Suing Il Choi

DOI: Vol.10(No.3) 137-156, 1994

Recent researches in advanced water treatment water treatment have been reviewed to see where we are. Of course, the researches cited here are not all the researches conducted nor all the representatives. They are cited because they are quite typical. The researches in Korea have been mostly examinations of acceptability of advanced technologies in Korean environments, which is the first step in technology transfer. By this time, considerable amount of experiences has been accumulated even though more experiences may be needed in some cases. Thus, the researches would be focused in modifying and/or creating technologies with more through investigation on kinetics and mechanisms.

Keith Mullette

DOI: Vol.10(No.3) 157-162, 1994

Yong Chung

DOI: Vol.10(No.3) 163-182, 1994

Graham B . Allison

DOI: Vol.10(No.3) 183-187, 1994

Eui So Choi , Geon Ha Kim , Zu Whan Yun

DOI: Vol.10(No.3) 189-199, 1994

The pollutant generation and discharge rates from the nonpoint sources(NPS) in selected areas were evaluated. An urban area as well as a typical agricultural area with feedlot farming region were considered for evaluation. The pollutant generation rate from the NPS in urban area was estimated as 4,822 ㎏COD/ha/year, 24,651 ㎏SS/ha/year, 203 ㎏T-N/ha/year, and 56 ㎏T-P/ha/year. Approximately 47% of the pollutants was discharged to the Han River during the flooding season of July to August. The NPS pollutant discharge rates from the urban area to the Han river were computed as 98 ㎏ COD/ha/year, 1,437 ㎏SS/ha/year, 76 ㎏T-N/ha/year, and 1.22 ㎏ T-P/ha/year, which were significantly less than the generation rates. The pollutant: generation rates fron the NPS in agricultural area was estimated as 53 ㎏BOD/ha/year, 175 ㎏COD/ha/year, 51 ㎏SS/ha/year, 12.6 ㎏T-N/ha/year. and 8.1 ㎏T-P/ha/year. The feedlot farming region in the agricultural area generated similar amount of pollutants per unit area compared to the urban area.

Seok Soon Park

DOI: Vol.10(No.3) 201-223, 1994

A stochastic multiconstituent model called STRESS (Segment Travel River Ecosystem Stochastic Simulation) was developed and validated in this study. The formulation. of STRESS is based on the moving segment approach in the Cell-In-Series(CIS) system where stream is assumed as a series of completely mixed flow reactors. The model was developed by incorporating Monte Carlo technique with the previously developed and validated determistic model called STREAM (Segment Travel River Ecosystem Autograph Model). STRESS was designed to be more representative of steep and shallow Streams with large variations of water quantity and quality which are typical in Korean peninsula. The model considers randomness in the head water, point source, non-point source conditions, and the travel time of water segment, and computes the frequency distributions, the mean values, and the standard deviations of the predicted water qualities. Major constituents included in STRESS are Dissolved Oxygen(DO), Biochemical Oxygen Demand(BOD), Suspended Solid(SS), Coliform Bacteria, Nitrogen Series, Phosphorus Series, and Phytoplankton. STRESS is executed on personal computer and designed for implementation with EGA/VGA color graphic. A demonstration application for the Tancheon, a tributary of the Han River, is presented to validate the stochastic nature of the model. The result indicated that STRESS could effectively simulate random variations of water qualities in steep and shallow streams.

Barry T . Hart

DOI: Vol.10(No.3) 225-242, 1994

Water quality management in Australia is undergoing a major change in focus towards increased ecologically-based management. A new National Water Quality Management Strategy, being developed by the Federal and State governments through the Australian and New Zealand Environment and Conservation Council(ANZECC) and the Australian Water Resources Council(AWRC), seeks to ensure that the nation`s water resources are managed on an ecologically sustainable basis. The associated Australian Water Quality Guidelines for Fresh and Marine. Waters reflect this ecological focus and include for the first time biological indicators of water quality. This paper discusses the main features of both the strategy and the guidelines, with a particular focus on the challenges facing the three major groups involved - the community, managers, and researchers if this strategy is to be successfully implemented in Australia Also discussed is the role of the new Cooperative Research Centre for Freshwater Ecology in providing aquatic ecological information essential to the process.

