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911.
912.
首先阐述了保护性耕作的国内外发展现状,指出我国保护性耕作存在的主要问题:关键技术创新研究不够,具有中国南方特色的稻田保护性耕作制度、模式及其技术体系尚未形成;与南方独特的自然地理条件、复杂的稻田耕作制度相匹配的保护性耕作机具研究亟待加强;技术推广保障体系薄弱,适合农村实际的推广机制有待进—步探索。其次,从土壤理化性状、土壤生物学特性、节能减排效应和病虫害生态调控等4方面综述了稻田保护性耕作的生态效应最新研究进展。最后,针对我国南方稻区特别是西南丘陵山区稻田保护性耕作的发展提出了3点建议:加大政策扶持力度,建立政策优惠、财政补贴、生态补偿等多元化长效投入机制;重点开展技术攻关,深入研究中稻-再生稻优质、高产、高效保护性耕作关键技术;丘陵山区稻田周年高效农作制度创新与配套保护性耕作技术,以及以水旱轮作为中心的稻田保护性耕作技术节能减排效应的技术机理;进一步强化现有技术集成,扩大技术成果的示范,加快技术成果向生产力的转变。 相似文献
913.
Challenges for physical characterization of silver nanoparticles under pristine and environmentally relevant conditions 总被引:1,自引:0,他引:1
MacCuspie RI Rogers K Patra M Suo Z Allen AJ Martin MN Hackley VA 《Journal of environmental monitoring : JEM》2011,13(5):1212-1226
The reported size distribution of silver nanoparticles (AgNPs) is strongly affected by the underlying measurement method, agglomeration state, and dispersion conditions. A selection of AgNP materials with vendor-reported diameters ranging from 1 nm to 100 nm, various size distributions, and biocompatible capping agents including citrate, starch and polyvinylpyrrolidone were studied. AgNPs were diluted with either deionized water, moderately hard reconstituted water, or moderately hard reconstituted water containing natural organic matter. Rigorous physico-chemical characterization by consensus methods and protocols where available enables an understanding of how the underlying measurement method impacts the reported size measurements, which in turn provides a more complete understanding of the state (size, size distribution, agglomeration, etc.) of the AgNPs with respect to the dispersion conditions. An approach to developing routine screening is also presented. 相似文献
914.
高炉出铁场二次烟尘治理技术 总被引:1,自引:1,他引:0
介绍高炉出铁场二次烟尘的特点、危害及常规捕集方式,着重叙述双侧吸+顶吸罩组合并强力抽风的技术方案,它将一、二次烟尘捕集相结合,强化出铁口区域的烟尘捕集,在风口平台区域将出铁口产生的烟气就地捕获,并给出2个工程实例的主要参数及运行后的效果. 相似文献
915.
Simulation of urban expansion patterns by integrating auto-logistic regression,Markov chain and cellular automata models 总被引:2,自引:0,他引:2
Yaobin Liu Lu Dai Huanhuan Xiong 《Journal of Environmental Planning and Management》2015,58(6):1113-1136
This research analyses urban expansion patterns and their eco-risks in the Poyang Lake region in China. A hybrid model consisting of auto-logistic regression, Markov chain and cellular automata (CA) is designed to improve the performance of the standard logistic regression model. An eco-risk assessment (ERA) index by integrating landscape fragmentation index and area weighted eco-service value index is established to promote the effectiveness for dynamically evaluating the environment and eco-security in watersheds. Scenario predictions are introduced to better understand the relationship between urban dynamics and their eco-risks. Three urban development scenarios such as historical development trend (HDT), environment protection priority (EPP) and goal-oriented restriction (GOR) are designed and transplanted into the CA model through the parameter self-modification method. The quantitative analysis results showed that in the period of the past five years, the urban growth primarily concentrated in the metropolitans. The simulations show that under the HDT scenario the urban growth will mainly emerge in the metropolitans, while under the EPP and GOR scenarios the urban growth will expand along with the metropolitans or the road networks and highways, respectively. Moreover, the ERA demonstrated that the GOR scenario was more effective in meeting the goal of environment protection and urban sustainable development for the study area. 相似文献
916.
Yuan Peng Mei Xue Shen Boxiong Ji Zhiyong Gao Hongpei Yao Yan Liang Cai Xu Hongjie 《Environmental science and pollution research international》2021,28(3):2959-2971
Environmental Science and Pollution Research - In the present work, the effects of relevant system parameters on the oxidation removal of NO using the Fenton method were discussed in detail.... 相似文献
917.
918.
Bioaugmentation with a pyridine-degrading bacterium in a membrane bioreactor treating pharmaceutical wastewater 总被引:1,自引:0,他引:1
The bacterial strain Paracoccus denitrificans W12, which could utilize pyridine as its sole source of carbon and nitrogen, was added into a membrane bioreactor (MBR) to enhance the treatment of a pharmaceutical wastewater. The treatment efliciencies investigated showed that the removal of chemical oxygen demand, total nitrogen, and total phosphorus were similar between bioaugmented and non-bioaugmented MBRs, however, significant removal of pyridine was obtained in the bioaugmented reactor. When the hydraulic retention time was 60 hr and the influent concentration of pyridine was 250-500 mg/L, the mean effluent concentration of pyridine without adding W12 was 57.2 mg/L, while the pyridine was degraded to an average of 10.2 mg/L with addition of W12. The bacterial community structure of activated sludge during the bioaugmented treatment was analyzed using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that the W12 inoculum reversed the decline of microbial community diversity, however, the similarity between bacterial community structure of the original sludge and that of the sludge after bioaugmentation decreased steadily during the wastewater treatment. Sequencing of the DNA recovered from DGGE gel indicated that sp., Sphingobium sp., Comamonas sp., and Hyphomicrobium sp. were the dominant organisms in time sequence in the bacterial community in the bioaugmented MBR. This implied that the bioaugmentation was affected by the adjustment of whole bacterial community structure in the inhospitable environment, rather than being due solely to the degradation performance of the bacterium added. 相似文献
919.
Caicai Wang Shengwang Gao Jianchao Zhu Xunfeng Xi Mingxin Wang Yanna Xiong 《环境科学学报(英文版)》2021,33(1):249-259
A series of Sr-doped BiFeO3 perovskites (Bi1-xSrxFeO3, BSFO) fabricated via sol-gel method was applied as peroxydisulfate (PDS) activator for ciprofloxacin (CIP) degradation. Various technologies were used to characterize the morphology and physicochemical features of prepared BSFO samples and the results indicated that Sr was successfully inserted into the perovskites lattice. The catalytic performance of BiFeO3 was significantly boosted by strontium doping. Specifically, Bi0.9Sr0.1FeO3 (0.1BSFO) exhibited the highest catalytic performance for PDS activation to remove CIP, where 95% of CIP (10 mg/L) could be degraded with the addition of 1 g/L 0.1BSFO and 1 mmol/L PDS within 60 min. Moreover, 0.1BSFO displayed high reusability and stability with lower metal leaching. Weak acidic condition was preferred to neutral and alkaline conditions in 0.1BSFO/PDS system. The boosted catalytic performance can be interpreted as the lower oxidation state of Fe and the existence of affluent oxygen vacancies generated by Sr doping, that induced the formation of singlet oxygen (1O2) which was confirmed as the dominant reactive species by radical scavenging studies and electron spin resonance (ESR) tests. The catalytic oxidation mechanism related to major 1O2 and minor free radicals was proposed. Current study opens a new avenue to develop effective A-site modified perovskite and expands their application for PDS activation in wastewater remediation. 相似文献
920.