Non-heating Period Research Articles

Associations between Built Environment, Air Quality, and Quality of Life in Xi’an, China

Associations between Built Environment, Air Quality, and Quality of Life in Xi’an, ChinaAbstract Number:2669 Meiling Gao*, Junji Cao, Edmund Seto, and Catherine Koshland Meiling Gao* University of California Berkeley, United States, E-mail Address: [email protected] Search for more papers by this author , Junji Cao Institute for Earth Environment Chinese Academy of Sciences, China, E-mail Address: [email protected] Search for more papers by this author , Edmund Seto University of Washington, United States, E-mail Address: [email protected] Search for more papers by this author , and Catherine Koshland University of California Berkeley, United States, E-mail Address: [email protected] Search for more papers by this author AbstractRapid economic development has led to dramatic changes in the physical environments of Chinese cities as they grow to accommodate a growing population. Changes in the urban environment has important public health implications by affecting how people live, travel, and access goods and services but this process is not well understood. This study examines the associations between built environment characteristics, air quality and quality of life in an urban Chinese population to inform how cities can be designed to promote health. Measures of neighborhood quality and quality of life were collected in a cross-sectional study of 1602 adults in 20 neighborhoods of Xi’an, China in 2013. Self-reported measures using the NEWS-A survey evaluated a neighborhood’s walkability, ease of access, safety, aesthetics and resources. Health-related quality of life using the SF-12 Health Survey included mental (MCS) and physical (PCS) component scales. Objective measures of walkability and accessibility were also assessed using Asian Development Bank’s Walkability survey and geographic information systems methods. Short-term deployments of 19 filter-based (MiniVol) and 34 passive monitors (Ogawa) in the heating and non-heating periods measured ambient PM2.5, NO2, SO2, and O3 concentrations. Using remote sensing, land-use regression, and principal components analysis, exposures to ambient pollution were estimated for the surveyed population. Preliminary analyses using population averaged models suggest self-reported measures of neighborhoods are more closely associated with the two components of health-related quality of life. Improving the pedestrian infrastructure and increasing access to resources within shorter walking distances is significantly associated with increases in both the MCS and PCS across the population.Results from this study can be used to inform how neighborhoods can be redesigned to improve health-related quality of life.

Research on the Utilization of Exhaust Gas Heat for Boilers

The exhaust heat loss of the power plant boiler can account for more half of the boiler heat loss, exhaust gas temperature is 110~160 °Ccommonly, so the exhaust gas heat can be used to reduce the coal consumption, raise the economic benefits. Before and after the desulfurization tower of a 350 MW unit, there installs two plate heat exchangers, heating condensation water respectively, which can improve the thermal efficiency. With two heat exchangers working under the design conditions, a test was carried out based on a 350 WM unit simulation system in order to test the influence of system for unit operation characteristics. Referring to the data, the investment of the heat exchanger can achieve 2.68 g/kWh coal saving during the non-heating period and 0.2531 g/kWh during the heating period.

Characterizations, relationship, and potential sources of outdoor and indoor particulate matter bound polycyclic aromatic hydrocarbons (PAHs) in a community of Tianjin, Northern China.

Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic air pollutants in China. However, because there are unsubstantial data on indoor and outdoor particulate PAHs, efforts in assessing inhalation exposure and cancer risk to PAHs are limited in China. This study measured 12 individual PAHs in indoor and outdoor environments at 36 homes during the non-heating period and heating period in 2009. Indoor PAH concentrations were comparable with outdoor environments in the non-heating period, but were lower in the heating period. The average indoor/outdoor ratios in both sampling periods were lower than 1, while the ratios in the non-heating period were higher than those in the heating period. Correlation analysis and coefficient of divergence also verified the difference between indoor and outdoor PAHs, which could be caused by high ventilation in the non-heating period. To support this conclusion, linear and robust regressions were used to estimate the infiltration factor to compare outdoor PAHs to indoor PAHs. The calculated infiltration factors obtained by the two models were similar in the non-heating period but varied greatly in the heating period, which may have been caused by the influence of ventilation. Potential sources were distinguished using a diagnostic ratio and a mixture of coal combustion and traffic emission, which are major sources of PAHs.

