• 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.

• Journal of Environmental Health Sciences
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• v.40 no.4
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• pp.322-329
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• 2014

Objectives: The purpose of this study was to investigate the effect of BIO-CLOD on advanced wastewater treatment for enhanced removal efficiency and meeting the stringent discharge water requirements of wastewater treatment plants. Methods: Two experimental apparatuses consisting of anaerobic, anoxic and aeration tanks were operated. One included a BIO-CLOD cultivation tank. Organic and nutrient parameters and removal efficiency were analyzed by pH, BOD, CODcr, SS, T-N and T-P. Results: The average removal efficiencies of BOD, COD and SS from the apparatus with BIO-CLOD tank installation were 95.5%, 88.6% and 92.9%, respectively, and these were higher than the results from the apparatus without BIO-CLOD. The average TP removal efficiency with BIO-CLOD tank marked 56.0%, higher than the 47.3% from the apparatus without one. BIO-CLOD showed a higher performance for TN removal at 49.6%, compared to the result without BIO-CLOD of 34.3% Conclusion: By reaction with BIO-CLOD, ammonia removal was effective in the aeration tank, as was phosphorus release in the anaerobic tank. Phosphorus luxury uptake and nitrification in aeration tank proceeded smoothly. The application of BIO-CLOD can improve the decrease of odor and settleability of activated sludge in a wastewater treatment plant, as well as increase the removal efficiency of organic and nutrient materials in water.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8665-8672
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• 2015

In this study, to investigate the feasibility of malodorous substance and organic matter removal by digest sludge in sewage treatment plants, ammonia, methyl mercaptan(MMC), and hydrogen sulfide($H_2S$) in a reactor submerged with BIO-CLOD(BIO-CLOD) and a reactor not submerged with BIO-CLOD(Non BIO-CLOD) were measured at 24 hours, 48 hours, and 72 hours after the submergence of BIO-CLOD. Whereas the reactor in which BIO-CLOD was submerged showed an ammonia removal rate of 48% and high $H_2S$ and MMC removal rates exceeding 98% in 24 hours, the reactor in which BIO-CLOD was not submerged showed an ammonia removal rate of 45%, an $H_2S$ removal rate of 71%, and an MMC removal rate of 84% in 24 hours indicating the possibility of removal of malodor using BIO-CLOD. A nitrification was shown in which ammonia concentrations decreased over time while nitrate nitrogen concentrations increased and sulfur based malodor components were oxidation decomposed indicating that BIO-CLOD had effects to increase sulfate concentrations in the solution and that sulfate concentration increases and atmospheric $H_2S$ removal rates were correlated with each other. With regard to decreases in organic matter in reactor effluents, BIO-CLOD did not affect in a short period of time and when reactors were operated with HRT 12 hours and HRT 24 hours, HRT 12 hours was considered desirable in terms of economy.

• Journal of Biosystems Engineering
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• v.43 no.3
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• pp.161-172
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• 2018

Purpose: During tillage operations, the selection of a working machine (tool) depends on the soil conditions as well as the type of tillage operation to be performed. The goal of this research was to ascertain the effects of varying working machine parameters of a compact disc harrow on tillage operations under various soil moisture content (SMC) conditions. Methods: The working machine parameters were the disc spacing and machine speed. The tillage parameters under investigation were the soil inversion ratio (SIR), tillage cutting depth (TCD), and soil clod breakage ratio (SCB). To determine the SIR, the areas of the white regions before and after tillage were obtained. The ratio of the difference of the areas of the white regions before and after tillage to the area of the white regions before tillage was considered as the SIR. The SCB was obtained as the ratio of the weight of soil clods after sieving with a mesh size of <0.02 m to the total weight of the soil clods before sieving. The soil TCD was measured using a tape measure at random points after the tillage operation. The resulting data were statistically analyzed in a one-way analysis of variance. Results: The highest soil inversion was achieved when the machine speed was 0.2 m/s with the disc spaced at 0.2 m in the 16.5% SMC. At a 0.4-m/s machine speed and 0.3-m disc spacing the highest soil breakage was achieved in the 26.5% SMC. The highest TCD was achieved at a 0.2-m/s machine speed and 0.2-m disc spacing in the 16.5% SMC. Conclusions: It was concluded that varying the working machine parameters, such as the disc spacing and machine speed, could significantly affect the soil inversion and soil clod breakage; however, it had no significant impact on the TCD.

• 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.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.2
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• pp.96-102
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• 2014

To meet the reinforced discharge standards, effect of coagulant PAC (Poly aluminium chloride, 10.4% as $Al_2O_3$) on phosphorous removal in advanced wastewater treatment process (a modified $A^2$/O). 15 mg/L of PAC determined by jar-test was added to influent of settling basin in a modified $A^2$/O consists of anaerobic, anoxic, and oxic chamber which contains Bio-clod and porous polyurethane media. Performance of PAC was tested by supernatant after settling. The removal efficiencies of BOD, COD, TP (total phosphorus) and SP (soluble phosphorus) on biological process with PAC were 96.1%, 88.8%, 97.0% and 98.6%, compared with those on biological process without PAC were 95.4%, 72.4%, 71.6% and 59.5% respectively. 18.4% of TP and 39.1% of SP removal efficiency was increased, although increase of BOD and COD removal rate was not significant. Only PAC addition to influent of settling basin in $A^2O$ process can help total phosphorus removal to 0.13 mg/L with following discharge standard.