• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.62-67
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• 2016

In this study, a pellet-type adsorbent was prepared by using the water-treatment sludge as a raw material, and its physical and chemical properties were analyzed through $N_2$-adsorption, XRD, XRF, and $NH_3$-TPD measurements. Adsorption performance for gaseous ammonia and formaldehyde was compared between the pellet-type adsorbents prepared from water-treatment sludge and the impregnated activated carbon. Although the surface area and pore volume of the pellet-type adsorbent produced from water-treatment sludge were much smaller than those of the impregnated activated carbon, the pellet-type adsorbent produced from water-treatment sludge could adsorb ammonia gas even more than that of using the impregnated activated carbon. The pellet-type adsorbent prepared from water-treatment sludge showed a superior adsorption capacity for ammonia which can be explained by chemical adsorption ascribed to the higher amount of acid sites on the pellet-type adsorbent prepared from water-treatment sludge. In the case of formaldehyde adsorption, the impregnated activated carbon was far superior to the adsorbent made from the water-treatment sludge, which can be attributed to the increased surface area of the impregnated activated carbon.

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.575-579
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• 2007

Sludge disposal technology has been studied with many researchers since disposal of sewage sludge has been a social problem. The current technologies include incineration, carbonization, pyrolysis, landfilling and fertilization. However, all of these processes require a dry process, because sewage sludge with more than 80% high water content is difficult to be used as a raw material. This study has the purpose to establish the optimal operation conditions and the technology as changing the variables: kiln residence time, sludge load, dryer temperature, by using the previous study that is rotary kiln type dryer designed as a numerical simulation study. As the results, optimum conditions are determined as follows: kiln residence time, sludge load, dryer temperature are $62.5kg/m^3{\cdot}hr$, 26.2 min, $330^{\circ}C$, respectively. Content of water, drying efficiency, weight loss, volume loss show that the results are $10{\pm}2$, 88, 80, 60%, and the dried sludge is released by a dryer below 10 mm.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.228-231
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• 2012

In this work, the mixture of sewage sludge incubated in an anaerobic bioreactor for 35 days and paperboard sludge was treated in a batch anaerobic digester equipped with a ultrasonicator, and methane production during the treatment was investigated. The Soluble Chemical Oxygen Demand (SCOD) increased with increasing the amplitude of ultrasonicator, which help solubilizing paperboard sludge more effectively. The optimum amplitude of ultrasonicator for the enhancing methane productivity was found to be $142.5\;{\mu}m$ and the methane production amount increased as the anaerobic digestion period became longer. In addition, the anaerobic digestion was performed with various biomass (6000, 9000 and 12000 mg/L) and methane production increased with higher cell mass. These results will be used as valuable data to enhance the methane production from anaerobic digestion of the high concentration of organic wastes containing the paperboard sludge and sewage sludge.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.1-8
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• 2016

This study assessed the feasibility of odor removal by the application of Bacillus sp. that has many advantages in sewage treatment to sewage sludge. The NH3 removal rates in the treatment of primary sludge using only aeration were measured at 24, 48, and 72 hours of treatment and the results were 12.5 %, 12 %, and 42.1 %, respectively. The NH3 removal rates of a reactor injected with BIO-CLOD made by solidifying Bacillus sp. concentrated 10 % together with other substances were measured after 24, 48, and 72 hours of treatment and the results were 43 %, 70 %, and 81 % respectively. In the cases where the Bacillus sp. cultured in NB medium was injected into the primary sludge reactor to reach injection rates of 0 %, 1.7 %, 3.3 %, and 6.7(v/v%), the TVOC removal rates measured when 72 hours had passed after the injection were 59 %, 71 %, 88 %, and 98 % respectively, which were higher than the NH3 removal rates as the NH3 removal rates measured at the same time were shown to be 29 %, 25 %, 31 %, and 48 %, respectively. In the sludge dewaterability conducted with various Bacillus sp. injection concentrations, a Bacillus sp. concentration of 4(v/v%) was considered to be suitable. The Bacillus sp. concentrations and reduction in the bad odor substances were correlated with each other. The results showed that aeration and Bacillus sp. injection will assist biological oxidation so that the bad odor substances can be removed. Based on the SRF values of the primary sludge and digested sludge, in which Alum and PAC were used, the appropriate amount of Alum aggregate reagent was judged to be 500 mg/L, and when PAC was used, 6 mg/L was judged to be appropriate.

