• Journal of Ecology and Environment
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• v.42 no.4
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• pp.191-198
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• 2018

Improper management and unsanitary approaches are implemented in disposal of leachate, which has resulted in groundwater pollution at village Uruli Devachi, Pune, India. Various physico-chemical treatment methods are commercially available for leachate treatment. However, the application of biological methods viz. phytoremediation to the municipal solid waste landfill leachate has been limited. We report the remediation ability of Typha aungstifolia and Acrorus calamus that is capable of reducing hazardous constituents from the landfill leachate. After 96 h of hydraulic retention time (HRT), it was observed that T. aungstifolia-treated sample showed high reduction potential in reducing biochemical oxygen demand, chemical oxygen demand, hardness, total dissolved solids, Na, Mg, Ca and Ni whereas A. calamus showed greater reduction capacity for alkalinity, Cl, Cu, Zn and Cr. Furthermore, it was also observed that T. aungstifolia withstood longer HRT than A. calamus. In situ application of T. aungstifolia and A. calamus for remediation of landfill leachate carries a tremendous potential that needs to be further explored.

• Advances in environmental research
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• v.9 no.4
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• pp.233-249
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• 2020

To date, there is no central wastewater (WW) treatment plant in Erbil city, Kurdistan region, Iraq. Therefore, raw WW disposes to the environment and sometimes it used directly for irrigation in some areas of Erbil city. Disposal of the untreated WW to the natural environment and using for irrigation it causes problems for the people and the environment. The aims of the current work were to study the characteristics, design of primary and different secondary treatment units and reusing of produced WW. Raw WW samples from Ashty city-Erbil city were collected and analyzed for twenty three quality parameters such as Total Suspended Solids (TSS), total dissolved solids, total volatile and non-volatile solids, total acidity, total alkalinity, total hardness, five-day Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), biodegradability ratio (BOD5/COD), turbidity, etc. Results revealed that some parameters such as BOD5 and TSS were exceeded the standards for disposal of WW. Design and calculations for primary and secondary treatment (biological treatment) processes were presented. Primary treatment units such as screening, grit chamber, and flow equalization tank were designed and detailed calculation were illustrated. While, Conventional Activated Sludge (CAS), Sequencing Batch Reactor (SBR) and Moving Bed Biofilm Reactors (MBBR) were applied for the biological treatment of WW. Results revealed that MBBR was the best and economic technique for the biological treatment of WW. Treated WW is suitable for reusing and there is no restriction on use for irrigation of green areas inside Ashty city campus.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.450-452
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• 2004

Using factor analysis and bivariate comparisons of major components in ground water, three geochemical processes were identified as controlling factors of ground water chemistry; 1) natural mineralization by water rock interactions, 2) effect of seawater which includes salinization by seawater near seashores and deposition of sea salt, and 3) nitrate contamination by N fertilization. Contribution of rainfall was also estimated from the measured composition of wet deposition. The geochemical processes were separated using total alkalinity as an indicator for natural mineralization, Cl for effect of seawater, and nitrate for N fertilization. Relatively high correlation of major components with nitrate suggests that nitrification of nitrogenous fertilizers significantly affects ground water chemistry. Total cations derived from nitrate sources have good linearity for nitrate in equivalent basis with a slope of 1.8, which is a mean of proton production coefficients in nitrification of two major compounds in nitrogenous fertilizers, ammonium and urea. Contribution of nitrate sources to base cations, Cl, and SO$_4$ in ground water was determined considering maximum contribution of natural mineralization to estimate a threshold of the effect of N fertilization for ground water chemistry, which shows W fertilization has a greatest effect than any other processes in ground water with nitrate concentration greater than 50 mg/L for Ca, Mg, Na and with concentration greater than 30 mg/L for Cl and SO$_4$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.103-110
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• 1983

The main purpose of the present study is to evaluate a revolving plate type biofilter system for mass culture of eel(Anguilla japonica) based on the experimental rearing for 120 days (Oct. 1982-Feb. 1983). Water quality changes, growth efficiency of fish and fish disease treatment were critically evaluated. A revolving plate type biofilter system was designed(Fig. 1). The system consisted of a glass tank (150 l), a revolving plate biofilter and a settling tank(150 l). The biofilter consisted of 60 submerged quadriangular plates ($28{\times}37$ cm) and 30 revolving plates (32 cm diameter) for a total of 19.0 $m^2$ of surface area. The revolving plates were made to rotate 10 time per minute, The total water volume of the rearing system were 300 l, and everyday 1/3 of the total water volume were changed with freshly prepared water. In the rearing system a total of 2 kg of eel (1,500 individuals, mean weight:1.3 g) were reared fed on the pellet feed and the dough feed. The growth efficiency were much better for the pellet feed (FC: 1.79) compared to the dough feed (FC: 3.56). During the experimental rearing water quality control was satisfactory. Total ammonia concentrations were 0.38-0.59 ppm and nitrite concentration were 0.83-1.19 ppm. On the other hand alkalinity decreased from 176ppm just after the water change to 17ppm just before the water change. The low alkaline condition was compensated by the regular change of water. Epidemics of parasitic gill-flocks (Pseudodactvlogylus sp.) was observed, and they were easily eliminated by the treatment of DDVP (1.0 ppm). Trichodina sp. and Costia sp. were observed, and they were also controlled by the treatment of potassium permanganate (4.0 ppm).

