• Journal of Soil and Groundwater Environment
• /
• v.19 no.1
• /
• pp.1-7
• /
• 2014

When processing the biomass by Hydrothermal carbonization (HTC), a slow pyrolysis process, it produces bio-gas, biooil, and biochar. Among these end products, biochar is known for isolating or storing carbon and being used as a soil amendment. In this study, the characteristics of biochar generated by HTC at $250^{\circ}C$ for 1 hour, 2 hours, 3 hours, and 20 hours with synthetic food wastes and wood wastes were analyzed for potential uses in soil contaminated with heavy metals. The yield of biochar (weight %) increased when the ratio of wood wastes increased and showed a decreasing tendency as reaction time increased. Elemental analysis of biochar based on various conditions showed a maximum of 70% carbon (C) content. The carbon content showed an increasing tendency with the increase of wood wastes. Iodine adsorption test was peformed to determine the optimum reaction condition, which was 15% wood waste for mixing ratio and 2 hours for reaction time. Using biochar generated at the optimum condition, its capability of adsorbing heavy metals (Cd, Cu, Pb, Zn, Ni) was evaluated. It was concluded that lead (Pb) was removed efficiently while zinc (Zn) and nickel (Ni) were hardly adsorbed by biochar.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.20 no.4
• /
• pp.86-96
• /
• 2012

Hydrogen gas production of anaerobic fermentative process from food waste as a substrate was 3.47 mg $H_2/g$ COD. The hydrogen production was little less than the synthetic wastewater with sucrose as a substrate (7.56 mg $H_2/g$ COD). The B/A ratios of the synthetic wastewater and food waste were 3.73 or 8.01 respectively. Butyric acid was more produced when hydrogen production was higher. Microbial community in the samples was analyzed as Escherichia sp., Klebsiella sp., Clostridium sp., Bacterium sp., and Enterobacter sp. Clostridium sp. was detected both samples but Klebsiella sp. was more active with fermentation process of the food waste. Taxonomic description shows that 60% of the microorganism was ${\gamma}-proteobacteria$ and Firmicute and Bacteria was 20% respectively.

• Journal of the Korean Applied Science and Technology
• /
• v.34 no.3
• /
• pp.683-693
• /
• 2017

Transport biofuels have been recognized as a promising means to resolve the following issues like global warming, oil depletion and environmental pollutions. Among various biofuels, biodiesel has several advantages such as less emission of air pollutants and higher cetane values compared to diesel oil. Demand for biodiesel in Korea is increasing that leads to higher dependence on the imported feedstocks. Therefore, it is important to utilize the waste materials collected domestically for biodiesel production. Food waste oil collected in waste treatment facility has not been used for biodiesel production due to high free fatty contents in the oil. In this work, biodiesel conversion of food waste oil by Amberlyst 15 was studied. Synthetic and actual food waste oils have been used in the study. First, the effects of the major operating parameters including reaction temperature, methanol to oil molar ratio and catalyst loading on the conversion rates and yields were determined with synthetic waste oil. Kinetic modelling work was also done to determine the activation energy of the reaction. From the work, optimization reaction conditions were determined to be 383K, 1: 26.1 for methanol molar ratio to oil, 10 wt.% for catalyst loading and 360 min for reaction time. Activation energy of the reaction is determined to be 29.75 kJ/mol, lower than those reported in the previous works. So the solid catalyst, Amberlyst 15, was more efficient for esterification than the solid catalysts employed in the other works. Agitation rates have the negligible effects on the conversion rates and yields. With the identified optimization conditions, conversion of the actual food waste oil was also carried out. The esterification yield of actual food waste oil in 60 min was 13% lower than that of synthetic waste oil but the final yields in 240 min were similar each other, 98.12% for synthetic oil and 97.62% for actual waste oil.

