Publications by authors named "Mingxing Sun"

18 Publications

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Determinants of smallholder farmers' choice on mulch film thickness in rural China.

Environ Sci Pollut Res Int 2021 Apr 18. Epub 2021 Apr 18.

Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.

Agricultural mulch film pollution has become a prevailing concern. Studies have shown that the thickness of mulch film is a key factor affecting mulch film recycling, but research about farmers' choice on mulch film thickness is lacking. Based on survey data from 2025 households in five Chinese provinces in 2018, the Heckman two-stage model was used to analyze the influencing factors of farmers' choice on mulch film thicknesses. Mulch film had been used by 21.98% of the sample households, and 41.47% of the used mulch film did not meet the national thickness standard. The econometric results showed that farmers' product cognition and market factors were the two most important factors, and there was a significant negative correlation with the choice of film thickness. In addition, the choice of mulch film with different thicknesses was affected by household characteristics, subjective norms, and farmland property rights. Strengthening and stabilizing farmland property rights is a long-term mechanism to promote farmers to choose thicker mulch film. In addition to strengthening the production and sale of substandard film supervision, farmers' choice of film thickness should be included in village regulations and other rural grass-roots governance systems, especially in the mechanism design between agricultural farmland protective subsidies and the prevention of mulch film pollution, rather than just considering the recycling itself.
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http://dx.doi.org/10.1007/s11356-021-13866-xDOI Listing
April 2021

Exploring the formulation of ecological management policies by quantifying interregional primary ecosystem service flows in Yangtze River Delta region, China.

J Environ Manage 2021 Apr 4;284:112042. Epub 2021 Feb 4.

Fudan Tyndall Center, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200438, China. Electronic address:

Ecosystem services (ESs) play an important supporting role in the development of human society and the economy. Despite the increasing number of ESs quantitative evaluation studies that have been conducted at different scales, the assessment of ESs flows between different administrative regions, which provides valuable implications for ecological protection and compensation, has drawn little attention. The aim of this study is to fill in this gap by providing a comprehensive ES interregional flow analysis method that evaluates ecosystem service values (ESVs) and quantifies the interregional flows in the Yangtze River Delta (YRD), which is home to one of the largest urban agglomerations in China. The results showed that the total ESV of the YRD increased from 2.02E+12 Chinese Yuan (CNY) in 2000 to 2.33E+12 CNY in 2019, a 15.23% increase rate. All types of ESVs displayed an increasing trend during the 20 years. According to the analysis of interregional ES flows in the YRD, Zhejiang province played a crucial role as a service providing area (SPA) for the spatial value transfer at the provincial level in both 2000 and 2019. Anhui province was the largest service benefitting area (SBA) of water conservation and CSOP, while Jiangsu province was the largest SBA of soil retention. The recognition of interregional ESV flows can provide valuable information for environmental planning and management to help improve China's ecological compensation policies for different administrative divisions.
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http://dx.doi.org/10.1016/j.jenvman.2021.112042DOI Listing
April 2021

1,3-Dichloropropene and chloropicrin emission reduction using a flexible CuInS/ZnS:Al-TiO photocatalytic film.

Environ Sci Pollut Res Int 2021 Feb 6;28(6):6980-6989. Epub 2020 Oct 6.

School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.

Soil fumigation using 1,3-dichloropropene (1,3-D) and chloropicrin (CP) is an important strategy for agriculture production; however, excessive emissions can cause air pollution and possible human exposure. In this study, solar light-driven CuInS/ZnS:Al-TiO photocatalytic film was prepared through spin-coating on the flexible polyethylene terephthalate (PET) substrate of 0.1 mm. Using the photocatalytic film, degradation of 1,3-D was inhibited in the Pci-clor 60 formulation of 1,3-D and CP. However, the degradation of CP was accelerated in this formulation, and the half-life was shortened from 0.66 to 0.40 h. Emissions of 1,3-D from soil to the air were reduced by 97.30%, 97.17%, 47.10%, and 7.88%, for treatments of D + Film, D + C + Film, D + PET, and D, respectively. The efficiencies for reducing 1,3-D emission were significantly improved by about 1.1 and 11.3 times using the film, compared with using the PET alone and no film, respectively. Furthermore, fumigation effects on nematodes could still achieve higher than 90%. The findings provided a basis for the practical application of quantum dot films to reduce soil fumigants emissions by photocatalytic degradation.
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http://dx.doi.org/10.1007/s11356-020-11039-wDOI Listing
February 2021

Climate change vulnerability assessment for smallholder farmers in China: An extended framework.

