• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.1
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• pp.61-66
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• 2009

Effects of aqueous ammonia soaking treatments to yellow poplar (Liriodendron tulipifera L.) were investigated to focus on chemical compositional changes and enzymatic hydrolysis characteristics changes by this treatment. Treatment temperature and time were main variables. At 3 different levels of aqueous ammonia soaking temperature and time ($145^{\circ}C$ -1 h, $90^{\circ}C$ -16 h and $45^{\circ}C$ - 6 days), lower temperature and longer soaking time led to more xylan removal based on carbohydrate compositional analysis. However, at higher temperature treatment led to more enzymatic saccharification of cellulose to glucose by commercial cellulose mixtures (Celluclast 1.5L and Novozym 342 from Novozyme, Denmark). Cellulose hydrolysis was gradually increased with increasing enzymatic hydrolysis time but xylan hydrolysis was leveled out at early stage (less than 10 h) of enzymatic hydrolysis.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.11
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• pp.843-851
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• 2015

Among various ammonium salts and metal ammine chlorides used as solid materials for the sources of ammonia with solid SCR for lean NOx reduction, magnesium ammine chloride was taken up for study in this paper because of its ease of handling and safety. Lab-scale synthetic method of magnesium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%). To understand material characteristics for lab-made magnesium ammine chloride, DA, IC, FT-IR, XRD and SDT analyses were performed using the published data available in literature. From the analytical results, the water content in the lab-made magnesium ammine chloride can be determined. A new test procedure for water removal was proposed, by which the adsorption rate of lab-made sample was found to be approximately 100%.

• Journal of Korean Society on Water Environment
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• v.36 no.3
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• pp.220-228
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• 2020

Anaerobic ammonium oxidation (AMX) is a cost-efficient biological nitrogen removal process. The coexistence of ammonia-oxidizing bacteria (AOB) in an AMX reactor is an interesting research topic as a nitrogen-related bacterial consortium. In this study, a sequencing batch reactor for AMX (AMX-SBR) was operated with a conventional activated sludge. The AOB in an AMX bioreactor were identified and quantified using terminal restriction fragment length polymorphism (T-RFLP) and real-time qPCR. A T-RFLP assay based on the ammonia monooxygenase subunit A (amoA) gene sequences showed the presence of Nitrosomonas europaea-like AOB in the AMX-SBR. A phylogenetic tree based on the sequenced amoA gene showed that AOB were affiliated with the Nitrosomonas europaea/mobilis cluster. Throughout the enrichment period, the AOB population was stable with predominant Nitrosomonas europaea-like AOB. Two OTUs of amoA_SBR_JJY_20 (FJ577843) and amoA_SBR_JJY_9 (FJ577849) are similar to the clones from AMX-related environments. Real-time qPCR was used to quantify AOB populations over time. Interestingly, the exponential growth of AOB populations was observed during the substrate inhibition of the AMX bacteria. The specific growth rate of AOB under anaerobic conditions was only 0.111 d^-1. The growth property of Nitrosomonas europaea-like AOB may provide fundamental information about the metabolic relationship between the AMX bacteria and AOB.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.436-442
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• 2017

This study was conducted to develop a wastewater treatment system to remove organic matter, nitrate nitrogen, and phosphate ion in synthetic wastewater. COD was removed almost 100% by the oxidation reaction of HClO and nitrate nitrogen was reduced to ammonia by electrolysis treatment, but ammonia was reoxidized into nitrate nitrogen by HClO treatment. Ammonia was removed almost 100% by heating evaporation and no ammonia was reoxidized into nitrate by HClO treatment. Phosphate ion could be removed by precipitation treatment by forming metal complex according to pH. Through electrolysis treatment and HClO treatment, removal efficiencies of COD 99.5%, nitrogen 97.3% and phosphorus 91.5% were obtained.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.896-904
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• 2011