• Journal of Korean Society of Water and Wastewater
• /
• v.24 no.6
• /
• pp.703-712
• /
• 2010

This study performed to extract operation factors of major organic wastes, which were food wastes and waste activated sludge generated in industries in order to use them as a substrate for bio-H2 production. According to the results of experimental analysis for hydrogen production capacity by various organic concentrations, the hydrogen production yield was the highest at 80 g/L, and the efficiency was improved by the pretreatment of waste activated sludge (acid treatment, alkali treatment). Hydrogen production efficiency was improved by mixing food wastes and waste activated sludge if waste activated sludge was below than 30%, however, it was decreased when it was more than 50%. The impacts of heavy metals on the hydrogen production shows that the inhibition level depends on the concentration of Cr, Zn, and Cu, Fe was able to enhance the hydrogen production.

• Journal of Korean Society on Water Environment
• /
• v.18 no.4
• /
• pp.371-377
• /
• 2002

The purpose of this study is to develop effective operating process in order to achieve more suitable conditions of Anoxic-Oxic-Anoxic-Stripper(AOAS) SBR through real-time control. To improve the removal efficiency, glucose, methanol and synthetic food waste acid fermentant were added as an external carbon source, In the case of glucose and synthetic food waste acid fermentant, TN, TP were removed to average 86.9%, 73.0% respectively. Methanol was removed to average 64.6%, 55.4% respectively. The synthetic food waste acid fermentant proved to be the most efficient and allowed for the substitution of an external carbon source. The removal rate of $COD_{Cr}$, was approximately 90% at all cases. The results of the study that a correlation between ORP (Oxidation-Reduction Potential), pH and DO and nitrification or denitrification when an external carbon source is added and when it isn't was showed that ${\Delta}ORP$ is suitable parameter. ORP reacted properly to denitrification (${\Delta}ORP<-10$) and nitrification (${\Delta}ORP<0$). The use of real-time control saved anywhere between 61 and 67 minutes at the anoxic(1) stage and 26 to 52 minutes at the oxic(1) stage. When the time saved from the anoxic(1) and oxic(1) was added to the anoxic(2) stage for the removal efficiency of TN and TP increased from 0.7 to 13.9% and 12 to 35 % respectively.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.18 no.5
• /
• pp.661-673
• /
• 1994

We have gathered a fatty acid to recycle the waste oil of food manufacturing process, and then made a soap from the waste oil by alkali saponification. Effects of the washing elements such as the concentration of the soap, temperature and time were evaluated to find out the optimum washing conditions, and results are as follows. 1. We could find soaps made from the soybean oil (A), corn oil (B), rape seed salad oil (C), cotton seed oil (D) and a soap consisting of the each oil 25% respectively (I) had the lowest surface tension at the concentration of 0.225% -0.25%. Compared with the single fatty-acid soap, the multi-component soap I showed the lower surface tension at the cmc. 2. All the samples of A-I showed the lowest contact angle for the solid material at the concentration of 0.25%. The multi-component soap of I showed higher contact angle than the single.component soaps of A, B, C and D. 3. The soap G, made from the waste oil, show lower surface tension than 5, made from the complex raw fats of the eatable fatty oil acid and H, commercial soap. 4. The washing efficiency depends on the washing time. Especially the 25-minute was found to be the optimum washing time. 5. The highest washing efficiency was found at the 0.25% cont. reagardless of the washing temperature. At 0.15% concentration level the washing efficiency reduces as washing tem- perature increases. At 0.3% concentration level the highest washing efficiency was found between $50^{\circ}$-$60^{\circ}$. 6. The soap made from the waste oil showed the highest washing efficiency in terms of concentration, temperature, and time. 7. The soap made from the waste oil showed the similiar concentration of hydrogen ion to the synthetic detergent. 8. The hand value of the fabric washed by the soap made from the waste oil was a little lower value than those washed by the synthetic detergent.