Paul Gene Chung

DOI: Vol.10(No.3) 243-256, 1994

Chlorination applied in water treatment plants is possible to produce some harmful organic chlorine compounds, of a which trihalomethanes (THM) have been recognized as potential carcinogens It has been reported that algae could be potential THM precursors in chlorination process used for the disinfection of drinking water This study was performed to investigate the possibility of THM formation during the chlorination of water containing pure culture of algae For the experiments, two forms of blue green algae, Anabaena flos aquae f. flos aquae and Microcystis aeruginosa f aeruginosa were used. The results showed that THM formation is different between two different species and ozonation prior to chlorination can reduce the THM formation potential of algae up to 83 %

S . Vigneswaran , H . H . Ngo

DOI: Vol.10(No.3) 257-271, 1994

Brian Bolto

DOI: Vol.10(No.3) 273-284, 1994

New water and wastewater treatment technologies are emerging from CSIRO which have high rates of reaction and separation, and are applicable to potable water production, sewage treatment, and the cleaning up of industrial wastes. As well as the treatment of liquids and slurries, the novel technology can be applied to sludge and sediment treatment. An overview of physicochemical methods for coagulation, adsorption and foam flotation is presented, with an emphasis in the first two cases on magnetic particle technology.

Soo Hong Noh

DOI: Vol.10(No.3) 285-297, 1994

A . G . Fane

DOI: Vol.10(No.3) 299-311, 1994

Membrane technology offers many potential advantages for waste water treatment, including the ability to recover valuable materials and providing compact systems, readily scaled-up. This paper describes two large-scale membrane applications to waste water in Australia and discusses the development of several emerging technologies.

Sang Eun Lee

DOI: Vol.10(No.3) 313-327, 1994

Paul F . Greenfield , Kin Man Ho , Linda L . Blackall , Peter R . F . Bell , Andre Krol

DOI: Vol.10(No.3) 329-355, 1994

Biological phosphorus and nitrogen removal and related sludge bulking control in both intermittent cyclic and continuous activated sludge systems are assessed. Experimental results from a laboratory-scale investigation using fermented domestic sewage indicated the advantages of achieving high levels of P ana N removal and good sludge-settling properties using the intermittent cyclic process, as compared to the space-oriented operation of a continuous facility. Accordingly, this cost-effective, simple and reliable technology is receiving wide acceptance as an appropriate technology for not only small treatment applications but in creasingly for large installations. The modified intermittently fed and decanted system incorporating non-mixing sequences produced an effluent quality of NO₃-N$lt;5 ㎎/ℓ, PO₄-P$lt; 1 ㎎/ℓ and NH₃-N$lt;2 ㎎/ℓ, with a nonbulking sludge having a sludge volume index $lt; 120 ㎖/g, despite unfavourable influent characteristics (TCOD:TKN $lt; 7, TKN$gt; 60㎎/ℓ, TP - 7 - 10 ㎎/ℓ and RBCOD $lt;30㎎/ℓ). In contrast, the modified 4-stage Bar-denpho process could not achieve an effluent PO₄-P concentration of $lt; 1 ㎎/ℓ The effluent NO₃-N concentration and sludge volume index (SVI) were always high and occasionally reached 16 ㎎/ℓ and 422 ㎖/g, respectively. The causative filaments were identified to be the low F:M growers - Types 0041/0675.

Tai Hak Chung , Dong Han Kim

DOI: Vol.10(No.3) 357-376, 1994

Laboratory experiments and extensive analysis of the results were conducted to investigate the effects of temperature on the removal of organic, nitrogen, and phosphorus in a sequencing batch reactor (SBR) system. Organic removal rate was nearly complete regardless of the temperature, while reduced rate of nitrogen and phosphorus removal was observed at low temperature But the reduction was not as great as reported because of long solids retention time and high liquor mixed suspended solids in a SBR. Nearly ⅔ of the applied organic was removed during the anaerobic fill period and major removal was coupled with phosphorus release. Nitrogen removal was limited by tie nitrification step at low temperature and by denitrification at high temperature. Major phosphorus release occurred at anaerobic fill period and phosphorus uptake took place mainly at the aerobic react period.

Peter Nadebaum

DOI: Vol.10(No.3) 377-391, 1994