Energy-efficient and cost-effective in-house substations bypass for improving thermal and DHW (domestic hot water) comfort in bathrooms in low-energy buildings supplied by low-temperature district heating

Using a bypass to redirect a small flow through the in-house DH (district heating) substation directly to the return pipe is a commonly used but energy-inefficient solution to keep the DH network “warm” during non-heating seasons. Instead, this water can be redirected to the bathroom FH (floor heating) to cool down further and thus reduce the heat lost from bypass operation while tempering the bathroom floor and guaranteeing fast provision of DHW (domestic hot water). We used the commercial software IDA-ICE to model a reference building where we implemented various solutions for controlling the redirected bypass flow and evaluated their performance. The effect on the DH network was investigated using Termis software. Bypass flow redirected into bathroom FH during the non-heating period resulted in comparison to the reference case on average in a 0.6 °C–2.2 °C increase of the floor surface temperature and additional cooling of bypass water by 3.9 °C, reducing the heat loss from the DH network by 13% and covering 40% of the heat used in the bathroom FH. The use of the bypass flow in bathroom FH is a cost-effective solution exploiting the heat that would otherwise be lost in the DH network to improve comfort for customers at discounted price.

Distribution of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in the Atmosphere of Beijing, China

Air samples were collected from six locations during the periods of February, 2011–March, 2012 in Beijing city. Samples were analyzed using HRGC-HRMS according to HJ 77. 2-2008. The concentrations, congener profiles, seasonal variation, spatial distribution, and sources identified were investigated. The mass concentrations of 2,3,7,8-substituted PCDD/Fs is 1750 to 10380 fg/m3 with an average of 3670 fg/m3. The highest concentration was observed at site DS in February 2011 and the lowest was at site NS in July 2011. The TEQ concentrations of PCDD/Fs ranged from 35.0 to 751 fg I-TEQ/m3, with an average of 251 fg I-TEQ/m3. The dominant contributor to total TEQ value is 2,3,7,8-PeCDFs, with an average contribution of 40%. Low-chlorinated PCDDs were observed in all samples in winter. The concentration and profiles exhibit obvious seasonal variation. The PCDD/Fs at six sampling sites did not show obvious spatial variation. Seasonal variation of PCDD/F concentrations indicated that the emission sources may be different. Fossil fuel combustion and automobiles may be the main dioxins emission sources during the heating period, whereas, in non-heating period, the automobiles alone are the main emission sources.

Spatial and seasonal variability of the mass concentration and chemical composition of PM2.5 in Poland

The seasonal changes in ambient mass concentrations and chemical composition of fine particulate matter (PM2.5) were investigated in three locations in Poland. The analyses included PM2.5-bound hazardous benzo(a)pyrene (BaP), As, Ni, Cd, and Pb. The samples of PM2.5 were collected daily in Katowice (southern Poland, urban background site), Gdańsk, and Diabla Góra (northern Poland, urban and regional background sites, respectively) during 1-year-long campaign in 2010. Based on monthly ambient concentrations of PM2.5-bound carbon (organic and elemental), water-soluble ions (Na+, NH4 +, K+, Mg2+, Ca2+, Cl−, NO3 −, SO4 2−), and elements As, Ni, Cd, Pb, Ti, Al, Fe, the chemical mass closure of PM2.5 was checked for each of the four seasons of the year and for the heating and non-heating periods at each site. Also, the annual concentrations of PM2.5 were determined and the annual PM2.5 mass closure checked. At each measuring point, the PM2.5 concentrations were high compared to its Polish yearly permissible value, 25 μg/m3, and its concentrations elsewhere in Europe. The highest annual PM2.5 concentration, 43 μg/m3, occurred in Katowice; it was twice the annual PM2.5 concentration in Gdańsk, and thrice the one in Diabla Góra. The high annual averages were due to very high monthly concentrations in the heating period, which were highest in the winter. PM2.5 consisted mainly of carbonaceous matter (elemental carbon (EC) + organic matter (OM), the sum of elemental carbon, EC, and organic matter, OM; its annual mass contributions to PM2.5 were 43, 31, and 33 % in Katowice, Gdansk, and Diabla Góra, respectively), secondary inorganic aerosol (SIA), the Na_Cl group, and crustal matter (CM)—in the decreasing order of their yearly mass contributions to PM2.5. OM, EC, SIA, Na_Cl, and CM accounted for almost 81 % of the PM2.5 mass in Katowice, 74 % in Gdańsk, and 90 % in Diabla Góra. The annual average toxic metal contribution to the PM2.5 mass was not greater than 0.2 % at each site. In Katowice and Gdańsk, the yearly ambient BaP concentrations were high (15.4 and 3.2 ng/m3, respectively); in rural Diabla Góra, the concentrations of BaP were almost equal to 1 ng/m3, the Polish BaP annual limit. The great seasonal fluctuations of the shares of the component groups in PM2.5 and of the concentrations of PM2.5 and its components are due to the seasonal fluctuations of the emissions of PM and its precursors from hard and brown coal combustion for energy production, growing in a heating season, reaching maximum in winter, and decreasing in a non-heating period. In Gdańsk, northern Poland, especially in the spring and autumn, sea spray might have affected the chemical composition of PM2.5. The greatest hazard from PM2.5 occurs in Katowice, southern Poland, in winter, when very high concentrations of PM2.5 and PM2.5-related carbonaceous matter, including BaP, are maintained by poor natural ventilation in cities, weather conditions, and the highest level of industrialization in Poland. In less industrialized northern Poland, where the aeration in cities is better and rather gaseous than solid fuels are used, the health hazard from ambient PM2.5 is much lower.

