 L/hour for 6 hours consisting of a waterfall coagulation unit for 5 seconds and alum as a coagulant. perforated wall flocculation unit with 30 minutes detention time and 1 hour CDF sedimentation unit. The study was conducted with 4 variations of CDF, namely 0%, 1%, 3%, and 5% with turbidity of 75.25 NTU. The results showed the greater the CDF value, the greater the decrease in turbidity that occurred. The highest level of turbidity removal occurred at 5% CDF value with an efficiency of 91,09%, a correlation value -0,927, and a significance value of 0,00 < 0,05. CDF value gives an influence on Reynolds numbers and Froude numbers in sedimentation units where Reynolds numbers are in the range 65,71-76,75 and Froude numbers 1,96x10-4-2,29x10-4. This shows the Reynolds number and the Froude number will get bigger as the value of the CDF and still matches the design criteria of the laminar. Keywords: The CDF sedimentation, Efficiency, and Turbidity.

scholarly journals Effect of Coagulants Variations in the Coagulation Unit on the Efficiency of Raw Water Turbidity Removal Sedimentation Unit Continuous Discharges Flow (CDF) as a New Method

2021 ◽  
Vol 1 (02) ◽  
Author(s):  
Ridwan Ridwan ◽  
Reri Afrianita ◽  
Resi Meilinta Danir Danir
Keyword(s):  
Ferric Chloride ◽  
Aluminum Chloride ◽  
New Method ◽  
Raw Water ◽  
Spearman Correlation ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Experimental Reactor ◽  
Discharge Ratio ◽  
Floc Characteristics

Variations in the type of coagulant resulted in different floc characteristics. The sedimentation unit with continuous discharges flow or (CDF) method is a sedimentation unit that applies the leaking tank phenomenon, so it is possible that it will affect the condition of the floc that has been formed and in the end can affect the efficiency of turbidity removal. This study was to determine the effect of the type of coagulant in the coagulation unit on the removal of raw water turbidity in the sedimentation unit using the CDF method with a 6% discharge ratio to the product discharge. The raw water used is Sungai Batang Kuranji water with a turbidity of 27.63 NTU. The experimental reactor consisted of a coagulation-flocculation unit and a sedimentation unit with various coagulants being Poly Aluminum Chloride (PAC), Ferric Chloride, and Alum. The results showed that the efficiency of removing turbidity from the Sungai Batang Kuranji by PAC coagulant was 90.12%, Ferric Chloride 86.99%, and Alum 81.72%. The Spearman correlation value of the coagulant variable on the efficiency of the removal of turbidity is 0.948, indicating a unidirectional effect between the two variables. The addition of 6% CDF flow in the settling zone did not break the floc because the flow formed was still laminar.

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.

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.

scholarly journals Optimization of the Horizontal Sedimentation Tank to Predict Turbidity Removal Efficiency in Water Treatment Plant in Iraq

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Yaser Ibrahim Jasem ◽  
Ali. Hadi . Ghawi
Keyword(s):  
Water Treatment ◽  
Removal Efficiency ◽  
Settling Tank ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Turbidity Removal ◽  
Dye Tracer ◽  
Sedimentation Tank ◽  
Time Simulation ◽  
Optimum Position

The goal of this research was to design and evaluate the efficiency of horizontal sedimentation tank for water treatment using different position of baffles. Turbid water was treated using alum in the condition with and without baffle in the settling unit. Turbidity was the main determinant in assessing the effectiveness of the settling tank processes. Visualization and profiling research was done using a dye tracer. Samples were collection at different baffle horizontal and vertical height, different flow rates and turbidity with respect to time. Baffle position was found to be capable of increasing turbidity removal efficiency considerably in the settling tank by diminishing the surface loading rate and increasing the retention time. Simulation displayed that turbidity can be eliminated higher than 95%. The type of water purified using optimum position of baffle was well below the WHO guideline for drinking water of <5 NTU.

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.

