• Journal of Environmental Science International
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• v.28 no.7
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• pp.607-615
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• 2019

The purpose of this study is to biological treatment of high salinity wastewater using Aerobic Granular Sludge (AGS). In laboratory scale's experiments research was performed using a sequencing batch reactor, and evaluation of the denitrification reaction in accordance with the injection condition of salinity concentration, surface properties of microorganisms, and sludge precipitability was performed. The results showed that the salinity concentration increased up to 1.5%, and there was no significant difference in the nitrogen removal efficiency; however, it showed a tendency to decrease gradually from 2.0% onward. The specific denitrification rate (SDNR) was 0.052 - 0.134 mg $NO_3{^-}-N/mg$ MLVSS (mixed liquor volatile suspended solid)${\cdot}day$. The MLVSS/MLSS (mixed liquor suspended solid) ratio decreased to 76.2%, and sludge volume index ($SVI_{30}$) was finally lowered to 57 mL/g. Using an optical microscope, it was also observed that the initial size of the sludge was 0.2 mm, and finally it was formed to 0.8-1.0 mm. Therefore, salinity injection provides favorable conditions for the formation of an AGS, and it was possible to maintain stable granular sludge during long-term operation of the biological treatment system.

• Journal of Applied Biological Chemistry
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• v.44 no.2
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• pp.95-97
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• 2001

• Journal of Life Science
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• v.33 no.1
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• pp.82-90
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• 2023

Biological process is used worldwide to treat domestic and industrial wastewater. The process generally uses a mixed microbial culture of sludge. The growth of microorganisms in the sludge produces excess sludge from the wastewater treatment process. Some of the excess sludge is recycled as inoculum for wastewater treatment, but the rest is removed as waste from the process. As wastewater production is increasing worldwide every year, the number of wastewater treatment plants (WWTPs) is also in- creasing, resulting in the generation of large amount of waste sludge. The increasing amount of waste sludge from WWTPs has led to concerns about its management. Sludge disposal has been reported to account for 50~60% of the total operating costs of a WWTP. Sludge disintegration is a new technology that can minimize volume of waste sludge and recover useful components (e.g., P, N, and soluble organic compounds) from it. Various methods of sludge disintegration have been developed based on physical, chemical, and biological treatments or combinations of these. In this review, we focus on sludge disintegration by acid hydrolysis, which is less studied among sludge disintegration methods. Such information can be useful in the development and implementation of a new technology for better sludge treatment.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.225-230
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• 2010

Dumping of waste sludge to ocean will be prohibited in Jananuary, 2012. Thus, various methods of sludge recycling are intensively studied. To present new way of sewage sludge recycling method, feasibility of making porous biological support media was investigated. Porous biological support media was made of sludge cake from sewage treatment plant and loess. They were mixed in varying ratio and burnt in high temperature to ensure sufficient mechanical strength. It was evaluated that about 67% of sewage sludge were ignitible. The ignitible portion play an important role in making pore in biomedia during ignition process. It was evaluated that optimum mixing ratio of loess to sludge cake was 25% in respect of compressive strength. In results of observation using scanning electron microscope (SEM), inner structure of biomedia become simple when the contents of loess are increased.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.561-570
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• 2013

There are two types of rectangular secondary clarifier at biological nutrient removal (BNR) facility to settle MLSS; conventional activated sludge secondary clarifier and Gould Type I clarifier. In this study, the performances of two types at respective biological nutrient removal facility are compared using weekly operational data. Surface Overflow Rate (SOR), Surface Loading Rate (SLR), Sludge Volume Index (SVI), secondary effluent SS concentration are studied. It has found that Gould Type I has 3.5 times less average secondary effluent SS concentration that is 2.4 mg/L than that of conventional activated sludge secondary clarifier. Both SOR and SLR have shown little effect on secondary effluent SS concentrations at Gould Type I clarifier in contrary that SOR affects the secondary effluent SS concentrations at conventional activated sludge rectangular secondary clarifier. From this study, it is recommended that Gould Type I must be considered for secondary clarifier when BNR plant is designed.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.77-88
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• 1994

