• Journal of Korean Society of Water and Wastewater
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• v.24 no.5
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• pp.603-608
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• 2010

More than 8 millions of chemical have been used for human activities and lots of chemicals can not be degraded by microbial activities in this world. To show the biodegradability of a chemical, biodegradability index (B.I.) is suggested using aerobic biodegradability by $BOD_5$/COD, anaerobic biodegradability by methane potential (M.P.) and toxicity by the luminiscent bacteria. In this study, PVA (polyvinyl alcohol), HEC (hydroxy ethyl cellulose), 2,4,6-TCP (tri-chloro phenol) and 2,4-DCP (di-chloro phenol) are used for test chemicals. Though they show little toxicity, PAV and HEC have low B.I. because they are polymers having high molecular weight. That means that there are no bacteria that has enzyme to degrade polymer molecules. Also, anaerobic treatment is suggested better than aerobic treatment from B.I. 2,4,6-TCP and 2,4-DCP show high toxicity and have low B.I. Their low biodegradabilities seem to be originated from their toxicities. If B.I. is used in wastewater treatment, better treatment process can be suggested and finally it can lead our society to make more environment-friendly chemicals.

• Advances in environmental research
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• v.5 no.4
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• pp.251-262
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• 2016

The biodegradability and decomposition efficiencies increase with the pre-treatment of sludge in a digestion process. In this study, the feasibility of ultrasound coupled with potassium permanganate oxidation as a disintegration method and digestibility of aerobic reactor fed with disintegrated sludge with ultrasound coupled potassium permanganate were investigated. The first stage of the study focused on determining the optimum condition for ultrasonic pre-treatment for achieving better destruction efficiency of sludge. The second part of the study, the aerobic digestibility of sludge disintegrated with ultrasound and potassium permanganate oxidation alone and combined were examined comparatively. The results showed that when 20 min of ultrasonic pre-treatment applied, the specific energy output was 49384 kJ/kgTS with disintegration degree of 58.84%. During the operation of aerobic digester, VS/TS ratios of digesters fed with disintegrated sludge decreased indicating that disintegration methods could obviously enhance aerobic digestion performance. The highest reduction in volatile solids was 75% in the digester fed with ultrasound+potassium permanganate disintegrated sludge at the end of the operation compared to digester fed with raw sludge. Total Nitrogen (TN) and Total Phosphorus (TP) levels in sludge supernatant increased with this combined method significantly. Besides, it promoted the production of ${\bullet}OH$, thus enhancing the release of Carbon (C), Nitrogen (N) and Phosphorus (P) from the sludge. Disintegration with all methods used in this study could not improve Capillary Suction Time (CST) reduction in disintegrated digesters during the operation. The results demonstrated that the combined ultrasound treatment and potassium permanganate oxidation method improves the biodegradability compared to control reactor or their single application.

• KSBB Journal
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• v.19 no.2
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• pp.132-137
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• 2004

Biodegradability test for various synthetic lubricant oil bases derived from biodiesel was carried out. The biodegradability was estimated under aerobic aqueous condition, according to the method by OECD 301 B, which is based on CO$_2$ evolution test. The ultimate biodegradability of pentaerythritol methyl esters were estimated as 61.1∼80.3%, at 28 day with which the test compounds were indicated as ultimately biodegradable. Among the tested samples, biodiesel showed the highest biodegradability (83.5%). The validation with several criteria, regarding relative errors of test results, toxicity control and procedure control, was performed through the biodegradability test. The test procedure was validated for all the tested lubricant oil bases and biodiesel, except for petroleum diesel.

• Journal of Environmental Science International
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• v.11 no.6
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• pp.569-576
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• 2002

Anaerobic/aerobic reactor system was used to treat a synthetic wastewater with glucose as carbon sources(0.38~2.29 kg COD/m3.day) and Acid Red 14(1.05 "24.00 g Acid Red 141m3.day, color degree of 570 ~ 1710). COD removal efficiency by the anaerobic stage in operation period were above 90 % organic loading rate of 0.38 ~ 2.29 kg COD/m3.day(except, adaptation period) and the removal efficiency of the whole system were above 96 %. The decolorization of the Acid Red 14 was through the alteration of the dye structure(or cleavage of the Azo bond) during the anaerobic treatment. In the A/A system, the anaerobic stage played an essential role in removing both color and COD. In addition it also improves biodegradability of dye f3r further aerobic treatment. After operation, average MLSS concentration of anaerobic sludge reactor, anaerobic fixed-bed reactor and aerobic fixed-bed reactor were 17100mg/L, 20000mg/L, and 10000mg/L, respectively.

