Doug Hee Rhew

The effect of total maximum daily loads (TMDL) program on water quality improvement in the Geum River basin, Korea

AbstractIn this study, an analysis using nonparametric statistical methods was conducted to assess the effect of Korean total maximum daily load (TMDL) program on the improvement of water quality in the Geum River basin, Korea. The result of analyzing the trend of long-term BOD change from 2003 to 2012 by seasonal Mann–Kendall test showed that there was no significant change (GR-1, GS-1, MH-1) or a trend of increase (GR-2) in “water quality improvement plan area,” whereas a trend of decrease was observed in “implementation plan area” (GR-3, GR-4, GR-5, GS-2, MS-2). The period of TMDL implementation was divided into four time sections, and the BOD in each time section was compared with the others using the Kruskal–Wallis test. Compared with pre-TMDL stage, the effect of water quality improvement did not appear in the early first stage but appeared first in the tributaries, Gap Stream (GS-2) and Miho Stream (MS-2) in the late first stage of TMDL. At the mainstream sites (GR-3, GR-4, GR-5), the effect of wat...

Determination of Veterinary Antibiotic Residues: IV. Comparable Analytical Methods with EPA Methods 1694_A Review

Abstract In this study, 16 antibiotics were selected from among the top 30 veterinary antibiotics sold in South Korea in 2014, as well as from among the pharmaceuticals targeted by EPA method 1694, in order to review analytical methods for the detection of trace levels of antibiotics in environmental samples: surface water, soils, animal origin foods, and manures. LC-MS/MS was heavily used. In the chromatography for the detection of the selected antibiotics, the C18 column was mostly used at the temperature of 30~40°C. Water and methanol/acetonitrile were commonly chosen as a nonpolar and a polar mobile phase, respectively. Gradient elution was applied to separate multiclass antibiotics. Volatile additives, such as formic acid, acetic acid, and ammonium acetate were mixed with the mobile phase to improve the ionization efficiency of analytes and the sensitivity in MS detection. Electrospray ionization (ESI) was widely used in the LC-MS/MS and positive ionization was preferred to determine the selected antibiotics. A protonated [M+H] molecule was selected as a precursor ion, and its two transitions were analyzed, one for quantitative measurement and the other for confirmation. This study reviewed linearity of the calibration curve, recovery, repeatability, method detection limits (MDLs), and method quantification limits (MQLs) for each target compound used to validate the developed analytical methods.

Research on the Development Management Basin and Goal for 3th T.W.Q on the Boundary between Metropolitan Cities/Dos Specified in Nakdong River Basin

The current Total Pollution Load Control (TPLC) sets the Target Water Quality (TWQ) by utilizing the delivery ratio, unit loads, and water quality modeling, it also allocates the watersheds permitted discharge load. Currently, common target pollutants of every unit watershed in TPLC are BOD and T-P. This study has reviewed the 1th and 2th of TWQ setting process for the Nakdong River 3th TWQ setting in Total Pollution Load Control (TPLC). As a result of review, 1th and 2th were divided into one management basin (mulgeum) for setting management goals. However, 3th was divided into six management basins (mulgeum, gnagjeong, geumho river, nam river, miryang river, end of nakdong river). The principle of management goal setting were to achieve the objective criteria of Medium Areas for the linkage of the water environment management policy. And Anti-Degredation (principle of preventing deterioration) were applied to the 3th TWQ. Also, additional indicators were considered in accordance with the reduction scenarios for the final management goals.

Introduction of the Basin Sewerage Plan in Japan through Case Studies of the Lake Biwa Sewerage System

We investigate the Japan’s Master Plan of Comprehensive Sewerage System (JMPS) and Lake Biwa basin sewerage and suggest future development direction of the Watershed Sewerage System Maintenance Plan in Korea enforced on February 2, 2013. The JMPS is designed for compliance with the environmental standard for water quality under the Environmental Policy Act. The effluent standards applied in the master plan of Lake Biwa’s Sewerage Plan for the Lake Biwa is tougher than the national standards. Therefore the Lake Biwa Baisn Sewerage System was the first in Japan to adopt facilities that perform advanced treatment for nitrogen and phosphorus removal. BOD, SS, T-N and T-P concentrations of discharge water of sewage are 0.9, 0.6, 5.5, 0.06 mg/L, respectively. Especially removal efficiency for BOD is 99.5 percent. It is necessary to study the diversification of the evaluation criteria, cost minimization approach, subsidy system improvement, economic concept of discharge load adjustment system and establishment of basin sewerage concept for the development of the basin sewerage plan in Korea.

A study on the runoff characteristics of livestock resources using artificial and natural rainfall

This study conducted a laboratory simulation using artificial and natural rainfall in order to investigate the runoff characteristics of livestock resources through the analysis of the surface runoff water and infiltration water by rainfall intensity and fertilization level. Cattle manure and pig liquid fertilizer was used as livestock resource. As a result of this study, it was observed that the surface runoff occurred over 32 mm/hr rainfall intensity, and flow rate of the surface runoff water and the runoff ratio of contaminant parameters from livestock resource was increased, as rainfall intensity was stronger. With doubled fertilization level, T-N increased in compost and the amount of runoff also considerably increased in liquefied fertilizer. In the case of natural rainfall, the runoff ratio of T-P clearly increased in compost and the T-N of final surface runoff ratio in compost and liquefied fertilizer was ranged from 0.13047 to 0.13623 with stronger rainfall intensity.