• Environmental Engineering Research
• /
• v.23 no.3
• /
• pp.258-264
• /
• 2018

The objectives of this research were to 1) isolate and identify thermophilic bacteria for food waste treatment; 2) investigate the capability of food waste treatment using Bacillus species; and 3) develop air-dried Bacillus starters for food waste treatment. Five Bacillus species were isolated from food wastes and identified as Bacillus licheniformis (B. licheniformis) G1, Bacillus circulans C2, Bacillus subtilis (B. subtilis) E1, Bacillus vanillea F1, and Bacillus atrophaeus G2 based on 16S rDNA sequencing. Each identified Bacillus and the mixture of Bacillus species were cultivated in the standard food waste at $45^{\circ}C$ for 8 d. Changes in cell count, solid contents, and pH of the food waste were monitored during cultivation. Air-dried Bacillus cell powders were prepared using wheat flour and lactomil as excipients, and the cell count and survival rate were determined. The cell count of B. licheniformis G1 exhibited the highest number among the tested Bacillus (${\sim}10^8CFU/mL$). The greatest reduction in solid contents of food waste was achieved by B. subtilis E1 (22.6%). The mixture of B. licheniformis G1 and B. subtilis E1 exhibited a synergistic effect on the reduction of solid contents. Lactomil was determined as better excipient than wheat flour based on the greatest survival rate of 95%.

• Journal of Environmental Health Sciences
• /
• v.15 no.2
• /
• pp.69-73
• /
• 1989

The objective of this study is to investigate the amount of disposal, the composition of solid wastes and environmental pollution (leachate, ground water) in a solid waste landfill. The results were as follows. 1. The amount of daily disposal in Taejon City is appoximately 1.5kg/c.d with the heat capacities of 2850 - 4200 kcal/kg. 2. The existing leackage treatment plant must be improved, because it has many problems. 3. It is desirable that urban solid wastes should be treated by sanitary landfill, incineration or compost.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2004.06a
• /
• pp.377-385
• /
• 2004

The quantity of radioactive waste generated from HANARO operation for the years of 1996 to 2003 has been analysed. It was found that the solid waste of $72, 999{\ell}$ and liquid waste of $263, 576{\ell}$ have been generated for the past 8 years. The amounts of Ar-41, I-131 and H-3 exhausted to the environment were 1, 225.6 Ci, 1.612E-2 Ci and 210 Ci, respectively.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.313-320
• /
• 2009

Indonesian Ministry of Environment estimates that each year 170 cities and regencies in Indonesia produce 45,764,354.30 $m^3$ or approximately 11,441,091.08 ton of solid waste. Unfortunately, unsustainable management system has created a severe waste problem, hazardous to health and environment. This paper deals with the problem and offers some solutions. They are 3R (Reduce Reuse and Recycle), waste-to-energy concept and landfill gas (LFG) utilization. While 3R policy has been adopted by the government, the remaining two technologies are still dormant. Thus the paper provides a complete yet compact analysis of technology, economics, and environment aspect of waste-to-energy and LFG. Given the facts of waste production and management in Indonesia, the purpose is to encourage Government of Indonesia and other stake holders (including international community) to explore and exploit this potential. Potential of reducing waste negative externality while receiving extra revenue. Two bird with a stone.

• Environmental Engineering Research
• /
• v.21 no.2
• /
• pp.145-151
• /
• 2016

Biodrying is a pre-treatment method that applies biological and mechanical concepts to drying solid waste. In Malaysia, municipal solid waste (MSW) is unseparated and contains a high level of moisture, making the use of technology such as solid waste burning unsuitable and harmful. MSW containing organic material can be processed naturally until the moisture content of the waste is reduced. This study on MSW biodrying was carried out on a laboratory scale to measure the percent moisture content reduction and to monitor temperature patterns under different ventilation periods. This work was conducted using five biodrying reactors volumes of 50 liters each. Reactors were ventilated for 5, 10, 15, 20 and 30 min every 3 h, with a 3 bar air supply. The duration of this process was 14 days for all samples. The results showed that the optimum ventilation time was 10 min, with an 81.84% reduction in moisture content, and that it required almost half of the electricity cost required for the 20 and 30 min ventilations.

• Journal of Environmental Science International
• /
• v.13 no.1
• /
• pp.79-87
• /
• 2004

Esterification of soybean oil with methanol was investigated. First of all, liquid-liquid equilibriums for systems of soybean oil and methanol were measured at temperatures ranging from 40 to 65$^{\circ}C$. Profiles of conversion of soybean oil with time were determined from the glycerine content in reaction mixtures for the different kinds of catalysts, such as NaOH, CaO, Ca(OH)$_2$, MgO, Mg(OH)$_2$, and Ba(OH)$_2$. The effects of dose of catalyst, cosolvent and reaction temperature on final conversion were examined. Esterification of waste vegetable oil with methanol was investigated and compared to the case of soybean oil. Solubility of methanol in soybean oil was substantially greater than that of soybean oil in methanol. When the esterification reaction of soybean oil was catalyzed by solid catalyst, final conversion was strongly dependent on the alkalinity of the solid catalyst, and increased with the alkalinity of the metal. Hydroxides from the alkali metals were more effective than oxides. When Ca(OH)$_2$ was used for the esterification catalyst, maximum value of final conversion was measured at dose of 4％. When CHCl$_3$ as a cosolvent, was added into the reaction mixture of soybean oil which catalyzed by Ba(OH)$_2$, maximum value of final conversion was appeared at dose of 3％. When waste vegetable oil was catalyzed by NaOH and solid catalysts, high final conversion, over 90％, and fast reaction rate were obtained.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.44 no.6
• /
• pp.58-69
• /
• 2012