The features of the capture reaction of $CO_2$ by ammonia solution have been investigated along with the effect of temperature on the reaction based upon computer program-utilizing calculation and thermodynamic estimation. The stable region of $CO{_3}^{2-}$ was observed to increase with temperature and the change of the stable region of $CO{_3}^{2-}$ with temperature was greater than the temperature variation of the stable region of other carbonate species. The distribution diagram for $NH_4{^+}-NH_3$ system was constructed and the rise of temperature resulted in the decrease of the stability of $NH_4{^+}$ ion, which was thought to be due to the endothermic nature of its acidic dissociation. Considering the introduction of $Ca^{2+}$ ion in the carbon capture reaction by $NH_4{^+}$, the temperature was observed to be important in the determination of the order of reaction between carbonate ion and these cations. The removal process of $CO_2$ gas by ammonia solution was presumed to occur in open system and the temperature variations of the concentration of carbonate system species along with their total concentration were calculated for the proper control and design of the real process.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.629-632
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• 1999

Constructed wetlands are being used for the removal of nutrients from livestock wastewater. However, natural vegetation typically used in constructed wetlands does not have marketable value. As an alternative, agronomic plants grown under flooded or saturated soil conditions that promote denitrification can be used. Studies on constructed wetlands for swine wastewater were conducted in wetland cells that contained either natural wetland plants or a combination of soybeans and rice for two years with the objective of maximum nitrogen reduction to minimize the amount of land required for terminal treatment. Three systems, of two 3.6 by 33.5 m wetland cells connected in series were used; two systems each contained a different combination of emergent wetland vegetation: rush/bulrush (system 1) and bur-reed/cattail (system 2). The third system contained soybean (Glycine max) in saturated-soil-culture (SSC) in the first cell, and flooded rice (Oryza sativa) in the second cell. Nitrogen (N) loading rates of 3 and $10kg\;ha^{-1}\;day^{-1}$ were used in the first and second years, respectively. These loading rates were obtained by mixing swine lagoon liquid with fresh water before it was applied to the wetland. The nutrient removal efficiency was similar in the rush/bulrush, bur-reed/cattails and agronomic plant systems. Mean mass removal of N was 94 % at the loading rate of $3kg\;N\;ha^{-1}\;day^{-1}$ and decreased to 71% at the higher rate of $10kg\;N\;ha^{-1}\;day^{-1}$. The two years means for above-ground dry matter production for rush/bulrushes and bur-reed/cattails was l2 and $33Mg\;ha^{-1}$, respectively. Flooded rice yield was $4.5Mg\;ha^{-1}$ and soybean grown in saturation culture yielded $2.8Mg\;ha^{-1}$. Additionally, the performance of seven soybean cultivars using SSC in constructed wetlands with swine wastewater as the water source was evaluated for two years, The cultivar Young had the highest yield with 4.0 and $2.8Mg\;ha^{-1}$ in each year, This indicated that production of acceptable soybean yields in constructed wetlands seems feasible with SSC using swine lagoon liquid. Two microcosms studies were established to further investigate the management of constructed wetlands. In the first microcosm experiment, the effects of swine lagoon liquid on the growth of wetland plants at half (about 175 mg/l ammonia) and full strength (about 350 mg/l ammonia) was investigated. It was concluded that wetland plants can grow well in at least half strength lagoon liquid. In the second microcosm experiment, sequencing nitrification-wetland treatments was studied. When nitrified lagoon liquid was added in batch applications ($48kg\;N\;ha^{-1}\;day^{-1}$) to wetland microcosms the nitrogen removal rate was four to five times higher than when non-nitrified lagoon liquid was added. Wetland microcosms with plants were more effective than those with bare soil. These results suggest that vegetated wetlands with nitrification pretreatment are viable treatment systems for removal of large quantities of nitrogen from swine lagoon liquid.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3267-3274
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• 2012