An assessment of particulate mercury and arsenic concentrations in size-fractioned total suspended particulate matter in urban areas

In this study, arsenic (As) and mercury (Hg) concentrations were determined in total suspended particulate matter (TSP) fractioned at nine different sizes (>8, 8–6.5, 6.5–5.2, 5.2–3.5, 3.5–2.6, 2.6–1.7, 1.7–1, 1–0.43, and 10) of As were observed within the fine particle size (<1 μm) at all stations. The EF values of As generally decreased with increasing particle size. A significant negative correlation was observed between the size of the particles and the As concentration in the heating period at the Besiktas and Rasathane stations, which are located in residential areas. Higher Hg concentrations were found in fine particles (<2.6 μm) at stations near the sea, specifically during non-heating periods.

PM LEVELS IN SELECTED URBAN MICROENVIRONMENTS NEAR THE COPER SMELTER COMPLEX, BOR, SERBIA

Background: Numerous epidemiological studies have associated exposure to PM in the outdoor environment to adverse health effects. Nowadays, the attention is paid to indoor air pollution, since people spend most of time in the indoor for which there is gap of PM data. Aims: The Municipality of Bor has been the major centre for mining and processing of copper and other precious metals, assumed as hot spot with the main source of air pollution of SO2 and toxic metals and metalloids in PM. However, annual values of outdoor PM in Bor town have been reported for several years as one of the lowest in Serbia. Our study is aimed to determine the level PM in selected indoor microenvironments as hospital, kindergarten, etc. Methods: In the real-time PM10 and PM2.5 were monitored in the outdoor air with the GRIMM EDM180 while in the indoor with Turnkey OSIRIS Model 2315. For calculation calibration factors at each location during the first week of campaign a 24-h samples were collected concurrently with reference gravimetric samplers for both PM fractions. Campaigns for microenvironments were conducted in duration of 240 days covering heating and non-heating period during work-shifts days in period of 2009-2012. Results:Mean PM10 levels at Hospital and Kindergarten surpassing the EU yearly air quality standard of 40 µg/m3. The number of days that exceed the daily limit value for ambient PM10 level was calculated equal to 52% and 63% respectively. Furthermore, the measured indoor PM10 concentrations were higher than the outdoor ones at both sites. At the both microenvironment during heating period, mean daily concentrations of PM2.5 were greater than 25 µg/m3. Conclusions: Correlation coefficient between 0.33 and 0.62 show influence of outdoor to indoor PM. Mean I/O ratios were found to vary depending on the indoor activities and the outdoor concentration levels. Further research should be carried out in order to fully confirm these findings and identify sources of indoor PM.

