• Proceedings of the Membrane Society of Korea Conference
• /
• 1997.04a
• /
• pp.55-62
• /
• 1997

In Japan, the membrane filtration is becoming a common technology for municipal water supply system especially for small plant. 6 years before (1991), the national research project of membrane filtration for small plant has started. The project was named as "MAC 21", MEMBRANE AQUA CENTURY 21. In the project the Ministry of Health and Welfare, 8 universities and 18 water treatment plant companies have been involved. This was the first attempt to research a common theme in joint with government, universities and private companies. After three years, the guide line for membrane filtration application for small plant has been established. This has promoted to install some actual plant. And also, another joint research for "RESEARCH OF MEMBRANE FILTRATION FOR ADVANCED WATER TREATMENT" has started in 1994 and completed in March, 1997. The project was named as MAC21. In the former project the main objectives were removal of turbidity and bacteria from water. However, in new project the objective was establishment of the further advanced membrane filtration technology which would be applicable for trace chemical components removal such as tri-halo-methane pre-courser, agricultural chemicals removal, offensive smell and taste removal and virus removal. For the objectives, application of nanofiltration and hybrid-system, a combination of micro-filtration ultra-filtration with biological, ozone and activated carbon treatment process have been studied. In addition, application of membrane filtration for treatment of back-wash waste water originated from membrane filters and conventional sand filters has.been studied. At the end of March of this year, about 30 membrane filtration plants are actually supplying the water, the total treatment capacity is about 6,000 m$^{3}$/day and another 20 will be installed within one year.led within one year.

• Journal of Korean Society of Water and Wastewater
• /
• v.10 no.2
• /
• pp.117-123
• /
• 1996

A bench-scale continuous activated sludge system was operated in order to study the effects of solid waste landfill leachate on municipal wastewater treatment. The leachate sample was collected from Nanjido landfill. During the 7 weeks of operational period, the leachate content in the influent fed to the system was increased stepwise from 3% to 5% and 7%. The solids retention time was the major process control parameter, and it was 10 days. With the municipal wastewater alone, COD removal was 75%. The removal percents, however, decreased to 60% and 45% when the leachate content was 3% and 7%, respectively. For the wastewater spiked with the leachate, the sludge production was higher than for the municipal wastewater alone. Sludge settleability determined by SVI deteriorated with the increase of leachate content. The specific oxygen uptake rate, however, was measured higher as leachate content increased.

• Textile Coloration and Finishing
• /
• v.7 no.1
• /
• pp.32-42
• /
• 1995

In order to reduce the amount of waste water generated from textile dyeing process and processing water, cotton fabric was bleached with ozone in ozone/water contact system, and dyed. The results obtained from the measurement of whiteness, reflectance, tensile strength, color difference, and K/S value of treated samples were as follow : 1) In ozone bleaching, factors affect whiteness most are treatment time and ozone dosage. As treatment time is lengthened, whiteness increases. Futhermore, bleaching effect is high in acidic treatment, but low in alkaline treatment. 2) As bleaching goes on, maximum absorption wave length shifts to shoter wavelengths. 3) As treatment time is lengthened or pH of treatment is low, tensile strenth of treated fabric decrease. 4) In all cases, color difference of dyed cotton fabrics in above 2% o.w.f. dyestuff concentration don't go beyond 1∼2 AN unit, compared with standard.

