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891.
892.
采用O3/KMnO4化学氧化法与曝气生物滤池(BAF)联用工艺处理生活污水二级出水,进行长期连续实验,考察pH、O3/KMnO4投加顺序和投加量对氧化效果的影响。结果表明:采用O3/KMnO4化学氧化法在pH为7.2~7.6的条件下,当O3和KMnO4投加量分别为10和1.5 mg/L时,ρ(BOD)/ρ(COD)由0.13提升至0.26,COD和UV254的去除率分别为30.90%和31.97%。在此基础上采用O3/KMnO4/BAF联用工艺,COD和UV254去除率分别提高至71.30%和74.86%。 相似文献
893.
Investigation of the hydrodynamic behavior of diatom aggregates using particle image velocimetry 总被引:1,自引:0,他引:1
The hydrodynamic behavior of diatom aggregates has a significant influence on the interactions and flocculation kinetics of algae. However, characterization of the hydrodynamics of diatoms and diatom aggregates in water is rather difficult. In this laboratory study, an advanced visualization technique in particle image velocimetry (PIV) was employed to investigate the hydrodynamic properties of settling diatom aggregates. The experiments were conducted in a settling column filled with a suspension of fluorescent polymeric beads as seed tracers. A laser light sheet was generated by the PIV setup to illuminate a thin vertical planar region in the settling column, while the motions of particles were recorded by a high speed charge-coupled device (CCD) camera. This technique was able to capture the trajectories of the tracers when a diatom aggregate settled through the tracer suspension. The PIV results indicated directly the curvilinear feature of the streamlines around diatom aggregates. The rectilinear collision model largely overestimated the collision areas of the settling particles. Algae aggregates appeared to be highly porous and fractal, which allowed streamlines to penetrate into the aggregate interior. The diatom aggregates have a fluid collection efficiency of 10%-40%. The permeable feature of aggregates can significantly enhance the collisions and flocculation between the aggregates and other small particles including algal cells in water. 相似文献
894.
Surface clogging process modeling of suspended solids during urban stormwater aquifer recharge 总被引:1,自引:0,他引:1
Aquifer recharge,which uses urban stormwater,is an effective technique to control the negative effects of groundwater overexploitation,while clogging problems in infiltration systems remain the key restricting factor in broadening its practice.Quantitative understanding of the clogging process is still very poor.A laboratory study was conducted to understand surface physical clogging processes,with the primary aim of developing a model for predicting suspended solid clogging processes before aquifer recharge projects start.The experiments investigated the clogging characteristics of different suspended solid sizes in recharge water by using a series of one-dimensional fine quartz sand columns.The results showed that the smaller the suspended particles in recharge water,the farther the distance of movement and the larger the scope of clogging in porous media.Clogging extents in fine sand were 1 cm,for suspended particle size ranging from 0.075 to 0.0385 mm,and 2 cm,for particles less than 0.0385 mm.In addition,clogging development occurred more rapidly for smaller suspended solid particles.It took 48,42,and 36 hr respectively,for large-,medium-,and small-sized particles to reach pre-determined clogging standards.An empirical formula and iteration model for the surface clogging evolution process were derived.The verification results obtained from stormwater recharge into fine sand demonstrated that the model could reflect the real laws of the surface clogging process. 相似文献
895.
文章阐述了现有环境绩效计量模型的不足,分析统计了国内外有关环境绩效评价的研究成果及手册、指南和法规中高频指标,在此基础上结合环境指标和财务指标建立了资源企业环境绩效评价体系,运用层次分析法和模糊数学的方法对兰花科创进行实证研究,得出其综合评价结果为82.558分,应控制用水量和减少烟尘的排放。以期将企业为环境所作的贡献量化,促进可持续发展战略在企业的具体实践。 相似文献
896.
王连龙 《中国环境管理干部学院学报》2013,(1):46-49
根据联合国政府间气候变化专门委员会推荐的方法,计算了秦皇岛市工业行业2005-2010年的能源消费碳排放。秦皇岛市工业效益偏低,重工业比例偏大和以煤炭为主的能源结构是碳排总量和碳排放强度的主要驱动力。改造提升传统主导产业,做强装备制造业,加快工业园区建设,完善产业链,改善能源结构等是秦皇岛市工业产业结构优化的主要途径。 相似文献
897.
对山海关滨海盐生植物及盐生植被景观和群落配置情况进行实地调查并参考历史文献,发现山海关滨海湿地共有盐生种子植物26科44属51种。结合山海关海岸带的气候、土壤理化性质及土地覆盖和利用的现状,选择乔、灌木类盐生植物3种,藤本类盐生植物1种,中生草本盐生植物5种,旱生草本盐生植物2种,湿生植物4种,共计15种作为滨海地区盐碱地改良和植被恢复的野生植物种类。 相似文献
898.
Chlorophyll a Simulation in a Lake Ecosystem Using a Model with Wavelet Analysis and Artificial Neural Network 总被引:2,自引:0,他引:2
Accurate and reliable forecasting is important for the sustainable management of ecosystems. Chlorophyll a (Chl a) simulation and forecasting can provide early warning information and enable managers to make appropriate decisions for protecting lake ecosystems. In this study, we proposed a method for Chl a simulation in a lake that coupled the wavelet analysis and the artificial neural networks (WA–ANN). The proposed method had the advantage of data preprocessing, which reduced noise and managed nonstationary data. Fourteen variables were included in the developed and validated model, relating to hydrologic, ecological and meteorologic time series data from January 2000 to December 2009 at the Lake Baiyangdian study area, North China. The performance of the proposed WA–ANN model for monthly Chl a simulation in the lake ecosystem was compared with a multiple stepwise linear regression (MSLR) model, an autoregressive integrated moving average (ARIMA) model and a regular ANN model. The results showed that the WA-ANN model was suitable for Chl a simulation providing a more accurate performance than the MSLR, ARIMA, and ANN models. We recommend that the proposed method be widely applied to further facilitate the development and implementation of lake ecosystem management. 相似文献
899.
900.