BAC Filtration Examples in Full-Scale Drinking Water Treatment Plants - Activated Carbon for Water and Wastewater Treatment - page 322

Humics Building Blocks LMW Acids Neutrals Biopolymers

80

70

60

50

40

30

20

10

-

Raw Water Coagulation

Effluent

Reservoir
Effluent

RS Filtration
Effluent

Ozonation
Effluent

Softening
Effluent

BAC Filter
Effluent

Treated
Water

Figure 10.5 The mean percent contribution of each of the five LC-OCD NOM fractions to the
bulk water across the treatment train [12](permission received).

of five NOM fractions: humic substances, building blocks (hydrolyzates of
humics), biopolymers, low-molecular-weight acids, and neutrals, as shown in
Figure 10.5 [12].
The main part of the NOM was composed of humics across the entire treatment.
The humic fraction, contributing about 70% of the total DOC, was mainly
removed by coagulation (30%) and by BAC filtration (42%), indicating that a
significant part was biodegradable. No low-molecular-weight (LMW) acids were
initially present in the raw water, but these formed as a result of ozonation and
contributed very little to the total DOC. They were largely removed by softening,
BAC filtration, and SS filtration.

10.2.7
Drinking Water Treatment Plants, Bendigo, Castlemaine, and Kyneton, Victoria,
Australia

The Aqua project in Australia incorporates three water treatment plants using
microfiltration, ozone, and BAC filtration technologies. The main plant in
Bendigo has a capacity of 126ML d -1 and features submerged microfiltration
technology (CMF-S), while the Kyneton 8ML d -1 plant and Castlemaine 18ML d -1
plant use conventional CMF designs [13]. The raw water supplied from reservoirs
is screened, then dosed with lime and carbon dioxide to stabilize the water to
prevent corrosion. Coagulation is then the next step for removal of particulates,
metals, and color. Microfiltration is introduced to remove particulates down to
0.2 m m and to guarantee the removal of Cryptosporidium and Giardia contamina-
tion from unprotected rural catchments. All plants use ozone and BAC filtration in
order to remove taste and odor compounds and blue-green algae toxins. Ozonation
breaks down complex organics. Subsequently, BAC filtration reduces organic
carbon, eliminates taste and odor compounds, and reduces blue-green algae