• Journal of Appropriate Technology
• /
• v.6 no.1
• /
• pp.37-44
• /
• 2020

Medical waste is any kind of waste that contains infectious material and recommended not to be transferred for infection control. As a means of disposal, incineration has better points than dumping or landfill in the quantity reduction, odorless and nonhazardous. However, open burning and incineration of health care wastes under bad circumstances, can result in the emission of environmental pollutants to air. A burial of biological waste brings pollution of soil and water. Most of sub divisional hospitals in Fiji transfer their medical wastes to divisional hospitals for incineration. In 2011, 62,518 kg of medical waste was incinerated in the three divisional hospitals. However, some medical wastes are considered as general waste and burnt or sent to landfill site, some are buried on site in some sub-divisional hospitals. In this regards, urgent education is necessary for awareness promotion to relevant personnel in medical waste treatment. On site incineration using small scale incinerator is more recommended than transportation of medical wastes treatment in Fiji. Moreover, remotely controllable and fixable small scale of incinerator is more desirable in sub-divisional hospitals. It is recommended that Fiji government to set up a legal framework for medical waste management (MWM), to develop specific guidelines for MWM, to set up a training system for MWM to ensure that all relevant personnel are trained, to develop a monitoring and supervision system for MWM, to clarify the future financing of MWM activities, and to improve the MWM infrastructure.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.1B
• /
• pp.51-60
• /
• 2006

Water quality improvement in mattress/filter system using porous material like slag from industrial activity and zeolite that has been studied for environment improvement and pollution abatement is very useful in polluted stagnant stream channel. Slag is consisted of CaO, $SiO_2$, $Al_2O_3$ and $Fe_2O_3$. Slag with large specific surface area of porosity has been used such as sludge settling and adsorptive materials. Because slag is porous, it can be used for purification filter. As slag is used as filled materials of mattress/filter system and the system has good advantages for the waste water treatment, water recycling, and the improvement of water quality at the same time and so on. Because zeolite has much advantage of cation exchange, adsorption, catalyst and dehydration characteristics, It is used for environment improvement of livestock farms, treatment of artificial sewage and waste water, improvement of drinking water quality, radioactive waste disposal and radioactive material pollution control. In this study, according to verifying effects of water quality improvement of fill materials by porosity that 38.6%, 45.8% and 49.8% respectively in the stagnant stream channel, water quality monitoring of inflow and outflow was conducted on pH, DO, BOD, COD, SS, T-N and T-P. Mattress/filter system was able to accelerate water quality improvement by biofilter as waste water flows through gap of mattress/filter fill materials and by contact catalysis, absorption, catabolism by biofilm. Mattress/filter system used slag and zeolite forms biofilm easily and accelerates adsorption of organic matter. As a result, mattress/filter system increases water self-purification and accelerates water quality improvement available for stream water clean-up.

• Journal of Korean Society on Water Environment
• /
• v.20 no.6
• /
• pp.583-588
• /
• 2004

This research examined the treatment efficiency and methane production rate in treating slurry-type swine waste using UASB (upflow anaerobic sludge blanket) reactor. The UASB reactor was operated at an organics volumetric loading rate (VLR) of $2.6-15.7kgCOD/m^3/day$. A stepwise increase of the VLR resulted in a temporary deterioration in the COD removal rate in UASB reactor but recovered quickly. The COD removal rate were 65-70% for VLR up to $5 kgCOD/m^3/day$. When organics VLR was $10kgCOD/m^3/day$, the COD removal rate decreased sharply and there was loss of 17.537g of the seeding biomass due to sludge washout. This result indicated that the UASB system cannot be adapted to more than $10kgCOD/m^3/day$ of VLR. As the organic load increased from 2.6 to $15.7kgCOD/m^3/d$, the biogas production rate varied from 3.2 to 10.8 L/d and the methane conversion rate of the organic matter varied from 0.30 to $0.23m^3CH_4/kg\;COD_{removed}$. The methane content showed the range of 70.1-81.5% during the experimental period. The volatile solids (VS) removal efficiency was similar at the low VLR (< $5 kgCOD/m^3/day$), but it decreased sharply at the high VLR (> $5 kgCOD/m^3/day$). The VS reduction rate was, moreover, large those of COD. The result shows that hydraulic retention time above 2 days is essential in case of treating wastewater containing 1% of solids.

