• Journal of Environmental Science International
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• v.7 no.4
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• pp.559-564
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• 1998

The effects of temperature, initial $Pb^{2+}$concentration and initial sludge concentration on the initial $Pb^{2+}$ removal rate and maximal $Pb^{2+}$removal amounts in activated sludge, respectively, were investigated. The removal of $Pb^{2+}$ in activated sludge was proved to be temperature-dependent process. The initial $Pb^{2+}$ removal rate increased from 187.5 to 261.4 mg $Pb^{2+}$/g sludge dry weight min, in response to the promoted temperature from 1$0^{\circ}C$ to 6$0^{\circ}C$, while the maximal $Pb^{2+}$removal amount (78.5 mg $Pb^{2+}$/g sludge dry weight) occurred at 30t . As the initial $Pb^{2+}$concentration increased from 36 to 228 mg $Pb^{2+}$/L at the constant temperature of 30C and initial sludge concentration of 1.5 g sludge dry weight/L, the time to reach an equilibrium state was almost independent of the initial $Pb^{2+}$concentration and the equilibrium $Pb^{2+}$/removal amount was increased Irom 41.9 to 73.6 mg $Pb^{2+}$/g sludge dry weight. On the contrary, the equilbrium $Pb^{2+}$ emoval amount was decreased from 87.7 to 65.3 mg $Pb^{2+}$/g sludge dry weight as the in- crease of initial sludge concentration from 0.22 to 1.76 g sludge dry weight/L.

• Korean Journal of Environmental Agriculture
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• v.22 no.1
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• pp.70-73
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• 2003

Nitrate contamination in the aquatic systems is the primary indicator of poor agricultural management. The influence of sewage sludge application rates (0, 10, 25, 50 and 100 dry Mg/ha) on distribution of nitrate originating from the sewage sludge in soil profiles was investigated. Soil profile monitoring of nitrate was carried out with a Lakeland clay soil in 1997. Irrespectively of the sewage sludge application rates up to 50 dry Mg/ha, the concentration of $NO_3$-N at the 120 cm depth was below 10 mg/kg and the difference due to the amount of sewage sludge application was negligible at this depth. There was virtually no $NO_3$-N below 120 cm depth and this was confirmed by a deep sampling up to 300 cm depth. Most of the nitrate remained in the surface 60 cm of the soil. Below 120 cm depth nitrate concentration was very low because of the denitrification even at high sewage sludge rate of 100 dry Mg/ha. The $NO_3$-N concentrations in the soil fluctuated over the growing season due to plant uptake and denitrification. The risk of groundwater contamination by nitrate from sewage sludge application up to high rate of 100 dry Mg/ha was very low in a wheat grown clay soil with high water table ( < 3 m).

• Journal of the Korea Institute of Building Construction
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• v.13 no.2
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• pp.131-138
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• 2013

This study was carried out to investigate the possibility of using basalt powder sludge instead of sand in a normal cement dry mortar as a way to recycle basalt powder sludge, which is a waste product from the manufacturing a process of basalt in Jeju. Basic performance evaluations of the dry mortar material included a compressive strength test, a flexural strength test, and SEM to observe the micro structure. The compressive and flexural strengths were increased to a replacement ratio of 21% of basalt powder sludge, whereby a strength enhancement of about 40% greater than that of normal dry mortar was shown. However, the creation of hydration products affected the replacement ratio of the basalt powder sludge. The possibility of using basalt powder sludge waste was identified in this study, and results showed that the basalt powder sludge waste could be used as a material for a secondary product of concrete.

• Analytical Science and Technology
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• v.15 no.5
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• pp.451-458
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• 2002

Determination were performed for the presence of three common environmental endocrine disrupting compounds (EDC), namely nonylphenol (NP), octylphenol (OP), di (2-ethylhexyl)phthalate in sewage sludge from 67 wastes plants, using Soxhlet extraction and GC/MS-SIM. NP and DEHP were detected in almost every sludges but OP was not detected. The range and mean value for NP of all sludge samples were nd~593, $62{\mu}g/g$ dry and the two statistic values for DEHP of those were 13~4733, $1176{\mu}g/g$ dry respectively. DEHP content was 20 times greater than NP in sludges. Concentrations of NP and DEHP in sludge from individual area were increased as following order ; Jeolla South and North Province (Cheju) < Chungcheong South and North Province (Kwangwon) < Gyungsang South and North Province < Wide City < Kyunggi Province.

• Asian Journal of Turfgrass Science
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• v.8 no.2
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• pp.93-100
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• 1994

This experiment was carried our in order to study effect of alum sludge compost of water treat-ment plant on the growth of Korean lawngrass (zoysia japonica Steud.) and on the change of soil chemical properties. Alum sludge compost was made out of chicken feces, sawdust and alum sludge. The results obtained are summarized as follows : 1. Alum sludge compost was appropriate for organic fertilizer of turfgrass management in golf course. 2.Application of alum sludge compost improved the chemical properties of soil such as pH, available phosphorous and exchangeable calcium. Also the growth of Korean lawngrass grown by the mixed application of alum and compost was more effective than that in single application of compost. 3.Chlorophyll content of Korean lawngrass had no differences in several treatments. 4. Alum promoted the uptake of potassium, calcium and the yield of dry weight hut the yield of dry weight was not affected by chemical fertilizer. 5.Alumimum toxicity was decreased by the mixed application of alum and compost but increased by single application of alum.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.52-60
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• 2004

