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 Organophosphate Flame Retardants and Perfluoroalkyl Substances in Drinking Water Treatment Plants from Korea: Occurrence and Human Exposure

2021 ◽  
Vol 18 (5) ◽  
pp. 2645
Author(s):  
Wonjin Sim ◽  
Sol Choi ◽  
Gyojin Choo ◽  
Mihee Yang ◽  
Ju-Hyun Park ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Water Samples ◽  
Flame Retardants ◽  
Hazard Index ◽  
Drinking Water Treatment ◽  
Perfluoroalkyl Substances ◽  
Raw Water ◽  
Treated Water ◽  
Water Treatment Plants

In this study, the concentrations of organophosphate flame retardants (OPFR) and perfluoroalkyl substances (PFAS) were investigated in raw water and treated water samples obtained from 18 drinking water treatment plants (DWTPs). The ∑13OPFR concentrations in the treated water samples (29.5–122 ng/L; median 47.5 ng/L) were lower than those in the raw water (37.7–231 ng/L; median 98.1 ng/L), which indicated the positive removal rates (0–80%) of ∑13OPFR in the DWTPs. The removal efficiencies of ∑27PFAS in the DWTPs ranged from −200% to 50%, with the ∑27PFAS concentrations in the raw water (4.15–154 ng/L; median 32.0 ng/L) being similar to or lower than those in the treated water (4.74–116 ng/L; median 42.2 ng/L). Among OPFR, tris(chloroisopropyl) phosphate (TCIPP) and tris(2-chloroethyl) phosphate (TCEP) were dominant in both raw water and treated water samples obtained from the DWTPs. The dominant PFAS (perfluorooctanoic acid (PFOA) and perfluorohexanoic acid (PFHxA)) in the raw water samples were slightly different from those in the treated water samples (PFOA, L-perfluorohexane sulfonate (L-PFHxS), and PFHxA). The 95-percentile daily intakes of ∑13OPFR and ∑27PFAS via drinking water consumption were estimated to be up to 4.9 ng/kg/d and 0.22 ng/kg/d, respectively. The hazard index values of OPFR and PFAS were lower than 1, suggesting the risks less than known hazardous levels.

scholarly journals Trophic status, phytoplankton diversity, and water quality at Kafr El-Shinawy drinking-water treatment plant, Damietta

2021 ◽  
Author(s):  
Mohamed Deyab ◽  
Magda El-Adl ◽  
Fatma Ward ◽  
Eman Omar
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Trophic Status ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Raw Water ◽  
Phytoplankton Diversity ◽  
Treated Water

Abstract This work aims to study the seasonal fluctuation in physicochemical characteristics, trophic status, and some pollutants influencing phytoplankton diversity, and water quality at a compact Kafr El-Shinawy drinking-water treatment plant, Damietta – Egypt seasonally during 2018. Phytoplankton distribution was affected by the trophic status of water, level of pollutants, and physicochemical treatment processes of water. The predominance of phytoplankton species, especially Aphanizomenon flos aquae (Cyanophyta), Gomphosphaeria lacustris (Cyanophyta), Microcystis aeruginosa (Cyanophyta), Nostoc punctiforme (Cyanophyta), Oscillatoria limnetica (Cyanophyta), Pediastrum simplex (Chlorophyta), and Melosira granulata (Bacillariophyta) in treated water was much less than that in raw water. Trihalomethanes (THMs) levels in treated waters were higher than in raw water, while lower concentrations of heavy metals were recorded in treated water. Intracellular levels of microcystins were lower, whereas the extracellular levels were higher in treated water than raw water, and the former recorded the highest level in raw water during summer. Hence, the levels of dissolved microcystins and THMs in treated water were higher especially during summer, the season of luxurious growth of Microcystis species. Trophic state index (TSI) was relatively high in raw water compared with treated water due to high concentrations of nutrients (total-P, total-N, nitrite, nitrate, and ammonia) in raw water.

scholarly journals Cyanobacteria and microcystin contamination in untreated and treated drinking water in Ghana