Non-linear Shapes of Concentration-Response Function for Particulate-Matter-related Mortality in High Concentration Range: Evidence from Taiyuan, China

Background: Several studies had examined the shape of concentration-response function (CRF) between airborne particles and daily deaths in low concentration range of air pollution, and had reported linear relations without significant threshold, however, the shape of CRF in the high concentrations range remains poorly explored. Aims: To explore and discuss the shapes of CRFs between PM10 and daily mortality in the high concentration range of 13.14-508.43µg/m3 in Taiyuan, China. Methods: We used generalized additive models (GAM) with log link and Poisson error to estimate the shape of the concentration response function. Since estimated CRFs were nonlinear, we used constrained piecewise linear functions to estimate the relative risks, with change points dynamically estimated using a multiple structural change detection algorithm. Cause-specific analyses were performed for both heating and non-heating periods. Results: We identified three shapes of concentration-response curves: C, S, and J. Among which, we observed evident thresholds in S and J shapes, which were located at 60-100?g/m3 range for S, and at 100-250?g/m3 range for J. Risks for non-heating C shapes were found to be significantly higher than risks for other shapes. Conclusions: The result suggested heterogeneity of susceptibility within population. For CRF shapes, C-shape groups were found to be the most susceptible, S-shape less susceptible, and J-shape the least susceptible. For heating periods, non-heating-period groups were found to be more susceptible than heating-period groups. Finally, for causes of death, the susceptibility ranking was (from high to low): respiratory disease, lung cancer, ischemic heart diseases, and cerebrovascular disease.

PAH indoor-to-outdoor relationship and exposure levels in Rome

PAH indoor-to-outdoor relationship and exposure levels in Rome Background. Polycyclic aromatic hydrocarbons (PAHs) are known to be harmful to human health. Spatial variability of the emissions, atmospheric dispersion, infiltration of the particles from outdoor to indoors, and population time-activity defines the exposures. Since the time spent inside is typically 80-90% (followed by time spent in traffic and outdoors), indoor exposures and thus particle infiltration from outdoors is a key issue. Aim. The aim of the work is to study the indoor-outdoor (I/O) relationship of PAH concentrations between non-heating and heating periods in different microenvironments (homes, schools, offices and traffic), and to estimate the population exposure levels in different seasons. This work is a part of the on-going Life+ EXPAH project. Methods. The current work uses PM2.5-bound PAH concentration measurements carried out in Rome, Italy, as an input data. The I/O relationships of PAHs are evaluated and entered to a mass-...

Combined use of WEPS and Models-3/CMAQ for simulating wind erosion source emission and its environmental impact

The wind erosion source is the greatest contributor of PM10 in Tianjin, China. It is difficult to establish a PM10 emission inventory for the wind erosion source because of the complicated conditions affecting PM10 emissions from wind erosion. In this study, a novel method is developed to establish a PM10 emission inventory for the wind erosion source by using the Wind Erosion Prediction System (WEPS) model with 1×1km spatial resolution. In 2011, the average annual emission of PM10 in Tianjin was 0.373 tons km−2 (1.113 tons km−2 in the heating period, 0.237 tons km−2 in the sand period, and 0.013 tons km−2 in the non-heating period), and the total PM10 emission was 904,871.6 tons (221,080.7 tons in the heating period, 52,977.8 tons in the sand period, and 1953.2 tons in the non-heating period). After establishing the PM10 emission inventory for the wind erosion source in this manner, the data were input into Model-3/SMOKE. The contribution of the PM10 concentration from the wind erosion source was estimated using the Community Multi-scale Air Quality (Model-3/CMAQ) model and was compared with the monitoring value and the source apportionment results using the chemical mass balance (CMB) method. For this comparison, over the entire year, the R2 was 0.711. More specifically, R2 was 0.664, 0.733, and 0.679 in the heating, non-heating, and sand periods, respectively. Thus, we have obtained a reliable method for estimating the source of PM10 from wind erosion.

