The flue dust emission of the coal fired power plants in Zhejiang Province attains target

According to statistics, the average dust collection efficiency of flue gas emission in the large and medium- sized power plants in Zhejiang Province at present has attained higher than 97% which surpasses the 95% standard as stipulated by the Ministry of Electric Power. The dust collection efficiency of the Beilungang Power Plant has already attained 99.92%. In recent years, Zhejiang Electric Power Corporation has stipulated that all the newly constructed generating units shall be equipped with high efficiency electrostatic precipitator (ESP) while the existing power plants shall speed up their renovation work for their dust collectors. In combination with the fourth stage project of the Taizhou Power Plant, the improvement work of the dust

Analyses of BioVOCs variation related to vegetation predominance in the Natural Park of Ampezzo Dolomites, UNESCO world heritage area of Dolomites

The determination of emitted Biogenic Volatile Compounds （BioVOCs） profile via Field Air Analysis （FAA） - Solid Phase Micro Extraction （75μm Carboxen/PDMS portable field sampler） was performed using GC-MS. The six sampling sites located in the Natural Park of Ampezzo Dolomites, part of the UNESCO＇s World Heritage List, are characterized by different predominating vegetation. The ubiquitous compound hexanal was chosen as internal standard, in order to compare the amounts of the different compound in the different sites. The main terpenes identified were α-pinene, 13-pinene, 6-3-carene and d-limonene, while 1,8 cineole was the highest abundant oxygenated terpene. In the site next the＇national road a higher amount of benzene derivatives （ben- zene, toluene, o-xylene, p-xylene and ethylbenzene） were observed. In the site relatively close to the road a marked decrease of benzene deriva- tives was observed. In the sites close to conifers （i.e. Fir, Pine and Larch） the terpenic content observed was higher than in the site close to the mixed forest （mainly large-leaf and some conifers）. Some terpenes were observed also in the high-quote meadow site, although of lower abun- dance than in the other sites. The highest abundance of terpenes was ob- served in the Pinus cerebra （Swiss Pine） site.

Characterization of odorous charge and photochemical reactivity of VOC emissions from a full-scale food waste treatment plant in China

Food waste treatment plants （FWTPs） are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound （VOC） emissions. This study investigated the VOC emissions from a selected full-scale FWTP in China. The feedstock used in this plant was mainly collected from local restaurants. For a year, the FWTP was closely monitored on specific days in each season. Four major indoor treatment units of the plant, including the storage room, sorting/crushing room, hydrothermal hydrolysis unit, and aerobic fermentation unit, were chosen as the monitoring locations. The highest mean concentration of total VOC emissions was observed in the aerobic fermentation unit at 21,748.2-31,283.3 μg/m^3, followed by the hydrothermal hydrolysis unit at 10,798.1-23,144.4 μg/m^3. The detected VOC families included biogenic compounds （oxygenated compounds, hydrocarbons, terpenes, and organosulfur compounds） and abiogenic compounds （aromatic hydrocarbons and halocarbons）. Oxygenated compounds, particularly alcohols, were the most abundant compounds in all samples. With the use of odor index analysis and principal components analysis, the hydrothermal hydrolysis and aerobic fermentation units were clearly distinguished from the pre-treatment units, as characterized by their higher contributions to odorous nuisance. Methanthiol was the dominant odorant in the hydrothermal hydrolysis unit, whereas aldehyde was the dominant odorant in the aerobic fermentation unit. Terpenes, specifically limonene, had the highest level of propylene equivalent concentration during the monitoring periods. This concentration can contribute to the increase in the atmospheric reactivity and ozone formation potential in the surrounding air.

CH_4 emission and conversion from A^2O and SBR processes in full-scale wastewater treatment plants

Wastewater treatment systems are important anthropogenic sources of CH4 emission. A full-scale experiment was carried out to monitor the CH4 emission from anoxic/anaerobic/oxic process （A2O） and sequencing batch reactor （SBR） wastewater treatment plants （WWTPs） for one year from May 2011 to April 2012. The main emission unit of the A2O process was an oxic tank, accounting for 76.2% of CH4 emissions; the main emission unit of the SBR process was the feeding and aeration phase, accounting for 99.5% of CH4 emissions. CH4 can be produced in the anaerobic condition, such as in the primary settling tank and anaerobic tank of the A2O process. While CH4 can be consumed in anoxic denitrification or the aeration condition, such as in the anoxic tank and oxic tank of the A2O process and the feeding and aeration phase of the SBR process. The CH4 emission flux and the dissolved CH4 concentration rapidly decreased in the oxic tank of the A2O process. These metrics increased during the first half of the phase and then decreased during the latter half of the phase in the feeding and aeration phase of the SBR process. The CH4 oxidation rate ranged from 32.47% to 89.52% （mean： 67.96%） in the A2O process and from 12.65% to 88.31% （mean： 47.62%） in the SBR process. The mean CH4 emission factors were 0.182 g/ton of wastewater and 24.75 g CH4/（person.year） for the A2O process, and 0.457 g/ton of wastewater and 36.55 g CH4/（person.year） for the SBR process.

Concentration-and flux-based dose-responses of isoprene emission from poplar leaves and plants exposed to an ozone concentration gradient

Supported by the National Key Research and Development Program of China,Key Research Program of Frontier Sciences,CAS,the Hundred Talents Program,Chinese Academy of Sciences(CAS),and National Natural Science Foundation of China,a cooperative study by the research groups led by Prof.

Mercury mass flow in iron and steel production process and its implications for mercury emission control

The iron and steel production process is one of the predominant anthropogenic sources of atmospheric mercury emissions worldwide. In this study, field tests were conducted to study mercury emission characteristics and mass flows at two iron and steel plants in China. It was found that low-sulfur flue gas from sintering machines could contribute up to41% of the total atmospheric mercury emissions, and desulfurization devices could remarkably help reduce the emissions. Coal gas burning accounted for 17%–49% of the total mercury emissions, and therefore the mercury control of coal gas burning, specifically for the power plant burning coal gas to generate electricity, was significantly important. The emissions from limestone and dolomite production and electric furnaces can contribute29.3% and 4.2% of the total mercury emissions from iron and steel production. More attention should be paid to mercury emissions from these two processes. Blast furnace dust accounted for 27%–36% of the total mercury output for the whole iron and steel production process. The recycling of blast furnace dust could greatly increase the atmospheric mercury emissions and should not be conducted. The mercury emission factors for the coke oven,sintering machine and blast furnace were 0.039–0.047 g Hg/ton steel, and for the electric furnace it was 0.021 g Hg/ton steel. The predominant emission species was oxidized mercury, accounting for 59%–73% of total mercury emissions to air.