• Journal of Environmental Health Sciences
• /
• v.40 no.4
• /
• pp.322-329
• /
• 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
• /
• v.16 no.12
• /
• pp.8665-8672
• /
• 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 Soil and Groundwater Environment
• /
• v.18 no.1
• /
• pp.46-56
• /
• 2013

Laboratory scale experiments to remove benzene in solution by using the bio-carrier composed of dead biomass have been performed. The immobilized bio-carrier with dead Bacillus drentensis sp. and polysulfone was manufactured as the biosorbent. Batch sorption experiments were performed with bio-carriers having various quantities of biomass and then, their removal efficiencies and uptake capacities were calculated. From results of batch experiments, 98.0% of the initial benzene (1 mg/L) in 1 liter of solution was removed by using 40 g of immobilized bio-carrier containing 5% biomass within 1 hour and the biosorption reaction reached in equilibrium within 2 hours. Benzene removal efficiency slightly increased (99.0 to $99.4%{\pm}0.05$) as the temperature increased from 15 to $35^{\circ}C$, suggesting that the temperature rarely affects on the removal efficiency of the bio-carrier. The removal efficiency changed under the different initial benzene concentration in solution and benzene removal efficiency of the bio-carrier increased with the increase of the initial benzene concentration (0.001 to 10 mg/L). More than 99.0% of benzene was removed from solution when the initial benzene concentration ranged from 1 to 10 mg/L. From results of fitting process for batch experimental data to Langmuir and Freundlich isotherms, the removal isotherms of benzene were more well fitted to Freundlich model ($r^2$=0.9242) rather than Langmuir model ($r^2$=0.7453). From the column experiment, the benzene removal efficiency maintained over 99.0% until 420 pore volumes of benzene solution (initial benzene concentration: 1 mg/L) were injected in the column packed with bio-carriers, investigating that the immobilized carrier containing Bacillus drentensis sp. and polysulfone is the outstanding biosorbent to remove benzene in solution.

• Journal of Korean Society on Water Environment
• /
• v.32 no.3
• /
• pp.303-309
• /
• 2016

This study aimed to assay the biological removal of TDS (total dissolved solids) from RO (reverse osmosis) rejected water. Following bio-sorption of TDS with AGS (aerobic granular sludge), the effects of TDS on biological nitrogen removal were examined. The bio-sorption of TDS after AGS treatment was confirmed by checking for TDS removal efficiency and surface analysis of microorganisms with SEM and EDS. Then, the effects of TDS on biological nitrogen removal and the denitrification efficiency were evaluated using the MBR reactor. According to the results, the bio-sorption of TDS with AGS was 0.1 mg TDS/mg AGS, and we confirmed that the microorganism surfaces had adsorbed the TDS. Biological nitrogen removal efficiency was measured at inhibiting denitrification at 4,000 mg/L of TDS-injected material. Based on this study, it is necessary to pretreat TDS-containing RO rejected water and to maintain TDS concentration lower than a specific value (≤4,000 mg/L), when considering biological nitrogen removal.

• Journal of Korean Society on Water Environment
• /
• v.37 no.5
• /
• pp.363-368
• /
• 2021

On the assessment results of the non-point source pollutant removability of bio-block using waste sewage sludge, at the reactor's initial operation stage, the removal efficiency of COD was slightly unstable. However, after the reactor was stabilized, the COD removal efficiency was higher in the reactor filled with bio-blocks compared to the reactor filled with broken stones. In terms of nitrogen and phosphorus, their removal efficiency was unstable at the initial stage of the reactor operation. This phenomenon was investigated through the bio-block elution experiments. Results indicated that nitrogen and phosphorus were eluted from the bio-blocks affecting their removal at the initial operation. Furthermore, based on elution tests conducted after the dry ashing of the waste sewage sludge, part of the nitrogen and phosphorus was eluted similar to the bio-block elution test results, although considerable amounts of nitrogen and phosphorus were reduced compared to the sludge cake. Prior to the use of the waste sewage sludge bio-blocks as a filter medium to remove non-point source pollutants, a stabilization period of 10 days was required. After the stabilization process, results showed similar characteristics as general aggregates. Moreover, to use the bio-block as a filter medium for the non-point pollutant removal, the filling ratio of 75% was the most suitable as it resulted in the highest nitrogen removal efficiency after the stabilization. The results of this study suggested that waste sewage sludge can be suitably recycled as a mixed raw material for the bio-blocks, with satisfactory application as a filter medium in artificial wetlands, stormwater runoff problems, stream water pollutants to eliminate non-point source pollutants.

