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A new approach of nonpoint source pollution/stormwater sludge treatment by an integrated thermal plasma system
Li, O.L.; Guo, Y.; Chang, J.S.; Urashima, K. & Saito, N.
Abstract
In this study, we designed and demonstrated
the effectiveness of an integrated waste
treatment system for contaminated stormwater sludge.
The system is comprised of two components: pulsed
arc electrohydraulic discharge (PAED) for aqueousphase
treatment and thermal plasma decontamination
for solid-phase treatment. PAED provided a reduction
of 80 % in total organic carbon (TOC) within a
treatment time of 5 min in the aqueous phase. With a
prolonged treatment of 30 min, the decontamination
of TOC reached over 90 % in the aqueous phase,
accompanied with 20 % carbon and 70 % sulfur
decreases in weight in the solid phase. A huge weight
reduction can be achieved prior to further solid
treatment. The solid phase, named as the PAEDtreated
sludge, was separated by sedimentation and
transferred to thermal plasma treatment. The thermal
plasma-treated sludge was slightly melted, and the
formation of slag was possible. X-ray energy dispersion
solid analysis showed that carbon and sulfur
were reduced to zero after treatment. Si, Mg, and Al
decreased by 25, 30, and 60 %, respectively, while Ca
and Fe enriched by 400 and 25 %, respectively. The
emission gas analyses demonstrated a possible energy
recovery from gaseous compounds with adequate
gaseous treatment devices. This research demonstrates
an innovative treatment approach of various sludge
types, especially those types that contain high water
contents and are severely contaminated by toxic
organic compounds.
Keywords
Nonpoint source pollution; Stormwater sludge; Thermal plasma; Pulsed arc electrohydraulic discharge; Integrated system
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