• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.2
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• pp.13-24
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• 2023

Sewage sludge has been widely used as an organic fertilizer in agriculture. However, sewage sludge can cause serious malodor problems resulting from the decomposition of organic compounds in anaerobic conditions. The malodor of sewage sludge mainly occurs due to a low carbon to nitrogen ratio (C/N), high moisture, and low temperature, which are ideal conditions for ammonia emissions. Therefore, in this study, we investigated the reduction of the odor-causing ammonia nitrogen (NH₃-N) in sewage sludge by co-application of microbes and methanol (MeOH). The physico-chemical properties of the municipal sewage sludge showed that the odor was mainly caused by a higher NH₃-N content (2932.2 mg L^-1). Supplementation with MeOH (20%) as a carbon source in the sewage sludge significantly reduced the NH₃-N up to 34.2% by increasing C/N ratio. Furthermore, the sewage sludge was treated with the NH₃-N reducing and plant growth promoting (PGP) bacteria Stenotrophomonas rhizophila SRCM 116907. The treatment with S. rhizophila SRCM 116907 significantly increased the seedling vigor index of Lolium perenne (10.3%) and Chrysanthemum burbankii (42.4%). The findings demonstrate that supplementing sewage sludge with methanol significantly reduces ammonia emissions, thereby mitigating malodor problems. Overall, the study highlights the potential of using a microbial and methanol approach to improve the quality of sewage sludge as an organic fertilizer and promote sustainable agriculture.

• Journal of Life Science
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• v.9 no.6
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• pp.698-703
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• 1999

For the nitrate removal in recirculating aquaculture system, a denitrifying bacterium, Pseudomonas fluorescens, was isolated from municipal sewage and the cells were immobilized in modified-polyvinly alchol (PVA) gel beads. The immobilized cells in both the fixed-and fluidized-bed reactors showed 98% of denitrification efficiency with 6hr HRT, and the removal efficiency of total organic carbon (TOC) was above 90%. Form scanning electron microscopy (SEM) observation, it was known that biofilm formed in fixed-bed reactor was thicker than that formed in fluidized-bed reactor as operation time passed.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2005.12a
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• pp.89-89
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• 2005

• Journal of Environmental Health Sciences
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• v.28 no.1
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• pp.93-97
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• 2002

The aim of this study was to evaluate on the removal effect of total nitrogen and phosphorus with municipal wastewater in ultrasonic nutrient removal (UNR) process using ultrasonic sludge carbon source. The removal efficiency for total nitrogen was 44.2% at biological nutrient removal (BNR) process, 50.8% at UNR process. The removal efficiency for total phosphorus was 45.6% at BNR process, 46.2% at UNR process. The removal of nitrogen was effectively influenced by ultrasonic sludge carbon source.

• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.366-373
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• 2004

Food waste is becoming by environmental problem nowdays increasing festinately in Korea during past 10 years. Food waste collected from garbage trucks that is offered in S municipal government that food waste mixs enough, and sewage sludge collected in the country. Composting experiment conditions achieved in the mixture ratio rate that food waste and sewage sludge are each 10:90, 30:70, 50:50, 60:40, 70:30 and 90:10 $wt\%$. The fermentation temperature was $18{\sim}22^{\circ}C$ at the beginning, and then it was sharply increased to $44{\sim}66^{\circ}C$ up to 1 day after fermentation, which was maintained for more than 3 days. Then, it was slowly decreased to $18{\sim}25^{\circ}C$ up to 8 days after fermentation, which was maintained all the time. It could be known from examiation of various conditions, including reaction rate, salinity. carbon/nitrogen(C/N) ratio, temperature, organic substance, etc.. Optimum mixture ratio rate of composting using food waste and sewage sludge was 60:40 $wt\%$.

• Journal of Environmental Science International
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• v.14 no.1
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• pp.23-32
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• 2005

Surface sediments (0$\~$4 cm) were sampled at 40 stations from Ulsan Bay and its adjacent areas of Korea, to evaluate the contamination by sewage-derived organic matters using fecal sterols. Some sterols were quantified by gas chromatography coupled to mass spectrometry (GC/MS). Total concentrations of eight sterols (co­prostanol, cholesterol, cholestanol, epicholestanol, epicoprostanol, ${\beta}-sitosterol,$ brassicasterol, and stigmasterol) in the sediments from Ulsan Bay and its vicinity varied from 929 to 23,444 ng/g dry weight. The most predom­inant sterols were cholesterol and coprostanol, accounting for $33\~72{\%}$ of total sterols. The concentration of coprostanol known as the indicator of human feces ranged from 141 to 8,257 ng/g dry weight. In particular, the coprostanol concentrations in the sediments from Jansaengpo Harbor and Taehwa River exceeded the value of 1,000 ng/g dry weight, suggesting that these areas could be considered as the hot-spot zones by municipal sewage contamination. Some molecular indices and multivariate data analysis were used to assess the origin of these sterols in the sediments. Results showed that the major routes of sewage contamination in Ulsan Bay and its vicinity were the input through Jansaengpo Harbor and Taehwa River.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.1-10
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• 1992

