• Journal of the Korea Organic Resources Recycling Association
• /
• v.28 no.1
• /
• pp.53-64
• /
• 2020

A 2㎥/d combined wastewater treatment pilot plant containing the multi-stage vertical stacking type nitrification reactor was installed and operated for more than 1 year under the operating conditions of the short-circuit nitrogen process (pH 8, DO 1mg/L and Internal return rate 4Q from nitrification to denitrification reactor). For economically the combination treatment of food wastewater and the leachate from a landfill, the optimal combination ratio was operated by adjusting the food wastewater with the minimum oil content to 5-25% of the total throughput. The main treatment efficiency of the three-phase centrifugal separator which was introduced to effectively separate solids and oil from the food wastewater was about 52% of SS from 116,000mg/L to 55,700mg/L, and about 48% of normal hexane (NH) from 53,200mg to 27,800 mg/L. During the operational period, the average removal efficiency in the combined wastewater treatment process of BOD was 99.3%, CODcr 94.2%, CODmn 90%, SS 70.1%, T-N 85.8%, and T-P 99.2%. The average concentrations of BOD, CODcr, T-N, and T-P of the treated water were all satisfied with the discharge quality standard for landfill leachate ("Na" region), and SS was satisfied after applying the membrane process. On-site leachate had a relatively high nitrite nitrogen content in the combined wastewater due to intermittent aeration of the equalization tanks and different monthly discharges. Nevertheless nitrite nitrogen was accumulated, denitrification from nitrite nitrogen was observed rather than denitrification after complete nitrification. The average input of anti-forming chemical during the operation period is about 2L/d, which seems to be economical compared to the input of methanol required to treat the same wastewater.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.4
• /
• pp.460-465
• /
• 2007

In this study, the removal characteristic of ammonia nitrogen and behavior of nitrogen was investigated using Leclercia adecarboxylata, which was derived from the culture contaminated by ammonia nitrogen of high concentration. The method of ammonia nitrogen removal was not biological nitrification and denitrification but elimination of nutrient salt with internal synthesis of microorganisms which use ammonia nitrogen as substrate. L. adecarboxylata(one of ammonia synthesis microorganisms) was highly activated and showed the most high removal efficiency in free salt condition but the removal efficiency decreased badly in salt concentration of more than 4%. About 80 mg/L of $NH_3-N$ was mostly removed within 20 hours and 500 mg/L of $NH_3-N$ showed less then removal efficiency of 50% because carbon source was not enough. However, ammonium nitrogen concentration was decreased again when the carbon source was inserted additionally thus, ammonium nitrogen removal efficiency by L. adecarboxylata, was related to amount of carbon source. pH decreased from 8.0 to 6.36 according to growth of L. adecarboxylata. Concentration of nitrite nitrogen and nitrate nitrogen did not increase and TKN concentration showed no variation while ammonia nitrogen was removed by L. adecarboxylata. In addition to, when content of protein in organic nitrogen was measured, protein was not detected at the beginning of microorganism synthesis but protein of 193.1 mg/L was detected after 48 hours. Hence, ammonium nitrogen was not decomposed as nitrate nitrogen and nitrite nitrogen but synthesized by L. adecarboxylata, which has excellent ability of nitrogen synthesis and can threat ammonia nitrogen of high concentration in wastewater.

• Journal of Korean Society on Water Environment
• /
• v.22 no.4
• /
• pp.711-719
• /
• 2006

The effluent from anaerobic digestion process of slurry-type piggery waste has a characteristic of very low C/N ratio. Because of high nitrogen content, it is necessary to evaluate nitrogen removal alternative rather than conventional nitrification-denitrification scheme. In this study, two parallel treatment schemes of SBR-like partial nitritation reactor coupled with anaerobic ammonium oxidation (ANAMMOX) reactor, and a nitritation reactor followed by nitrite denitrification process were evaluated with a slurry-type piggery waste. The feed to reactors adjusted with various $NH_4-N$ and organics concentration. The nitrite accumulation was successfully accomplished at the loading rate of about $1.0kgNH_4-N/m^3-day$. The $NO_2-N/NH_4-N$ ratio 1~2.6 in nitritated effluent that operated at HRT of 1 day indicated that SBR-like partial nitritation was applicable to ANAMMOX operation. Meanwhile, the nitrite accumulation of 87% was achieved at SBR operated with HRT of 3 days and $0.4mgO_2/L$ for denitritation. Experimental results further suggested that HRT (SRT) and free ammonia(FA) rather than DO are an effective control parameter for nitrite accumulation in piggery waste.

• Journal of Sensor Science and Technology
• /
• v.30 no.3
• /
• pp.154-164
• /
• 2021

In this study, the IoT sensor technology required for improving the survival rate and high-density productivity of individual shrimp in smart shrimp farming (which involves the usage of recirculating aquaculture systems and biofloc technology) was analyzed. The principles and performances of domestic and overseas water quality monitoring IoT sensors were compared. Furthermore, the drawbacks of existing aquaculture monitoring technologies and the countermeasures for future aquaculture monitoring technologies were examined. In particular, for farming white-legged shrimp, an IoT sensor was employed to collect measurement indicators for managing the water quality environment in real-time, and the IoT sensor-based real-time monitoring technology was then analyzed for implementing the optimal farming environment. The results obtained from this study can potentially contribute to the realization of an autonomous farming platform that can improve the survival rate and productivity of shrimp, achieve feed reduction, improve the water quality environment, and save energy.