Identification and prioritization of performancelimiting factors for water treatment plantoptimization in Korea

2006 ◽  
Vol 6 (2) ◽  
pp. 71-76
Author(s):  
N.-S. Park ◽  
J.-H. Kim ◽  
C.-H. Bae ◽  
Y.-T. Moon ◽  
H.-W. Ahn
Keyword(s):  
Water Treatment ◽  
Drinking Water Treatment ◽  
Ammonia Nitrogen ◽  
Limiting Factors ◽  
Limiting Factor ◽  
Manganese Ions ◽  
Injection Point ◽  
Mixing Intensity ◽  
Upward Velocity ◽  
Flocculation Process

Performance limiting factors (PLFs) derived from 161 drinking water treatment plants (DWTPs), assessed by the International Technical Diagnosis and Assistance Center, were analyzed and evaluated in this study. In order to conduct research, 161 DWTPs were divided into five categories depending on their capacity, and into twelve groups according to processes and facilities. From the results of analysis, PLFs and their distribution ratio derived from each category were significantly different. Filtration was the most important performance limiting factor in all DWTPs of five categories, and PLFs in filtration were backwashing velocity, media configuration, bed depth, and formation of mud-ball. The PLFs in coagulation–flocculation process were found to be coagulant dose, mixing intensity, mechanical problems, and others in the order of frequency of occurrence. Also, insufficient disinfection ability, is resulting from insufficient hydraulic detention time, improper chlorine dose and injection point, is the most significant among PLFs in a clear well. In the case of sedimentation, inappropriate baffle structure and excessive upward velocity were PLFs. In addition, the results showed that high turbid water and low alkalinity in rainy season, ferric and manganese ions, and ammonia nitrogen have contributed significantly to the performance of DWTPs.

Dosing ratios for reduced bromate formation by dissolved ozone dosing

2005 ◽  
Vol 5 (5) ◽  
pp. 35-40
Author(s):  
A.W.C. van der Helm ◽  
P.W.M.H. Smeets ◽  
E.T. Baars ◽  
L.C. Rietveld ◽  
J.C. van Dijk
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Water Flow ◽  
Flow Reactor ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Limiting Factor ◽  
Drinking Water Treatment Plant ◽  
Side Stream

Bromate formation experiments were carried out in a 100 l/h bench-scale dissolved ozone plug flow reactor (DOPFR) with natural filtered water from the drinking water treatment plant Leiduin of Amsterdam Water Supply at gross ozone dosages of 0.7–3.4 mg/l. In the DOPFR, ozone is dosed by intensively mixing a dissolved ozone water flow (side stream) with a test water flow (mainstream). The side stream is pre-treated to remove bromide and DOC and to lower the pH. For full-scale application of the DOPFR concept, it is most cost effective to apply the smallest possible side stream. This research is done to establish the effect of decreasing the ratio of the dissolved ozone side stream to the mainstream from 1:10 to 1:25, by increasing the ozone concentration and decreasing the flow of the side stream. The results show that the dosing ratio has no influence on the bromate formation in the ozone dosing range of 0.7–1.4 mg/l. The gross ozone dosages that are currently applied at the drinking water treatment plant Leiduin are 0.8–1.0 mg/l. This means that for application of dissolved ozone dosing at Leiduin the amount of ozone that can be dissolved in the side stream will be the limiting factor for the minimal flow of the dissolved ozone side stream.

scholarly journals Mechanism of Coagulation Using Chitosan from Mytilus Virdis Linneaus Shells in Water Treatment

2018 ◽  
Author(s):  
sinardi ◽  
Prayatni Soewondo ◽  
Suprihanto Notodarmojo ◽  
cynthia radiman
Keyword(s):  
Water Treatment ◽  
Inorganic Compounds ◽  
Drinking Water Treatment ◽  
Turbid Water ◽  
Degree Of Deacetylation ◽  
Green Mussel ◽  
Environment And Health ◽  
Residual Aluminum ◽  
Mussel Shells ◽  
Flocculation Process

Green mussel (Mytilus viridis Linnaeus) is one of the shells from marine source that can be used as chitosan. On the other side of drinking water treatment using synthetic coagulant such us aluminum sulphate (Al2 (SO4)3) concerns about the residual aluminum in the water that contains inorganic compounds are carcinogenic so it is necessary to do research about potential use of chitosan as a coagulant. This study conducted on laboratory-scale use of chitosan from green mussel shells as a coagulant in coagulation-flocculation process using turbid water from Tirtawening in Bandung City, Indonesia. The purpose of this study was to determine the mechanism of coagulation-flocculation process based on the characteristics of chitosan. Preparation of chitosan with deproteination process done using a solution of NaOH 3.5% 10: 1 (v: w), stirring 2 hours 65oC. Demineralization process using a solution of HCl 1 N 15: 1 (v: w), stirring 30 minutes 50 °C. Deacetylation process using a solution NaOH 60% 20:1 (v: w) stirred 60 minutes 120oC produce chitosan with degree of deacetylation about 77.8% and molecular mass about 4,26x104 g / mol. The degree of deacetylation of chitosan effect ability formation of flock and the molecules of mass of chitosan effect in binding colloids in turbid water into one and form a flock large. The results concluded that chitosan from green mussel shells can be used as a coagulant for turbidity removal in water treatment and use it safe for the environment and health because from natural compounds and biodegradable.