• Journal of Korean Society on Water Environment
• /
• v.22 no.4
• /
• pp.666-671
• /
• 2006

Effects of a rainfall event (July 28, 2005) on the hydrochemical characteristics of the Jungrang river, the biggest tributary of the Han river, was investigated. Significant spatial variations in the hydrochemical characteristics were observed. At JR2 location, concentrations of T-N and T-P were relatively low indicating occurrence of active oxidation in the stepped drop structure. At JR3 location, concentrations of Na, K, Cl, $NH_4-N$ and EC were elevated suggesting increased discharge from the nearby waste-water treatment plant and tributaries. The rain event diluted major dissolved ion concentrations in the river by 12~52%. The $NO_3-N$ levels were preserved during the rain then increased about twofold after rainfall, suggesting increased discharge of nitrate-contaminated groundwater. Heavy metals including Cd, Co, Cr, Cu and Pb were not detected in all water samples and the leachates from surface sediment samples. Concentrations of Fe, Mn, Al and Zn were below the Korean Drinking Water Guideline. Results of this study suggested that establishment of water-quality monitoring protocols describing temporal and spatial variations in parameters sensitive to rainfall events, relatively steady factors, and contaminant sources is required.

• Resources Recycling
• /
• v.16 no.6
• /
• pp.52-60
• /
• 2007

Denitrification from aqueous solution was investigated through patent analysis and electrochemical denitrification experiment. Among several candidates, biological treatment and oxidation/reduction method are mainly discussed. Recently, patent pending concerning to electrochemical treatment is increasing. Based on basic electrochemical study, total nitrogen was removed up 47% by 1-hour galvanostatic electrolysis with Fe cathode and Pt anode. More applicable technique to industry could be mentioned combination of two or more technologies suitable to waste water characteristics. In the case of small and concentrate effluent, combination of chemical and electrochemical treatment would be recommendable because nitrate could be easily converted to nitrite by chemical treatment, and in that case denitrification by electrolysis becomes more efficient and metal ions from chemical treatment can be recovered during electrolysis.

• Journal of the Korea Institute of Building Construction
• /
• v.1 no.2
• /
• pp.165-173
• /
• 2001

This study examinated the application in construction field and the development of waterproofing material system by the spray water-soluble rubber asphalt to solve the problems of synthetic polymer sheet and gio membrane(A mat sheet of Bentonite) that had been used domestic waterproofing material in advance. As the result of study, characters of study water-soluble rudder asphalt are the follows: 1) The amount of water absorption was '0.06'g and the seepage quality was '0'g in result. 2) The tensile strength was about 30.7kgf/$\textrm{cm}^2 and the elongation was about 72.4% in result. 3) After reliance of temperature test had been ended, the tensile strength was about 72.4kgf/$\textrm{cm}^2 in low temperature and about 30.7kgf/$\textrm{cm}^2 in normal temperature. 4) After acid and alkaline treatment had been ended, the tensile strength was about 19.7kgf/$\textrm{cm}^2$ and about 21.9kgf/$\textrm{cm}^2 in result. 5) After chlorine ion treatment had been ended, the tensile strength was 28.5kgf/$\textrm{cm}^2$ and the elongation was 250% in result. 6) The impact performance was subsided at 1.5m height. 7) After promotion weathering had been ended, the tensile and elongation was about 26.0kgf/$\textrm{cm}^2, 214% in result. So, this study can propose the spray water-soluble rubber asphalt to satisfy the and durability of waste filled land.

• Membrane and Water Treatment
• /
• v.11 no.1
• /
• pp.25-29
• /
• 2020

The purpose of this study was to investigate the characteristics of lignin fractionated from waste wood (WW) using a two-step process of ethanol organosolv pretreatment followed by ultrafiltration with membranes of different molecular weight cut-offs (1, 5 and 20 kDa). The different permeates obtained were characterized by fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA) and gel permeation chromatography (GPC). The analysis by FT-IR and NMR of these lignins showed that the lignin core was successfully separated from WW. TGA curves confirmed that the thermal properties of lignin fractionated by ultrafiltration were almost identical to each other. The results from GPC confirmed that fractionating of lignin was achieved by ultrafiltration. For the membrane fractionation process, values of molecular weight decreased as the cut-offs used to obtain the fractions became smaller. As a result, fractionating lignin by a two-step process allowed separating different fractions of lignin of different molecular weights yielded high purity without interference from existing pollutants in WW. The two-step process offers the possibility of using fractionated WW as an untapped source of lignin.