The basic approach to sewage sludge is organic waste minimization, promotion of energy recovery; volume and weight reduction by final treatment, and environmentally final disposal of natural circulation. Dry and pyrolysis of maize was experimentally investigated in full-scale rotary kiln in semi-continuous operation. The operational parameters varied are the operating temperature $160{\sim}175^{\circ}C$ of dry and $450{\sim}800^{\circ}C$ of pyrolysis, the solids residence time 9 min for pyrolysis. Important parameters studied include the running time, water content of sewage sludge, solids amount of sewage sludge(TS%) by the varied temperature. Also, with the increasing of temperature, how the yield of oil and char product change was observed, and the distribution of gas production components was observed. The gas of $C_1{\sim}C_3$ yield increased and oil of $C_4{\sim}C_6$ yield decreased along with pyrolysis temperature of $670^{\circ}C$ by the run time of 9 min.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.735-742
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• 2008

In order to evaluate the levels and distribution patterns, the concentrations of PAHs and chlorophenols were investigated in sludge samples discharged from 6 WWTPs located along Nak-dong river and 7 STPs in Busan, Korea. Levels of 16 PAHs and 19 chlorophenols in sludge samples ranged from 1.28 to 44.9 mg/kg dry wt. and from 213 to 3,850 $\mu$g/kg dry wt., respectively. Levels of PAHs in sludge samples except I5 and S4 were detected lower than those of previous studies. The distribution patterns of PAHs and chlorophenols varied with industrial wastewater sludge samples because industrial wastewater sludge had different industrial input sources. However, the distribution patterns of PAHs and chlorophenols in sewage sludge were pretty similar. Phenanthrene, fluoranthene and pyrene were dominant and the fractions of these 3 PAHs relative to 16 PAHs in sewage sludge ranged from 30.8 to 50.7%. 2-chlorophenol is dominated in most sewage sludge samples and the fraction ranged from 36.0 to 66.8%.

• Journal of environmental and Sanitary engineering
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• v.12 no.2
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• pp.13-21
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• 1997

The effect of upflow velocity on size distribution and activity of granular sludge was studied in laboratory-scale Expended Granular Sludge Bed(EGSB) reactor fed with non-fat dry milk and sucrose as sole carbon and energy source. High upflow velocity advanced size and activity of granular sludge by distribution and floatation of granular sludge. Therefore, the reactor operation of an apt upflow velocity was needed and an apt upflow velocity in this experimental was estimated to 1-10m/hr.

• Korean Journal of Organic Agriculture
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• v.9 no.1
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• pp.37-49
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• 2001

This experiment was carried out to investigate the effects of application levels of nightsoil sludge compost(NSC) in 3 and 4 cuttings per annum on the dry matter yields and nutritive value of orchardgrass(Dactylis glomerata L.). Annual nightsoil sludge compost(NSC) were applied at levels of 0, 10, 20, 40 and 80 ton $㏊^{respectively}$ . Relative yields of each cut to annual dry matter yield were 29.9%, 46.% and 23.2% for 1st cut, 2nd cut and 3rd cut in 3 cutting system, 23.7%, 29.3%, 34.0% and 13.0% for 1st cut, 2nd cut, 3rd cut and 4th cut in 4 cutting system, respectively. Significantly higher dry matter yield of orchardgrass obtained were 8.11 ton $㏊^{-1}$ at level of 40 ton ㏊$^{-1}$ $yr^{-1}$ in 3 cutting systems, ranges of 7.50~10.71 ton $㏊^{-1}$ at level of 10~80 ton ㏊$^{-1}$ $yr^{-1}$ in 4 cutting systems than those of non application level of NSC, respectively(p〈0.05). The mean efficiency of dry matter production to application of NSC(kg DM/ton NSC) were 46 and 102 kg in 3 and 4 cutting systems, respectively. Although th contents of crude protein(CP, %) of orchardgrass were significantly higher at the application levels of 10~80 ton $㏊^{-1}$ $yr^{-1}$ -1/ by NSC than those of the application levels at the 0 ton $㏊^{-1}$ $yr^{-1}$ in 3 and 4 cutting systems(p〈0.05), the contents of neutral detergent fiber(NDF, %) and acid detergent fiber(ADF, %) were lower in NSC plots than those at the non-application plots of NSC. The contents of total digestible nutrient(TDN, %) and relative feed value(RFV) of orchardgrass were significantly increased with increase the applicaton levels of NSC(p〈0.05).

• Journal of Korean Society of Water and Wastewater
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• v.28 no.1
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• pp.135-142
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• 2014

The performance of inorganic sludge separation system is evaluated. Anaerobic digester effluent sludge is used for feed sludge of this system and hydrocyclone is used for inorganic sludge separation. For phosphorus removal and recovery $MgCl_2$ is pumped into MAP growth tank, a component of inorganic sludge separation system. Using this system inorganic sludge which contained less than 40 % of organic matter can be discharged stably and the maximum amount of separated inorganic sludge is 13.4 % of influent sludge based on dry solid. The amount of phosphorus recovered as MAP(as P) is 16.7 % to influent T-P.