• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.310-317
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• 2022

BACKGROUND: The salt in soil interrupts crop growth. Therefore, water resources are used to remove any salt found in the soil. However, water resources have been reduced by global warming; thus, a new study is required into reducing the salt in soil. Recently, the bottom ash (BA) of a biomass power plant was found to be similar to biochar. Hence, it can be used to remove heavy metals and wastewater through the adsorption characteristics of BA. The objective of this study was to evaluate the improvement effects on crop growth in saline soil containing the BA from biomass power plants. METHODS AND RESULTS: The effect on crop growth in the saline soil supplemented with BA was studied with the crop-planted pots, which were packed by reclaimed greenhouse soils collected from Byolyang, Suncheon. The BA application level was 25, 50, 100, 200, and 400 kg/10a (referred as BA25, BA50, BA100, BA200, and BA400, respectively). The BA increased the fresh weights of the leaf and root, while nitrogen uptake increased by approximately 24-102% and 54-77%, respectively for the lead and root. The phosphorous uptake increased by 38%, although only in the leaf of the lettuce. In the case of soil, BA increased water content, pH, EC, CEC, and NH₄⁺ and the SAR of the soil decreased by 5-15%. The bottom ash increased the contents of Ca²⁺ and Mg²⁺, and fixed the amount of Na⁺. CONCLUSION(S): It was confirmed the bottom ash of a biomass power plant, based on wood pellets, improved crop growth, and increased the nutrient uptake of crops in saline soil. In addition, bottom ash, which has a wide range of porosity and high values of pH and EC, improved properties of the saline soil. However, the BA has a large amount of B, As, and heavy metals. Finally, it may require a study on the safety and contamination of heavy metals contained in the bottom ash, which would be applied in soil for a long time.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.343-348
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• 2010

The objective of this study was to investigate the effects of starvation periods with aerobic or non-aerobic conditions on the organic removal efficiencies and physical characteristics of activated sludge for treating saline and non-saline wastewater. During the experiment, MLSS, MLVSS, sludge volume index (SVI), floc size and fractal dimension, $COD_{Mn}$ removal efficiencies were monitored. The reductions of MLSS, MLVSS and SVI with maintaining the sludge under a non-aerobic condition during starvation periods were smaller than those under a aerobic condition. Floc size, fractal dimension and $COD_{Mn}$ removal efficiencies were less decreased under non-aerobic condition than under aerobic condition. And SVI were strongly correlated with floc size and fractal dimension. Consequently, the result showed that maintaining the activated sludge under non-aerobic starvation conditions was better strategy than that under aerobic starvation conditions as it adapted and resisted to starvation.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.234-240
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• 2010

The effectiveness of adding powdered zeolite and granular activated carbon (GAC) before starvation into biological reactor for recovering its performances was investigated. Two types of carrier addition in Sequencing Batch Reactor (SBR) system for non-saline and saline wastewater were evaluated after starvation periods. During the experiment, settleablity (SVI), floc size, fractal dimension, $COD_{Mn}$, T-N, T-P removal efficiencies and recovery time were monitored. When the wastewater feeding was resumed after starvation period for 5days, the SVI increased at the beginning of resumption and then decreased with time in both types. And the larger the floc size and fractal dimension of floc, the more increased removal efficiency for $COD_{Mn}$, T-N and T-P was also. Its performance recovery was strongly correlated with floc size and fractal dimension of activated sludge. After resuming the wastewater feeding, the SVI, floc size, fractal dimension, $COD_{Mn}$, T-N, T-P removal efficiency of SBR with carrier improved and reached its initial value faster compared to those of SBR without carrier.

• Advances in Energy Research
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• v.4 no.2
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• pp.147-161
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• 2016

To start with, finding a sustainable method to produce sweet water and electricity by using renewable energies is one of the most important issues at this time. So, experimental and theoretical analysis of the performance of a closed solar powered still, which is jointed to photovoltaic cells and vacuum pump and equipped by nano plate, as the principle stage of zero discharge desalination process is investigated in this project. Major goal of this work is to reuse the concentrated brine of the Mobin petrochemical complex in order to produce potable, sweet water from effluent saline wastewater and generating electricity in the same time by using solar energy instead of discharging them to the environment. It is observed the increase in brackish water temperature increases the average daily production of solar desalination still considerably. Therefore, the nano plate and vacuum pump are added to augment the evaporation rate. The insolation rate, evaporation rate, the average brackish temperature, ambient temperature, density are investigated during a year 2013. In addition to obtain the capacity of solar powered still, the highest and lowest amount of water and electricity generation are reported during a twelvemonth (2013). Results indicate the average daily production is increased 16%, which represents 7.78 kW.h energy saving comparing with traditional solar still.

