Water & Wastewater Asia May/Jun 2021

IN THE FIELD
FROM PEAT WATER
TO DRINKING WATER:
Development of
drinking water supply
for Dumai City
To improve drinking water services in Dumai, Indonesia,
the city government partners the consortium of PT
Adhi Karya and PT Adaro for the construction of Water
Treatment Plant (WTP) in Dumai City. The pilot plant
involves the installation of NX Filtration’s Hollow Fibre
Nanofiltration (HFNF) membrane technology, which treats
peat water into drinking water.
Mesjid River as a
source of raw water
for WTP of Dumai
City
SOURCE OF RAW WATER
Raw water for WTP Dumai City is
sourced from Mesjid River, which
crosses Dumai City. The permit for the
utilisation of surface water from Mesjid
River was issued by the Directorate
General of Water Resources of the
Ministry of Public Works and Settlement
in 2018.
The challenge in developing WTP
for Dumai City is the quality of raw
water, which is peat water, as it has
the characteristics of low pH value
between three to five, low turbidity level
below 10 nephelometric turbidity units
(NTU), and high colour content of more
than 100 true colour units (TCU).
The colour content in peat water is a
true colour formed by Natural Organic
Matter (NOM) from humus soil.
NOM has a particle size of less than
10nm, and molecular weight cut-off
(MWCO) in the range of 800-50,000
Daltons. However, the colour content
in peat water is unable to be reduced
to the required standard quality by
using conventional WTP technology.
Drinking-water quality standards,
according to Regulation of Indonesia
Ministry of Health No. 492/2010,
requires that the colour content in
drinking water should be less than 15
TCU.
With an aim to increase drinking
water services for the people in
Dumai City from 1% to 35% by 2023,
the Water Treatment Plant (WTP)
in Dumai will be built with a total
production capacity of 450L/s, and
will be implemented in three stages
of development – the first stage
with capacity production of 50L/s,
continued with capacity production
200L/s in the next two stages of
development.
The central government of Indonesia,
through the Ministry of Public Work,
has also been developing 50L/s
WTP for Dumai City under a funding
scheme by the World Bank.
HFNF TECHNOLOGY
Colour content contained in peat water
is difficult to remove by conventional
WTP technology as it is unable to
optimally filter NOM particles, which
are smaller than the porosity of the
sand filter. Modification of conventional
WTP to reduce the colour content in
peat water requires a high consumption
of coagulant and flocculant chemicals,
which, in turn, increases the operational
cost in producing the drinking water.
Moreover, it has not been able to reach
the expected colour required.
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