Time filter

Source Type

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.

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

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.

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.

Discover hidden collaborations