Performance of Polluted Source Water Treatment by Biological Aerated Filter (BAF) with Zeolite, Activated Carbon and Anthracite Media

2013 ◽  
Vol 777 ◽  
pp. 117-121
Author(s):  
Dong Wang ◽  
Li Ping Qiu ◽  
Chun Hui Guo ◽  
Qiang Liu
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Removal Efficiency ◽  
Ammonia Nitrogen ◽  
Source Water ◽  
Raw Water ◽  
Biological Aerated Filter ◽  
Turbidity Removal ◽  
N Removal ◽  
Aerated Filter

The performance of three BAFs with zeolite, activated carbon and anthracite media for the treatment of polluted Huaihe raw water were investigated. All three BAFs performed promising permanganate index (CODMn) and ammonia nitrogen (NH4+-N) removal efficiency as well as the turbidity removal was over 60%. Moreover, the CODMn and NH4+-N removal in the three BAFs were affacted by the characteristics of filter media. Activated carbon and anthracite had better CODMn removal than zeolite. Zeolite had the best NH4+-N removal, followed by activated carbon, anthracite was the worst.

A Study of the Relationships between Nursing Students’ Meanings of Life, Positive Beliefs, and Well-Being

2018 ◽  
Vol 3 (01) ◽  
Author(s):  
Fu-Ju Tsai ◽  
Cheng-Yu Chen ◽  
Gwo-Liang Yeh ◽  
Yih-Jin Hu ◽  
Chie-Chien Tseng ◽  
...  
Keyword(s):  
Health Promotion ◽  
Nursing Students ◽  
Analysis Of Variance ◽  
Rank Correlation ◽  
Meaning Of Life ◽  
Well Being ◽  
Social Health ◽  
Cross Sectional ◽  
Nursing Educators ◽  
Spearman’S Rank Correlation

Background: Nursing educators should train nursing students to pursue physical, psychological, spiritual, and social health promotion. The purpose of this study was to explore relationships between nursing students’ meaning of life, positive beliefs, and well-being. Methods: A cross-sectional correlational study with a quantitative approach was adopted. Purposive sampling was used. A total of 170 nursing students voluntarily participated in this study. A 56-item questionnaire was used to examine nursing students’ meaning of life (1-25 items), positive beliefs (1-11 items), and well-being (1-20 items). The content validity index (CVI) of the study questionnaire was established as 0.95 by seven expert scholars. The reliability values for the three parts of the measure were as follows: meaning of life, Cronbach’s α 0.96; positive beliefs, Cronbach’s α 0.93; and well-being, Cronbach’s α 0.95. Percentages, frequencies, means, SDs, Kruskal-Wallis one-way analysis of variance by rank, Spearman’s rank correlation, one-way analysis of variance, Spearman’s rho correlation, and regression analysis were used for the data analysis. Results: Nursing students had the following mean scores: meaning of life with 4.02 (SD 0.56); positive beliefs with 3.92 (SD 0.62); and well-being with 3.95 (SD 0.57). The results indicate that for all nursing students, meaning of life was positively correlated with positive beliefs, r=0.83 (P<.01); similarly, all nursing students had positive beliefs that were positively correlated with meaning of life, r=0.83 (P<.01). In the results of the study, the nursing students’ background, meaning of life and positive beliefs explained 63% of the variance in well-being (Adjusted R2 squared =0.63, F=33.41, P<.001). Conclusions: Nursing students’ sense of meaning of life and positive beliefs may impact their well-being. Therefore, nursing educators can promote meaning of life and positive beliefs to nursing students as a way to increase their well-being for physical, psychological, spiritual, and social health promotion.

scholarly journals Deregulation of lncRNA HIST1H2AG-6 and AIM1-3 in peripheral blood mononuclear cells is associated with newly diagnosed type 2 diabetes

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Hui Jiang ◽  
Peian Lou ◽  
Xiaoluo Chen ◽  
Chenguang Wu ◽  
Shihe Shao
Keyword(s):  
Roc Curve ◽  
Multivariate Logistic Regression Analysis ◽  
Rank Correlation ◽  
Differentially Expressed ◽  
Healthy Controls ◽  
Biological Functions ◽  
Multivariate Logistic Regression ◽  
Spearman’S Rank Correlation ◽  
Spearman’S Rank Correlation Coefficient

