• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.687-693
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• 2006

The Stone Powder Sludge(below SPS) is the by-product from the process that translates stone power of 8mm under as crushed fine aggregate. It is the sludge as like cake that has average particle size of $7{\mu}m$, absorbing water content of 20 to 60%, and $SiO_2$ content of 60% over. Because of high water content of SPS, it is not only difficult to handle, transport, and recycle, but also makes worse the economical efficiency due to high energy consuming to drying. This study is aim to recycle SPS as it is without drying. Target product is the lightweight foamed concrete that is made from the slurry mixed with pulverized mineral compounds and foams through hydro-thermal reaction of CaO and $SiO_2$. Although in the commercial lightweight foamed concrete CaO source is the cement and $SiO_2$ source is high purity silica powder with $SiO_2$ of 90%, we tried to use the SPS as $SiO_2$ source. From the experiments with factors such as foam addition rate and replacement proportion of SPS, we find that the lightweight foamed concrete with SPS shows the same trends as the density and strength of lightweight foamed concrete increases according to decrease of foam addition rate. But in the same condition, the lightweight foamed concrete with SPS is superior strength and density to that with high purity silica. This trends is distinguished according to increase of replacement proportion of SPS, also the analysis of XRF shows that the hydro thermal reaction translates SPS to tobermorite. Although SPS has low $SiO_2$ contents, the lightweight foamed concrete with SPS has superior strength and density, because it reacts well with CaO due to extremely fine particles. We conclude that it is possible to replace the high purity silica as SPS in the lightweight foamed concrete experimentally.

• Journal of the Korean GEO-environmental Society
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• v.10 no.5
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• pp.33-39
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• 2009

This study was conducted to evaluate production of complex odor and 12 specific odorous compounds in a pilot-scale (capacity : $100m^3$) ultra thermophilic aerobic composting. There were three types input: municipal wasted sludge, livestock manure and slurry, and food waste produced in Jung-Eb city. Each raw material was mixed with seed material and operated for two periods (1st : 50 days, 2nd : 60days). During composting, the temperature hit $90{\sim}95^{\circ}C$ after every mixing in both periods. Therefore, it was concluded that increasing temperature also saves the time which required for composting and high reduction of organics and water contents. The primary odorous compounds were ammonia, methyl mercaltan, dimethyl disulfide and trimethylamine. The concentration of the primary compounds and complex odor during the operation were higher than those on final day and most compounds did not exceed the allowable exhaust standard for odor. Also, it was found that optimal mixing time and control of high temperature are the most important parameters for odor control in ultra thermophilic aerobic composting.

• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.27-36
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• 2010

This study was conducted to evaluate physicochemical parameters; temperature, pH, C/N ratio, water content, organic contents and volume in a pilot-scale(capacity : $100m^3$) ultra thermophilic aerobic composting. There were three types input: municipal wasted sludge, livestock manure and slurry, and food waste produced in Jung-Eb city. Each target material was carried out by the first fermentation(organic waste + seed culture) and the second one(organic waste + seed culture + recycle compost), respectively. During composting, only with supply of air and mixing, the temperature increased $90{\sim}105^{\circ}C$ after every mixing in both periods. The changes of pH, $O_2$, $CO_2$ and $NH_3$ represented typical organic decomposition pattern by microorganisms. Also, all other physicochemical parameters of ultra thermophilic aerobic composting process showed similar or better performance than these of general aerobic composting. Heavy metal concentration of fermented compost adapted to compost fertilizer regulation standard in the heavy metal and hazardous analysis.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.532-539
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• 2012

This study was carried out to investigate the effect of substrate to inoculum ratio on ultimate methane potential ($B_u$) from piggery wastes. BMP(Biochemical methane potential) assays were executed for the three samples that have different organic characteristics (Filtrate of pig slurry, LF; Thermal hydrolysate of piggery sludge cake, TH; Mixture of LF and TH at the ratio of 4 to 1, Mix), and $B_u$ values obtained from BMP assays were compared with the theoretical methane potential ($B_{th}$) of each samples. While $B_u$ values (0.27, 0.44, and $0.46Nm^3\;Kg^{-1}-VS_{added}$) of TH sample that was pretreated with thermal hydrolysis were below the $B_{th}$ at all S/I ratios (0.1, 0.3, and 0.5), and $B_u$ values of LF (0.64 and $0.53Nm^3\;Kg^{-1}-VS_{added}$ for the S/I ratios of 0.1 and 0.3, respectively) at the lower S/I ratios of 0.1 and 0.3 exceeded the $B_{th}$ values ($0.418Nm^3\;Kg^{-1}-VS_{added}$). And also biodegradability ($B_u/B_{th}$) of LF sample were obtained as 152.07%, 122.67%, and 95.71% at the S/I ratios of 0.1, 0.3, and 0.5, respectively, and unreasonable $B_u/B_{th}$ values were presented at lower S/I ratios of 0.1 and 0.3. $B_u$ and $B_u/B_{th}$ of Mix sample showed a similar tendency with those of LF sample. Therefore, TH sample by thermal hydrolysis pretreatment showed lower anaerobic biodegradability than those of other samples (LF and Mix) and ultimate methane potentials of LF and Mix samples were overestimated in the lower S/I ratio of 0.1 and 0.3.

