Sludges
CONFIDENTIAL
12
-
2.22
treat me nt
The
sew age
a mount of s lu dge from water and
plants and from other wastewaters is expected to
increase from the present 1.3 million tonnes to a total of
2.6 million tonnes by the year 2001.
2.23
from Sha
will be
The current practice of disposing of the sludges
Tin water treat ment works into the Sha Tin nullah
replaced by a marine disposal scheme for disposal
at sea, which will a lso dispose of some treated sewage
sludges.
The pipelines, tanks and jetty for this scheme
are being built at Shing Mun and a specialist contractor is
scheduled to commence disposal operations in 1991. The
disposal site, south east of Waglan Island, has been
monitored for several years, and the EPD will continue
monitoring during the 5 year life of the scheme, so that
appropriate action can be taken in the unlikely event that
are signs of adverse effects on the marine
there
environment.
2.24
long-term
EP D
is
best
Marine disposal is not necessarily the
option for the disposal of sewage sludges, so the
gi ving consideration to alternative, recently
processes for dealing with sludges such as
bed incineration, high efficiency filtration and
the production of oil from sludge.
developed
fluidised
Coal Ash
2.25
The
produced
by
large quantities of pulverised fuel ash (PFA)
coal-fired power stations at Lamma Island
the
CONFIDENTIAL