J Environ Manage 2020 Dec 7;276:111315. Epub 2020 Sep 7.

Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; International Ecosystem Management Partnership, United Nations Environment Programme, Beijing, 100101, China.

Climate change brings uncertainty and challenges to achieving sustainable development goals. The dually vulnerable regions in terms of the environment and economy are facing substantial threats from climate change; particularly, smallholder farmers who heavily rely on natural ecosystems in these regions are being the most affected. Paying attention to the vulnerability assessment of these regions is conducive to precisely improving the ability of their people to cope with climate change. This study aimed to construct an extended framework of climate change vulnerability assessment at the household level by combining the Intergovernmental Panel on Climate Change vulnerability assessment framework with the sustainable livelihood framework. Four typical regions with different climatic and geographical conditions in China, including the Inner Mongolia Autonomous Region (marked as AOHAN, representing the type of grassland, similarly hereinafter), Qinghai Province (HYMH, plateau), Yunnan Province (YLNL, mountain), and the Guangxi Zhuang Autonomous Region (NNQZ, coastal zone), were selected to apply the framework. In total, 29 villages from these four regions were selected at random, and 360 face-to-face interviews were conducted in selected villages based on a pretested questionnaire. The results show that AOHAN had the greatest vulnerability, as well as the highest exposure level among the four regions, which was also the major source of differences in vulnerability. Further analysis shows that although the sensitivity and adaptive capacity showed relatively small differences, the sources of sensitivity and adaptation strategies were quite different among the four regions. In terms of sensitivity, YLNL had the highest level of sensitivity in housing, water, and livestock, and AOHAN assumed the highest sensitivity in land. The advantages and disadvantages in terms of adaptive capacity also varied widely among the four regions. More specifically, AOHAN had a balanced adaptive capacity; YLNL largely relied on the advantages in social and human capitals to compensate for the disadvantage in physical capital; and the strengths in physical and financial capitals are the main sources of adaptive capacities for NNQZ and HYMH, respectively. In general, the vulnerability assessment framework proposed in this study provides guidelines for vulnerability assessments at the household level in the face of climate change. In addition, heterogeneous measures to cope with the threats of climate change should be put forward precisely, based on the climatic, geographical and socioeconomic characteristics of each region.
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http://dx.doi.org/10.1016/j.jenvman.2020.111315DOI Listing
December 2020

Sustainability evaluation based on the Three-dimensional Ecological Footprint and Human Development Index: A case study on the four island regions in China.

J Environ Manage 2020 Jul 13;265:110509. Epub 2020 Apr 13.

Fudan Tyndall Center, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200438, China; Institute of Eco-Chongming (IEC), No.3663 Northern Zhongshan Road, Shanghai, 20006, China. Electronic address:

Sustainable development emphasizes the sustainability of natural resources and the environment as well as the development of social welfare. Under the background of resource scarcity and environmental constraints, maximizing social welfare is an inevitable choice to achieve sustainable development. Ecological Wellbeing Performance (EWP) can comprehensively reflect the efficiency of natural capital conversion into social welfare, and improving EWP is a feasible measure to achieve sustainable development. Moreover, island areas are the extremely complicated ecological-social-economic systems due to the traits that are geographical isolation, scarce resources, and frequent natural disasters, so that emphasizing the sustainability of island systems is a key step for achieving sustainable development goals. This study developed the EWP model based on the improved Three-dimensional Ecological Footprint (EF) and urban-scale Human Development Index (HDI), to synthetically evaluate and analyze the sustainable development of four major island regions in China with the data in 2017. Results found that: (1) The four regions are all in ecological deficits, being in exchange for overdraft natural capital for economic development. The EF is greater than the original length 1 indicating the excessive consumption of the natural capital stock. The EF reflects the abundance and liquidity of regional natural capital, all the four regions are with the generally low level of flow capital utilization. Hainan with highest EF 0.428 is due to its comparatively sparse population density, abundant resources, and strong ecological capacity, while the relatively large population density and more restricted natural capital flows make Taiwan in the lowest value. (2) Judging from the evaluation results of the HDI, Chongming (0.796) and Hainan (0.773) high development level are relatively behind Taiwan (0.912) and Zhoushan (0.827) very high development level, for the impact of income is greater, that is, economic development in Hainan and Chongming is slightly weak. (3) Taiwan, with the highest EWP 3.646, shows the excellent natural resource utilization efficiency and sustainability, followed by Zhoushan, Chongming, and Hainan. In general, increasing HDI while reducing EF can be an ideal way to improve the efficiency of ecological resources and achieve sustainable urban development.
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http://dx.doi.org/10.1016/j.jenvman.2020.110509DOI Listing
July 2020

