Results
3.1. Total methane emission from the WWTP
The daily average methane emission from the entire treatment
plant at Kralingseveer during the measuring campaign
(from 14 October 2010 until 28 September 2011) was
302 kg CH4 d1, with a standard deviation of 83 kg CH4 d1. The
reported total methane emission comprises all methane in the
off-gas that is collected in the plant’s ventilation system and
sent to the ozone washer, but the plant has two parts of which
the off-gas is not collected for disinfection in the ozone
washer: the uncovered secondary settlers and the exhaust of
the gas engines of the cogeneration plant. The secondary
settlers may emit some methane, but from the mass balance
over the secondary settlers it appears that this amount will be
very low (Table 2). The measured methane slip due to
incomplete combustion in the gas engines was 1.3%, resulting
in an additional methane emission of 38 kg CH4 d1.
The Dutch Ministry of Housing, Spatial Planning and the
Environment (VROM, 2008) provided emission factors that are
based on the IPCC inventory guidelines (IPCC, 2006). In order to
allow comparison with these emission factors and with the
results from other studies, the plant’s total methane emission
can be normalized in several ways: by population served, by
wastewater flow or by incoming COD. Table 1 summarizes the
resulting emission factors, as well as the emission factors
from the other reported full-scale studies and the VROM
emission factors. Apparently, about 1% (0.53e1.20%) of the
incoming COD is emitted as methane in the Dutch treatment
plants. At the Durnham plant, 0.16% of the incoming BOD5
was emitted as methane, while at the Jinan plant, the emission
factor was 0.08% of the incoming COD.
Results
3.1. Total methane emission from the WWTP
The daily average methane emission from the entire treatment
plant at Kralingseveer during the measuring campaign
(from 14 October 2010 until 28 September 2011) was
302 kg CH4 d1, with a standard deviation of 83 kg CH4 d1. The
by AdBlocker Manger" style="border: none !important; display: inline-block !important; text-indent: 0px !important; float: none !important; font-weight: bold !important; height: auto !important; margin: 0px !important; min-height: 0px !important; min-width: 0px !important; padding: 0px !important; text-transform: uppercase !important; text-decoration: underline !important; vertical-align: baseline !important; width: auto !important; background: transparent !important;">reported total methane emission comprises all methane in the
off-gas that is collected in the plant’s ventilation system and
sent to the ozone washer, but the plant has two parts of which
the off-gas is not collected for disinfection in the ozone
washer: the uncovered secondary settlers and the exhaust of
the gas engines of the cogeneration plant. The secondary
settlers may emit some methane, but from the mass balance
over the secondary settlers it appears that this amount will be
very low (Table 2). The measured methane slip due to
incomplete combustion in the gas engines was 1.3%, resulting
in an additional methane emission of 38 kg CH4 d1.
The Dutch Ministry of Housing, Spatial Planning and the
Environment (VROM, 2008) provided emission factors that are
based on the IPCC inventory guidelines (IPCC, 2006). In order to
allow comparison with these emission factors and with the
results from other studies, the plant’s total methane emission
can be normalized in several ways: by population served, by
wastewater flow or by by AdBlocker Manger" style="border: none !important; display: inline-block !important; text-indent: 0px !important; float: none !important; font-weight: bold !important; height: auto !important; margin: 0px !important; min-height: 0px !important; min-width: 0px !important; padding: 0px !important; text-transform: uppercase !important; text-decoration: underline !important; vertical-align: baseline !important; width: auto !important; background: transparent !important;">incoming COD. Table 1 summarizes the
resulting emission factors, as well as the emission factors
from the other by AdBlocker Manger" style="border: none !important; display: inline-block !important; text-indent: 0px !important; float: none !important; font-weight: bold !important; height: auto !important; margin: 0px !important; min-height: 0px !important; min-width: 0px !important; padding: 0px !important; text-transform: uppercase !important; text-decoration: underline !important; vertical-align: baseline !important; width: auto !important; background: transparent !important;">reported full-scale studies and the VROM
emission factors. Apparently, about 1% (0.53e1.20%) of the
by AdBlocker Manger" style="border: none !important; display: inline-block !important; text-indent: 0px !important; float: none !important; font-weight: bold !important; height: auto !important; margin: 0px !important; min-height: 0px !important; min-width: 0px !important; padding: 0px !important; text-transform: uppercase !important; text-decoration: underline !important; vertical-align: baseline !important; width: auto !important; background: transparent !important;">incoming COD is emitted as methane in the Dutch treatment
plants. At the Durnham plant, 0.16% of the by AdBlocker Manger" style="border: none !important; display: inline-block !important; text-indent: 0px !important; float: none !important; font-weight: bold !important; height: auto !important; margin: 0px !important; min-height: 0px !important; min-width: 0px !important; padding: 0px !important; text-transform: uppercase !important; text-decoration: underline !important; vertical-align: baseline !important; width: auto !important; background: transparent !important;">incoming BOD5
was emitted as methane, while at the Jinan plant, the emission
factor was 0.08% of the by AdBlocker Manger" style="border: none !important; display: inline-block !important; text-indent: 0px !important; float: none !important; font-weight: bold !important; height: auto !important; margin: 0px !important; min-height: 0px !important; min-width: 0px !important; padding: 0px !important; text-transform: uppercase !important; text-decoration: underline !important; vertical-align: baseline !important; width: auto !important; background: transparent !important;">incoming COD.
การแปล กรุณารอสักครู่..