Data assimilation in a simple marine ecosystem model based on spatial biological parameterizations

Assuming that a set of constant parameters fits for marine ecosystem modeling and parameter estimation studies on large space scales is questionable since ecosystem types spanning long distances are quite different. In this study, SeaWiFS chlorophyll-a data are assimilated into a simple NPZD model by the adjoint method in a climatological physical environment provided by FOAM. To improve the assimilation results, different spatial parameterization schemes are utilized. The results show that the values of the selected sensitive parameters are spatially variable and the application of spatial parameterizations can improve the assimilation results significantly.     

消耗臭氧层物质(ODS)管理研究

自从人类发现南极上空臭氧层空洞以来,国际社会和各国政府为保护臭氧层,加速淘汰消耗臭氧层物质(简称ODS)做了不懈努力.自1989年《蒙特利尔议定书》生效至今,已经召开了25次缔约方大会,超过191个国家和地区加入了该议定书.中国于1991年加入该议定书后,积极履约,进行了大量关于ODS淘汰工作,当前还在进行加强地方消耗臭氧层物质淘汰履约能力建设二期项目工作,加快提升中国的ODS物质淘汰工作进度.     

Treatment of mature landfill leachate by biofilters and Fenton oxidation

A series of processes by biofilter and Fenton oxidation to treat mature landfill leachate has been devised. At a hydraulic loading rate of 20 l m^?3 d^?1, a biofilter packed with aged refuse is found to remove 80% of chemical oxygen demand (COD), 89% of ammonia nitrogen and 96% of total phosphorus (TP). Particularly, TP levels dropped below 1 mg l^?1. The optimal condition for Fenton oxidation was selected to be an initial pH of 5, a dosage of 0.01 and 0.02 mol l^?1 of FeSO₄ and H₂O₂, respectively, and a duration of 3 h, where COD removal efficiency reaches 58.6%, and BOD₅/COD ratio is raised from 0.05 to 0.20. Subsequent treatment by a biofilter packed with slag reduces COD, ammonia nitrogen levels to less than 100, 25 mg l^?1, respectively. A pilot scale experiment conducted in situ demonstrates that this series of processes exhibits a high efficiency in removing pollutants from mature landfill leachate and it is viable for application.     

垃圾渗滤液原位处理工艺初步研究

垃圾填埋场渗滤液处理是垃圾填埋场配套设施中占有重要地位的一部分,垃圾填埋场运行费用中占有很大比例。文章利用铁碳床技术在模拟试验装置中进行垃圾渗滤液原位处理进行了研究。试验装置经过26周的运行表明,结合铁碳床的垃圾填埋工艺装置COD去除率为93.88%,BOD5脱除率达到93.64%,氨氮去除率为42.13%,渗滤液的BOD5/COD比值从0.276升高到0.287。与回灌技术和渗滤液铁碳后处理工艺相比,结合铁碳床的垃圾填埋工艺在渗滤液各指标处理方面具有较大的优势,处理效果优于回灌技术和渗滤液铁碳后处理结合的效果。     

钽铌冶炼厂含氟废水资源化治理技术

采用合金膜电渗析法分离富集钽铌冶炼厂含氟废水中的F^-和SO₄^2-。最优的工艺运行条件为：膜对电压0.500 V,膜面流速4.09 cm/s。在此条件下电渗析30 min,F^-去除率达97.53%,SO₄^2-去除率接近100%。优化条件下运行电渗析器,一段淡水中大部分的F^-和SO₄^2-均被去除,可以直接回用。一段电渗析的浓水再经多段电渗析浓缩,以LiOH·H₂O沉淀F^-得到LiF产品,该LiF产品纯度达99.06%,满足GB/T 22666—2008标准的3级品要求。LiF收率为84.92%,F^-整体回收率为79.45%。     

活性炭吸附二硫化碳解析气相色谱法测定废气中乙酸乙酯和乙酸丁酯研究

采用活性炭管吸附废气中的乙酸乙酯和乙酸丁酯,经二硫化碳萃取解析,使用DM-1色谱柱分离后FID检测.实验结果表明:(1)采用活性炭管吸附废气中的目标组份,富集效率良好,二硫化碳解析率可达92％以上;(2)当乙酸乙酯和乙酸丁酯的含量为6.8～102 ng时,测定结果的相对标准偏差分别在1.8％ ～4.2％和3.2％ ～6.1％之间(n=6);(3)当样品采集量为30 L时,方法检出限分别为0.02 mg·m-3和0.02 mg·m-3.因此,方法能满足实验对空气废气中的乙酸乙酯和乙酸丁酯的检测要求.     

列车引发地面振动的现场测试及数值分析

通过现场测试,对提速列车引发的铁路线附近地面振动的时域特性、频域特性、传播规律及其影响因素进行了研究,并利用有限元软件ANSYS建立了大地振动三维有限元模型对提速列车引发的地面振动进行了数值分析.结果表明,列车引发的地面振动属于低频振动,地面对高频振动具有衰减作用;地面振动随距轨道中心线距离的增大呈递减分布,并且与车速和机车牵引类型有关,地面的竖向振动大于横向振动l地面振动随列车速度的提高而增大,随列车轴重的增加而增大.     

Impact of climate factors on cyanobacterial dynamics and their interactions with water quality in South Taihu Lake,China

Cyanobacterial bloom events in South Taihu Lake cause serious water quality problems and disturb aesthetic view of lake’s environment. In this study, correlations between cyanobacterial blooms and hydro-meteorological factors, including water quality, temperature and precipitation were investigated. Results demonstrated that South Taihu Lake was heavily affected by cyanobacteria and the proliferation of cyanobacteria due to variations in hydro-meteorological factors and water quality conditions. Water quality parameters, including COD, NH₃-N, TN and TP improved significantly since 2008 even at an elevated cyanobacterial bloom situation. Correlation analyses have shown that the development of cyanobacterial density and chlorophyll a concentration was sensitive to a wider temperature variation. The optimum temperature for cyanobacteria was 20°C, while extremely low and high temperatures were found to suppress their growth. Moreover, unusual rainfall patterns were measured during the study period (2003–2009), which showed an adverse impact on cyanobacterial development. Findings from this study suggested that seasonal lake’s water quality monitoring; suitable treatment of cyanobacterial blooms and strict policy implementation can solve the water quality issues in highly eutrophic lakes like Taihu.     

畜禽养殖业清洁生产初探

中国畜禽养殖业正由传统方式向规模化养殖不断推进,在经济的快速发展的同时产生了大量的环境问题。本文从畜禽养殖业环境污染现状和原因出发,从环境压力、政策导向、企业需求三个方面分析了畜禽养殖业实施清洁生产的必要性,提出了发展畜禽养殖业清洁生产应鼓励使用环保生态饲料,着重实施粪便资源化、无害化,加强法律法规体系和技术规范完善与监管。在此基础上,尝试建立新型农牧结合的互利机制,促进畜禽养殖业的清洁生产推进,进而实现地区农业可持续发展。