In this study, hydrothermal carbonization is used to recover energy from sludge. This hydrothermal carbonization is a feasible sustainable energy conversion technology to produce biofuel for renewable energy. The experiments were conducted at 170oC up to 220oC for a 30-min holding period to determine the optimum conditions for hydrothermal carbonization in a lab-scale reactor to apply to a scale-up reactor (1 ton/day). The biochars from sludge were assessed in terms of dewaterability characteristics and fuel properties. The results showed that the optimum temperature of labscale hydrothermal carbonization was 190oC. The 1 ton/day hydrothermal carbonization pilot plant operated at 190oC. The biochar had higher energy content but the char yield sharply decreased. Therefore, an energy of about 49% could effectively be converted from sludge biomass. This sludge from municipal wastewater treatment is a potential energy resource because sludge is composed of organic substances.

In this study, content and leaching tests of heavy metals (14 items) were analyzed to evaluate the recyclability of the sludge from wastewater treatment facilities. Additionally, this was compared with and examined with the standard of controlled waste, certification standards of compost materials, etc. In the results of the content test, Cr6+ (30.82 mg/kg) of waste from the leather, fur, and textile industries (EWC 04) and Cr6+ (103.13 mg/kg) of waste from the manufacture formulation, supply, and use of coatings (EWC 08) were higher than the proposed criteria of Cr6+ (20 mg/kg). The high level of Cr6+ concentration was observed because of the use of sodium dichromate and chromic anhydride in the materials of dyestuffs and pigments and ink in the EWC 04 and EWC 08 processes. The results on sludge in this study did not meet the standard of the Fertilizer Control Act and quality standard of fuels. In particular, the high levels of Pb and Cd was the main reason.

This paper assesses the feasibility of producing fuel energy from sewage sludge via four processes: microwave-induced pyrolysis/gasification and conventional pyrolysis/gasification. Both pyrolysis and gasification produced gas, char, and tar. The gas produced for the gasification contained mainly hydrogen and carbon monoxide with a small amount of methane and hydrocarbons (C2H4, C2H6, C3H8). However, the gasification produced higher carbon monoxide instead of the hydrogen. The microwave gasification generated higher heavy tar compared to other processes. As a light tar, benzene generated higher value for both the pyrolysis and gasification. The sludge char showed a vitreous-like texture for the microwave process and a deep crack shape for the conventional heating process. These results indicate that the gas produced from the microwave processes of wet sewage sludge might be usable as a fuel energy source, but this would require removal of the condensable PAH tars. The sludge char produced could also be used as a solid fuel or adsorbent.

In this study, GC-MS linked with an automatic thermal desorber was used to quantitatively analyze the odorous and volatile compounds in the gas emitted from a sewage sludge drying facility. In addition, the removal characteristics of these compounds were investigated by using a pilot-scale packed bed wet scrubber. A quantitative analysis for 58 odorous and volatile compounds in the gas was successfully achieved with GC-MS and GC-FPD. The a quantitative analysis revealed the major odorous compounds were hydrogen sulfide and acetaldehyde. In addition, D-type siloxane compounds such as octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), were quantitatively measured. The concentrations of siloxane compounds measured in the gas were in the range of 4.54- 7.36 ppmv, higher than those in landfill gas. The average removal efficiency of the odorous and volatile compounds in a wet scrubber was 67.37%. D4, D5, and D6, which are hydrophobic compounds, were also removed by as much as 50.68%, 44.56%, and 70.26%, respectively.

This research intends to develop a photocatalytic concrete enabling to decompose the nitrogen oxides (NOx) using a titanium oxide photocatalyst for reducing the cost. In details, this research develops the mix composition of the photocatalytic concrete exhibiting photolytic characteristics and establish the technology enabling to reduce the emission of air pollutant caused by nitrogen oxides.

In this study, the recycling water that produced during remicon manufacturing was activated by desulfurization gypsum, and then mortar with activated-sludge was made. As a result, possibility of activated-sludge in remicon was verified via flow and compressive strength test.

In this paper, we investigate the pozzolanic reaction of the waste glass sludge incorporating precipitation additives experimentally. The consumption of calcium hydroxide, and the compressive strength were tested for two different types of the waste glass sludge depending on whether precipitation additives were used.

Concrete and bar of bond performance used in the most RC structure. So Through recent studies and experiments for the attachment behavior of concrete and steel issues and evaluate their characteristics. Bar are two was used as the D13 and D16. The Bond stress was increased result of experiment by placing a variable length according to the Bond stress formulation according to the diameter and reinforced.

