Identifying the sanitation efficacy in reducing contaminations entering the environment is an important step for water pollution controls and developing management strategies to further improve sanitation conditions. With continuous efforts in sanitation improvement during the past decade, reductions in discharges of aquatic nutrients are expected in China. In this study, we estimated the aquatic nitrogen discharges from human excreta in 31 provinces in China during 2006–2014. The results indicated that the nitrogen discharges entering the environment from human excreta are largely determined by both local population and sanitation conditions. In 2014, the nitrogen discharges from human excreta in the rural areas (2118(1219–3140) Gg per year) (median and 95% confidence interval) are higher than those in the urban areas (1485(626–2495) Gg per year). The significant relationship (R2 = 0.38, n = 29) between the total nitrogen concentrations in lakes and corresponding local nitrogen discharges indicated that, the lakes might be potentially affected by the contaminant inputs from human excreta. The further calculations under two policy scenarios showed that through sanitation improvement, further reduction of nitrogen discharges from human excreta in the developed regions might be limited. The sanitation improvement in the less-developed regions, such as Tibet, Qinghai, and Ningxia, should be considered a priority due to the larger reduction potentials.
As an important way to increase industrial energy efficiency, Waste Heat to Power (WHP) technologies have been gaining popularity in recent years. In order to appraise the market potential of WHP technologies in Southeast Asia, a techno-economic assessment for WHP technologies is conducted in this paper. The technical and economic market potential of WHP in Southeast Asia is estimated to be 1788MW and 1188MW respectively. The main market drivers and barriers for WHP market expansion in Southeast Asia are also analyzed. Given the fact that WHP is a far cheaper power generation technology as compared with traditional and renewable power generation, the WHP market is expected to increase fast in the coming years. Mounting electricity price from grid, government emissions regulations and subsidies, the integration of WHP products with original equipment manufacturer, capital cost reduction induced by technology development are identified as the key drivers for the market growth. The above arguments are proofed through the analysis of a power plant WHP project in Southeast Asia.
Organic aerosol (OA) constitutes a substantial fraction of fine particles and affects both human health and climate. It is becoming clear that OA absorbs light substantially (hence termed Brown Carbon, BrC), adding uncertainties to global aerosol radiative forcing estimations. The few current radiative-transfer and chemical-transport models that include BrC primarily consider sources from biogenic and biomass combustion. However, radiocarbon fingerprinting here clearly indicates that light-absorbing organic carbon in winter Beijing, the capital of China, is mainly due to fossil sources, which contribute the largest part to organic carbon (OC, 67 ± 3%) and its sub-constituents (water-soluble OC, WSOC: 54 ± 4%, and water-insoluble OC, WIOC: 73 ± 3%). The dual-isotope (Δ14C/δ13C) signatures, organic molecular tracers and Beijing-tailored emission inventory identify that this fossil source is primarily from coal combustion activities in winter, especially from the residential sector. Source testing on Chinese residential coal combustion provides direct evidence that intensive coal combustion could contribute to increased light-absorptivity of ambient BrC in Beijing winter. Coal combustion is an important source to BrC in regions such as northern China, especially during the winter season. Future modeling of OA radiative forcing should consider the importance of both biomass and fossil sources.
A new polymer acceptor, naphthodiperylenetetraimide-vinylene (NDP-V), featuring a backbone of altenating naphthodiperylenetetraimide and vinylene units is designed and applied in all-polymer solar cells (all-PSCs). With this polymer acceptor, a new record power-conversion efficiencies (PCE) of 8.59% has been achieved for all-PSCs. The design principle of NDP-V is to reduce the conformational disorder in the backbone of a previously developed high-performance acceptor, PDI-V, a perylenediimide-vinylene polymer. The chemical modifications result in favorable changes to the molecular packing behaviors of the acceptor and improved morphology of the donor-acceptor (PTB7-Th: NDP-V) blend, which is evidenced by the enhanced hole and electron transport abilities of the active layer. Moreover, the stronger absorption of NDP-V in the shorter-wavelength range offers a better complement to the donor. All these factors contribute to a short-circuit current density (J(sc)) of 17.07 mA cm(-2). With a fill factor (FF) of 0.67, an average PCE of 8.48% is obtained, representing the highest value thus far reported for all-PSCs.