Abstract Background Type 2 diabetes mellitus (T2DM) is mainly affected by genetic and environmental factors; however, the correlation of long noncoding RNAs (lncRNAs) with T2DM remains largely unknown. Methods Microarray analysis was performed to identify the differentially expressed lncRNAs and messenger RNAs (mRNAs) in patients with T2DM and healthy controls, and the expression of two candidate lncRNAs (lnc-HIST1H2AG-6 and lnc-AIM1-3) were further validated using quantitative real-time polymerase chain reaction (qRT-PCR). Spearman’s rank correlation coefficient was used to measure the degree of association between the two candidate lncRNAs and differentially expressed mRNAs. Furthermore, the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway and GO (Gene Ontology) enrichment analysis were used to reveal the biological functions of the two candidate lncRNAs. Additionally, multivariate logistic regression analysis and receiver operating characteristic (ROC) curve analysis were performed. Results The microarray analysis revealed that there were 55 lncRNAs and 36 mRNAs differentially expressed in patients with T2DM compared with healthy controls. Notably, lnc-HIST1H2AG-6 was significantly upregulated and lnc-AIM1-3 was significantly downregulated in patients with T2DM, which was validated in a large-scale qRT-PCR examination (90 controls and 100 patients with T2DM). Spearman’s rank correlation coefficient revealed that both lncRNAs were correlated with 36 differentially expressed mRNAs. Furthermore, functional enrichment (KEGG and GO) analysis demonstrated that the two lncRNA-related mRNAs might be involved in multiple biological functions, including cell programmed death, negative regulation of insulin receptor signal, and starch and sucrose metabolism. Multivariate logistic regression analysis revealed that lnc-HIST1H2AG-6 and lnc-AIM1-3 were significantly correlated with T2DM (OR = 5.791 and 0.071, respectively, both P = 0.000). Furthermore, the ROC curve showed that the expression of lnc-HIST1H2AG-6 and lnc-AIM1-3 might be used to differentiate patients with T2DM from healthy controls (area under the ROC curve = 0.664 and 0.769, respectively). Conclusion The profiles of lncRNA and mRNA were significantly changed in patients with T2DM. The expression levels of lnc-HIST1H2AG-6 and lnc-AIM1-3 genes were significantly correlated with some features of T2DM, which may be used to distinguish patients with T2DM from healthy controls and may serve as potential novel biomarkers for diagnosis in the future.

scholarly journals Magnetic resonance cisternography imaging findings related to the leakage of Gadolinium into the subarachnoid space

2021 ◽  
Author(s):  
Rei Nakamichi ◽  
Toshiaki Taoka ◽  
Hisashi Kawai ◽  
Tadao Yoshida ◽  
Michihiko Sone ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Subarachnoid Space ◽  
Area Under The Curve ◽  
Rank Correlation ◽  
Predictive Performance ◽  
Roc Curves ◽  
Imaging Findings ◽  
Spearman’S Rank Correlation ◽  
Sagittal Sinus ◽  
Magnetic Resonance Cisternography

Abstract Purpose To identify magnetic resonance cisternography (MRC) imaging findings related to Gadolinium-based contrast agent (GBCA) leakage into the subarachnoid space. Materials and methods The number of voxels of GBCA leakage (V-leak) on 3D-real inversion recovery images was measured in 56 patients scanned 4 h post-intravenous GBCA injection. Bridging veins (BVs) were identified on MRC. The numbers of BVs with surrounding cystic structures (BV-cyst), with arachnoid granulations protruding into the superior sagittal sinus (BV-AG-SSS) and the skull (BV-AG-skull), and including any of these factors (BV-incl) were recorded. Correlations between these variables and V-leak were examined based on the Spearman’s rank correlation coefficient. Receiver-operating characteristic (ROC) curves were generated to investigate the predictive performance of GBCA leakage. Results V-leak and the number of BV-incl were strongly correlated (r = 0.609, p < 0.0001). The numbers of BV-cyst and BV-AG-skull had weaker correlations with V-leak (r = 0.364, p = 0.006; r = 0.311, p = 0.020, respectively). The number of BV-AG-SSS was not correlated with V-leak. The ROC curve for contrast leakage exceeding 1000 voxels and the number of BV-incl had moderate accuracy, with an area under the curve of 0.871. Conclusion The number of BV-incl may be a predictor of GBCA leakage and a biomarker for waste drainage function without using GBCA.

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