Factory employment exposure and human health: Evidence from rural China.

Environ Pollut 2020 Apr 19;259:113619. Epub 2019 Nov 19.

Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; UN Environment-International Ecosystem Management Partnership (UNEP-IEMP), Beijing 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.

Quantitating the health effects of employment history in factories, especially polluting ones, is essential for understanding the benefits or losses of industrialization in rural areas. Using a traced subset of nationwide panel data from 2005 covering five provinces, 101 villages, and 2026 households (collected recently in 2016) and the econometric models, this study estimated the effect of factory employment history on workers' health. The results showed that: the absolute number of factory workers increased from 1998 to 2015, and the proportion of factory workers was 7.68% in 2015; the absolute number and the proportion of farmers decreased from 63.84% in 1998 to 29.06% in 2015. Given that all the respondents live in rural areas, the HlthPlace (the first place the individual went to for their last illness in 2015) was selected as the main dependent variable of interest, and Hlthexp (Healthcare expenditure per person at last illness in 2015) and self-reported health were used as auxiliary dependent variables. The findings revealed that, after controlling the characteristics of individual, household, hospital and area, a one year increase of factory employment history corresponded to a 0.035 level increase in the probability of people choosing high-level hospital (p < 0.01) and a 237.61 yuan increase in healthcare expenditure (p < 0.1). The results also showed the adverse effect of self-reported health on factory employment history (p < 0.01). In addition, the relationship between the farming history and health was evaluated, and the econometric results showed that compared with factory employment history, farming history had opposite impacts on health (p < 0.01). Finally, the robustness check showed that the empirical results were reliable and that the initial results were robust. Generally, this study revealed the effect of overall factory employment on health, which is a useful research supplement to the studies on the health effects of specific pollution exposure.
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http://dx.doi.org/10.1016/j.envpol.2019.113619DOI Listing
April 2020

Management principles for heavy metal contaminated farmland based on ecological risk-A case study in the pilot area of Hunan province, China.

Sci Total Environ 2019 Sep 25;684:537-547. Epub 2019 May 25.

Key laboratory of ecosystem network observation and modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; International Ecosystem Management Partnership, United Nations Environment Programme, Beijing 100101, China.

A pilot project for farmland soil remediation was carried out in the Changsha-Zhuzhou-Xiangtan (CZX) area of Hunan province, China. However, the pilot project focused mainly on the risk of exposure to heavy metals on grain safety, and little attention was paid to the risk to ecosystem quality. The study selected three areas in counties of in the CZX, and focused on five high toxicity heavy metals-Cd (cadmium), Cr (chromium), Pb (lead), As (arsenic), Hg (mercury) to explore the potential ecological risks of the soil. Probabilistic ecological risk assessment (new method) and traditional methods were introduced to quantitatively evaluate the ecological risk. Two target criteria levels (LC/EC/IC and NOEC/LOEC) were employed. Through constructing species sensitivity distribution (SSD) models and joint probability curves (JPC), the predicted no effect concentrations (PNECs) derived from the SSD models were 0.21, 1.57, 3.05, 0.86 and 0.16 mg/kg for Cd, Cr, Pb, As and Hg, respectively. Compared with the ecological risk assessment results of the traditional methods, the new method reached a different conclusion, Cr showed the highest risk, at 84.3%, which signified that there was an 84.3% probability that 5% of the species with their NOEC/LOECs exceeded in County C. Despite differences among the risk assessment approaches, all methods indicated that County C was the most contaminated. The case study signifies that traditional methods underestimated the soil ecological risk of exposure to heavy metals and there should be a strong focus on farmland ecosystem security. At the same time, this study provided a scientific basis for goal-setting in species protection and prioritizing ecosystem protection as a management principle for heavy metal contaminated farmland from the perspective of ecological risk.
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http://dx.doi.org/10.1016/j.scitotenv.2019.05.015DOI Listing
September 2019

Sustainability evaluation and implication of a large scale membrane bioreactor plant.