• Journal of Integrative Natural Science
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• v.4 no.2
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• pp.103-112
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• 2011

This study was carried out on 4 batch reactors to determine the specific ammonium oxidizing rate (SAOR), specific nitrate forming rate (SNFR) and inhibitory degree of nitrifying activities with saline concentrations. Under salt free condition ammonia was consumed during the reaction period within 200 min. When the salt level increased to 10, 20 and 30 g $NaClL^{-1}$ in reactor, ammonia depletion took 250, 300 and above 350 min, respectively. During concentration above 10 g $NaClL^{-1}$, there was nitrite accumulation. Also, at 30 g $NaClL^{-1}$ ammonia did not depleted and $NO_2{^-}$-N accumulated until the final reaction. Nitrate formation rates decreased with increasing salt concentration. SAOR and SNFR showed a decreasing trend as salinity concentrations were increased. The SAOR was reduced from 0.2 to 0.08 mg $NH_4{^+}$-N $g^{-1}VSS\;day^{-1}$ as the salt concentration increased from 0 to 30 g $NaClL^{-1}$. Similarly, the SNFR decreased from 0.26 kg $NO_3{^-}$-N $kg^{-1}VSS\;day^{-1}$ at saline free to 0.1 kg $NO_3{^-}$-N $kg^{-1}VSS\;day^{-1}$ at saline 30 g L-1. A severe inhibition of nitrifiers activity was observed at increased salt concentrations. The inhibition ratio of specific ammonium oxidation rates were 17, 47 and 60% on the reactor of 10, 20 and 30 g $NaClL^{-1}$ added, respectively. The inhibition ratio of specific nitrate forming rates also were inhibited 30, 53 and 62% on the reactor of 10, 20 and 30 g $NaClL^{-1}$ added, respectively. As the salinity concentrations increased from 0 to 30 mg $NaClL^{-1}$, the average MLSS concentration increased from 1,245 to 1,735 $mgL^{-1}$. The SS concentration of supernatant in reactor which settled about 30 minutes was not severely difference between concentration of salt free reactor and one of those high salt contained reactors.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.635-638
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• 2003

For the acute assessment on biological toxicity of wastewater, surface plasmon resonance(SPR) based cell viability detection was performed using gold surface-confined cell as a result of adhesion-modifying chemicals. Escherichia coli O157:H7 (E. coli O157:H7) was investigated after exposure to EDTA. Cells were immobilized on gold coated slide glass for SPR analysis by the method of cross-linking carboxyl group on the bacterial surface with amine group of poly-L-lysine that had been coupled to the gold surface modified by a self-assembled monolayer of 11-mercaptounde canoic acid (11-(MUA)). Reflective intensity of each flow step was changed with respect to confect of ethylenediaminetetraacetic acid (EDTA) disodium salt and phosphate-buffered saline (PBS) solution. The proposed detection technique can be used for biological toxicity test.

• Journal of Korean Society on Water Environment
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• v.18 no.3
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• pp.237-243
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• 2002

The effect of a salinity on the performance of a biological nutrient removal system was investigated using a model SBR(Sequencing Bach Reactor) system. The system was operated at a 12hr, 18hr, 24hr, and 36hr HRT with a salinity level of 20,000mg/L and compared with a system similarly operated with fresh water. The influent salinity level of 8,000 mg/L does not have a significant effect on BOD removal efficiency, there is a noticeable decrease in BOD removal rate from 10,000 mg Cl-/L. The Nitrogen could be removed from the saline wastewater with the same efficiency as for the fresh water because of low C/N ratio in anoxic period. The excess biological phosphorous removal is highly affected by the increase in the influent salinity. The efficiency is decreased from 96.6% to 43.4% when the influent salinity is increased from 0 to 20,000mg/L.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7227-7236
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• 2015