As the meaning of dictionary terminology, scum refers to a layer of impurities that accumulates at the surface of a liquid. In papermaking process, scum indicates the floated solid waste generated by a flotation process during the primary wastewater treatment. In this study, different kinds of stocks and scums collected from newspaper, liner, tissue and fine paper were analysed in details. The purpose of this study was firstly to demonstrate the composition characteristics of different sources of scum, secondly the analysis of environmental hazardous materials, and thirdly the evaluation of reutilization ability of fibrous materials from collected scum. As mentioned the meaning of solid waste, scum was actually differ from the waste sludge in sources, compositions and recycling abilities. In the same manner of waste paper, the sludge which is generated within onsite of papermaking processes would be reused as a raw material. The general compositions of scum from waste water were mainly inorganic ash materials, fine fibre fractions, recycled fibre debries, and ink particles. If the scum is able to reuse as fibrous additives in papermaking process, it could contribute to the savings of running costs in both the subsidiaries of fibrous material and the solid waste treatment with even small quantity.

• Environmental Engineering Research
• /
• v.25 no.4
• /
• pp.462-469
• /
• 2020

This study is proposing a System Dynamics Model for estimating Greenhouse Gas (GHG) emission from treating Municipal Solid Waste (MSW) in South Korea for years 2000 to 2030. The government of country decided to decrease the total GHG emission from waste sector in 2030 as per Business-as-usual level. In context, four scenarios are generated to predict GHG emission from treating the MSW with three processes i.e., landfill, incineration and recycling. For prior step, MSW generation rate is projected for present and future case using population and waste generation per capita data. It is found that population and total MSW are directly correlated. The total population will increase to 56.27 million and total MSW will be 21.59 million tons in 2030. The methods for estimating GHG emission from landfill, incineration and recycling are adopted from IPCC, 2006 guidelines. The study indicates that Scenario 2 is best to adopt for decreasing the total GHG emission in future where recycling waste is increased to 75% and landfill waste is decreased to 7.6%. Lastly, it is concluded that choosing proper method for treating the MSW in country can result into savings of GHG emission.

• Journal of the Korean Solar Energy Society
• /
• v.36 no.1
• /
• pp.19-26
• /
• 2016

Biomass has been used for energy sources from the prehistoric age. Biomass are converted into solid, liquid or gaseous fuels and are used for heating, electricity generation or for transportation recently. Solid biofuels such as bio-chips or bio-pellet are used for heating or electricity generation. Liquid biofuels such as biodiesel and bioethanol from sugars or lignocellulosics are well known renewable transportation fuels. biogas produced from organic waste are also used for heating, generation and vehicles. Biomass resources for the production of above mentioned biofuels are classified under following 4 categories, such as forest biomass, agricultural residue biomass, livestock manure and municipal organic wastes. The energy potential of those biomass resources existing in Korea are estimated. The energy potential for dry biomass (forest, agricultural, municipal waste) were estimated from their heating value contained, whereas energy potential of wet biomass (livestock manure, food waste, waste sludge) is calculated from the biological methane potential of them on annual basis. Biomass resources potential of those 4 categories in Korea are estimated to be as follows. Forest biomass 355.602 million TOE, agricultural biomass 4.019 million TOE, livestock manure biomass 1.455 million TOE, and municipal organic waste 1.074 million TOE are available for biofuels production annually.

• Journal of environmental and Sanitary engineering
• /
• v.14 no.1
• /
• pp.70-79
• /
• 1999

A questionary survey was conducted to investigate citizen's attitude to treatment facilities of municipal solid waste in Miryang during 8. June of 1998 and 22 June of 1988. Collection effiencies was 86.7%, as 260 individuals of the 300 individuals. The survey showed that 43.0% of answers recognized seriousness of problem of the waste treatment and 33.1% of respondents concerned about recycle of organic waste. 40.8% of total answers said that they most hated landfill site among waste treatment facilities, and most citizens wanted as much distant as possible from waste treatment facilities. It was investigated that the greater part of respondents wanted the greatest compensation. About 58% of respondents was opposed to complete waste treatment facilities. 36.2$ among answers wanted establishment of waste treatment facilities in an industrial complex or an industrial area. The majority of respondents was willing to increase recycle rate and recognized seriousness of landfill site security. The majority of citizens do not trust environmental administration of Miryang City and they think that democracy and open of administration need for overcome MINBY.