• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.3
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• pp.35-40
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• 2021

In order to investigate the degree of solubilization of sewage sludge using sono-activated persulfate(UV/PP), VSS reduction rate, solubilization rate and extracellular polymeric substances were measured. Ultrasonic(US) and alkali·ultrasonic method using sodium hydroxide(US/SH) were compared. Under the persulfate·ultrasonic conditions, the VSS reduction rate and the solubilization rate increased to 27.6% and 58.9%, respectively. TB-EPS as Carbohydrate and Protein were extracted by 770 mg/L and 2,162 mg/L. Compared to the other methods, US and US/SH, the VSS reduction rate and solubilization rate were higher. And also, according to the TB-EPS values, cell wall destruction was more efficient.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.1
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• pp.5-17
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• 2021

This study is a literature review on the recovering phosphorus from Incinerated Sewage Sludge Ash(ISSA), which has relatively high content of phosphorus. Experimental conditions and influencing factors related to the recovery of P and removal of heavy metals by wet and thermochemical methods were discussed. For the practical application of the recovery of P from ISSA, an integrated process linked to incineration facilities is required in terms of economy from the perspective of the entire system including disposal of wastewater and residues generated during the recovery process, and minimizing added chemicals and energy consumption.

• Animal Bioscience
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• v.36 no.5
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• pp.818-828
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• 2023

Objective: The purpose of this study was to analyze the effect of the hydrothermal pretreatment of anaerobic digestion sludge cake (ADSC) of cattle manure on the solubilization of organic matter and the methane yield to improve the anaerobic digestion efficiency of cattle manure collected from the sawdust pens of cattle. Methods: Anaerobic digestion sludge cake of cattle manure was thermally pretreated at 160℃, 180℃, 200℃, and 220℃ by a hydrothermal pressure reactor, and the biochemical methane potential of ADSC hydrolysate was analyzed. Methane yield recovered by the hydrothermal pretreatment of ADCS was estimated based on mass balance. Results: The chemical oxygen demand solubilization degree (COD_s) of the hydrothermal hydrolysate increased to 63.56%, 67.13%, 70.07%, and 66.14% at the hydrothermal reaction temperatures of 160℃, 180℃, 200℃, and 220℃, respectively. Considering the volatile solids content obtained after the hydrothermal pretreatment, the methane of 10.2 Nm³/ton-ADSC was recovered from ADSC of 1.0 ton, and methane yields of ADSC hydrolysate increased to 15.6, 18.0, 17.4, and 17.2 Nm³/ton-ADSC. Conclusion: Therefore, the optimal hydrothermal reaction temperature that yielded the maximum methane yield was 180℃ based on mass balance, and the methane yield from cattle manure containing sawdust was improved by the hydrothermal pretreatment of ADSC.

• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.74-79
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• 1991

In order to use of new organic matter source, soil samples collected from paddy, upland and orchard treated with kraft and paper board mill sludge were analysed comparing with non-treated soil in view of some soil properties, soil microorganisms and soil enzyme activities. Also, the value of fertilizer was estimated with kraft and paper board mill sludge. 1. Paper mill sludge showed more than 55% of organic matter content, and higher total nitrogen and phosphorus, and CEC. 2. Soils treated with kraft sludge were higher contents than non-treated 2.5-3 for organic matter, 1.5-2 for total-nitrogen, 2 for $NO_3$-N, 1.5 for phosphorus and 1.4 times for CEC. Also, 12-1.9 for bacteria and 3 times for fungi, and 1.4-1.5 of cellulase, 1.5-1.8 of phosphatase and 1.5-1.8 times of urease activities. 3. Organic matter contents, number of fungi, and activities of cellulase and phosphatase in soil treated with paper board sludge were 1.4-22, 2.4, 1.5-1.6 and 1.3-1.4 times higher than non-treated soil, respectively. 4. Paper mill sludge was evaluated as a good organic matter source to increase of soil organic matter, CEC, inorganic components, soil microbes and enzyme activities.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.2
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• pp.92-100
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• 2005

