Zhang Y.,Tsinghua University |
Chen L.,Tsinghua University |
Chen L.,Yangtze University |
Sun R.,Peking University |
And 5 more authors.
Applied Microbiology and Biotechnology | Year: 2016
The community structure of ammonia-oxidizing microorganisms is sensitive to various environmental factors, including pollutions. In this study, real-time PCR and 454 pyrosequencing were adopted to investigate the population and diversity of ammonia-oxidizing archaea (AOA) and bacteria (AOB) temporally and spatially in the sediments of an industrial effluent receiving area in the Qiantang River’s estuary, Hangzhou Bay. The abundances of AOA and AOB amoA genes fluctuated in 105–107 gene copies per gram of sediment; the ratio of AOA amoA/AOB amoA ranged in 0.39–5.52. The AOA amoA/archaeal 16S rRNA, AOB amoA/bacterial 16S rRNA, and AOA amoA/AOB amoA were found to positively correlate with NH4 +-N concentration of the seawater. Nitrosopumilus cluster and Nitrosomonas-like cluster were the dominant AOA and AOB, respectively. The community structures of both AOA and AOB in the sediments exhibited significant seasonal differences rather than spatial changes in the effluent receiving area. The phylogenetic distribution of AOB in this area was consistent with the wastewater treatment plants (WWTPs) discharging the effluent but differed from the Qiantang River and other estuaries, which might be an outcome of long-term effluent discharge. © 2016 Springer-Verlag Berlin Heidelberg
Zhang Y.,Tsinghua University |
Zhang Y.,University of Alberta |
Chen L.,Tsinghua University |
Chen L.,Yangtze University |
And 4 more authors.
Applied Microbiology and Biotechnology | Year: 2015
Ammonia was observed as a potential significant factor to manipulate the abundance and activity of ammonia-oxidizing microorganisms (AOMs) in water environments. For the first time, this study confirmed this phenomenon by laboratory cultivation. In a series of estuarine sediment-coastal water microcosms, we investigated the AOM’s phylogenetic composition and activity change in response to ammonia concentration. Increase of ammonia concentration promoted bacterial amoA gene abundance in a linear pattern. The ratio of transcribed ammonia-oxidizing bacteria (AOB) amoA gene/ammonia-oxidizing archaea (AOA) amoA gene increased from 0.1 to 43 as NH4+-N increased from less than 0.1 to 12 mg L−1, and AOA amoA transcription was undetected under 20 mg NH4+-N L−1. The incubation of stable isotope probing (SIP) microcosms revealed a faster 13C-NaHCO3 incorporation rate of AOA amoA gene under 0.1 mg NH4+-N L−1 and a sole 13C-NaHCO3 utilization of the AOB amoA gene under 20 mg NH4+-N L−1. Our results indicate that ammonia concentration manipulates the structure of AOM. AOA prefers to live and perform higher amoA transcription activity than AOB in ammonia-limited water environments, and AOB tends to take the first contributor place in ammonia-rich ones. © 2015, Springer-Verlag Berlin Heidelberg.
Li X.,China Agricultural University |
Lin C.,China Agricultural University |
Sha J.,China Agricultural University |
Sha J.,Beijing Yingherui Environmental Engineering Co. |
And 2 more authors.
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2015
With the rapid development of the sewage treatment, dewatered sludge, as an inevitable byproduct, is increasing its amount. Anaerobic digestion performance of dewatered sludge flocculated by polyacrylamide under different biopretreatments conditions were studied. The feeding concentration was 3% of total solid, and the digestion temperature was 35℃. The cumulative biogas yield, methane content, pH value, ammonia nitrogen content and total chemical oxygen demand (TCOD) were analyzed to explore the effect of fungus-Paecilomyces variotii on anaerobic digestion process. The result showed that biopretreatment of dewatered sludge prior to anaerobic digestion was an alternative method. Direct addition and 2 d biopretreatments can both enhance cumulative biogas yield and methane content with faster hydrolysis rate and better organic matter degradation rate. Compared with the pure sludge treatment, direct addition of Paecilomyces variotii was optimal, and its cumulative biogas production and methane production were increased by 85.79% and 42.76%, respectively. While 1 kg dewatered sludge can produce 12.69 L methane with an increase of 42.74% of sludge without pretreatment. The result would provide theoretical basis for solving the problem of dewatered sludge resourceful treatment. ©, 2015, Chinese Society of Agricultural Machinery. All right reserved.