Bioresour Technol 2018 Dec 28;269:246-254. Epub 2018 Aug 28.

Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute, Shenzhen 518055, PR China. Electronic address:

Membrane bioreactor (MBR) technology is receiving increasing attention in wastewater treatment and reuse. This study presents an integral sustainability evaluation of a full scale MBR plant. The plant is capable of achieving prominent technical performance in terms of high compliance rate, low variation in effluent quality and high removal efficiency during long term operation. It is also more responsive to the new local standard with rigorous limits. However, electricity consumption is found to be the dominant process resulting in elevated life cycle environmental impacts and costs, accounting for 51.6% of the costs. As such, it is suggested to optimize energy use in MBR unit and implement sludge treatment and management. The prolonged membrane life span could also contribute largely to reduced life cycle environmental concerns and expenses. This study is of great theoretical significance and applicable value in guaranteeing the performance and sustainability of large scale MBR schemes.
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http://dx.doi.org/10.1016/j.biortech.2018.08.107DOI Listing
December 2018

Life-cycle assessment of tobacco stalk utilization.

Bioresour Technol 2018 Oct 1;265:119-127. Epub 2018 Jun 1.

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:

The aim of this work was to investigate the environmental performance of different tobacco stalk methods using Life Cycle Assessment (LCA). Three scenarios were established: biodegradable plant nursery tray (PNT) making, open burning, and indoor incineration. The results showed that 3380, 1590, 1320 kg CO-eq, 25.7, 1.97,1.99 kg SO-eq are generated for global warming and acidification in biodegradable PNT making, open burning, and indoor incineration scenarios respectively. The overall environmental impact for biodegradable PNT making is higher than that of open burning, and indoor incineration. The dominant factors contributing to environmental impact in biodegradable PNT making include electricity consumption, solid waste landfill etc. Through technical optimization, the environmental impact of biodegradable PNT making could be reduced greatly. Biodegradable PNT making with tobacco stalk, which follows the cyclic economy principles of maximum material utilization and waste minimization, provides an alternative for agricultural residue utilization.
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http://dx.doi.org/10.1016/j.biortech.2018.05.110DOI Listing
October 2018

Environmental performance of straw-based pulp making: A life cycle perspective.

Sci Total Environ 2018 Mar 27;616-617:753-762. Epub 2017 Oct 27.

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:

Agricultural straw-based pulp making plays a vital role in pulp and paper industry, especially in forest deficient countries such as China. However, the environmental performance of straw-based pulp has scarcely been studied. A life cycle assessment on wheat straw-based pulp making in China was conducted to fill of the gaps in comprehensive environmental assessments of agricultural straw-based pulp making. On average, the global warming potential (GWP), GWP excluding biogenic carbon, acidification potential and eutrophication potential of wheat straw based pulp making are 2299kg CO-eq, 4550kg CO-eq, 16.43kg SO-eq and 2.56kg Phosphate-eq respectively. The dominant factors contributing to environmental impacts are coal consumption, electricity consumption, and chemical (NaOH, ClO) input. Chemical input decrease and energy recovery increase reduce the total environmental impacts dramatically. Compared with wood-based and recycled pulp making, wheat straw-based pulp making has higher environmental impacts, which are mainly due to higher energy and chemical requirements. However, the environmental impacts of wheat straw-based pulp making are lower than hemp and flax based pulp making from previous studies. It is also noteworthy that biogenic carbon emission is significant in bio industries. If carbon sequestration is taken into account in pulp making industry, wheat straw-based pulp making is a net emitter rather than a net absorber of carbon dioxide. Since wheat straw-based pulp making provides an alternative for agricultural residue management, its evaluation framework should be expanded to further reveal its environmental benefits.
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http://dx.doi.org/10.1016/j.scitotenv.2017.10.250DOI Listing
March 2018

Stable and Flexible CuInS2/ZnS:Al-TiO2 Film for Solar-Light-Driven Photodegradation of Soil Fumigant.

ACS Appl Mater Interfaces 2016 Aug 26;8(31):20048-56. Epub 2016 Jul 26.