• Korean Journal of Microbiology
• /
• v.38 no.4
• /
• pp.235-240
• /
• 2002

Protease producing bacterium, PB16 was isolated from food processing wastewater sludge and paddy field soil samples and selected by the clear zone and enzyme activity test. The isolate was gram negative, rod type and its protease productivity was 6.49 U/ml. As a result of API20NE kit test and 16S rDNA sequencying, the isolated PB16 was identified as Aeromonas hydrophila (99%). The growth rate ($h^{-1}$) was 0.21 in synthetic waste water only and 0.26 in synthetic waste water containing vitamin and mineral using a bioscreen C. Synthetic wastewater removal rate was 59 and 87%, respectively after 1 and 3 day reaction (intial CODcr was 2,472 mg/l).

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.27 no.3
• /
• pp.141-147
• /
• 2021

The foreign trends of noncompliance occurring frequently in food contact materials during the period of 2011-2019 was investigated by analyzing the food safety risk information DB in the National Food Safety Information Service (NFSI). A total of 2,042 cases of noncompliance of food utensils, containers, and packages were classified into 5 violation categories; administrative procedures, manufacturing and processing standards, residues and migration standards, labeling and advertising, and quality standards. This was again subcategorized according to non-compliance causative factors. The non-compliances in residues and migration standards comprised the largest proportion (76.4%) of the violative categories. The number of noncompliance information collected in 2011 was 88 cases and increased to 373 cases in 2019. A 72.8% of the non-compliance case was identified to be products of 4 countries (China 64.2%, Germany 4.0%, Japan 3.2%, and Taiwan 3.1%), those produce large quantities of containers and packaging products. During the period of 2011-2019, the number of illegal use of hazardous materials and illegal recycling of waste synthetic resins has decreased to less than one a year since 2014. On the other hand, after 2016, inconsistency of heat-resisting temperature labeling (Taiwan), non-compliance in paper container's strength standards, violation of printing standards, and the risk of consumer injury while using the products were newly reported due to the strengthening of consumer safety protection regulations. Migration of hazardous substances in synthetic polymer products such as heavy metals, melamine and formaldehyde in melamine tableware, primary aromatic amines which are colorant components in kitchenware such as ladles and spatulas, and phthalate plasticizers have been continuously reported with high frequency.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.1
• /
• pp.1-14
• /
• 2023

Polyethylene terephthalate (PET) is a plastic material commonly applied to beverage packaging used in everyday life. Owing to PET's versatility and ease of use, its consumption has continuously increased, resulting in considerable waste generation. Several physical and chemical recycling processes have been developed to address this problem. Recently, biological upcycling is being actively studied and has come to be regarded as a powerful technology for overcoming the economic issues associated with conventional recycling methods. For upcycling, PET should be degraded into small molecules, such as terephthalic acid and ethylene glycol, which are utilized as substrates for bioconversion, through various degradation processes, including gasification, pyrolysis, and chemical/biological depolymerization. Furthermore, biological upcycling methods have been applied to biosynthesize value-added chemicals, such as adipic acid, muconic acid, catechol, vanillin, and glycolic acid. In this review, we introduce and discuss various degradation methods that yield substrates for bioconversion and biological upcycling processes to produce value-added biochemicals. These technologies encourage a circular economy, which reduces the amount of waste released into the environment.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.15 no.3
• /
• pp.71-79
• /
• 2007

The effects of synthetic bulking agent (SBA) on the composting reaction were investigated with a lab-scale composting reactor. The positive effects of SBA addition were observed in composting reactions where relatively tough composting conditions like high water content and no addition of seed compost were provided. Such effects were assumed to be caused by the enhanced free air space in compost mixture. It was additional benefits of using SBA, a bulking agent, that the amount of saw dust, another bulking agent, could be reduced to 50% compared to composting without SBA. Although SBA would be used as a bulking agent, two options are thought to be very important to ensure composting reaction well. One is that optimal water content should be maintained around 60%. The other is that saw dust is inevitable bulking agent to prevent food waste from lumping, so combination use of two ones are necessary.