This study was conducted to find suitable methods for screening organic resources useful for compost. Twenty-seven industrial and domestic sludges were collected from various cities and industrial areas. Contents of organic matters in the sludges were in the range of 79.3-98.0%, and the contents were much higher than the regulation level (60%) for raw materials of compost. Contents of total nitrogen were in the range of 0.8-2.6%. Contents of Fe and Al were very high. Content of HEM was highest in textile sludge ($257mg\;kg^{-1}$) and the contents in the others were in the range of $12.6-90.3mg\;kg^{-1}$. Content of PAHs was lowest in food sludge ($739.1{\mu}g\;kg^{-1}$ and pulp-mill sludge had the highest PAHs content ($3461.8{\mu}g\;kg^{-1}$). $Microtox^{(R)}$ $EC_{50}$ values were higher in the sludges which were classified as a possible material in composting after analysis and investigation. Lettuce root elongation and $EC_{50}$ values were relatively lower in pulp-mill sludge, sewage sludge 3 (Large city), food sludge and leather sludge. Therefore, mineral nutrients, heavy metals, organic compounds (HEM, PAHs, PCBs), and bioassay ($Microtox^{(R)}$ $EC_{50}$, Relative root elongation test) are recommended to be included in the screening system of raw material of compost in addition to the current regulation with organic matter and 8 heavy metals.

• Journal of Environmental Health Sciences
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• v.41 no.5
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• pp.327-334
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• 2015

Objectives: In order to review both the effects of sewage sludge dewaterability and deodorizing ability in the existing advanced sewage treatment process, BIO-CLOD (a solidified mixture of 10% Bacillus concentrate and inorganics) was used as an inorganic conditioner effective for deodorization treatment in addition to the removal of organic matter and nutritive salts. Methods: Sludge dewaterability was evaluated using specific resistance to filtration (SRF) experiments with six agitators and two types of commercially available BIO-CLOD; one that is made by grinding solid matter (powdered BIO-CLOD) and one that has been obtained by sieving a separation with a particle diameter of 100 mesh (100 mesh BIO-CLOD). For deodorization odor treatment experiments, 20 g of commercially available solid BIO-CLOD was submerged in four liters of sewage sludge and mixed and agitated for 45 days. Results: When BIO-CLOD was injected into sewage sludge to experimentally compare specific resistance to filtration (SRF), the optimum amount of BIO-CLOD to be injected was shown to be 2% w/v and the SRF value in this case was $1.35{\times}10^{12}m/kg$. pH changes following BIO-CLOD injection were within 6.5-7.0. By 14 days after submerging BIO-CLOD into the sewage sludge to evaluate its deodorizing ability, $H_2S$ decreased by 68% and methyl mercaptan decreased by 74%. By 45 days after the submergal, both items decreased by 100%, indicating deodorizing ability. Conclusion: To compare the levels of dewaterablity of sewage sludge at different particle sizes of inorganic conditioner, powdered BIO-CLOD, particle size 100 mesh BIO-CLOD, and bentonite were tested. It could be seen that as the powdered BIO-CLOD increased, the precipitability increased up to 62% in 30 minutes. As an inorganic conditioner, BIO-CLOD was identified as a stable sludge conditioner that does not affect pH.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.2
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• pp.102-111
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• 1998

Large amount of sludge have been generating in the process of water and wastewater treatment in urban area, and it has been making many environmental problems. Currently almost of sludge is landfilled, and since sludge is difficult to handle and dehydrate, the permeated water from the filled-in ground contaminate the surrounding soil and groundwater which may cause serious environmental and sociological problems. The organic component in sludge can be almost removed through the heat treatment process, and the final product is called artificial soil or artificial media according to the temperature control. To produce artificial media using sludge, chabazite and lime were used as an additive, and the mixture of sludge & additives was thermally treated in the firing kiln at about 800~1, 100。C for about fifteen minutes. The physical and chemical characteristics of the produced artificial media were analyzed, and it showed that it can be used as an artificial media for plant production or soil conditioner for farmland. The concentrations of the toxic heavy metals in the artificial media were lower than the soil quality standard for farmland. The characteristics of produced artificial media, using the mixture of sludge and additives through the heat treatment, is similar to the natural chabazite and soil. The analyzed result of the mineral composition of artificial media showed that it has a characteristics similar to natural stable soil, so the produced artificial media may be applied to farmland or water culture without causing adverse effect. Therefore this study showed that the above process can be a feasible alternative for sludge treatment.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1780-1782
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• 2001