Gas/particle partitioning of polycyclic aromatic hydrocarbons in coastal atmosphere of the north Yellow Sea, China

Samples of gas- and particle-phase polycyclic aromatic hydrocarbons (PAHs) were collected at three sampling stations (Xiaomai Island, Laohutan, and Zhangzi Island) in the north Yellow Sea, China during November 2008 and September 2009 to study their atmospheric transport potential and the gas/particle distributions. The composition of PAHs was dominated by gaseous compounds. The percentages of the particle-phase PAHs to the total concentrations were found to be higher during the heating period than the non-heating period. The ratios of naphthalene and acenaphthene to phenanthrene, chrysene and dibenzo(a,h)anthracene showed an increasing trend from Xiaomai Island to Zhangzi Island, which can be called as the local atmospheric distillation of PAHs. Gas/particle partitioning coefficients (K p) and their relationship with the sub-cooled liquid vapor pressures (pºL) of PAHs were investigated. The regressions of logK p versus logpºL gave significant correlations for all samples of the three sites with r (2) values in the range 0.56-0.66 (p<0.01). Both Junge-Pankow adsorption model and octanol-air partition coefficient absorption model tended to underestimate the sorption for most PAHs, but the absorption model appeared to be more suitable for predicting the particle fraction of PAHs than the Junge-Pankow model.

Determination of air quality zones in Turkey

In this study, the particulate matter (with an aerodynamic diameter <10 μm; PM10) profile of Turkey with data from the air quality monitoring stations located throughout the country was used. The number of stations (119) was reduced to 55 after a missing data treatment for statistical analyses. First, a classification method was developed based on ongoing national and international (European Commission directives) legislations to categorize air zones into six groups, from a “Very Clear Air Zone” to a “Polluted Air Zone.” Then, a Geographic Information System (GIS)-based interpolation technique and statistical analyses (correlation analysis and factor analysis) were used to generate PM10 pollution profiles of the annual heating time and nonheating time periods. Finally, the coherent air pollution management zones of Turkey, based on air quality criteria and measured data using a GIS-based model supported by statistical analyses, were suggested. Based on the analysis, four hot spots were identified: (i) the eastern part of the Black Sea region; (ii) the northeastern part of inland Anatolia; (iii) the western part of Northeastern Anatolia; and (vi) the eastern part of Turkey. The possible reasons for the elevated PM10 levels are discussed using topographic, climatologic, land use, and energy utilization parameters. Finally, the suggested air zones were compared with the administrative air zones, which were newly developed by the Turkish Ministry of Environment and Forestry, to evaluate the level of agreement between the two. Implications: The evaluation of air quality profiles of specific regions is important in the development and/or application of an effective air quality management strategy. Factor analysis (FA), together with correlation analysis (CA), provides useful information to classify air pollution management areas over regional networks that have historical time-series air quality data. In this study, which relied on a FA- and CA-based methodology, the coherent air pollution management zones of Turkey after using a GIS-based model were suggested. Policy makers and scientist can use these suggested zones to construct better air quality management strategies.

Chemical compositions and sources of atmospheric PM10 in heating, non-heating and sand periods at a coal-based city in northeastern china

Mass concentrations and chemical components (18 elements, 9 ions, organic carbon [OC] and elemental carbon [EC]) in atmospheric PM(10) were measured at five sites in Fushun during heating, non-heating and sand periods in 2006-2007. PM(10) mass concentrations varied from 62.0 to 226.3 μg m(-3), with 21% of the total samples' mass concentrations exceeding the Chinese national secondary standard value of 150 μg m(-3), mainly concentrated in heating and sand periods. Crustal elements, trace elements, water-soluble ions, OC and EC represented 20-47%, 2-9%, 13-34%, 15-34% and 13-25% of the particulate matter mass concentrations, respectively. OC and crustal elements exhibited the highest mass percentages, at 27-34% and 30-47% during heating and sand period. Local agricultural residuals burning may contribute to EC and ion concentrations, as shown by ion temporal variation and OC and EC correlation analysis. Heavy metals (Cr, Ni, Zn, Cu and Mn) from coal combustion and industrial processes should be paid attention to in heating and sand periods. The anion/cation ratios exhibited their highest values for the background site with the influence of stationary sources on its upper wind direction during the sand period. Secondary organic carbon were 1.6-21.7, 1.5-23.0, 0.4-17.0, 0.2-33.0 and 0.2-21.1 μg m(-3), accounting for 20-77%, 44-88%, 4-77%, 8-69% and 4-73% of OC for the five sampling sites ZQ, DZ, XH, WH and SK, respectively. From the temporal and spatial variation analysis of major species, coal combustion, agricultural residual burning and industrial emission including dust re-suspended from raw material storage piles were important sources for atmospheric PM(10) in Fushun at heating, non-heating and sand periods, respectively. It was confirmed by principal component analysis that coal combustion, vehicle emission, industrial activities, soil dust, cement and construction dust and biomass burning were the main sources for PM(10) in this coal-based city.

