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471.
472.
为了提高钝顶螺旋藻生长过程中的固碳速率,从CO2浓度、温度和光周期3个主要环境因子进行优化。实验结果表明,钝顶螺旋藻在2 L三角瓶中培养时,最佳培养条件为10%CO2,温度30℃,光周期16/8。最佳培养条件下,钝顶螺旋藻对数生长期内比生长速率与固碳速率均达到峰值0.512 d-1和42.506 mg/(L.h)。此外,钝顶螺旋藻的底物消耗表明培养液中的N、P足量,其初始添加量可以满足藻体的生长需要;生长过程中补加10%CO2一方面补充钝顶螺旋藻可吸收碳源,另一方面有利于缓解培养液pH升高对藻生长的影响。 相似文献
473.
以养猪场废水作为研究对象,采用序列间歇式活性污泥法SBR,通过实验研究了供气量、pH、排泥量、原水稀释倍数、水力停留时间(HRT)对SBR出水水质的影响。结果表明,供气量为375 L/(min·m3)、pH为8.0,并添加排泥100 mL的操作,可使SBR处理效果明显提高,COD、磷和凯氏氮去除率最高分别可达96.37%、94.14%、99.38%。逐步降低进水稀释倍数有利于培养出处理高浓度有机养猪废水的活性污泥,可将平均COD、磷和凯氏氮含量高达9 161.24、33.41和1 502.77 mg/L的养猪废水处理至出水的490.11、5.35和17.84 mg/L。降低HRT对SBR去除率影响不大。 相似文献
474.
475.
产酸克雷伯氏菌Klebsiella oxytoca对硝基苯及4-氯硝基苯的降解 总被引:1,自引:0,他引:1
硝基苯类化合物生物降解菌的筛选及性能研究,是制药、染料等行业废水达标的重要基础。以浓度梯度升高法筛选到一株硝基苯厌氧降解菌Klebsiella oxytoca NBA-1。考察了该菌对氧气的需求,以及在厌氧条件下,温度、pH值、外加葡萄糖及硝基苯初始浓度等环境因子对菌株降解硝基苯能力的影响,并进一步讨论菌株对氯取代硝基苯类化合物的降解情况。结果表明,该菌在厌氧条件下生长比好氧条件下慢,但降解速度更快;厌氧降解硝基苯的最佳pH值和温度和分别为8.3和30~35℃;加入0.3%~0.5%的葡萄糖可促进降解,且对300 mg/L以下的硝基苯均有降解能力;该菌能将4-氯硝基苯转化为4-氯苯胺,并进一步脱氯为苯胺。研究结果可为硝基苯及含氯硝基苯的处理工艺选择提供相关的参考依据。 相似文献
476.
Yong Geng Wan-xia Ren Bing Xue Tsuyoshi Fujita Feng-ming Xi Ye Liu Mei-ling Wang 《Journal of Material Cycles and Waste Management》2013,15(3):310-320
Medical waste management is of great importance due to its potential environmental and public health risks, especially in developing countries where both financial and technological resources on medical waste management are still lacking. Although many studies have focused on country-scaled medical waste management, few have paid close attention to regional (city-scale) management, particularly in China. This paper fills such a gap by employing a case study approach. Due to its representative nature, Shenyang was selected as the case study. After a review of China’s medical waste management, an empirical study in Shenyang was conducted in order to analyze the current state as well as identify key challenges on regional medical waste management. Based upon the local realities and aiming to better manage medical wastes, an integrated medical waste management framework is developed. Such a platform encourages the establishment of a specific medical waste management authority, a city scaled capacity building program on improving the general public’s awareness, an information platform, application of state-of-the-art technologies, as well as creation of an effective financial system. The combination of such initiatives can significantly improve the overall eco-efficiency of medical waste management at the regional level and should be promoted to other developing cities. 相似文献
477.
The Stepwise Behavioral Response Model (SBRM), which is a conceptual model, postulated that an organism displays a time-dependent sequence of compensatory Stepwise Behavioral Response (SBR) during exposure to pollutants above their respective thresholds of resistance. In order to prove the model, in this study, the behavioral responses (BRs) of medaka (Oryzias latipes) in the exposure of Arprocarb (A), Carbofuran (C) and Methomyl (M) were analyzed in an online monitoring system (OMS). The Self-Organizing Map (SOM) was utilized for patterning the obtained behavioral data in 0.1 TU (Toxic Unit), 1 TU, 2 TU, 5 TU, 10 TU and 20 TU treatments with control. Some differences among different Carbamate Pesticides (CPs) were observed in different concentrations and the profiles of behavior strength (BS) on SOM were variable depending upon levels of concentration. The time of the first significant decrease of BS (SD-BS) was in inverse ratio to the CP concentrations. Movement behavior showed by medaka mainly included No effect, Stimulation, Acclimation, Adjustment (Readjustment) and Toxic effect, which proved SBRM as a time-dependence model based on the time series BS data. Meanwhile, it was found that SBRM showed evident stress-dependence. Therefore, it was concluded that medaka SBR was both stress-dependent and time-dependent, which supported and developed SBRM, and data mining by SOM could be efficiently used to illustrate the behavioral processes and to monitor toxic chemicals in the environment. 相似文献
478.