371 strains of marine bacteria were isolated from Gwangyang bay in Korea. The dominant species were identified as Pseudomonas aeruginosa, Aeromonas hydrophila, P. fluorescens, P. paucimobilis, Chryseomonas luteola and P. vescularis. To screen marine bacteria capable of removing nutrients and organics, marine bacteria was inoculated in 10 mL of marine broth 2216 (DIFCO) with $NH_3-N$ (100 mg/L), ${NO_3}^{-}-N$ (100 mg/L), and ${PO_4}^{-3}-P$ (10 mg/L) with 1.0% (v/v), and incubated for 12 h. Results from the screening test, showed that the removal efficiencies for $COD_{Cr}$, ammonia niterogen, nitrate nitrogen, and phosphate were over 25% for 16 strains, 15% for 9 strains, 50% for 63 strains, and 15% for 80 strains, respectively. Aeromonas hydrophila, Chryseomonas indologenes, Pseudomonas diminuta, Vibrio parahaemolyticus were selected for nutrients removal experiments. For the batch test, 4 species of marine bacteria were inoculated in modified marine broth containing with nutrients($COD_{Cr}$ 250 mg/L, $NH_3-N$ 40 mg/L, ${NO_3}^{-}-N$ 40 mg/L, ${PO_4}^{3-}-P$ 10 mg/L, respectively), incubated for 10 hr and the removal efficiencies were measured.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.941-946
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• 2012

Macrophyte plays an important role in purification of wastewater. They have capacity to improve the water quality by absorbing nutrients, with their effective root system. In this study, removal of nutrient as well as organic matter was observed by some important macrophytes i.e. Pistia stratoites, Hydrocharis dubia and Salvinia sp. indepe ndently as well as in mixed culture under the laboratory condition. The highest total nitrogen removal was observed for Pistia stratoites (86.47%) in monoculture and Salvinia sp. + P. stratoites (76.11%) in mixed culture system. Corresponding figures for total phosphorous were observed for P. stratoites (75.60%) in monoculture and Salvinia sp. + P. stratoites (71.11%) in mixed culture system. Similar result was observed for ammonia removal in both systems. Additionally, P. stratoites showed the highest removal of organic matter, in monoculture system (68.46%) where as Salvinia sp. + P. stratoites showed the highest removal of organic matter in mixed culture system (82.73 %).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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• pp.254-262
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• 2003

Effect of the air distributor pore size for the removal of aquacultural waste, such as protein, total suspended solids (TSS), chemical oxygen demand (COD), turbidity and total ammonia nitrogen (TAN) from sea water was investigated by using foam separator. With the increase of pore size of air distributor, removal rates and efficiency of protein decreased. Removal rate by commercial air stone was in the range between the removal rates by G2 and G4 sintered glass discs. Within the range of pore size distributor from Gl to G4, the removal efficiency of protein were ranged from 21 to $42\%.$ The changes of removal rates and efficiencies of TSS, COD and turbidity were similar to proteins. TAN was removed by stripping. The pore size of air distributor for a higher overall oxygen mass transfer coefficient and saturation efficiency provided the condition for higher protein removal rate. Also the foam separator could be used as an aerator.

• Journal of Korean Society on Water Environment
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• v.18 no.4
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• pp.355-363
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• 2002

A demonstration plant was carried out to investigate the removal efficiency of $NH_3-N$ and $KMnO_4$ consumption depending on the existence of pre-chlorination for the ozonation and activated carbon process in the S water treatment plant which is located at the middle of Keum River. The averge removal efficiency of $KMnO_4$ consumption for $O_3/GAC$ processes with pre-chlorination and $O_3/BAC$ processes without pre-chlorination were 48.6% and 50% respectively. It is similar to removal effect of $KMnO_4$ consumption for GAC and BAC process depending on the existence of pre-chlorination. Otherwise, the removal of THMFP for GAC and BAC process was 58% and 68% respectively. $NH_3-N$ was not almost removed by sand filter and ozonation, but the average removal efficiency in the BAC process was about 31%. Especially, $NH_3-N$ was not almost removed by $O_3/BAC$ processes at the low temperature (below $$10^{\circ}C$$) in the winter season, $O_3/BAC$ processes have the advantage of removal of organic substance when it is compared to pre -chlorination followed by $O_3/GAC$ processes. Pre-chlorination followed by $O_3/GAC$ processes were required to remove $NH_3-N$ in the winter season because the removal of $NH_3-N$ was almost ineffective by $O_3/BAC$ process.