RO/NFUF

MBR

Chemicals

CASE STUDY

RO | UF | MBR

Drinking Water
Gongju, Korea

Toray UF Technology Purifies Wastewater at Korea's First Large-Scale
Membrane Filtration Plant in Gongju
INTRODUCTION
Th e G o n g j u Wate r Tre at m e nt Pl a nt c a m eonline in 2003 using conventional treatment
processes to purify wastewater for municipal
reuse. The conventional treatment comprised of
powdered activated carbon (PAC), coagulationand flocculation, sedimentation, and rapid sandfiltration. However, stable production of highquality permeate was needed, and in 2004,
advanced membrane technology was introducedby K-water, a renowned engineering firm inKorea. K-water would design a pilot plant to begin
operation in September 2005.
The feed water is lake/pond water collected fromthe Daecheong Dam and has an average of 1.5
NTU turbidity, with the highest being 12.1 NTU.
Furthermore, this surface water experiences spikes
in taste and odor during summer and autumn due
to fluctuations in algae and other odor inducers.
The membrane filtration process aimed to reduce
Figure 1: UF membrane system at Gongju WTPturbidity and pathogenic micro-organisms despite
the temporary occurrence of taste and odor problems.
Table 1 — Quick Facts

EVALUATION
K-water conducted a seven-month pilot study of three different UF membrane
manufacturers where. K-water selected Toray based on evaluations of operating safety
and economic feasibility.
As illustrated in Figure 2, ultrafiltration replaced the sedimentation and rapid sandfiltration processes. Coagulation and flocculation were reduced from 3 stages to 1 tominimize membrane contamination caused by micro-floc formation. The PAC injection
process helped control the taste and odor during high algae season in summer andautumn.

Location

Gongju, South Korea

Capacity

30,000 m3/d

Membrane typepressurized UF

No. of trains

4

No. of modules

480

Toray UF model

HFS-2020

Flux

40.8 LMH

Recovery

94.6%

Commissioned

July 2009

Filtrate turbidity≤ 0.05 NTU

Note: one train (120 modules) was replaced in 2019from Toray's HFS-2020 to HFU-2020 model.

Figure 2: Conventional treatment scheme (top) vs.
Advanced membrane filtration system design (bottom)

03-KR-MB2-Gongju-202108

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C A S E S T U DY
RO | UF | MBR

Table 2 — Target and Actual Water Qualities
Parameter

Drinking Water Quality Standard*

Target Water Quality Value

Site Analysis Results (2018)

Turbidity

1.0 NTU(tap water = 0.5 NTU)

≤ 0.1 NTU, 95%
max. ≤ 0.3 NTU
avg. ≤ 0.05 NTU< 0.08 NTU

Trihalomethane (THM)≤ 0.1 mg/L

≤ 0.08 mg/L

< 0.051 mg/L

Haloacetic acids (HAA)≤ 0.1 mg/L

≤ 0.06 mg/L

< 0.004 mg/L

Chloral hydrate (CH)

≤ 0.03 mg/L

≤ 0.02 mg/L

< 0.0058 mg/L

Taste & odor

Odorless (excluding disinfectants≤ 10 TON (odor)≤ Geosmin, 2-MIB 15 mg/L each

NDpH

5.8–8.5

6.5–8.5

7.1–7.8

Iron (Fe)≤ 0.3 mg/L

≤ 0.2 mg/L

ND

Manganese (Mn)

≤ 0.05 mg/L

≤ 0.2 mg/L

< 0.008 mg/L

Residual chlorine≤ 4.0 mg/L

≤ 1.0 mg/L

< 0.75 mg/L

*As set by the Ministry of Environment, Korea

IMPLICATIONSThe Gongju Water Treatment Plant produces 30,000 cubic
meters per day and is currently the largest in South Korea
that utilizes pressurized UF membranes. Table 2 shows how
Toray's UF modules help meet water quality requirements andcontinue to produce stable operation for over ten years since its
commissioning in 2009. The Gongju WTP has become a standard
model for membrane plants in South Korea.

Figure 3: UF train at Gongju WTP

TORAY INDUSTRIES, INC.
Head Office: Nihonbashi Mitsui Tower 24th Floor, 1-1, Nihonbashi-Muromachi 2 chome, Chuo-ku,Tokyo, 103-8666, JAPANwww.water.toray+81 3 3245-4540

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All information presented herein is believed reliable and in accordance with accepted engineering practices. Toray makes nowarranties as to the completeness of this information. Users are responsible for evaluating individual product suitability forspecific applications. Toray assumes no liability whatsoever for any special, indirect or consequential damages arising from thesale, resale or misuse of its products. © 2021 Toray Industries, Inc. Subject to change without notice.
03-KR-MB2-Gongju-202108

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