School of Environmental Science and Engineering, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, China.

Semiconductor quantum dots (QDs) are suitable light absorbers for photocatalysis because of their unique properties. However, QDs generally suffer from poor photochemical stability against air, limiting their applications in photocatalysis. In this study, a stable solar-light-driven QDs-containing photocatalytic film was developed to facilitate photocatalytic degradation of the soil fumigant 1,3-dichloropropene (1,3-D). Highly stable CuInS2/ZnS:Al core/shell QDs (CIS/ZnS:Al QDs) were synthesized by doping Al into the ZnS shell and controlling ZnS:Al shell thickness; the CIS/ZnS:Al QDs were subsequently combined with TiO2 to form a CIS/ZnS:Al-TiO2 photocatalyst. The optimized ZnS:Al shell thickness for 1,3-D photodegradation was approximately 1.3 nm, which guaranteed and balanced the good photocatalytic activity and stability of the CIS/ZnS:Al-TiO2 photocatalyst. The photodegradation efficiency of 1,3-D can be maintained up to more than 80% after five cycles during recycling experiment. When CIS/ZnS:Al-TiO2 was deposited as photocatalytic film on a flexible polyethylene terephthalate substrate, over 99% of cis-1,3-D and 98% of trans-1,3-D were depleted as they passed through the film during 15 h of irradiation under natural solar light. This study demonstrated that the stable CIS/ZnS:Al-TiO2 photocatalyst both in powder and film form is a promising agent for photodegradation and emission reduction of soil fumigants.
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http://dx.doi.org/10.1021/acsami.6b05587DOI Listing
August 2016

Catalytic degradation of the soil fumigant 1,3-dichloropropene in aqueous biochar slurry.

Sci Total Environ 2016 Nov 17;569-570:1-8. Epub 2016 Jun 17.

School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China. Electronic address:

Biochar has been explored as a cost-effective sorbent of contaminants, such as soil fumigant. However, contaminant-loaded biochar probably becomes a source of secondary air pollution. In this study, biochars developed from cow manure and rice husk at 300°C or 700°C were used to investigate the catalytic degradation of the soil fumigant 1,3-dichloropropene (1,3-D) in aqueous biochar slurry. Results showed that the adsorption of 1,3-D on the biochars was influenced by Langmuir surface monolayer adsorption. The maximum adsorption capacity of cow manure was greater than that of rice husk at the same pyrolysis temperature. Batch experiments revealed that 1,3-D degradation was improved in aqueous biochar slurry. The most rapid 1,3-D degradation occurred on cow manure-derived biochar produced at 300°C (C-300), with t1/2=3.47days. The degradation efficiency of 1,3-D on C-300 was 95.52%. Environmentally persistent free radicals (EPFRs) in biochars were detected via electron paramagnetic resonance (EPR) techniques. Dissolved organic matter (DOM) and hydroxyl radical (·OH) in biochars were detected by using a fluorescence spectrophotometer coupled with a terephthalic acid trapping method. The improvement of 1,3-D degradation efficiency may be attributed to EPFRs and DOM in aqueous biochar slurry. Our results may pose implications in the development of effective reduction strategies for soil fumigant emission with biochar.
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http://dx.doi.org/10.1016/j.scitotenv.2016.06.092DOI Listing
November 2016

A New Hydrogen-Producing Strain and Its Characterization of Hydrogen Production.

Appl Biochem Biotechnol 2015 Dec 14;177(8):1676-89. Epub 2015 Sep 14.

College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, China.

A newly isolated photo non-sulfur (PNS) bacterium was identified as Rhodopseudomonas palustris PB-Z by sequencing of 16S ribosomal DNA (rDNA) genes and phylogenetic analysis. Under vigorous stirring (240 rpm), the hydrogen production performances were greatly improved: The maximum hydrogen production rate and cumulative hydrogen production increased by 188.9 ± 0.07 % and 83.0 ± 0.06 %, respectively, due to the hydrogen bubbles were immediately removed from the culture medium. The effects of different wavelength of light on hydrogen production with stirring were much different from that without stirring. The ranking on the photo-hydrogen production performance was white > yellow > green > blue > red without stirring and white > yellow > blue > red > green under stirring. The best light source for hydrogen production was tungsten filament lamp. The optimum temperature was 35 °C. The maximal hydrogen production rate and cumulative hydrogen production reached 78.7 ± 2.3 ml/l/h and 1728.1 ± 92.7 mol H2/l culture, respectively, under 35 °C, 240 rpm, and illumination of 4000 lux. Pyruvate was one of the main sources of CO2 and has a great impact on the gas composition.
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http://dx.doi.org/10.1007/s12010-015-1845-2DOI Listing
December 2015

Optimization of ultrasonic-assisted extraction for determination of polycyclic aromatic hydrocarbons in biochar-based fertilizer by gas chromatography-mass spectrometry.