Wang J.-S.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research |
Wang J.-S.,Renmin University of China |
Feng J.-G.,Renmin University of China |
Chen B.-X.,Rural Energy & Environment Agency |
And 7 more authors.
Journal of Mountain Science | Year: 2016
Alpine treeline ecotones are harsh environment for tree establishment due to low temperature. Tree establishment at treelines requires favorable clim ate, suitable microsites, and viable seeds. But most researches have been addressed treeline m icroclimate and its effects on tree regeneration, the knowledge of seed quantity and quality and its controls on seedling recruitment were limited. We measured seed rain, soil seed bank, seed germination rate and seedling recruitment in natural forests in combination with seed transplanting manipulation to evaluate the controls of seed quantity and quality on seedling recruitment of Abies georgei var. smithii (smith fir) along altitudinal gradient, with focus on treeline ecotone in the Sygera Mountains, southeastern Tibetan Plateau. Both seed quantity and seed quality of smith fir decreased with increasing altitude and was thereby associated with decline in seed germination rate. Seed quantity and seedling recruitment were better in north-facing slope than in south slope. The treeline ecotone above 4200 m appeared as the threshold altitude to sharply decrease seed quality and seedling recruitment. The emergence and overwintering rates of transplanting seeds from 3600–3800 m also went down remarkably above 4200 m at north-facing slope. It also underpins the fact that treeline ecotone is the bottleneck of seedling recruitment. Our results suggest that seed quantity and quality are the principal limitation of treeline upward advance. This study also provides evidence to support stable treeline position in southeastern Tibetan Plateau. © 2016 Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg
Zheng S.-A.,Rural Energy & Environment Agency |
Zheng S.-A.,Agro Environmental Protection Institute |
Li X.-H.,Rural Energy & Environment Agency |
Li X.-H.,Agro Environmental Protection Institute |
Xu Z.-Y.,Rural Energy & Environment Agency
Huanjing Kexue/Environmental Science | Year: 2014
This study was designed to pinpoint the impact of salinity (NaCl and Na2SO4, added at salinity levels of 0-5%, respectively) on the adsorption behavior of mercury in wastewater-irrigated areas of Tianjin City by batch and kinetic experiments. The results showed that, the Langmuir isotherm and the Elovich equation can well fitted batch and kinetic experimental data, respectively. As NaCl spiked in soil, Hg(Ⅱ) adsorption capacity and strength had marked decreases, from 868.64 mg·kg-1 and 1.32 at control to 357.48 mg·kg-1 and 0.63 at 5% salinity level of NaCl, respectively. As Na2SO4 spiked in soil, Hg(Ⅱ) adsorption capacity (parameter qm in Langmuir isotherm) and strength (parameter k in Langmuir isotherm) changed slightly, from 868.64 mg·kg-1 and 1.32 at control to 739.44 mg·kg-1 and 1.18 at 5% salinity level of Na2SO4, respectively. Kinetic data showed that, Hg(Ⅱ) adsorption rate (parameter b in Elovich equation) in soil was not influenced by Na2SO4 addition. However, the addition of NaCl had a great effect on mercury adsorption rate. Hg(Ⅱ) adsorption capacity as a function of Cl- or SO4 2- content in soil could be simulated by the natural logarithm model, while Hg(Ⅱ) adsorption rate as a function of Cl- content in soil could be simulated by the linear model. The study manifested that NaCl can significantly increase migration of Hg(Ⅱ) in the soil irrigated with wastewater, which may enhance Hg(Ⅱ) bioavailability in the soil and cause a hazard to surface water. Especially, it will be harmful to human body through the food chain.