• KSBB Journal
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• v.22 no.4
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• pp.244-248
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• 2007

The treatment of a model wastewater containing high concentration, 10 $g/{\ell}$, of phenol in an integrated wet oxidation-aerobic biological treatment was investigated. Partial wet oxidation under mild operating conditions was capable of converting the original phenol to biodegradable organic acids such as maleic acid, formic acid and acetic acid, the solution of which was subjected to the subsequent aerobic biological treatment. The wet oxidation was carried out at 150$^{\circ}C$ and 200$^{\circ}C$ and the initial pH of 1 to 12. The high temperature of 200$^{\circ}C$ and the acidic initial condition in the wet oxidation led to effluents of which biodegradability was higher in the subsequent biological oxidation process, as assessed by chemical oxygen demand (COD) removal. Homogeneous catalyst of $CuSO_4$ was also used for increasing the oxidation rate in the wet oxidation at 150$^{\circ}C$ and initial pH of 3.0. However, the pretreatment with the catalytic wet oxidation resulted in effluents which were less biodegradable in the aerobic biological process compared to those out of the non-catalytic wet oxidation at the same operating conditions.

• Polymer(Korea)
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• v.26 no.1
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• pp.145-151
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• 2002

Thermoplastic starch(TPS) was prepared from mixing starch and glycerol by twin extruder. The blends were then prepared from high density polyethylene(HDPE) and TPS. Mechanical properties, thermal properties, and morphology of the blends were investigated. Their biodegradability was also studied by using aerobic composting method(ISO14855). Tensile strength, modulus and elongation at break decreased as the content of TPS increased. In particular elongation at break decreased rapidly even at the lower content of TPS. The melting temperatures of the blends were not changed, which showed that HDPE and TPS were immiscible. The morphology of the fractured surface of blend films was investigated by scanning electron microscopy(SEM). It was found that phases were separated. After composting for 45days, the biodegradability of the blends increased as the content of TPS increased.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.451-451
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• 2003

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.280-280
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• 2005

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.64-71
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• 2018

The purpose of this study is to investigate the characteristics of the substrate of dairy wastewater through aerobic biodegradation and to use the results as the basic data for the efficient treatment of dairy wastewater. The SCODcr of the part of the matter that consisted of readily biodegradable organics (Ss) was 84.2%, which is higher than those of seafood processing wastewater (75.8~77.9%) and pigpen wastewater (58.2%). The proportion of non-biodegradable organics (SI) ranged from 5.6% to 6.4%, and the proportion of inert organics (SIi) generated by microbial metabolism ranged from 3.6 to 3.7%. The content coefficient (YI) of the non-biodegradable dissolved organic matter was in the range of 0.092 to 0.099, and the generation coefficient (Yp) of the inert substance produced by the microbial metabolism was in the range of 0.039 to 0.040. The analysis results of the organic component coefficient showed that approximately 91.0% of the dissolved organic matter of the dairy wastewater was biodegradable, and approximately 92.5% of the dissolved organic matter was the Ss component. Furthermore, the proportion of biodegradable organic matter in the total organic matter (TCODcr) was 89.3%. The proportions of non-biodegradable organics (SI) and non-biodegradable suspended organics (XI) were 3.0% and 7.7%, respectively, which are lower than those in similar wastewater. This means that the milk processing wastewater has a high aerobic biodegradability.

• Journal of Environmental Health Sciences
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• v.34 no.6
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• pp.452-458
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• 2008

This study was undertaken to establish the biological reaction characteristics of the marine products industry wastewater which contains high concentrations of organic matter and saline. As the S/I is varied from 0.3 to 1.2, the results were follows : the observed ultimate anaerobic biodegradability varied from 72.0 to 88.0%, the first order reaction rate varied from 0.1735 to $0.3420\;day^{-1}$ and the second order reaction rate varied from 0.0132 to $0.0295\;day^{-1}$. When S/I was 0.9, the first order reaction rate had a maximum value, but the variations of the second order reaction rate were less than 1st-order reaction rate. When the operation time exceeded 2 days the gas production rapidly increased. The source of this rapid increase was due to that the activity of the granular sludge used in this study being faster than that of conventional sludge. Under aerobic condition, the characteristics of organic matter were as follows: the marine industry wastewater used in this study contained about 81% of biodegradable matter, and it was divided into readily biodegradable COD(Ss), slowly biodegradable COD(Xs), soluble COD(Si) and inert suspended COD (Xi). The percentages of each COD were 87.3%, 23.9%, 6.4% and 12.4% respectively.