Since 1960's along with industrialization and urbanization, economic growth has been . achieved, however, at the same time, environmental condition has been seriously deteriorated. . Currently, volume of wastewater has been increasing at annual rate of 7% in sewage and 20% in industrial wastewater. However, the nation's sewage treatment serves only 33% of the municipal wastewater as of 1991. Major portion of air pollutants comes from combustion of oil and coal which comprise 81% of total energy use and emission gases from motor vehicles increasing at an accelerated rate. It is known that Korea generates the highest amount of waste per capta. Nevertheless, it is not sufficient to reduce the volume of waste by means of resources recovery and recycling. Recognizing the importance of global environmental problems such as ozone layer depletion, global warming and acid rain, international society has been making various efforts since the 1972 Stockholm conference. In particular, it is expected that the Rio conference which has adopted the Rio declaration and Agenda 21 will form a crucial turning point of the emerging new world order after the Cold War confrontation. To cope with such issues as domestic pollution and global environmental problems, the fundamental national policy aims at harmonizing "environmental protection and sustainable development". The Ministry of Environment has recently set up a mid-term comprehensive plan which includes annual targets for environmental protection. According to the government plan, gradual improvement of various environmental conditions and specific measures to achieve them is planned in time frame. Additional sewage treatment plants will be constructed in urban areas with the target to treat 65% of the nation's municipal sewage by 1996. Supply of clean fuels such as LNG will also be expanded starting from large cities as a cleaner substitute energy for coal and oil. In parallel with expansion of LNG, emphasis will be placed on installation of stack monitoring system. Due to the relatively limited land, government's basic policy for solid waste treatment is to develop large scale landfill facilities rather than small sized ones. Thirty three regional areas have been designated for the purpose of waste management. For each of these regions, big scale landfill site is going to be developed. To increase the rate of waste recycling the government is planning to reinforce separate collection system and to provide industries with economic incentives. As a part of meeting the changing situation on global environmental problems after UNCED, and accommodation regulatory measures stipulated in the global environmental conventions and protocols, national policy will try to alter industrial and economic structure so as to mitigate the increasing trends of energy consumption, by encouraging energy conservation and efficiency. In this regard, more attention will be given to the policy on the development of the cleaner technology. Ultimately, these policies and programs will contribute greatly to improving the current state of national public health.

• Membrane and Water Treatment
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• v.1 no.3
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• pp.207-214
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• 2010

Approximately 80% of water used in urban areas reappears as municipal wastewater (MWW). Reclamation of MWW is an attractive proposition under the present scenario of water stressed cities in India. In this paper, we attempted to reclaim MWW using lab-scale hollow- fiber (HF) membrane modules for possible reuse in non-potable applications. Experiments were conducted to evaluate the efficiency of virgin HF ($M_1$) and modified HF ($M_2$) modules. The $M_2$ module consists of HF modified with a skin layer formed through interfacial polymerization of m-phenylenediamine with trimesoyl chloride (MPD-TMC). The molecular weight cut-off (MWCO) of $M_1$ was 44000 g/mol and that of $M_2$ 10000 -14000 g/mol on the basis of rejection of polyethylene glycol. The combination of $M_1$ and $M_2$ modules was able to reduce concentrations of most of the pollutants in sewage and improved the treated water quality to the acceptable limits for non potable reuse applications. It is found that about 98-99% of the initial flux is recovered by the backwashing process, which was approximately two times in a month when operated continuously.

• Journal of Environmental Science International
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• v.16 no.11
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• pp.1219-1223
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• 2007

The removal of nitrogen compounds from a wastewater is essential and it is often accomplished by bio-logical process. An aerobic nitrate-removing bacterium was isolated from a municipal sewage treatment plant and soil. On the basis of its morphological, cultural and physiological characteristics and 16S rRNA sequencing data, this strain was identified as Pseudomonas fluorescens, and named as P. fluorescens K4. The optimal conditions of the initial pH and temperature of media for its growth were $7.0{\sim}8.0$ and $30^{\circ}C$, respectively. P. fluorescens K4 was able to remove 99.9% of nitrate after 24 h in a culture. The strain could grow with a nitrate concentration up to 800 mg/l and was able to remove 99.9% of nitrate after 104 h of incubation. The optimal electron donor was sodium citrate for a nitrate removal. The strain K4 showed a capability of a complete nitrate removal when the initial C/N ratio was 1.0. An effect of the initial seed concentration was observed for a cell of 10% (v/v) for a nitrate removal. Especially P. fluorescens K4 could completely remove 200 mg/l ammonium for 3 days.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.47-60
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• 2007

The rapid development of economy in China at the expense of consuming huge amount of energy and resources, water resource in particular, which has resulted in the production and discharge of increasing amount of wastewater to the water environment. In order to effectively control the increasing water pollution trend, the State Council has stipulated that all the cities with population over 500,000 should reach wastewater treatment rate of 60% by 2005, and all the cities should reach the rate of 60% by 2010, of which Capital Beijing and all the province capital cities and important tourism cities should reach 70% then. By the end of 2005, of the 661 cities in China, 393 have built and operated municipal wastewater treatments with a total number of 790 sets, total treatment capacity of $80.91{\times}106m^3/d$ and total treatment rate of > 48%. Other 73 cities have started the construction of municipal wastewater treatment plants, and other 168 cities have started to prepare, planning and design of wastewater treatment plants. Most of municipal wastewater treatment plants in big cities in China operate normally and perform well with good quality of effluent in terms of wastewater treatment train, but the sewage sludge treatment is usually poor with big problems. It has been found that the small scale WWTPs using activated sludge process in the towns are usually operated and maintained abnormally because of lack of fund, skilled operators and energy. It is therefore suggested that the small scale MWWTPs in small cities and towns adopt appropriate technologies, of which the most available ones are multi-stage ponds, constructed wetlands and the combination of them for further purification and reuse of treated wastewater.