• Journal of Animal Environmental Science
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• v.11 no.3
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• pp.169-176
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• 2005

The farm house structure, ventilation system and manure treatment of two-storey buildings and sawdust pig houses were surveyed and analyzed. Based on the data for ten selected farms in five provinces during eight months, the goal is to eventually establish a standard two-storey pig house. Manure treatments were composting, slurry and activated sludge in two-storey pig houses, while fermentation method was done in sawdust pig house. The depth of sawdust as a litter material were 10 to 60cm, with a duration of 1/2, 1, 3 and 6 months, respectively. The ventilation systems were the mechanical type in two-storey pig houses and natural system in the sawdust pig house. Side wall in the two-storey pig house was enclosed with insulation materials such as block, colored metal sheet and sandwich panels. The minimum ceiling height in the first floor of the two-storey pig house was 2.0m and the maximum was 3.0m. On the second floor, ceiling height ranged from 2.0 to 2.7m. The construction cost in the two-storey systems were $700\~140$, and sidewall curtain systems were $30\~40$ thousand Won/pyung.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.3
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• pp.91-100
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• 2006

In this study, the characterization of unit load generation and discharge from various type stall of piggery was conducted by investigation and analysis of contaminants loading from piggery urine, manure and wastewater. The results are summarized as follows: The unit load generation of filth increases as piggery grow older, but there was not large enough difference among those values of unit load evaluated for various stall types if mean values of each type of stall are considered. The generation amounts of manure and urine were total 4.57kg/head/d of 1.49kg manure/head/d and 3.08kg urine/head/d with consideration of 3 seasons and live weight. The finalized mean unit load generation of filth were estimated at BOD 199.5g/head/d, $COD_{cr}\;413.5g/head/d$, T-N 27.8g/head/d, T-P 5.3g/head/d with consideration of seasons and the type of stalls. The wastewater unit loads discharged from cement type stall were estimated at BOD 31.3g/head/d, $COD_{cr}\;95.6g/head/d$, T-N 8.9g/head/d, T-P가 3.1g/head/d. The sum of manure unit load generation considered with manure collection ratio(80%, 90%) and wastewater unit load was almost similar when compared to the unit load discharged from slurry type stall even though more or less difference were appeared according to each contaminants and parameters.

• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.67-75
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• 2024

In the context of Korean residential heating systems, Ondol pipelines are a prevalent choice. However, the maintenance of these pipelines becomes a complex task once they are embedded within concrete structures. As time progresses, the accumulation of sludge, corrosive oxides, and microorganisms on the inner surfaces of these pipelines diminishes their heating efficiency. In extreme scenarios, this accumulation can induce corrosion and scale formation, compromising the system's integrity. Consequently, this research introduces an ultrasonic generation system tailored for the upkeep of Ondol pipelines, with the objective of empirically assessing its practicality. This investigation delineates three variants of ultrasonic generating apparatuses: those employing surface vibration, external generation, and internal generation techniques. To emulate the presence of contaminants within the pipelines, substances in powder, slurry, and liquid forms were employed. The efficacy of the cleaning process post-ultrasonic wave application was scrutinized over time, with image analysis methodologies being utilized to evaluate the outcomes. The findings indicate that ultrasonic waves, whether generated externally or internally, exert a beneficial effect on the cleanliness of the pipelines. Given the inherent characteristics of Ondol pipelines, external generation proves impractical, thereby rendering internal generation a more viable solution for pipeline maintenance. It is anticipated that future endeavors will pave the way for innovative maintenance strategies for Ondol pipelines, particularly through the advancement of internal generation technologies for pipeline applications.