Domestic sewerage treatment plant is operated by activated sludge method and its modified method by using microorganism. In most cases, a method of using microorganism is directly controlled by the operator based on individual judgment through factors of DO, pH and ORP. In addition, under aerobic condition in bioreactor, energy consumption including excessive air injection is learned to be somewhat plenty. In order to solve this problem, in most of the process, improvement of internal recycling and activated environmental factor of microorganism were researched extensively. However, as factors are changed depending on various conditions, it is not sufficient as an indicator of judgment. As such, a research on operation of bioreactor that measures metabolic change in short time by directly measuring activated condition of microorganism using NADH fluorometer is required in reality.It is considered that the method like this could supplement problem of energy consumption being occurred in the existing treatment method and operational optimization of bioreactor would be enabled by controlling optimal air volume. Therefore, in this study, in order to obtain optimal operational indicator of bioreactor, proper air volume control test was performed and through batch test and site evaluation, possibility of NADH sensor being utilized as operational control indicator of bioreactor is intended to be analyzed. In order to compare with measured value, DO, ORP that are operational control indicator of existing bioreactor were used. As MLSS concentration was increased through batch test, NADH value was increased and site evaluation also showed similar tendency to batch test. Resultantly, it could be confirmed that changing level of NADH fluorometer was a sensor that could measure bioreactor condition effectively and optimized scale of bioreactor is considered to be utilized.

The objective of this study was to evaluate the microwave drying characteristics of mixtures of chemical wastewater sludge (70~90%) and anthracite coal (10~30%) with respect to physical and economic factors such as mass, volume reduction, moisture content, drying rate and heating value when the wastes were dried at different weight mixing ratio and for different microwave irradiation time. The drying process were carried out in a microwave oven, the combined drying process with a 2,450 MHz frequency and 1 kW of power. Maximum dry rates per unit area on the microwave drying of mixtures with chemical wastewater sludge and anthracite coal were 35.5 kg H2O/m2·hr for Cs90-Ac10; 40.1 kg H2O/m2·hr for Cs80-Ac20 and 35.0 kg H2O/m2·hr for Cs70-Ac30. The result clearly indicated that moisture can be effectively and inexpensively removed from the wastes through use of the microwave drying process.

Since sewage sludge has low heating value as an energy source, it is desirable that sewage sludge is mixed with woody waste to enhance energy potential. Among thermal methods for waste to energy, carbonization process is used in this study. In order to estimate reaction kinetics for carbonization process using mixture of woody waste and sewage sludge, the content of sewage sludge is varied from 10 ~ 30% in mixture of woody waste and sewage sludge in carbonization process. Carbonization time is changed from 10 min to 50 min and carbonization temperature is varied from 250oC to 350oC. The carbonization process for mixture of woody waste and sewage sludge was optimized at carbonization temperature of 300oC for 20 min, 20% of sewage sludge content. As increased carbonization temperature, reaction rate constant, frequency factor and degree of carbonization were increased. As increased the content of sewage sludge, conversion, ash content and degree of carbonization were decreased. At optimal conditions for carbonization process, frequency factor and activation energy in Arrhenius equation can be decided by 3.61 × 10−2 min−1, 7,101.8 kcal/kmol respectively.

By the strengthening of sewage treated quality law and the amount of sewage sludge every year is increasing in Korea. However, it is difficult to disposal of sewage sludge due to ocean dumping restriction. As an alternative to this, drying, incineration, anaerobic digestion etc. is applied, which is uneconomical in most be processed by the consumption of energy. In particular, anaerobic digestion technology has been installed in the sewage treatment 65 plats in Korea’s STP(sewage treatment plant). It is most of the digestion efficiency requires the application of improved technology to less than 50%. As an improvement technology for most anaerobic digester, ultrasonic, electronic beam, ozone etc. solubilization method using has been mainly used. Therefore, in this study, after the wet milling particles of sludge to subject the sludge that has not been decomposed in the digested sludge circulating fluid of anaerobic digestion, was let examine the characteristic at the time of ozonation. The size of the particles before and after the wet milling, which is the measurement at each 105.26 μm and 77.18 μm, solubilization rate is increased to 23.5%. When ozonation after wet milling using sludge is determined as possible to improve the efficiency.

Methanogenic community shift and comparison were determined by 454 pryosequencing for two different full-scale anaerobic digesters treating municipal sludge. For monitoring long-term of microbial communities, samples were collected for two year at three-monthly basis. The two mesophilic AD bioreactor were operated at similar operating conditions, but different substrate streams. Methanospirillum were identified as the key drivers of methanogenesis in full-scale anaerobic digester treating municipal sludge. In Joongrang (JR) digester, Methanospirillum was dominant (48%±10.3) over almost all period, but the dominant genus move to Methanosaeta and Methanoculleus due to low acetate concentration (0.02 g/L), total ammonia nitrogen concentration, respectively. In Asan digester (AS), Methanospirillum also was dominant (41%±12.6) like JR digester, but methanogenic community shift was examined twice. One of those was from Methanospirillum to Methanophaerula due to pH sharply decrease (<5.5) and second shift was Methanosaeta increase due to low VFAs concentration (0.25 g/L).

The composting characteristics of BM sludge and the control sludge were compared. Feasibility of using coffee groundsas a bulking agent was examined, along with sawdust. It was observed that composting of BM sludge had a faster rateof reaction than with the control sludge, and higher temperatures were reached. When using coffee grounds as a bulkingagent, the caffeine in the coffee seemed to absorb the odors, allowing a composting with almost no odors. Moreover,when coffee grounds used as the bulking agent, total organic matter content increased by approximately 17% over sawdust,while total nitrogen increased by 49%, and available phosphorus by approximately 3%.