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.117-122
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• 1990

The Jido Pond system was investigated from April, 1979 through March, 1980, in respect of seasonal changes in physico-chemical factors: i.e., temperature, pH, DO, BOD, COD, $Cl^-, \; Mg^{++}$, alkalinity, detergent, $SiO_2, PO_4\;^{3-}, NH_4\;^+, NO_2\;^-, NO_3\;^-$, total N, OM and OC; phytoplankton community growth; and the ecosystem metabolism. The phytoplankton community was represented by 23 species belonging to Chlorophyta, Bacillariophyta and Cyanophyta; each sharing 11, 9 3 respectively. The Chlorophyceans dominated the phytoplankton community contributing 75% of the total ？미 counts. The ranges of biotic diversity indices were, d, 0.85~2.80; H, 1.10~2.40; c, 0.13~0/40; and 3, 0.56~0.90. The chlorophyll standing crop varied in between 0.043 and 0.385g/$\textrm{cm}^2$ surface area. The ranges of photosynthetic and respiratory rates were 0.36~4.50; and 0.10~1.40 $O_2$ mg/1/hr, respectively. The monthly areal net primary production varied from 23.9 to 305.1C g/$\textrm{m}^2$/month. The Eu of the net production seasonally varied in between 0.31 and 7.80%, and the annual mean was 2.44%. The annual turnover times of phosphorus and nitrogen were 20 and 3 days, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.7
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• pp.418-425
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• 2015

Anaerobic Filters (AF) packed with porous ceramic floating media were operated at different operational conditions to identify the feasibility of the renewable bioenergy, methane production from swine wastewater and to verify the suitability of effluent from anaerobic filters for the subsequent biological nitrogen and phosphorus removal. Stepwise increase in organic loading rates (OLRs) or decrease in hydraulic retention times (HRTs) with influent TCOD concentration of 14,000 mg/L were utilized at mesophilic temperature. The maximum methane productivity of 1.74 volume of $CH_4$ per volume of reactor per day (v/v-d) was achieved at an hydraulic retention time (HRT) of 0.5 day (OLR 28 g TVS/L-d). Based on the biogas production, the highest total volatile solids (TVS) removal efficiency of 63% was obtained at an HRT of 3 days (OLR 4.67 g TVS/L-d), however based on the result from the effluent total chemical oxygen demand (TCOD) analysis, the highest TCOD removal efficiency of 75% was achieved. The effluent alkalinity concentration over the range of 2,050~2,980 mg/L as $CaCO_3$ at all operational conditions, could compensate the alkalinity destruction caused by nitrification. The effluent from the anaerobic filter operated under the HRT of 2 days showed the COD/TKN ratio of 15~35 and COD/TP ratio of 38~56. Therefore effluent C/N/P ratio is able to satisfy the optimum COD/TKN ratio of greater than 8.0 and COD/TP ratio of 33 for the subsequent biological nutrient removal.

• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.532-536
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• 2016

In this study, single-stage continuous anaerobic reactors to treat sewage sludge were operated under different temperature (55 and $35^{\circ}C$; $R_{TAD}$ and $R_{MAD}$) to evaluate the reactor stability and performance of the thermophilic and mesophilic anaerobic digestion. During the overall digestion, both anaerobic reactors maintained quite stable and constant pH and total alkalinity (TA) values in the range of 6.5-8.0 and 3-4 g $CaCO_3/L$, respectively. After the start-up period, $R_{TAD}$ showed 10% higher VS removal efficiency than that of $R_{MAD}$ ($R_{TAD}$; 43.3%; $R_{MAD}$ : 33.6%). Although organic acids such as acetic and propionic acid were detected in both anaerobic reactors at the start-up period, all organic acids in $R_{TAD}$ and $R_{MAD}$ were consumed at the steady state condition. Also $R_{TAD}$ showed 31.4 % higher methane production rate (MPR) than that of $R_{MAD}$ at the steady state condition ($R_{TAD}$; 243 mL $CH_4/L/d$; $R_{MAD}$ : 185 mL $CH_4/L/d$). Meanwhile, the experimental results indicated similar methane yield between $R_{TAD}$ and $R_{MAD}$.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.949-956
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• 2010