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Gloria Naa Dzama Addico ◽  
Jörg D. Hardege ◽  
Jiri Kohoutek ◽  
Kweku Amoaku Atta DeGraft-Johnson ◽  
Pavel Babica
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Human Health ◽  
Metropolitan Area ◽  
Cyanobacterial Blooms ◽  
Maximal Concentration ◽  
Raw Water ◽  
Treated Water ◽  
Treated Drinking Water ◽  
Who Guideline

<p>Although cyanobacterial blooms and cyanotoxins represent a worldwide-occurring phenomenon, there are large differences among different countries in cyanotoxin-related human health risk assessment, management practices and policies. While national standards, guideline values and detailed regulatory frameworks for effective management of cyanotoxin risks have been implemented in many industrialized countries, the extent of cyanobacteria occurrence and cyanotoxin contamination in certain geographical regions is under-reported and not very well understood. Such regions include major parts of tropical West and Central Africa, a region constisting of more than 25 countries occupying an area of 12 million km<sup>2</sup>, with a total population of 500 milion people. Only few studies focusing on cyanotoxin occurrence in this region have been published so far, and reports dealing specifically with cyanotoxin contamination in drinking water are extremely scarce. In this study, we report seasonal data on cyanobacteria and microcystin (MC) contamination in drinking water reservoirs and adjacent treatment plants located in Ghana, West Africa. During January-June 2005, concentrations of MCs were monitored in four treatment plants supplying drinking water to major metropolitan areas in Ghana: the treatment plants Barekese and Owabi, which serve Kumasi Metropolitan Area, and the plants Kpong and Weija, providing water for Accra-Tema Metropolitan Area. HPLC analyses showed that 65% samples of raw water at the intake of the treatment plants contained intracellular MCs (maximal detected concentration was 8.73 µg L<sup>-1</sup>), whereas dissolved toxins were detected in 33% of the samples. Significant reduction of cyanobacterial cell counts and MC concentrations was achieved during the entire monitoring period by the applied conventional water treatment methods (alum flocculation, sedimentation, rapid sand filtration and chlorination), and MC concentration in the final treated water never exceeded 1 µg L<sup>-1</sup> (WHO guideline limit for MCs in drinking water). However, cyanobacterial cells (93-3,055 cell mL<sup>-1</sup>) were frequently found in the final treated water and intracellular MCs were detected in 17% of the samples (maximal concentration 0.61 µg L<sup>-1</sup>), while dissolved MCs were present in 14% of the final treated water samples (maximal concentration 0.81 µg L<sup>-1</sup>). It indicates a borderline efficiency of the water treatment, thus MC concentrations in drinking water might exceed the WHO guideline limit if the treatment efficiency gets compromised. In addition, MC concentrations found in the raw water intake might represent significant human health risks for people living in areas with only a limited access to the treated or underground drinking water.</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.

scholarly journals Drinking water treatment by ferrate(VI) and toxicity assessment of the treated water

2016 ◽  
Vol 57 (54) ◽  
pp. 26369-26375 ◽  
Author(s):  
Jia-Qian Jiang ◽  
Hari B.P. Durai ◽  
Michael Petri ◽  
Tamara Grummt ◽  
Rudi Winzenbacher
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Toxicity Assessment ◽  
Treated Water

scholarly journals Simulation of NOM events in pilot plant evaluation of DAF/Ozone/BAC for drinking water treatment

2017 ◽  
Vol 17 (6) ◽  
pp. 1793-1800
Author(s):  
Y. Yan ◽  
M. Carter ◽  
A. Mercer
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Pilot Plant ◽  
Drinking Water Treatment ◽  
Natural Occurrence ◽  
Raw Water ◽  
Humic Materials ◽  
Pilot Investigation ◽  
Brewing Method ◽  
Plant Evaluation

Abstract Pilot plant testing is invaluable for ascertaining the robustness of water treatment processes against raw water quality events such as turbidity and colour spikes, whether it be for stress testing of an existing process or designing of a new process. Unfortunately, the natural occurrence of such events (particularly colour) can be difficult to predict and commercial humic materials generally fail to closely match the indigenous natural organic matter (NOM) present in the raw water. Therefore, it is highly desirable to be able to simulate NOM event conditions. This paper describes a simple brewing method that we developed and used in our recent pilot plant evaluation of a proposed DAF/Ozone/BAC process for drinking water treatment. Using this method we successfully prepared, by using fallen leaves etc. collected from the local catchment area, large quantities of a concentrated NOM stock solution with its specific ultraviolet absorbance (SUVA), when diluted, very close to the median SUVA of historical NOM events. The brewed solution showed broadly similar NOM characteristics to those of the raw water encountered during the pilot investigation period in terms of molecular weight distribution and fractionation. The coagulation behaviour was also examined for the spiked and non-spiked raw water.