PubMed | Source Point, Rural Energy & Environment Agency and Chinese Academy of Agricultural Sciences
Type: Journal Article | Journal: Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA | Year: 2016
Pollution by heavy metals, such as copper and lead, has become a limiting factor for the land application of faecal manures, such as pig manure. This study was conducted to investigate the influence of composting process parameters, including aeration rate, moisture content and composting period, on the distribution of heavy metal species during composting, and to select an optimal parameter for copper and lead inactivation. Results showed that the distribution ratios of exchangeable fractions of copper and lead had a bigger decrease under conditions of aeration rate, 0.1m(3)min(-1)m(-3), an initial moisture content of 65% and composting period of 50days. Suboptimal composting process conditions could lead to increased availability of heavy metals. Statistical analysis indicated that the aeration rate was the main factor affecting copper and lead inactivation, while the effects of moisture content and composting period were not significant. The rates of reduction of copper-exchangeable fractions and lead-exchangeable fractions were positively correlated with increased pH. The optimal parameters for reducing heavy metal bioavailability during pig manure composting were aeration rate, 0.1m(3)min(-1)m(-3), initial moisture content, 65%, and composting period, 20days.
Wang H.,Chinese Academy of Agricultural Sciences |
Wang F.,Rural Energy & Environment Agency |
Sun R.,Rural Energy & Environment Agency |
Gao C.,Chinese Academy of Agricultural Sciences |
And 4 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2016
The developed countries have already marched a long way and accumulated rich experience in utilizing crop straw, which is fairly ahead of China particularly in the fields of the administrative policies and regulations. The total yield of crop straw in China ranks the first place in the world in recent years. Yet the policies and regulations of crop straw management in China are insufficient, and it is of great importance to learn the specific practice and advanced management measures from foreign countries. Based on a large amount of literature research and analysis, in the paper we reviewed the policies and regulations of crop straw utilization in foreign countries and summarized the successful experiences. The results show that crop straw in developed countries gives priority to recycle as fertilizer to the field, which plays an important role in forming reasonable fertilization structure. And major developed countries have established mature and efficient system of straw collection, storage and transportation, which is the key issue to develop crop straw utilization industry. In order to make full use of crop straw and reduce open burning, many developed countries have carried out some pertinent policies and regulations. Policies of straw utilization in foreign countries mainly focus on target strategy, government investment and financial support, tax incentives and concessional loans, as well as incentive mechanism. The main 2 types of laws and regulations on crop straw utilization in foreign countries are agriculture-type regulation and energy-type regulation. The former type mainly involves the regulations on tillage conservation and soil fertilization by crop straw returning. The latter one involves the regulations on renewable energy and biomass energy. The crop straw in China has the characteristics of large quantity, scattered distribution, and so on. Policies and regulations of crop straw utilization and management should be made according to the reality in China. Based on the advanced experiences in foreign countries, the recommended policies and regulations on how to improve straw utilization in China are proposed as follows: 1) Clarify targets and dominant modes of crop straw utilization; the goals of straw utilization will be broken into achievable goals, projects and actions in different years and areas, and straw returning is recommended to establish the fertilization system in China which also includes stable manure and chemical fertilizer; 2) Bring government's function into full play to improve investment supporting in order to provide various financial supports, and the main measures are as follows: supports on technology equipment development and industrialization demonstration project, financial subsidy of green products, purchase allowance on agricultural machinery, and subsidies of mechanization of straw returning based on working area; 3) Make and implement tax, and credit and loan preference polices on straw processing and utilization of enterprises, as well as straw collection and transportation companies, carry out investment tax compensation and deduction of value added tax (VAT) policy on straw utilization projects, and formulate and implement different carbon tax policies, such as laying high carbon tax on fossil energy but free carbon tax on biomass energy; 4) Establish policy incentive mechanism by improving the incentives for investing, such as building fund-raising system including central and local government and management body, and implementing rural electricity price on straw collection, storage and processing, and reduction and exemption policy on road and bridge toll; 5) Formulate and promulgate laws and regulations of straw utilization and set up relatively mature law system; amend laws about crop straw utilization, for example, add regulations of raising animal with crop straw to Animal Husbandry Law, and add relevant regulations of conservation tillage to Soil and Water Conservation Law, and establish regulations on crop straw collection-storage system and "5F" (fertilizer, fuel, fodder, fiber, feed stock) utilization. Requirement and relevant standards of straw comprehensive utilization and safe handling should be clarified in regulation of new countryside and beautiful countryside construction. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Wang F.,Northwest Agriculture and Forestry University |