Occurrence and separation of Cryptosporidium oocysts in drinking water treatment

2000 ◽  
Vol 41 (7) ◽  
pp. 159-163 ◽  
Author(s):  
P. Dolejš ◽  
O. Ditrich ◽  
T. Machula ◽  
N. Kalousková ◽  
G. Puzová
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Removal Efficiency ◽  
Drinking Water Treatment ◽  
Water Sources ◽  
Mixing Conditions ◽  
Drinking Water Sources ◽  
Cryptosporidium Oocysts ◽  
Mixing Intensity ◽  
Treatment Train

The presence of Cryptosporidium sp. in Czech drinking water sources was monitored. High numbers of Cryptosporidium oocysts were found in the Slezska Harta reservoir after 1997 summer floods. The influence of iron (III) coagulant dose, mixing conditions and preozonation on the removal efficiency of Cryptosporidium oocysts was studied. Low mixing intensity produced flocs with poor settling features. The efficiency of sedimentation expressed as residual iron after sedimentation was proportional to removal efficiency of oocysts. Both underdosing or overdosing of iron (III) coagulant resulted in decrease of COD, turbidity and oocyst removal. Preozonation positively influenced removal efficiency of oocysts in the conventional drinking water treatment train studied.

scholarly journals Influence of density flow on treated water turbidity in a sedimentation basin with inclined plate settler

2017 ◽  
Vol 17 (4) ◽  
pp. 1140-1148
Author(s):  
K. Takata ◽  
R. Kurose
Keyword(s):  
Drinking Water ◽  
Particulate Matter ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Raw Water ◽  
Inclined Plate ◽  
Treated Water ◽  
Sedimentation Basin ◽  
Density Flow ◽  
Upward Velocity

The removal efficiency of particulate matter from a sedimentation basin with an inclined plate settler in drinking water treatment facilities is sometimes reduced by density flow caused by temperature increases in the raw water. In this study, the structure of the density flow and its prevention are investigated by means of three-dimensional computational fluid dynamics (CFD). The results of CFD show that upward velocity is uniform and normal operations are performed before the increase in inlet water temperatures. After the onset of a temperature increase in the raw water, the upward flow velocity on the inclined plate settler increases, especially in the upstream zone of the plate. This velocity increment has a strong correlation with increase in turbidity as a result of the overflow of particulate matter. The effects of the installation of baffle plates on the inclined plate settler to reduce turbidity were explored. The CFD results using baffle plates show a significant decrease in upward velocity on the inclined plate settler. This suggests that baffle plates are effective in suppressing the overflow of particulate matter. To verify the prediction by CFD, baffle plates were installed in a drinking water treatment facility. The results show that the turbidity of treated water was reduced by the proposed procedure.

scholarly journals Does the recycling of waste streams from drinking water treatment plants worsen the quality of finished water? A case assessment in China

2016 ◽  
Vol 17 (2) ◽  
pp. 597-605
Author(s):  
Zhiquan Liu ◽  
Yongpeng Xu ◽  
Xuewei Yang ◽  
Rui Huang ◽  
Qihao Zhou ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Ammonia Nitrogen ◽  
Raw Water ◽  
Waste Streams ◽  
Filter Backwash Water

The overall purpose was to assess the feasibilities of recycling filter backwash water (FBWW) and combined filter backwash water (CFBWW) in a drinking water treatment plant in south China. The variations of regular water-quality indexes, metal indexes (Al, Mn and Cd), polyacrylamide and disinfection by-product indexes (trihalomethanes and their formation potentials) along with the treatment and the recycling processes were monitored. Results showed the recycling procedure caused increases of turbidity, total solids, ammonia nitrogen (NH3-N), permanganate index (CODMn), and dissolved organic carbon, Al, Mn and Cd concentrations in a mixture of raw water and FBWW or CFBWW compared to those in raw water. However, the recycling procedure had negligible impacts on the qualities of settled water and filtered water because most of the contaminants could be effectively removed by the conventional water treatment process. Although recycling did cause slight increases of NH3-N and CODMn levels in settled water and filtered water, the quality of finished water always conformed to Chinese standards for drinking water quality according to the surveyed indexes in the present study. Thus, it is appropriate to recycle waste streams in water-stressed areas if the source water is well managed and the water treatment processes are carefully conducted.