In this experiment, an attempt to use the sludge pellets as catalyst for NO removal from simulated gas is experimentally investigated by using $BaTiO_3$-sludge packed-bed reactor of plate-plate geometry. An experimental investigation has been conducted for NO concentration of 50[ppm] balanced with air, a gas flow rate of 5[1/min]. $BaTiO_3$ pellets are filled at upstream of reactor for corona discharge and sludge pellets are put at downstream of reactor for catalystic effect. The volume rate of sludge pellets to $BaTiO_3$ pellets is 50[%] and AC voltage to dischare the gases was supplied. In the result, when sludge pellets is seperated to $BaTiO_3$ by other reactor and AC voltage is supplied to $BaTiO_3$ and sludge pellets NO, $NO_2$ removal rate is higher. When gas temperature increase from room temperature to 100[$^{\circ}C$], NO removal is decreased while $NO_2$ concentration is independent on gas temperature. This result suggest that the removal mechanism of active oxyzen species and $NO_2$ in sludge is not absorption, but chemical reaction. Temperature of heating treatment is on sludge pellets increased, $NO_x$ removal rate is decrease. It is thought that organic compound is removed by heating treatment.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.06a
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• pp.113-133
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• 1998

In activated sludge process, sludge settling condition is affected by organic loading rate or operation condition, and if settling condition is getting worse, it is common that overall process fails due to wash-out of biomass causing low concentration in the aeration tank. Also activated sludge process has such several problems as requiring large area, consuming a lot of power and producing large volume of sludge. Increased public concern over health and the environment combined with a strong desire to reduce capital, operating and maintenance costs, have created a need for innovative technologies for building new high quality effluents which vail meet 21st century crkeria. MBR(Membrane Bioreactor) process consists of a biological reactor and ultrafiltration(UF) membrane system that replaces the conventional clarifier of an activated sludge process. The main operating advantages of this system are that the quality of the effluent is independent of the settleability of the mixed liquor and that the effluent is free of suspended solids in any operating condition. It is possible to eliminate clarifier and to reduce the volume of aeration tank because it can afford to accumulate high biomass concentration in the bioreactor(20, 000~30, 000mg/L), which would not be possible in a conventional activated sludge process. Therefore, this process reduces overall treatment plant area. In addition to those advantages, Longer SRT condition enables higher sludge digestion in MBR process so the sludge volume produced is 50 to 70% lower than that of conventional activated sludge process There are two kinds of MBR process according to the allocations of membrane. One is cross flow type MBR of which module is located outside of the bioreactor and mixed liquor is driven into the membrane module. The other is submerged type MBR process of which module is submerged in the bioreactor and mixed liquor is generally sucked from the lumen side. addition to that the cake layer is often removed by the uplifting flow of bubbling air. A submerged MBR process is superior to a crossflow MBR in regard to the power consumption because suction pressure of a submerged MBR is generally lower than that of a crossflow MBR which has recirculation pump. A submerged MBR, therefore, has the potential to be applied to small wastewater treatment plants that need low cost treatment systems.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.317-323
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• 2014

People could not imagine living without tab water. However, the water filtering process at a purification plant used to produce tab water creates tons of sludge, which is generally wasted. This sludge waste consists of (1) mineral elements, such as sand, (2) organic materials, and (3) a coagulant, which agglomerates the two. As an enormous amount of sludge waste is generated every year, numerous studies have been carried out to identify how to deal with this problem. Currently, however, most of the sludge waste is directly discarded in landfills. In the present study, water-purified sludge waste received a heat treatment at $1300^{\circ}C$ and was then ground into particles to be used as a ceramic material. Next, the resultant particles were compounded with chamotte substitutes to produce grogged clay that is suitable for wheel-throwing ceramics. Consequently, the plasticity of the sludge waste decreased as the content of calcination increased. Thus, it is considered that wheel throwing is available only up to PBF-3. Thus, it is available for wheel throwing and has a high strength of 864 $kgf/cm^2$ with less than 0.2 percent of porosity and absorption ratio were displayed in PBF-2 at $1280^{\circ}C$ with 20 percent of calcination from the purified sludge. Therefore, the PBF-2 body produced in this study was considered to be capable of replacing grogged clay in the market.