Wang F.,Rural Energy & Environment Agency |
Qiu L.,Northwest Agriculture and Forestry University |
Shen Y.,Chinese Academy of Agricultural Sciences |
And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015
With the popularity of understanding of pollution-free agricultural products by the public, government pays much attention to the safe application of organic fertilizer during the agricultural production process. Manure is not only the main raw material of organic fertilizer, but also one of the important factors affecting the quality of agricultural products. Due to the intensive and large-scale of livestock farming rapid development, some heavy metals such as Cu, Zn, As, Cr, Pb are widely used in feed additives. The biological potency of these trace elements is low, and with the use of animal manure into the environment, brings potential environmental risks and hazards to human health. In order to strengthen the source control of heavy metal, and further form the heavy metal resistance control system for organic fertilizer of agricultural products, in this paper, the heavy metal content in livestock and poultry feed was sampled for investigation and analysis. The results showed that the mainly exceeded elements of heavy metal in the livestock were Cu, Zn. Heavy metals Pb, Cr, As followed, and Cd, Ni, Hg were not exceeded. The exceedance of these elements in pig manure and broile manure were the most serious for all kinds of animal manure, beef cattle manure and egg chicken manure followed, and the cow dung was not exceeded. The value of the exceeded rate of Cu, Zn for pig manure and broile manure were up to 100% and 91.67%, respectively. The mainly pollutants for broile were Cr, Cu, Zn, and the value of exceeded rate were 50%, 66.67%, and 50%, respectively, but the egg chicken manure only had Cu exceeded, exceeding the rate of 11.11%. Different livestock feed exceedances of heavy metals in pig feed and beef cattle feed werethe most serious, and broile feed and cow feed followed. According to the Ministry of Agriculture's 1224 announcement for the Cu, Zn standard, Cu and Zn in pig feed exceeded the rate of 66.67% and 80.00% respectively, and broile feed Zn exceeded 62.50%; According to the feed hygiene standards for Cr, Pb, heavy metals Cr and Pb in beef cattle exceeded 83.33% and 66.67%, Cr in cow feed exceeded 60%, Pb in egg chicken feed exceeded 53.85%, and Cd in different animal feeds were not exceeded. The content of heavy metals Cd, Cr, Cu, Zn in animal manure showed a significant positive correlation with livestock feed (P<0.01), and the content of Pb in animal manure showed a significant correlation with livestock feed (P<0.05). The research helps to grasp the North China heavy metal pollution status in feed-animal manure, revealing the problem for heavy metals exceeded in manure and organic fertilizer which should be controlled from the source. This research to further reduce heavy metal pollution in the region and to ensure the quality and safety of agricultural production has an important significance. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Yan C.,Chinese Academy of Agricultural Sciences |
He W.,Chinese Academy of Agricultural Sciences |
Xue Y.,Rural Energy & Environment Agency |
Liu E.,Chinese Academy of Agricultural Sciences |
Liu Q.,Chinese Academy of Agricultural Sciences
Shengwu Gongcheng Xuebao/Chinese Journal of Biotechnology | Year: 2016
Plastic film has become an important agriculture production material in recent years. Over the past three decades, the amount and application area of plastic film have increased steadily, and in 2014, which are 1.4 million tons and more than 180 million hm2 respectively. It plays a key role for ensuring the supply of agricultural goods in China. Meanwhile, plastic film residual pollution becomes more and more serious, and in some regions, the amount of plastic film residues has reached over 250 kg/hm2. In part of the Northwest region, soil structure of farmland has been destroyed by plastic film residues and then crop growth and farming operations were suppressed. It is recognized as a good choice to replace plastic film with biodegradable plastic film, an effective measure to solve the plastic film residue pollution. Now, it is in a critical stage of study and assessment of biodegradable plastic film in China and fortunately some biodegradable plastic films show effects in the production of potatoes, peanuts and tobacco. Overall, a series of challenges has still been faced by the biodegradable plastic film, mainly including improving the quality of biodegradable plastic products, such as tensile strength, flexibility, improving the controllability of rupture and degradation, enhancing the ability of increasing soil temperature and preserving soil moisture, and to satisfy the demand of crops production with mulching. In addition, it is essential to reduce the cost of the biodegradable film and promote the application of biodegradable film on large-scale. With the development of biodegradable plastic technology and agricultural production environment, the application of the biodegradable film will have a good future. © 2016 Chin J Biotech, All right reserved.