Anal Bioanal Chem 2015 Aug 6;407(20):6149-57. Epub 2015 Jun 6.

Department of Environment and Resource, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.

Application of biochar-based fertilizers is increasingly being considered for its potential agronomic and environmental benefits. However, biochar may contain residues of polycyclic aromatic hydrocarbons (PAHs) as a result of its production by pyrolysis. The strong adsorption of PAHs to biochar makes extraction and analysis of biochar-based fertilizers difficult. This study optimizes the extraction of PAHs in biochar-based fertilizer samples by using an ultrasonic bath for quantification by gas chromatography-mass spectrometry. Among 12 solvents, acetone-cyclohexane (1:1) mixture was selected as the optimum solvent for extraction. Three variables affecting the extraction were studied by Box-Behnken design. The optimum conditions were 57 °C extraction temperature, 81 min extraction time, and two extraction cycles, which were validated by assessing the linearity of analysis, LOD, LOQ, recovery, and levels of PAHs in real biochar-based fertilizer samples. Results revealed that the 16 U.S. EPA PAHs had good linearity, with squared correlation coefficients greater than 0.99. LODs were low, ranging from 2.2 ng g(-1) (acenaphthene) to 23.55 ng g(-1) (indeno[1,2,3-cd]perylene), and LOQs varied from 7.51 ng g(-1) to 78.49 ng g(-1). The recoveries of 16 individual PAHs from the three biochar-based fertilizer samples were 81.8-109.4 %. Graphical Abstract Use of RSM to optimize UAE for extraction of the PAHs in biochar-based fertilizer.
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http://dx.doi.org/10.1007/s00216-015-8790-3DOI Listing
August 2015

Response surface optimization of a rapid ultrasound-assisted extraction method for simultaneous determination of tetracycline antibiotics in manure.

J Anal Methods Chem 2015 1;2015:290903. Epub 2015 Apr 1.

Department of Environment and Resource, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.

A rapid and cleanup-free ultrasound-assisted extraction method is proposed for the simultaneous extraction of oxytetracycline, tetracycline, chlortetracycline, and doxycycline in manure. The analytes were determined using high-performance liquid chromatography with ultraviolet detector. The influence of several variables on the efficiency of the extraction procedure was investigated by single-factor experiments. The temperature, pH, and amount of extraction solution were selected for optimization experiment using response surface methodology. The calibration curves showed good linearity (R (2) > 0.99) for all analytes in the range of 0.1-20 μg/mL. The four antibiotics were successfully extracted from manure with recoveries ranging from 81.89 to 92.42% and good reproducibility (RSD, <4.06%) under optimal conditions, which include 50 mL of McIlvaine buffer extraction solution (pH 7.15) mixed with 1 g of manure sample, extraction temperature of 40°C, extraction time of 10 min, and three extraction cycles. Method quantification limits of 1.75-2.32 mg/kg were obtained for the studied compounds. The proposed procedure demonstrated clear reductions in extraction time and elimination of cleanup steps. Finally, the applicability to tetracyclines antibiotics determination in real samples was evaluated through the successful determination of four target analytes in swine, cow manure, and mixture of animal manure with inorganic fertilizer.
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http://dx.doi.org/10.1155/2015/290903DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4397494PMC
April 2015

Optimization and determination of polycyclic aromatic hydrocarbons in biochar-based fertilizers.

J Sep Sci 2015 Mar 23;38(5):864-70. Epub 2015 Jan 23.

Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, P. R. China.

