A4 Conference proceedings

An advanced process for thermal treatment of municipal sewage sludge


Publication Details

Authors: Peltola Petteri, Myöhänen Kari, Laasonen Arttu, Hyppänen Timo

Publication year: 2021

Language: English

Related journal or series: European Biomass Conference And Exhibition

Title of parent publication: 29th European Biomass Conference and Exhibition

Start page: 113

End page: 118

Number of pages: 6

eISSN: 2282-5819

JUFO level of this publication: 0

Permanent website address: http://www.etaflorence.it/proceedings

Open Access: Not an Open Access publication


Abstract

Sewage
sludge, a by-product of the wastewater treatment process, should not be
considered as a waste, but as a potential resource for renewable energy and nutrient
recovery. However, sewage sludge contains harmful contaminants (e.g. pathogens,
pharmaceutical residuals, and microplastics) as well, and if the sludge – composted
or digested – is utilized directly in agriculture, these contaminants may leak into
the environment. To tackle this issue, an advanced combustion scheme is proposed.
In this process, mechanically dewatered sludge (20–25 wt% dry solids content)
from a nearby wastewater treatment plant is first dried at 110 °C in a circulating
mass dryer and then combusted at 850 °C in a circulating mass reactor. Thereby,
all the unwanted organic compounds are eliminated, and the ash – relatively
high in nutrients and sufficiently low in heavy metals – can be further
processed into fertilizers and used in forestry or farming. The process is
self-sufficient in terms of energy; the excess heat extracted from the process can
be utilized, e.g., as district heat. This paper describes the process in detail
and reviews initial experiences from the first commercial plant at Rovaniemi,
Finland. Also, the potential of the technology for efficient and sustainable
handling of municipal sewage sludge is discussed.


Last updated on 2021-27-10 at 14:55