The survey revealed that, due to the discharge characteristics of seafood wastewater, irregular inflow loads were caused, making it difficult to treat the wastewater safely. It is crucial for the operation of pressure and floating tanks for the treatment of high-concentration organic wastewater such as seafood wastewater. The survey of operation factors for the pressure and floating tanks revealed this: A/S ratio 0.05 (design criteria 0.01), the pressurized air pressure 8bar(design criteria 6bar), the pressure tank pressure 6bar (design criteria 4.5bar), and HRT 60sec(design criteria: 10sec). Also, the recirculation rate was changed to over 40%(design criteria: 30%), and the surface load rate was changed to under $13.7m^3/m^2{\cdot}hr$(design criteria: under $17.7m^3/m^2{\cdot}hr$); thus, compared to the initial design criteria, the operation factors were changed according to inflow characteristics, thus enhancing the pressure and floating tank performance. The survey of inflow load revealed BOD 140.7%, $COD_{Mn}$ 120.32%, and SS 106.3%, compared to the inflow design criteria, as well as T-N 135.5% and T-P173.3%, higher than the design criteria. The survey of the treatment facility annual operation cost revealed high portions in sludge treatment cost(27.7%) and chemicals costs(26.0%), and the sludge treatment cost will likely further increase due to the ban on ocean dumping. The unit cost for the treatment of seafood wastewater was found to be KRW 3,858 per ton, more than 27 times higher than the sewage treatment cost(KRW 142.6/ton), presumably because the seafood wastewater contains high-concentration organic substances and nutritive salts.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.256-263
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• 2010

The study was performed to evaluate the effects of chloride concentrations on the ultimate aerobic biodegradability and to use the result as the fundamental data for sea food wastewater treatment. When the organic removal efficiency by chloride concentrations (1,400~18,000 mg/L) was evaluated, microbes adapted to the saline at ${\leq}$ 6,000 mg/L of chloride but treatment efficiency was not improved at ${\geq}$ 12,000 mg/L of chloride because of delayed reaction time. Functional coefficient $Y_I$ of non-biodegradable soluble organic and inert material production coefficient Yp by microbe metabolism increased as chloride concentrations increased. Soluble organic matter ratio by chloride concentration (0~18,000 mg/L) was 10.8~13.1%, inert material production efficiency by microbes metabolism was evaluated as 7.0~24.6%. $NH_3$-N removal efficiencies were 96.2, 96.5, 90.2 and 90.3% using original wastewater HRT 18 hr, 6,000 mg/L chloride concentration HRT 22 hr, 12,000 mg/L chloride concentration HRT 30 hr, and 18,000 mg/L chloride concentration HRT 45 hr, respectively. Nitrification process was more sensitive to salt concentration than organic matter removal to salt concentration. Under ${\geq}$ 6,000 mg/L chloride concentration, conversion rate from $NO_s$-N to $NO_2$-N was low.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.1
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• pp.107-113
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• 2012

Pollutants in aquaculture system effluent mostly originated from solid wastes including uneaten feed and excreta of cultured species. In this research, DAF(Dissolved Air Flotation) unit is suggested as an integrated solid control unit especially as a form of IIBG(Inline Injection Bubble Generation) process in aquaculture system. Solid removal performance of DAF unit was examined under various operation and salinity conditions with turbidity and suspended solid. Solid waste removal efficiencies were found to be affected by operation conditions including saturator pressure, recycle ratio, coagulant concentration. Solid removal efficiency was higher under higher saturator pressure and recycle ratio under which condition larger number of bubbles is generated. Coagulant is thought to have important role in creating bubble-particle aggregate by showing better removal efficiency with higher concentration. However higher saline water showed less effectiveness in removing solids by DAF(IIBG). Application of DAF(IIBG) process also showed additional effect in phosphate removal and DO(Dissolved Oxygen) supply. Phosphate existed in polluted water was removed up to 46% after treatment, which is thought to attribute to aluminium phosphate precipitation. And DO concentration was found to increase over 50% of initial saturation concentration after the injection of micro-bubbles. Through experiments on solid removal from aquaculture effluent, DAF(IIBG) process is estimated to be effective solid control method. This property can help aquaculture system being installed and operated simply and effectively.