vol 77 n° 5 2011 - Office International de l'Eau

STUDII SI CERCETARI
socio-political reception of sewage sludge recycling
and with it the amount of wastewater
to be treated. The quantity
of contaminants has hardly changed,
however, so that their concentration
has increased and in
turn resulted in higher unit quantities
of sludge. This has adversely
affected water utility companies,
because wastewater charges in
Hungary are billed on the basis of
water consumption, not on the
amount of wastewater. The increased
costs have to be met from
decreasing income.
nutrients in the sludge; high-quality
compost, for example, can be
produced industrially, with a nutrient
content that could enable
partial replacement of artificial
fertiliser. The marketing of these,
however, is still very difficult.
There is a noticeable difference
in the sludge recycling options taken
up in the western half of Europe
– the EU 12 countries – and
the newer EU members. Here,
thermal recycling, which is very
classification). Landfill must be regarded
as a solution of last resort,
to be avoided if at all possible.
The burden of regulation and
restrictions have caused what is
actually a useful secondary raw
material to be regarded as waste
to be got rid of. Climate change
and energy scarcity are new challenges
which could assist progress
to a solution.
The role of the government is
to support recycling (biogas generation,
agricultural, renewable
energy, etc.) and bring environmental
considerations into balance
with economic and social factors
(service charges, job creation).
Figure 3: Water charges as a proportion of income in towns with both services, by average population,
2009 [18]
The tightening of environmental
regulations and the reduction in
scope for agricultural utilisation
were accompanied, or very quickly
followed, by social demands which
have increasingly directed public
attention towards sewage sludge.
Although new technology has
opened up the potential for treatment
and recycling, the investment
and operating costs are constantly
rising. There is now no technical
barrier to the exploitation of plant
widespread in the west of Europe,
is almost totally absent. Acceptance
of thermal recycling is not universal.
A good example is Denmark’s
recent introduction of a
tax on incineration of certain kinds
of sludge.
Considering the potential of
domestic sewage sludge as a primary
energy source, and one of
increasing quantity, there is a definite
need to rethink its classification
as “waste” (as in the EWC
Consumers’ decisions are clearly
guided by both the level of
charges and their own income.
The response to both higher charges
and lower income is lower
consumption. Water consumption,
however, cannot be reduced below
a certain level; instead of (or as
well as) holding back on water
use, some consumers choose to
pay their bills late or partially, if
at all. [18].
We have come to the point in
Hungary where service charges
could hardly be further increased,
this however could be a barrier to
service improvements.
A positive improvement is that
with EU support, biogas plants
are launched for large-scale energetic
valorisation of sewage sludge.
nr.5 / 2011 www.romaqua.ro
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