• Environmental Engineering Research
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• v.18 no.2
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• pp.103-108
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• 2013

Vietnam is a developing country with the rate around 5%-6% per year, especially in urban areas. Rapidly developed urban areas lead to stress for infrastructure and the water supply is also stressed. In Hanoi city, total water capacity from the manufactories is around one million cubic meters per day and almost the entire main water source is groundwater but it is not enough to supply all of Hanoi's people, especially in the summer. A demo project is implemented in Hanoi University of Civil Engineering (HUCE) to produce drinking water by using the rainwater and membrane system and supply for people. In this project, rainwater is collected on the rooftop of the lecture building with an area of around $500m^2$ and $100m^3$ volumetric rainwater tanks. Afterwards, the rainwater is treated by the micro-membrane system and supplied to the tap water. Total cost for construction, technology and operation in the first year is around USD 48,558. In the long-term (15 yr) if HUCE invests in the same system, with $20m^3$ volumetric storage tank, it can provide drinking water for 500 staffs in every year. The cost of investment and operation for this system is lower than 30% compared to buying bottled water with the price USD 1.8/bottle. The drinking water parameters after treatment are pH, 7.3-7.75; turbidity, 0.6-0.8 NUT; total dissolved solids, 60-89 mg/L; coliform, 0; heavy metal similar with water quality in the bottle water in Vietnam.

• Coupled systems mechanics
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• v.8 no.6
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• pp.489-500
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• 2019

With drinking water standards becoming more rigorous and increasing demands for additional water quantities, while water resources are becoming more polluted, mathematical models became an important tool to improve water treatment processes performance in the water supply system. Water treatment processes models reflect the knowledge of the processes and they are useful tools for water treatment process optimization, design, operator training for decision making and fundamental research. Unfortunately, in the current practice of drinking-water production and distribution, water treatment processes modeling is not successfully applied. This article presents a review of some existing water treatment processes simulators and the experience of their application and indicating the main weak points of each process. Also, new approaches in the modeling of water treatment are presented and recommendations are given for the work in the future.

• Advances in environmental research
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• v.7 no.2
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• pp.87-107
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• 2018

Water quality monitoring network needs periodic evaluations based on environmental demands and financial constraints. We used a genetic algorithm to optimize the existing water quality monitoring stations on the Sefid-Rud River, which is located in the North of Iran. Our objective was to optimize the existing stations for drinking and irrigation purposes, separately. The technique includes two stages called data preparation and the optimization. On the data preparation stage, first the basin was divided into four sections and each section was consisted of some stations. Then, the score of each station was computed using the data provided by the water Research Institute of the Ministry of energy. After that, we applied a weighting method by providing questionnaires to ask the experts to define the significance of each parameter. In the next step, according to the scores, stations were prioritized cumulatively. Finally, the genetic algorithm was applied to identify the best combination. The results indicated that out of 21 existing monitoring stations, 14 stations should remain in the network for both irrigation and drinking purposes. The results also had a good compliance with the previous studies which used dynamic programming as the optimization technique.

• Journal of Environmental Health Sciences
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• v.9 no.1
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• pp.77-84
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• 1983

A study was carried out to find drinking water qualities of 56 simple piped water supply systems and 37 water pumps in Chun Sung Conutry, Kang Won Province from 1st July to 30th August 1981. 1. The results of all kinds of water test are found to be safe at only one out of fifty six samples of simple piped water supply system at two out of thirty-seven samples of water pump and unsafe at the others. 2. In general Count of Bacteria test, twelve (21.4%) out of fifty six samples of the simple piped water are found to be safe for the legitimate standard of safty water, and five (13.5%) out of thirty=seven samples of pump water. 3. Escherichia coli group is negative at seven (12.5%) out of fifty-six samples of simple piped water, and eight (21.6%) out of thirty-seven samples of pump water. 4. The results of the physical and chemical examination of drinking water specimen are found to be safe at twelve out of fifty-six samples of simple piped water and at twenty-eight out of thirty-seven samples of pump water.

• Journal of Environmental Health Sciences
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• v.47 no.4
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• pp.356-365
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• 2021