This study was intended to estimate the effect of adding stone dust sludge into concrete strength characteristics. it was found that the partial replacement of fine aggregate with stone dust sludge had an positive effect on the strength of concrete.

For the CLMS using FA as powder and S and SS as fine aggregates, respectively, in order to improve flowability by preventing material separation and securing quantity of minimum unit and to secure maximum strength by repressing bleeding, the most reasonable and optimal combinations of FA+S and FA+SS were f/a 20 and f/a 60, respectively.

This study provides an experimental result of thermal mercury reduction and condensation characteristics for inventing a mercury recovery technology from the waste sludge which contains high concentration of mercury. Thermal treatment was conducted in the temperature range of up to 900oC from 600oC with different residence time using a waste sludge from domestic industrial facility. Properties of powder material condensed after thermal treatment were analyzed to assess the effectiveness of thermal processing. Leaching characteristics of bottom ash and condensed powder material were analyzed by Korean Standard Leaching Test method (KSLT). Cold vapor atomic absorption spectroscopy (CVAAS) Hg analyzer was used for the analysis of mercury content in solid and liquid samples. We found that mercury contents was concentrated compared with waste sludge. However, the mercury concentration of leached solution from the condensed powder material was very low. The chemical characteristics of condensed powder material was estimated using experimental analysis and literature survey. In order to recover purified elemental mercury, the further researches of refining experiments would be required.

According to the elementary analysis on organic wastes, the C/N ratio, a major condition for anaerobic digestion, is 5.40 to 9.23, except for food waste leachate (FWL). Defined by Tchobanoglous’ mathematical biogas prediction model, methane gas and biogas productions increased, depending on the mixing rate of FWL. Furthermore, anaerobic digestion both wastewater sludge and food waste leachate based on the right mixing ratio, increases methane gas productions compared to digesting wastewater sludge alone. In other words, co-anaerobic digestion is more likely to realize biogasification than single anaerobic digestion. We mix food waste leachate and wastewater sludge from the dairy and beer manufacturing industry by the proportion of 1 : 9, 3 : 7 and 5 : 5. It turns out that they produced 118, 175 and 223 CH4 mL/g VS in the dairy manufacturing and 176, 233 and 263 CH4 mL/g VS in beer manufacturing of methane gas. The result suggests that as the mixing rate of food waste leachate rises, the methane gas productions increases as well. And more methane gas is made when co-digesting wastewater sludge and food waste leachate based on the mixing ratio, rather than digesting only wastewater sludge alone. Modified Gompertz and Exponential Model describe the BMP test results that show how methane gas are produced from organic waste. According to the test, higher the mixing rate of food waste leachate is, higher the methane gas productions is. The mixing ratio of food waste leachate that produces the largest volume of methane gas is 1 : 9 for the dairy industries and 3 : 7 for brewery. Modified Gompertz model and Exponential model describe the test results very well. The correlation values (R2) that show how the results of model prediction and experiment are close is 0.920 to 0.996.

Torrefaction is a treatment which serves to improve the properties of biomass in relation to thermochemical processing techniques for energy generation. In this study, the torrefaction of sewage sludge, which is a non-lignocellulosic waste was investigated in a horizontal tubular reactor under nitrogen flow at temperature ranging from 150-600℃. The torrefied sewage sludge products were characterized in terms of their energy yield, ash content and volatile fraction. The energy and mass yields decreased with an increase in the torrefaction temperature. The pelletization and the combustion characteristics of the torrefied sewage sludge was studied in isothermal and non-isothermal conditions.

This study of the electrolysis reaction fillers and electrolytic treatment sludge generated by checking the status and properties of the sludge before and after electrolysis filler caused by a reaction to examine the water-soluble cutting oil sludge and organic matter removal mechanism of filling in the packed bed bipolar electrolytic reactor was to identify the characteristics. Delivery was analyzed using a SEM (scanning electron microscope) recording method for the filling material in the GAC surface characterization of the packed bed bipolar electrolytic reactor to look at the reaction of the waste water generated by the electrolytic removal reaction. Sludge generated in order to analyze the properties of XRD(x-ray diffraction) was analyzed using the device. The video of the GAC surface before and after the reaction was taken by SEM, it can be known indirectly the change between the voids in the GAC in figure before and after. Prior to the electrolytic treatment can be seen that there is some contamination between the pores, but it can be seen that after the treatment, rather than clean the pores of the GAC. This photograph of the surface after the electrolytic treatment, GAC is decomposed organic material adsorbed on the surface by dissolution of ions at the anode acting on bipolar electrolytic, it is corroded, it is possible to observe what happens. It was found to form iron oxide when analyzing the electrolytic sludge using XRD. Properties of the sludge generated after electrolysis, was composed primarily of oxygen and iron. These results wastewater treatment by filling in the electrolytic cell is that it indirectly proves to occur by electrolysis removal, it is considered to be able to demonstrate the deletion mechanism indirectly.