There is increasing evidence indicating the critical role of ammonia (NH3) in the formation of secondary aerosols. Therefore, high quality NH3 emission inventory is important for modeling particulate matter in the atmosphere. Unfortunately, without directly measured emission factors (EFs) in developing countries, using data from developed countries could result in an underestimation of these emissions. A series of newly reported EFs for China provide an opportunity to update the NH3 emission inventory. In addition, a recently released fuel consumption data product has allowed for a multisource, high resolution inventory to be assembled. In this study, an improved global NH3 emission inventory for combustion and industrial sources with high sectorial (70 sources), spatial (0.1 degrees X 0.1 degrees), and temporal (monthly) resolutions was compiled for the years 1960 to 2013. The estimated emissions from transportation (1.59 Tg) sectors in 2010 was 2.2 times higher than those of previous reports. The spatial variation of the emissions was associated with population, gross domestic production, and temperature. Unlike other major air pollutants, NH3 emissions continue to increase, even in developed countries, which is likely caused by an increased use of biomass fuel in the residential sector. The emissions density of NH3 in urban areas is an order of magnitude higher than in rural areas.
There is a potential for silver nanowires (AgNWs) to be inhaled, but there is little information on their health effects and their chemical transformation inside the lungs in vivo. We studied the effects of short (S-AgNWs; 1.5 mum) and long (L-AgNWs; 10 mum) nanowires instilled into the lungs of Sprague-Dawley rats. S- and L-AgNWs were phagocytosed and degraded by macrophages; there was no frustrated phagocytosis. Interestingly, both AgNWs were internalized in alveolar epithelial cells, with precipitation of Ag2S on their surface as secondary Ag2S nanoparticles. Quantitative serial block face three-dimensional scanning electron microscopy showed a small, but significant, reduction of NW lengths inside alveolar epithelial cells. AgNWs were also present in the lung subpleural space where L-AgNWs exposure resulted in more Ag+ve macrophages situated within the pleura and subpleural alveoli, compared with the S-AgNWs exposure. For both AgNWs, there was lung inflammation at day 1, disappearing by day 21, but in bronchoalveolar lavage fluid (BALF), L-AgNWs caused a delayed neutrophilic and macrophagic inflammation, while S-AgNWs caused only acute transient neutrophilia. Surfactant protein D (SP-D) levels in BALF increased after S- and L-AgNWs exposure at day 7. L-AgNWs induced MIP-1alpha and S-AgNWs induced IL-18 at day 1. Large airway bronchial responsiveness to acetylcholine increased following L-AgNWs, but not S-AgNWs, exposure. The attenuated response to AgNW instillation may be due to silver inactivation after precipitation of Ag2S with limited dissolution. Our findings have important consequences for the safety of silver-based technologies to human health.
BACKGROUND AND OBJECTIVES: Childhood obesity is increasing. However, little is known about the changes in di-etary factors and supportive facilities associated with childhood obesity. We aimed to document the changes in various dietary factors and supportive facilities and their associations with obesity among pre-school children. METHODS AND STUDY DESIGN: Among 42,531 children 4-5 years old, recruited between 2004 and 2013 in the Jiax-ing Birth Cohort, we examined the changes in the prevalence of various dietary factors and supportive facilities and overweight/obesity over 10 years. We used logistic regression to investigate the cross-sectional association between these factors and childhood overweight/obesity risk, adjusting for potential confounders. RESULTS: The prevalence of childhood overweight/obesity increased steadily from 11.8% (boy: 14.8%; girl: 9%) during 2004-2005 to 18% (boy: 21.4%%; girl: 15%) during 2012-2013. The prevalence of meal/snack frequency 3 times /day decreased substantially from 23% during 2004-2005 to 8% during 2012-2013, with more children having 5 times /day: from 32% to 45.6%. Children with a fair/bad appetite, compared with those with a good appetite, had a 45% (OR: 0.55; 95% CI: 0.49, 0.62) lower risk of overweight/obesity. Children with a meal frequency >=6 times/day (compared with 3 times/day) had a 0.12 (95% CI: 0.03, 0.2) higher BMI-z-score. CONCLUSIONS: The prevalence of childhood overweight/obesity has increased substantially within a decade in southeast China. A better appetite and greater eating frequency were associated with the increased prevalence.
Abstract Economic restructuring, energy planning and environmental protection are subject to inherent uncertainties in a compound system with competing decision objectives. Therefore, an inexact multi-objective programming model for regional economy-energy-environment system management has been developed to obtain absolutely “optimal” solutions. Under two comparative scenarios, three subsystems, six industries, four types of energy, and three kinds of air pollution were considered in an optimization model, and a net system benefit and trade-off analysis between subsystems was conducted. The methods of interval-parameter programming and multi-objective programming were incorporated into the model to tackle the uncertainties and complexities reflected in the case study. The model results indicated that the developed model could provide effective linkages among the economy-energy-environment systems and offer decision makers great insight into the reliability tradeoffs for the adjustment of the existing management policy.