This experiment was carried out to investigate the effect of sewage sludge compost amended soils on the growth and accumulation patterns of heavy metals in plant parts of Orchardgrass seedlings, changes in physical properties and chemical composition, and heavy metal residue in soils. Mixture ratios of sewage sludge compost and soil(loam) were 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100(control), respectively. The results obtained were as follows; 1. The physical properties and chemical compostion of soils were improved by increase in mixture ratios of sewage sludge compost. 2. The biological yield of Orchardgrass seedlings was increased with mixture ratios of sewage sludge compost. 3. The dry weight of shoot(SH) was increased with both of yield components(NT and WT) and biological yield of Orchardgrass seedlings. 4. The total nitrogen concentrations(TN) of plants was increased with quadratically up to the biological yield of 100% mixture ratio of sewage sludge compost. 5. Lead(Pb) concentration of soil in over the 60% mixture ratios of sewage sludge compost were in excess of limiting level(50ppm) of organic fertilizers.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.3
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• pp.35-43
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• 2011

In this study, anaerobic biological decomposition were attempted after solubilization treatment of sewage sludge with the complex pre-treatment (acid/base treatment with ultrasonic radiation). Solubilization ratios were compared for ultrasonic treatment at acid or base condition. Solubilization effect of the complex pre-treatment was more effective at higher pH. Biological decomposition of complex pre-treated sludge was faster than non treated (raw) sludge, showing 10 times higher total gas production. Biological digestion of the sludge shows more biogas production. B/A ratio. which indicates hydrogen production potential, was 50% higher with complex pre-treated sludge than raw sludge but lactic acid or propionic acid were also detected during anaerobic decomposition process.

• Journal of Applied Biological Chemistry
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• v.42 no.3
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• pp.134-139
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• 1999

The distributions of Cd, Cu, and Zn concentration in soil treated with one (1988) or two (1988 and 1993) applications of sewage sludge at rates of 0, 25, 50, and $100Mg\;ha^{-1}$ (dry weight basis) were determined to assess the accumulation and mobility of the heavy metals. The heavy metals accumulated almost entirely in 0 to 15 cm soil depths. Small amounts of the metals moved out of the tillage zone (0-15 cm depth) into the subsoil, but even at the high rate of sewage sludge, little movement of heavy metals occurred below 100 cm depth. The water-extractable Cd, Cu, and Zn concentrations were very low regardless of the rate of sewage sludge application. Availability of metals as determined by DTPA extraction showed the percentage of DTPA-extractable/total concentration increased with sewage sludge application. In the 0-15 cm depth of sewage sludge treated soil, the percentage of DTPA-extractable/total concentration was higher than 46% for Cd, but the value was less than 27% and 17% for Cu and Zn, respectively. The Cd, Cu, and Zn added to this calcareous clay soil by sewage sludge application were not very mobile, and the amount of plant available form was very small.

• Journal of Environmental Science International
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• v.17 no.3
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• pp.343-350
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• 2008

The fate of two cyclic ethers, THF(Tetrahydrofuran) and 1,4-Dioxane, in conventional biological wastewater treatment plants was investigated using sequential activated sludge process. Removal efficiency of THF were about 86% in average, which was greater than that of 1,4-Dioxane, 30%. However, it was not clear whether the removal of cyclic ethers in biological system was caused by microbial activity or not. Thus treatability tests were conducted by batch experiments. The effects of mixing, aeration and the addition of activated sludge on the removal of cyclic ethers were investigated in batch experiments. THF was totally removed by mixing and aeration in 24 hours while removal ratio of 1,4-Dioxane was at most 30% for the same period. This results could be ascribed to the differences in Henry's law constants between the two chemicals. In addition, biological degradation including biosorption was not obviously observed in these batch tests.

• Journal of Microbiology
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• v.41 no.2
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• pp.83-88
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• 2003

The taxonomic position of actinomycete strain SCNU5$\^$T/, isolated from extensive foam in the aeration basin of an activated sludge process, was clarified by phenotypic, chemotaxonomic and phylogenetic analyses. The strain possesses wall chemotype IV, MK-9(H$\^$0/), as the major menaquinone, and contains saturated, monounsaturated and 10-methyl branched fatty acids. The G+C content of its DNA is 68.1 mol%. Phenotypic data and DNA relatedness to known species indicate that the strain SCNU5$\^$T/ represents a new species within the genus Tsukamurella, for which we propose the name Tsukamurella sunchonensis SP. NOV. The type Strain Of T. sunchonensis is SCNU5$\^$T/ (=KCTC 9827$\^$T/).