Background: Concerns have been raised regarding the criteria of groundwater, in particular in Gwangwon-do Province where many residents drink groundwater due to the poor supply of tap water and a high nonconformity rate with water quality criteria nationwide. Objectives: Water quality monitoring and risk assessment were conducted for groundwater in Hoengseong, Gangwon-do Province. Methods: A total of 46 items required for meeting drinking water criteria were analyzed from 258 samples collected from March 2017 through August 2018 (152 sites in 2017 and 106 sites in 2018). Risk assessment was conducted for two non-carcinogens (F^- and NO₃-N), and one carcinogen (i.e., arsenic) based on their high nonconformity to water quality criteria. Results: Water quality analysis revealed that the total proportion of nonconformities was determined to be 27.9%. The nonconformity rate for each content item is as follows: total colony counts (1.6%), total coliform (6.2%), Escherichia coli (1.2%), F^- (8.1%), arsenic (4.7%), NO₃-N (8.1%), pH (1.2%), manganese (0.4%), and turbidity (5.8%). Risk assessment indicated that fluoride induced a hazard quotient greater than 1 with the 95% UCL (Upper Confidence Limit) concentration of the total 258 sites and average, median, and 95% UCL concentrations of nonconformity sites. For NO₃-N, there was no human health risk. For arsenic, the excess cancer risk exceeded the acceptable cancer risk of 1×10^-6 with the average and 95% UCL concentrations of total 258 sites and average, median, and 95% UCL concentrations of nonconformity sites. Conclusions: This study suggests that it is necessary to expand water quality monitoring of groundwater and conduct a more detailed risk assessment in order to establish a health care plan for the residents of Hoengseong, Gangwon-do Province.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.10
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• pp.556-560
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• 2017

This research carried out to evaluate the disadvantage of pre-chlorination and the effect of polyamine as coagulant aids for treating the blooming water with Microcystis sp.. Pre-chlorination on blooming water makes the colony of Microcystis sp. to the smaller size. Coagulation with polyamine advanced treatment efficiency not only turbidity but also particulate matters especially less then $5{\mu}m$ size for the blooming water compared with using alum alone. Particle count was more sensitive than turbidity on water quality management of settlement and filtrate.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.164-168
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• 2008

Perchlorate, which is still unregulated, is found in tap water, posing a threat to public health. In and out of Korea, there is no clear standard for drinking water quality or discharge. To make matters worse, Perchlorate study is in its infancy in Korea. This research tracked fresh water and purified water of water purification facility A and B located at the city of D, where Nak-dong River is being utilized as the purified water. And it was found that purified water shows no particular pattern in Perchlorate concentrations but represented a higher level of concentration compared to fresh water. With utilizing the research results, the study sought the impact of activated-carbon treatment process on Perchlorate elimination and found out that Perchlorate concentrations increased 38% after the process. The result proves that conventional water purification process can't eliminate Perchlorate. Therefore, it is reasonable that Perchlorate discharge from sources should be minimized.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2004.05a
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• pp.48-48
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• 2004

• Journal of environmental and Sanitary engineering
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• v.8 no.2
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• pp.99-108
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• 1993

It is well known that we should take 2L of drinking water per day to maintain our health. The drinking water quality is becoming worse owing to sewage discharge and industrial wastewater. Surface water is polluted by various kinds of contaminants and ground water were known as clean and unpolluted water, but through recent many reports the ground waters are also contaminated by waste disposal and intrusion of organic and bacterial movement. This research was undertaken to make a water index of water contamination by referringcations cations and anions. NH$_{4}$, Fe, Mn, and Pb are chosen as cations and $NO_3$, Cl, and $SO_4$ ions are chosen as anions to make a index, and the following water index was made as the contamination index. (Fe+Mn+Pb)/0.7+$(NH_4+NO_3+Cl+SO_4)$/10.5<6.0 By using ton Chromatography the cations and anions are rapidly analyzed and plotting the analyzed data to the equation, we can easily get the degree of contaminations by avoiding analysis of over 37 water parameters in several days. Of course this index of water contamination is not perfect and detail one, but in case of emergent case or to know the overall trends of contamination, it is convenient to use this index. Among the tested 5 kinds of samples the ground water showed contamination index of 6.87. Authors used the already published healthy index and tasty index and differentiated their degrees in detail.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1163-1170
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• 2015

This study carried out continuous column test for estimating the regeneration efficiency with regeneration times and temperatures. More times regenerated granular activated carbon (GAC) has more ash in the GAC and has less apparent density. Two times regenerated GAC ($2^{nd}$ re-GAC) could removed the Trihalomethanes (THMs) in the water for the first two week after starting continuous column test, on the other hand five times regenerated GAC ($5^{th}$ re-GAC) did not have adsorption capacity. The THMs concentration in the effluent was almost equal or higher than that of influent at the first time of continuous column test. $2^{nd}$ re-GAC showed much more DOC adsorption capacity than $5^{th}$ re-GAC and the GAC which was regenerated with $700^{\circ}C$ had highest DOC removal efficiency among the GACs with 600, 700, 800, $900^{\circ}C$ regeneration temperatures. It is anticipated the cost of GAC regeneration could be saved more 100 million won by reducing the furnace temperature of 3rd~4th and 5th~6th about $150^{\circ}C$ compared to the current regeneration condition.