Atmospheric polycyclic aromatic hydrocarbons in an industrialized city, Kocaeli, Turkey: study of seasonal variations, influence of meteorological parameters and health risk estimation

Ambient gas and particle phase samples were collected during two sampling periods from a residential area of an industrialized city, Kocaeli, Turkey. The sampling occurred during winter months when structures were being heated, and summer months when structures were not being heated. Σ(13)PAH (gas + particle) concentrations ranged between 6.2 ng m(-3) (DahA) and 98.6 ng m(-3) (Phe) in the heating (winter) period and 3.0 ng m(-3) (BaA) and 35.1 ng m(-3) (Phe) in the non-heating (summer) period. Phe, Flt and Pyr were found to be at high concentrations in both sampling periods. Winter time to summer time concentration ratios for individual ambient PAH concentration ratios ranged between 1.2 (DahA) and 17.5 (Flu), indicating the effect of the emissions from residential heating on measured concentrations of PAHs, but great industrial plants and the only incinerator facility of Turkey are other important pollution sources around the city. Temperature dependence of gas phase PAHs was investigated using the Clausius-Clapeyron equation. A high slope obtained (5069.7) indicated the effect of the local sources on measured gas phase PAHs. Correlation of the supercooled vapor pressure (P) with the gas particle partitioning coefficient (K(p)) and particle phase fraction was also evaluated. The relationship between the meteorological parameters and individual PAH (gas + particle) concentrations was investigated further by multiple linear regression analysis. It was found that the temperature had a significant effect on all of the measured PAH concentrations, while the effects of the wind speed and direction were not significant on the individual PAHs. On the other hand, PAH concentrations showed a strong linear relationship with the ventilation coefficient (VC) which showed the influence of local sources on measured PAHs. Benzo[a]pyrene toxic equivalent (BaP(eq.)) concentrations were used for health risk assessment purposes. The winter period risk level (2.92 × 10(-3)) due to the respiratory exposure to PAHs was found to be almost 3 times higher than in the summer period (1.15 × 10(-3)).

STUDY ON THE IMPACT OF THE TRAFFIC ON AIR QUALITY BY USING DIFFUSIVE SAMPLING METHOD IN VESZPREM

Air quality is mainly determined by traffic, domestic heating and pollutions originating from industrial activities. However, it also depends on pollution which comes from greater distances influenced by the meteorological parameters. The Institute of Environmental Engineering, University of Pannonia carried out a series of extensive air pollution measurements at ten different sites in City of Veszprem. The research was conducted during a heating and a non-heating period of the year. The primary point of view in selecting the sampling sites was to monitor and follow up the impact of the traffic/transportation on the air pollutant concentrations with special emphasize on different traffic patterns at different locations and time within the city. For the characterization of the air quality the generally accepted indicators – the nitrogen-dioxide and benzene concentrations – were used, which well characterizes the changes in air pollution stemming from the traffic and domestic heating as well. Results show clearly that nitrogen-dioxide and benzene concentrations are both higher at those measuring points where the direct impact of traffic on the air pollutant concentrations is significant. During the heating period of the year these values increase due to pollution stemming from the domestic heating.