Controls on coarse wood decay in temperate tree species: birth of the LOGLIFE experiment 总被引:1,自引:0,他引:1
Cornelissen JH Sass-Klaassen U Poorter L van Geffen K van Logtestijn RS van Hal J Goudzwaard L Sterck FJ Klaassen RK Freschet GT van der Wal A Eshuis H Zuo J de Boer W Lamers T Weemstra M Cretin V Martin R Ouden Jd Berg MP Aerts R Mohren GM Hefting MM 《Ambio》2012,41(Z3):231-245
Dead wood provides a huge terrestrial carbon stock and a habitat to wide-ranging organisms during its decay. Our brief review highlights that, in order to understand environmental change impacts on these functions, we need to quantify the contributions of different interacting biotic and abiotic drivers to wood decomposition. LOGLIFE is a new long-term 'common-garden' experiment to disentangle the effects of species' wood traits and site-related environmental drivers on wood decomposition dynamics and its associated diversity of microbial and invertebrate communities. This experiment is firmly rooted in pioneering experiments under the directorship of Terry Callaghan at Abisko Research Station, Sweden. LOGLIFE features two contrasting forest sites in the Netherlands, each hosting a similar set of coarse logs and branches of 10 tree species. LOGLIFE welcomes other researchers to test further questions concerning coarse wood decay that will also help to optimise forest management in view of carbon sequestration and biodiversity conservation. 相似文献
479.
Bonton A Bouchard C Rouleau A Rodriguez MJ Therrien R 《Journal of contaminant hydrology》2012,128(1-4):1-18
Groundwater contamination by nitrate was investigated in an agricultural area in southern Quebec, Canada, where a municipal well is the local source of drinking water. A network of 38 piezometers was installed within the capture zone of the municipal well to monitor water table levels and nitrate concentrations in the aquifer. Nitrate concentrations were also measured in the municipal well. A Water flow and Nitrate transport Global Model (WNGM) was developed to simulate the impact of agricultural activities on nitrate concentrations in both the aquifer and municipal well. The WNGM first uses the Agriflux model to simulate vertical water and nitrate fluxes below the root zone for each of the seventy agricultural fields located within the capture zone of the municipal well. The WNGM then uses the HydroGeoSphere model to simulate three-dimensional variably-saturated groundwater flow and nitrate transport in the aquifer using water and nitrate fluxes computed with the Agriflux model as the top boundary conditions. The WNGM model was calibrated by reproducing water levels measured from 2005 to 2007 in the network of piezometers and nitrate concentrations measured in the municipal well from 1997 to 2007. The nitrate concentrations measured in the network of piezometers, however, showed greater variability than in the municipal well and could not be reproduced by the calibrated model. After calibration, the model was validated by successfully reproducing the decrease of nitrate concentrations observed in the municipal well in 2006 and 2007. Although it cannot predict nitrate concentrations in individual piezometers, the calibrated and validated WNGM can be used to assess the impact of changes in agricultural practices on global nitrate concentrations in the aquifer and in the municipal well. 相似文献
480.
Johannes H. C. Cornelissen Ute Sass-Klaassen Lourens Poorter Koert van Geffen Richard S. P. van Logtestijn Jurgen van Hal Leo Goudzwaard Frank J. Sterck René K. W. M. Klaassen Grégoire T. Freschet Annemieke van der Wal Henk Eshuis Juan Zuo Wietse de Boer Teun Lamers Monique Weemstra Vincent Cretin Rozan Martin Jan den Ouden Matty P. Berg Rien Aerts Godefridus M. J. Mohren Mariet M. Hefting 《Ambio》2012,41(3):231-245
Dead wood provides a huge terrestrial carbon stock and a habitat to wide-ranging organisms during its decay. Our brief review highlights that, in order to understand environmental change impacts on these functions, we need to quantify the contributions of different interacting biotic and abiotic drivers to wood decomposition. LOGLIFE is a new long-term ‘common-garden’ experiment to disentangle the effects of species’ wood traits and site-related environmental drivers on wood decomposition dynamics and its associated diversity of microbial and invertebrate communities. This experiment is firmly rooted in pioneering experiments under the directorship of Terry Callaghan at Abisko Research Station, Sweden. LOGLIFE features two contrasting forest sites in the Netherlands, each hosting a similar set of coarse logs and branches of 10 tree species. LOGLIFE welcomes other researchers to test further questions concerning coarse wood decay that will also help to optimise forest management in view of carbon sequestration and biodiversity conservation. 相似文献