Biomass development in GAC columns receiving influents with different levels of nutrients

2016 ◽  
Vol 16 (4) ◽  
pp. 1024-1032 ◽  
Author(s):  
Xiaobin Liao ◽  
Rusen Zou ◽  
Chao Chen ◽  
Baoling Yuan ◽  
Zhenming Zhou ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Organic Contaminants ◽  
Oxygen Demand ◽  
Drinking Water Treatment ◽  
Nitrogen Addition ◽  
Ammonia Nitrogen ◽  
Limiting Factor ◽  
Stable Operating ◽  
Biodegradable Dissolved Organic Carbon ◽  
Biofilm Development

Indigenous bacteria are essential for the performance of bio-filters for drinking water treatment. Yet it is slow and difficult to develop biofilm in a granular activated carbon (GAC) filter with low nutritional levels in the influent, especially during winter. In this study, the biofilm development in three laboratory-scale GAC columns with different types of influent was investigated in southeast China during winter. The results indicated that nitrogen was the limiting factor for biofilm development in GAC columns for this source water. The biomass density in the column with ammonia nitrogen addition was much higher than those of the other two filters, while its microbial diversity and biological activity were lower. Moreover, the ammonia-feeding column also showed the highest removal of organic contaminants during the stable operating periods, i.e. chemical oxygen demand (CODMn), assimilable organic carbon as well as biodegradable dissolved organic carbon. Therefore, nitrogen amendment favors the formation of biofilm. It could shorten the start-up time of a GAC filter and enhance the bio-stability of its effluent. This might add some new insights towards the operation of GAC filters with low nutritional levels in the influent during winter.

scholarly journals Effect of the Recycling Process on Drinking Water Treatment: Evaluation Based on Fluorescence EEM Analysis Using the Peak-Picking Technique and Self-Organizing Map

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3456
Author(s):  
Hudori Hudori ◽  
Maulana Yusup Rosadi ◽  
Toshiro Yamada ◽  
Sartaj Ahmad Bhat ◽  
Fusheng Li
Keyword(s):  
Humic Acid ◽  
Water Treatment ◽  
Fulvic Acid ◽  
Drinking Water Treatment ◽  
Self Organizing Map ◽  
Peak Picking ◽  
Recycling Process ◽  
Fluorescence Excitation ◽  
Flocculation Process ◽  
Self Organizing

The recycling process is applied in many water treatment plants (WTPs), although this process can lead to adverse effects. The effect of the recycling process on the characteristics of dissolved organic matter was evaluated based on a fluorescence excitation-emission matrix using the peak-picking technique and self-organizing map (SOM). In this study, an evaluation of two WTPs, one with and one without a recycling system, was carried out. Both WTPs show moderate efficiency during the coagulation–flocculation process in removing DOC, fulvic acid-like, humic acid-like, and tryptophan-like substances. The recycling process causes increased values of fulvic acid-like, humic acid-like, and tryptophan-like substances and specific ultraviolet absorbance (SUVA) after the filtration process of about 31.0%, 35.7%, 22.2%, and 6%, respectively. Meanwhile, the WTP without recycling showed a reduction in the level of fulvic acid-like, humic acid-like, and tryptophan-like substances and SUVA by 23.3%, 52.9%, 27.8%, and 21.1%, respectively. Moreover, SOM analysis based on the peak-picking technique can determine differences in sample clusters due to the recycling process.

scholarly journals Neural network for fractal dimension evolution

2018 ◽  
Vol 78 (4) ◽  
pp. 795-802 ◽  
Author(s):  
Alessandra da Silva Oliveira ◽  
Verônica dos Santos Lopes ◽  
Ubirajara Coutinho Filho ◽  
Rodrigo Braga Moruzzi ◽  
André Luiz de Oliveira
Keyword(s):  
Fractal Dimension ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Ann Model ◽  
Shear Rates ◽  
Ann Modeling ◽  
Essential Step ◽  
Model Complex ◽  
Apparent Color ◽  
Flocculation Process

Abstract The coagulation/flocculation process is an essential step in drinking water treatment. The process of formation, growth, breakage and rearrangement of the formed aggregates is key to enhancing the understanding of the flocculation process. Artificial neural networks (ANNs) are a powerful technique, which can be used to model complex problems in several areas, such as water treatment. This work evaluated the evolution of the fractal dimension of aggregates obtained through ANN modeling in the coagulation/flocculation process conducted in high apparent color water (100 ± 5 PtCo), using alum as coagulant in dosages varying from 1 to 12 mg Al3+ L−1, and shear rates from 20 to 60 s−1 for flocculation times from 1 to 60 minutes. Based on raw data, the ANN model resulted in optimized condition of 9.5 mg Al3+ L−1 and pH 6.1, for color removal of 90.5%. For fractal dimension evolution, the ANN was able to represent from 95% to 99% of the results.

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