• Journal of Environmental Science International
• /
• v.17 no.11
• /
• pp.1265-1271
• /
• 2008

Aerated submerged bio-film (ASBF) pilot plant has been developed. The presented studies optimized an inexpensive method of enhanced wastewater treatment. The objectives of this research were to describe pilot scale experiments for efficient removal of dissolved organic and nitrogen compounds by using ASBF reactor in plug-flow reactor (PFR) and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynamic relationships between heterotrophs and autotrophs in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. This direct gas-phase contact should increase the oxygen transfer rate into the bio-film, as well as increase the micro-climate mixing of water, nutrients, and waste products into and out of the bio-film. This research also investigated the efficiency of dissolved organic matter and ammonia nitrogen removals in the ASBF. As it was anticipated, nitrification activity was highest during periods when the flow rate was lower, but it seemed to decline during times when the flow rate was highest. And ammonia nitrogen removal rates were more sensitive than dissolved organic matter removal rates when flow rates exceeded 2.2 L/min.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.260-263
• /
• 2008

KEPCO(Korea Electric Power Corporation) is performing the nation's first biogas-MGT project as an effort to encourage the utilization of wasted biogas which contains useful CH4. The goals of this project are to develop the Pretreatment system of Livestock bio-gas and set up the biogas-MGT co-generation system. The project will not only utilze flared biogas as precious energy but also improve the economics of the plant a lot. The pretreatment system mainly consists of sulfur removal tower, biogas compressor and many filtering systems. A computational fluid dynamics study in the bio gas sulfur removal tower and sulfur absorption filter was carried out. Understanding of the flow in the sulfur removal tower and sulfur adsorption filter obtained by this study can be used to identify the problems in the sulfur removal tower and to improve the sulfur removal efficiency of the sulfur removal tower. Resistance material modeling is used to simulate the sulfur adsorption filter, and the resistance coefficient was adjusted to reflect the experimental pressure loss value. And the pressure loss change with the flowrate is predicted

• Journal of Microbiology and Biotechnology
• /
• v.16 no.3
• /
• pp.414-422
• /
• 2006

Before applying PVA bio-beads to practical biological treatment of nitrate-containing wastewater, their characteristics were examined. PVA bio-beads could steadily produce nitrogen gas from nitrate for 28 batches with 0.04 ml/l/h of the maximum gas production rate; however, the maximum gas production rate dropped remarkably thereafter with apparent deformation of beads. Addition of 2.2% solution containing 1% casamino acid, 1% yeast extract, 0.1% mineral solution, and 0.1% vitamin solution to the culture medium resulted in not only recovery of activity of deactivated beads, but also a higher rate of gas production. Calculation of economic benefit for the use of bio-beads in a long-run operation indicated that reactivation of bio-beads by chemicals had economical advantages over packing new bio-beads in the system. The continuously stirred bioreactor exhibited a satisfactory performance at HRT of 20.0 h. With a 9.5 mg $NO_{3}^{-}N/l/h$ nitrate removal rate, nitrate could completely be removed without nitrite accumulation. The use of PVA bio-beads in nitrate removal appears very promising.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.30 no.4
• /
• pp.15-25
• /
• 2022

In this study, the efficiency of treatment of moisture and organic matter in food waste was analyzed according to the air blast volume and preheating using the bio-drying method. Te mount of air blast volume and preheating were determined by the evaluation of temperature and CO2 during food waste treatment using the bio-drying method. As a results, the increase in the air blast volume increased the moisture removal efficiency and removal rate, but, lowered the temperature inside the bio-drying by the decease in microbial activity. In order to maintain the activity of microorganisms, it was estimated that it was necessary to inject an appropriate air blast rate according th the properties of the food waste. In this study, the injection of air blast volume at 15L/min was optimal. It was evaluated that the organic matter and water removal rates according to the presence or absence of air preheating, the organic matter removal rate and water removal rate increased by 3-5% when air preheating was not performed. Also, there was no internal aggregation caused by the generation of condensate inside the bio-drying. Therefore, for effective bio-drying of food waste, it is necessary to maintain an appropriate air blast volume to maintain microbial activity, and it is considered that injection through preheating of air is required.

• Environmental Engineering Research
• /
• v.11 no.2
• /
• pp.106-125
• /
• 2006

Cesium and strontium are two important fission products and the removal/speciation of these two cations with several inorganic/bio-materials is an interesting topic to discuss. It is to be noted that inorganic materials are found to be fairly effective and efficient in the removal/speciation of these cations. Moreover, these solids are to be found promising as they show fairly good radiation and temperature stability. Hence, they play an important role in the radioactive waste management studies. However, various studies reveal that in addition to inorganic materials various biosorbents can also be employed in the removal/speciation of these ions. But the radiation and temperature stability of these bio-sorbents and dead biomasses are still the topic lying among the researchers to be investigated.