Earticle

In this study, inflow and infiltration of combined sewer system were analyzed at 4 sampling sites in Daejeon city during 1 month. Analyzing methods of Inflow and Infiltration(I/I) were water-use evaluation, maximum-minimum daily flow evaluation, maximum daily flow evaluation, and average-minimum daily flow evaluation. The investigation research results showed that average flow and ratio of I/I to total sewage were 599~6,422m3/d and 9.4~21.4% according to sampling sites. Average I/I production ratio per diameter and length of sewer according to sampling sites were evaluated 0.0123m3/d/mm-km(site of daedong), 0.0965m3/d/mm-km(site of gayang), 0.0178m3/d/mm-km(site of daejeon) and 0.0168m3/d/mm-km(site of yudeung), respectively.

Increasingly, water loss via leakage is acknowledged as one of the main challenges facing WDS (water distribution system) operations. The leakage is losses of an economy, an energy and a water resource. The pressure management is known as one most cost-benefit method in the currently available methods of leakage reduction and prevention. In this paper, an optimization model of water pressure in WDS was developed which was considered a PRV (pressure reduction valve) as a way of pressure management. Xu-Jowitt (1990) model was used to consider a pressure-dependent leakage, GA (genetic algorithm) was used to search a optimal location and numbers of PRV and LP (linear programming) was used to solve a valve control. The model results was compared to EPANET's simulation results for an example network to verify a robustness.

Recently the fiber filter is proven to be able to replace the suspended solids removal in the wastewater treatment process and the coagulation settling in the water treatment process. The objective of this study was to evaluate the treatment characteristics and the treatment efficiency change of the two stage fiber filter(PCF), which was used to minimize the breakthrough time of the filter.The turbidity of the filtered water was 2.0 NTU as maximum in the early filtering process, but the turbidity was stabilized fast less than 0.2 NTU during the filtering process. Also there was no breakthrough phenomenon at the end of the filtering process and there was no changes of filtered water quality during the continuous operation.

In this study, a new apparatus which induced surface water into hypolimnetic zone in reservoir using the wind power was developed and evaluated with its performance for enhancing DO and the water quality. Its apparatus was the downward guide apparatus of wind-driven flow by wind, which was aimed to prevent anaerobic condition of hypolimnetic zone in order not to dissolve phosphate and heavy metals such as Fe, Mn, to promote biodegradation of organic matter by microorganisms, and to control the growth of phytoplankton by artificial circulation of epilimnetic zone. In order to study, Sucheoli reservoir in Asan city was selected, and five times of field work during September to November, 2008 were performed to assess the effect on water quality by the downward guide apparatus.Result of field study showed that water qualities of sites near to guide apparatus were better comparing with those of sites far from guide apparatus, especially for DO, and chlorophyll-a. It was concluded that the downward guide apparatus was useful to enhance the water quality of reservoir, and to prevent eutrophication.

This was shown the performance of anaerobic digestion by thermal pretreatment with organic solid wastes containing papers and food wastes. Batch experiment was carried out to assess biodegradability from various organic materials such as food, tissue paper, newspaper, and copy paper. As results of batch experiment, biodegradable substances like carbohydrate containing papers were easily degraded, while organic matters like lignin were slowly degraded. Biogas production in newspaper with thermal pretreatment added acid addition was 614mL/gTS in 60 minutes, 450mL/gTS in 120 minutes, and 490mL/gTS in control.

The body has its own healing potency, although it may sometimes need support when its own natural sources of healing energy are depleted or unbalanced. When humans got a sick, it is important to investigate their bad habits before resentment to oneself or another person. They must be changed themselves after investigate about their life habits, food habits, and mind. So they need to train education for correction of bad habits for health life. Especially humans must make their life simply, and moderate terribly for wellbeing. They must not stay at past time, and must forget. If they do not forget, they have no present time. As they are hung on past time, they are become an object of present health concern. As all kinds of diseases come from past time, they are making a living present time in pain. They are strenuous in today's life because of being tied up themselves by past habits. Many are sick people because of past habits, although the doctor said it is all right by diagnosis. These men are person caught by not in present time but in past time. They are slaves caught by past time and try to cure of their diseases. We make a living together with diseases. There are much problems that make body unhealthy states. So we must realize to listen the self-body's messages in order to diagnose and manage for ourselves about our body for good health.We must pray in undivided attention, work by the sweat of our brow in daytime, study hard in night time. Also, always do exhausting work not to loose from free mind and be very healthy. Health is to protect the self body. So must free from delusion, especially. Make a ceaseless effort for making good habits. It is that to make a ceaseless effort is to study, to study is to model after a pattern and to behave oneself. And try to change from habits to character. And not be a slave with greed because all kinds of diseases come from greed. So if they throw greeds, and if they change bad habits, all kinds of their diseases will be cured. For that we must change our environment.

Bacteria spreaded in the air was measured in the indoor space which a large number of people used, and installed the photocatalyst sterilization devices in the indoor space with the frequency of access of people and investigated the performance effects of it for a disease prevention. As the performance effect of this sterilizer result, following results were obtained from this experiment. After 30 minutes operation with the sterilizer, the general bacteria was showed the sterilization effect in more than 50% in all indoor space, and after 60 minutes, according to the average effectiveness of 74.3%. The fungi showed the sterilization effect in more than 50% in the washroom and heath-room after 30 minutes, and showed the sterilization effect in more than 50% in air environmental laboratory after 60 minutes and showed to perish perfectly in heath-room after 60 minutes. The enterobacteria only appeared within the washroom showed the sterilization effect in more than 68.7% after 60 minutes and showed to perish perfectly in after 90 minutes.