dc.description.abstract | Abstract
Sewage systems are an indispensable public facility of modern urban areas,
and are an indicator of national competitiveness. As part of its active efforts in
developing nationwide sewerage systems, the Executive Yuan ratified the
“Phase 5 Sewage System Construction Plan” of the Construction and Planning
Agency, which aims to increase the ratio of household pipelines connected to
public sewage to 35.10% and the overall ratio of sewage treatment to 60.80%
between 2015 and 2020; sewage sludge volume is expected to show sequential
growth each year.
Sewage sludge is rich with organic matter, inorganic matter, and heavy metals.
This study collects data on domestic and foreign laws and regulations related to
sewage sludge reuse, reuse technologies, characteristics of sewage sludge in
Taiwan, corresponding laws and regulations, government policy, and the
national situation. Sewage sludge reuse technology is divided into three
categories, namely “renewable energy,” “green farmland” and “construction
material,” and the strengths and weaknesses of each technology is analyzed from
the perspective of technology, market, environment, and laws and regulations,
evaluating the most technology for sludge reduction and discussing its
feasibility.
Considering that there are many methods for reusing sewage sludge, but sewage
sludge reuse products cannot be used in farmland due to current laws and
regulations, as well as objections from the Council of Agriculture (COA), this
study proposes the use of sewage sludge carbonization equipment together with
a cement kiln, so as to produce a product that conforms to current laws and
regulations and satisfies the COA’s requirements.
This study mainly uses waste heat from a cement kiln to carbonize sewage
sludge. The organic waste gas generated from drying and carbonizing the
sewage sludge is channeled back into the cement kiln for combustion, and then
the carbonized product (auxiliary fuel) is mixed with coal and used as fuel for
the cement making process. The ultimate objective is to mix sewage sludge ash
into coal ash and directly uses it as part of the pozzolanic material application
system. | en_US |