The agronomic benefit of biochar has attracted widespread attention to biochar-based fertilizers. However, the inevitable presence of polycyclic aromatic hydrocarbons in biochar is a matter of concern because of the health and ecological risks of these compounds. The strong adsorption of polycyclic aromatic hydrocarbons to biochar complicates their analysis and extraction from biochar-based fertilizers. In this study, we optimized and validated a method for determining the 16 priority polycyclic aromatic hydrocarbons in biochar-based fertilizers. Results showed that accelerated solvent extraction exhibited high extraction efficiency. Based on a Box-Behnken design with a triplicate central point, accelerated solvent extraction was used under the following optimal operational conditions: extraction temperature of 78°C, extraction time of 17 min, and two static cycles. The optimized method was validated by assessing the linearity of analysis, limit of detection, limit of quantification, recovery, and application to real samples. The results showed that the 16 polycyclic aromatic hydrocarbons exhibited good linearity, with a correlation coefficient of 0.996. The limits of detection varied between 0.001 (phenanthrene) and 0.021 mg/g (benzo[ghi]perylene), and the limits of quantification varied between 0.004 (phenanthrene) and 0.069 mg/g (benzo[ghi]perylene). The relative recoveries of the 16 polycyclic aromatic hydrocarbons were 70.26-102.99%.
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http://dx.doi.org/10.1002/jssc.201400834DOI Listing
March 2015

Effect of biochar on nitrous oxide emission and its potential mechanisms.

J Air Waste Manag Assoc 2014 Aug;64(8):894-902

Extensive use of biochar to mitigate nitrous oxide (N2O) emission is limited by the lack of understanding on the exact mechanisms altering N2O emission from biochar-amended soil. Biochars produced from rice straw and dairy manure at 350 and 500 degrees C by oxygen-limited pyrolysis were used to investigate their influence on N2O emission. A quadratic effect of biochar levels was observed on the N2O emissions. The potential mechanisms were explored by terminal restriction fragment length polymorphism (T-RFLP) and real-time polymerase chain reaction (qPCR). A lower relative abundance of bacteria, which included ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), was observed at 4% biochar application rate. Reduced copy numbers of the ammonia monooxygenase gene amoA and the nitrite reductase gene nirS coincided with decreased N2O emissions. Therefore, biochar may potentially alter N2O emission by affecting ammonia-oxidizing and denitrification bacteria, which is determined by the application rate of biochar in soil. Implications: Biochar research has received increased interest in recent years because of the potential beneficial effects of biochar on soil properties. Recent research shows that biochar can alter the rates of nitrogen cycling in soil systems by influencing nitrification and denitrification, which are key sources of the greenhouse gas nitrous oxide (N2O). However, there are still some controversial data. The purpose of this research was to (1) examine how applications of different dose of biochar to soil affect emission of N2O and (2) improve the understanding of the underlying mechanisms.
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http://dx.doi.org/10.1080/10962247.2014.899937DOI Listing
August 2014

Determination of iodine and bromine in coal and atmospheric particles by inductively coupled plasma mass spectrometry.

Talanta 2010 Apr 23;81(1-2):473-6. Epub 2009 Dec 23.

Technique Test Lab., Shanghai Entry-Exit Inspection and Quarantine Bureau, No. 1208, Minsheng Road, Pudong New District, Shanghai 200135, China.

Bromine and iodine in atmospheric particles or coal can cause environmental problems such as destruction of ozone in the atmosphere; therefore, the presence of these compounds has recently received increased attention. Here, a rapid and reliable method for the simultaneous determination of total bromine and iodine using ICP-MS analysis is described. Samples were dissolved in mixtures of 5 mL of HNO(3) and 2 mL of H(2)O(2) in a high pressure microwave digester. The solution was then oxidized by per-sulfate (Na(2)S(2)O(8)) in addition to a small amount of silver nitrate, after which the total bromine and iodine were measured simultaneously by ICP-MS. The signal memory effects of bromine and iodine during analysis were effectively decreased by washing with a new mixture agent (2% alcohol acidic solution, pH 1-2 adjusted with HCl). The detection limits for bromine and iodine using this method were about 3.2 microg L(-1) and 1.1 microg L(-1), respectively. Additionally, the spike recoveries were between 78.7% and 121% for bromine and iodine analysis, while the relative standard deviations ranged from 4.3% to 9.7%, and from 1.5% to 3.4% for bromine and iodine, respectively. The results of this study indicate that the method described here is suitable for the analysis of micro-amounts of bromine and iodine in atmospheric particles and coal samples.
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http://dx.doi.org/10.1016/j.talanta.2009.12.026DOI Listing
April 2010