• Environmental Engineering Research
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• v.14 no.1
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• pp.48-52
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• 2009

Solubilization of sewage sludge creates favorable conditions for anaerobic microorganisms to produce biogas. In this paper, we quantify the effect of heating pretreatment on the degree of solubilization of sewage sludge. The pretreatment process was carried out using a lab-scale industrial microwave unit (2450 MHz frequency). Response surface analysis was applied to determine the combination of temperature-increase rate (ramp rate) (2.9 to 17.1 ${^{\circ}C}$/min) and terminal temperature (52 to 108${^{\circ}C}$). Both ramp rate and temperature significantly affected the solubilization degree of sludge. Within the design boundaries, the conditions predicted to maximize the solubilization degree of 15.8% were determined to be 2.9 ${^{\circ}C}$/min and 104${^{\circ}C}$.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.287-290
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• 2007

We investigated the effect of ultrasound on the dewaterability of sewage sludge. Because, dewatering and disposal of waste sludge is a major economical factor in the operation of wastewater treatment plants. Capillary Suction Time(CST) and Specific Resistance to Filtration (SRF) were used to evaluate the sludge dewatering behaviors. From the results of the experiment, it was found that ultrasonic treatment can improve the dewaterability. We discovered that CST and SRF were highly related, according to the correlation coefficient($R^{2}$).

• Journal of the Korea Safety Management & Science
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• v.21 no.4
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• pp.45-49
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• 2019

The basalt fiber is expected to become a trend for industrial fibers as they have better properties of heat-resistant, non-combustion, absorbent, soundproof, moistureproof, lightweight, corrosion resistant, and high strength properties. Also, the fiber is found to be non-toxic and harmless to the human body. Therefore, in this study, we analyzed the chemical and mineral compositions of powdered sludge of basalt produced at seven sites on Jeju Island for the development of fire resistance insulating material for a building. The results showed that the basalt stone sludge is made from only sodium calcium aluminum silicate and ferridioside components unlike the basalt rock.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.150-152
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• 1998

Now the lack of water is serious problem all over the world because of the growth of population and expansion of industrial activities. So wastewater recycle and reuse is essential in many countries. One of the most popular wastewater treatment processes is conventional activated sludge system. In spite of significant degree of treatment rate the biological process has some operational difficulties and capital disadvantages. In conventional activated sludge process, sludge settling condition is getting worse in case of sludge bulking, it is common that overall process fails due to wash-out of biomass causing low concentration of MLSS in the aeration tank. Because of the absence of claifier the membrane bioreactor(MBR) process is less affected by such problems.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.613-619
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• 2018

In this study, various influent sludge pre-treatment methods and the internal recirculation of thickened sludge from effluents using a liquid/solid separation unit were adopted to investigate their effects on the sludge digestion and methane production in a combined mesophilic anaerobic and thermophilic aerobic sludge digestion process. A lab-scale combined sludge digestion process was operated during 5 phases using different feed sludge pre-treatment strategies. In phase 1, the feed sludge was pre-treated with a thermal-alkaline method. In contrast, in phases 2, 3 and 4, the internal recirculation of thickened sludge from the effluent and thermal-alkaline, thermal, and alkaline pre-treatment (7 days) were applied to the combined process. In phase 5, the raw sludge without any pre-treatment was used to the combined process. With the feed sludge pre-treatment and internal recirculation, the experimental results indicated that the volatile suspended solid (VSS) removal was drastically increased from phases 1 to 4. Also, the methane production rate with the thermal-alkaline pre-treatment and internal recirculation was significantly improved, showing an increment to 285 mL/L/day in phase 2. Meanwhile, the VSS removal and methane production in phase 5 were greatly decreased when the raw sludge without any pre-treatment was applied to the combined process. Considering all together, it was concluded that the combined process with the thickened sludge recirculation and thermal-alkaline pre-treatment can be successfully employed for the highly efficient sewage sludge reduction and methane gas production.

• Resources Recycling
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• v.25 no.1
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• pp.10-15
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• 2016

In recent years, in terms of environmental protection and efficient use of the land, efficient utilization of byproducts and wastes generated in industrial areas are emerging. In this study, for the effective utilization of using ever increasing amount of utilizing sewage sludge incineration ash to increase sewage sludge, it is evaluated the use of as an construction material. After making concrete specimens, it is evaluated compressive strength, carbonation and environmental resistance. From the experimental results, compared with concrete without sewage sludge it is obtained satisfactory results for compressive strength and carbonation and results of the leaching test also satisfies the standard value. So, it is sufficient possibility using of concrete aggregate and the replacement rates is judged to be about 10%.