The Use of Aluminosilicate Sorbent for the Purification of Natural Waters from Heavy Metals

2020 ◽  
Vol 24 (3) ◽  
pp. 19-23 ◽  
Author(s):  
A.S. Kutergin ◽  
T.A. Nedobukh
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Water Treatment ◽  
Mechanical Strength ◽  
Natural Waters ◽  
Drinking Water Treatment ◽  
Exchange Capacity ◽  
Filtration Process ◽  
Treated Water ◽  
Dynamic Exchange

The possibilities of using natural granular glauconite in standard water treatment schemes have been investigated. Resource tests of the studied material were carried out in dynamics, simulating possible conditions of use. As a result of the experiments, it was established: during the filtration process, alkalization of water occurs, but the result does not exceed pH = 6÷9, which are the norm for drinking water; the use of a sorbent based on natural glauconite does not impair the hardness indicator of the treated water. The dynamic exchange capacity was: for iron – 3.09 mg/g of absorbent, copper – 19.15 mg/g of absorbent, zinc – 4.82 mg/g of absorbent. The resource of the filter was determined with the loading of granulate with a volume of 1 dm3: for iron – 2918 dm3, for copper – 5425 dm3, for zinc – 273 dm3. The mechanical strength acquired by the sorbent as a result of granulation made it possible to wash the load by the countercurrent method, freeing intergranular pores from the sediment accumulated in them. The revealed capabilities of granular glauconite will allow its use in drinking water treatment schemes for purifying natural waters from heavy metals: iron, zinc, copper.

scholarly journals PENINGKATAN KUALITAS AIR BAKU DENGAN PROSES BIOFILTER TERCELUP MENGGUNAKAN MEDIA STRUKTUR SARANG TAWON

2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Nusa Idaman Said ◽  
Arie Herlambang
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
River Water ◽  
Residence Time ◽  
Drinking Water Treatment ◽  
Organic Substances ◽  
Raw Water ◽  
Treatment Unit ◽  
High Organic Matter

Contamination of rivers has reached an alarming level, especially in the rivers passing through major cities, agricultural areas and industrial areas. Among the contaminants that often appear dominant and very disturbing is the organic substance. The existence of high organic matter within the river water is often expressed in permanganate number that has passed the quality standard. River that contain high organic matter usually the water smell and the color is black, besides it can also cause disturbances in the water treatment process, which is an increasing use of coagulants, chlorine, activated carbon, and the emergence of substances that are not desired, and the quality of treatment results are unsatisfactory. Many ways to reduce the organic matter in river water, one of them is by using the biofilter honeycomb structure. The target of the reduction of organic substances is that the river water could be used as a raw drinking water quality standards or meet the category B, Regulation of Jakarta Governor Number 582, 1995. Raw water used for this study were taken from Krukut River which is the raw water for Regional Water Company PALYJA, Production Installation III Cilandak, South Jakarta and Cengkareng Drain river water, which is currently used as a source of raw water for PAM Taman Kota, West Jakarta using a biofilter reactor aerobic system, the capacity of 50 - 200 m3, Capasity of Blowers 300 l /min, Residence Time 6 hours up to 1 hour. Test results on the residence time of 1 hour, parameters pH, TSS, turbidity, organic substances, detergents, manganese, ammonia, nitrite, nitrate, can meet the standard, except for iron which still exceeds the standard. To improve the removal  efficiency of organic matter and iron, at the beginning of processing before entering into the drinking water treatment unit need to be added powder active carbon and an oxidizing agent with a sufficient dose. Keywords: Organic substances, biofilter, aerobic, honeycomb plastic media.

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