Contamination assessment of copper, lead, zinc and chromium in dust fall of Jinan, NE China

To assess the pollution of heavy metal in dust fall, nine dust fall samples were collected during the heating period and non-heating period from Jinan, a city in northeastern China. The samples were analyzed for Cu, Pb, Zn and Cr and the contamination level of heavy metals was assessed on the basis of the geo-accumulation index (Igeo). The results indicated that all of the four investigated metals accumulated significantly in the dust fall of Jinan, and the metal concentrations were much higher than background values. During the heating period, the mean values for Cu, Pb, Zn and Cr in the dust fall were 354.9, 688.5, 2,585.5 and 478.6 mg kg−1. During the non-heating period, the mean values for Cu, Pb, Zn and Cr in the dust fall were 228.2, 518.2, 1,933.9 and 96.3 mg kg−1, respectively. The Igeo values calculated based on background values revealed that the contamination level of heavy metal in the dust fall ranges from moderately contaminated to heavily contaminated, and it mainly originates from traffic and industry. In this work, the dust fall residue compared to the standard reference was also chosen as the background value to calculate the Igeo value. This method is useful for situations in which the background value is difficult to obtain.

Study on the Pollution Characteristics of Pb and Zn in Atmospheric Particulate

In the research, HNO3-HClO 4 method and Tessier method were chose to extract the total content and chemical form of Pb、Zn in the total suspended particles (TSP) in both heating period and non-heating period. The pollution characteristics of Pb、Zn in TSP of Xi’an was analysed by discussing their total content、chemical form and the distribution characteristics of bioavailability. The result indicated that in the heating period, total content of Pb in January was bigger then it in February and residual was the advantage state. Total content of Zn changed greatly and the highest level appeared in January and the advantage state was exchangeable. However, in the non-heating period, the highest level of Pb、Zn appeared in June and April respectively, and the lowest level appeared in April and May. In this period, the advantage state of Pb、Zn was bound to carbonates and its distribution characteristics of bioavailability was contrary to it in heating period.

Chemical composition of urban airborne particulate matter in Ulaanbaatar

Abstract Atmospheric pollution caused by airborne particulate matter in the winter season in Ulaanbaatar, Mongolia is a very serious problem. However, there is a complete lack of scientific observation data to define the situation prior to any remediation. PM10 and PM2.5 average monthly values obtained by continuous monitoring showed the concentrations of particles of both size categories exceeded 100 μg m −3 during November to February (winter). PM10 particles were sampled with filters in January (i.e. during the heating period) and June (i.e.non-heating period) of 2008 in central Ulaanbaatar. To determine the composition of urban airborne particulate matter we analyzed a range of ionic components, multiple elements including heavy metals, and organic and inorganic carbon (soot). We also measured the stable carbon isotope ratio of the soot. Total carbon (sum of organic carbon and inorganic carbon) accounted for 47% of the mass of the PM10 during the heating period and 33% during the non-heating period, and was the largest component of urban airborne particulate matter in Ulaanbaatar. Stable isotope ratios (δ 13 C) of soot generated during the heating period (−23.4 ± 0.2‰) approximated the ratios for coal used in Ulaanbaatar (−21.3 to −24.4‰), while the ratios during the non-heating period (−27.1 ± 0.4‰) were clearly different from the coal values. In the heating period, a very high correlation was observed between soot and organic carbon, SO 4 2– , NO 3 − , F − , Zn, As, and Pb, and we concluded that they were derived from coal combustion along with soot. In addition, the concentrations and their ratios relative to each other of Al, Fe, Ca, K, Na, Mg, and Mn hardly differed between the heating period and the non-heating period, and it was concluded that they were derived from soil dust.

Long term operation of a solar assisted ground coupled heat pump system for space heating and domestic hot water

This paper introduces a solar-assisted ground-coupled heat pump (SAGCHP) system with heat storage for space heating and domestic hot water (DHW) supply. The simulation results of the system's detailed operating performance are presented. The optimization of the system design is carried out by the TRNSYS and a numerical simulation is performed for continuous operation of 20 years under the meteorological conditions of Beijing. Different control strategies are considered and the operational characteristics of each working mode are studied. The simulating results show that the long term yearly average space heating efficiency is improved by 26.3% compared to a traditional ground coupled heat pump (GCHP) system because the solar thermal collecting system is used to elevate the thermal energy in the soil and to provide direct space heating with heat storage. At the same time, the underground heat load imbalance problem for a heating load dominated GCHP is solved by soil recharging during non-heating periods, while extra solar energy is utilized to supply DHW. The flexibility and high efficiency of the SAGCHP system could offer an alternative for space heating and DHW supply by heat pump technology and solar energy in cold winters of northern China.