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Estimation of intracellular phosphorus content of phosphorus-accumulating organisms at different P:COD feeding ratios 总被引:1,自引:0,他引:1
The intracellular phosphorus content of phosphorus-accumulating organisms (PAO) was determined based on a stoichiometric equation and phosphorus balance for an enhanced biological phosphorus removal system fed with different P:COD ratios. The data indicated that a higher P:COD feeding ratio could significantly promote the growth of PAO. As the P:COD feeding ratio increased from 0.02:1 to 0.04:1 and 0.16:1, the phosphorus in the sludge increased considerably from 0.053 to 0.084 and 0.205 mg P (mg VSS(aerobic))(-1), respectively, indicating a dynamic condition in the microbial population. From the calculations, the mass fractions of the PAO, glycogen-accumulating organisms, and ordinary heterotrophs changed from 0.10-0.15, 0.83-0.88, and 0.02 at 0.02:1 to 0.19-0.28, 0.70-0.79, and 0.02 at 0.04:1 and to 0.478-0.71, 0.26-0.50, 0.03 at 0.16:1 P:COD feeding ratios, respectively. Despite the variation in microbial diversity, the calculated phosphorus contents of the PAO at all P:COD feeding ratios were consistent between 0.241 and 0.378 mg P (mg VSS(PAO))(-1). The initial specific phosphorus release and uptake rates were 84.7-167.9 mg P (g VSS(PAO))(-1)h(-1) and 52.8-90.0 mgP (g VSS(total))(-1)h(-1), respectively. 相似文献
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Thongchai Alapha Meeinkuirt Weeradej Taeprayoon Puntaree Pichtel John 《Environmental science and pollution research international》2019,26(9):8737-8747
Environmental Science and Pollution Research - In recent years, ornamental plants have come under investigation as phytoremediation agents. In addition to reducing contaminant concentrations in... 相似文献
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Accurate emission inventory (EI) is the foremost requirement for air quality management. Specifically, air quality modeling
requires EI with adequate spatial and temporal distributions. The development of such EI is always challenging, especially
for sporadic emission sources such as biomass open burning. The country of Thailand produces a large amount of various crops
annually, of which rough (unmilled) rice alone accounted for over 30 million tonnes in 2007. The crop residues are normally
burned in the field that generates large emissions of air pollutants and climate forcers. We present here an attempt at a
multipollutant EI for crop residue field burning in Thailand. Available country-specific and regional primary data were thoroughly
scrutinized to select the most realistic values for the best, low and high emission estimates. In the base year of 2007, the
best emission estimates in Gigagrams were as follows: particulate matter as PM2.5, 128; particulate matter as PM10, 143; sulfur dioxide (SO2), 4; carbon dioxide (CO2), 21,400; carbon monoxide (CO), 1,453; oxides of nitrogen (NOx), 42; ammonia (NH3), 59; methane (CH4), 132; non-methane volatile organic compounds (NMVOC), 108; elemental carbon (EC), 10; and organic carbon (OC), 54. Rice
straw burning was by far the largest contributor to the total emissions, especially during the dry season and in the central
part of the country. Only a limited number of EIs for crop residue open burning were reported for Thailand but with significant
discrepancies. Our best estimates were comparable but generally higher than other studies. Analysis for emission uncertainty,
taking into account possible variations in activity data and emission factors, shows considerable gaps between low and high
estimates. The difference between the low and high EI estimates for particulate matter and for particulate EC and OC varied
between −80% and +80% while those for CO2 and CO varied between −60% and +230%. Further, the crop production data of Thailand were used as a proxy to disaggregate
the emissions to obtain spatial (76 provinces) and temporal (monthly) distribution. The provincial emissions were also disaggregated
on a 0.1° × 0.1° grid net and to hourly profiles that can be directly used for dispersion modeling. 相似文献
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