A method for simultaneous removal of nitrogen and phosphate from sewage by elemental sulfur denitrification with membrane bioreactor was proposed, and capacity $10\;m^3$/day of pilot plant was operated for 350 days. This study was investigated to have the effect of denitrification rate and T-P removal with the addition of Alum in Sulfur denitrification Reactor (SDR). The addition of Alum and alkalinity ($NaHCO_3$) in the effluent of MBR was tried to remove simultaneous phosphate and nitrogen in SDR. Characteristics of total nitrogen (T-N) and total phosphate (T-P) removal was compared without and with the addition of Alum as a coagulant. T-N removal without and with the addition of Alum was 92.1% and 87.8%, respectively. And denitrification efficiency was 93.8% and 87.1%, respectively. T-P removal rate was increased to 75.6% in SDR by addition of Alum (2.6~4 mg/L as Al), but T-P removal rate was about 26.7% without the addition of Alum. Therefore, denitrification rate was 6.7% of reduction but T-P removal rate was increased by addition of Alum.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.1
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• pp.17-32
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• 2022

The buffer capacity of southern Korean waters in summer was quantified using data set of temperature, salinity, dissolved inorganic carbon, total alkalinity obtained from August 2020 cruise. The geographical distribution and variability of six buffer factors, which amended the existing Revelle factor, are discussed their relationship with the hydrological parameters of temperature and salinity. The calculated results of six buffer factors showed the spatial variations according to the distributions of various water masses. The buffer capacity was low in the East Sea Surface Mixed Water (ESMW) and South Sea Surface Mixed Water (SSMW) where upwelling occurred, and showed an intermediate value in the Yellow Sea Surface Water (YSSW). In addition, the buffer capacity increased in the order of high temperature Tsushima Warm Current (TWC) and Changjiang Diluted Water (CDW). This means that the Changjiang discharge water in summer strengthens the buffer capacity of the study area. The highest buffer capacity of CDW is due to its relatively higher temperature and biological productivity, and a summer stratification. Temperature showed a good positive correlation (R²=0.79) with buffer capacity in all water masses, whereas salinity exhibited a poor negative correlation (R²=0.30). High temperature strengthens buffer capacity through thermodynamic processes such as gas exchange and distribution of carbonate system species. In the case of salinity, the relationship with buffer capacity is reversed because salinity of the study area is not controlled by precipitation or evaporation but by a local freshwater input and mixing with upwelled water.

• Journal of environmental and Sanitary engineering
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• v.5 no.1
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• pp.7-13
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• 1990

The water environmental characters of the Nakdong River, Geumho River and Sin Stream, both before-flood (Aug. 24) and after-flood (Sept. 8), have been compared, and their effects on the growth of Spirodela polyrhiza Shleiden have been examined. Before the flood, the concentrations of most of the chemical components of the Geumho River were similar to those of the Sin Stream; (COD, 19.6~21.4; alkalinity, 177~183; $NH_4\;^+$, 20.7~24.4; $NO_3\;^-$, 3.9~4.3; $PO_\;4^{3-}$, 3.4~3.7; $Mg^{2+}$, 42; $Ca^{2+}$, 68.5~69.7; $Cl^-$, 90~92; $SiO_2$, 10.4~11.2; , 11~32; LAS, 3.0~3.8; , 0.007~0.010ppm) but much higher than those of the Nakdong River (30~40 fold for $NH_4\;^+$, , $PO_\;4^{3-}$ and LAS, and 2~5 fold for COD, alkalinity, $NO_3\;^-$, $Mg^{2+}$, Cl- and ). Especially in the Geumho River, Secchi disk transparency was very low (17cm) and DO was not detected. The flood caused significant increases in some chemical components: $NH_4\;^+$, 1.0;$NO_3\;^-$, 9.6; , 12.8 and , 5.4 ppm in the Nakdong River; DO, 1.0; $NO_2\;^-$, 0.92; $NO_3\;^-$, 22.2 and $SiO_2$, 17.6ppm in the Geumho River; DO, 3.0; $NO_2\;^-$, 1.4; $NO_3\;^-$, 22.2; SiO2$SiO_2$, 19.2 and , 25.0ppm in the Sin Stream. General species diversity index (H) of phytoplankton community in the Nakdong River, Geumho River and Sin Stream before flood was 3.1, 2.7 and 1.6, respectively. After the flood, the phytoplankton growth was highly sparse in each river water, hence indices have no significance. The growth of S. polyrhiza was enhanced in Geumho River water (max. RGR=26%/day), while it ceased within 7days in Nakdong River water.