ASM No.2d模型模拟SBR工艺同步脱氮除磷效能

SBR工艺由于处理上的高效性和操作上的灵活性在世界范围的污水处理领域得到广泛应用.采用国际水质协会1999年提出的ASM No.2d模型,利用matlab作为程序开发工具编制计算模型,并利用该模型对一实验室规模SBR系统进行模拟.模拟过程中动力学和化学计量参数采用ASM No.2d给出的典型参数值,并结合实际SBR系统进行了修正.结果表明,该模型能够较好模拟SBR工艺同步脱氮除磷效能,说明应用ASM No.2d进行SBR系统的模拟能够对SBR系统的优化和控制起辅助作用.     

Estimation of no effect concentrations from exposure experiments when values scatter among individuals

The parameters that are most commonly used in risk assessment, LC_x values or no observed effect concentrations, both have serious drawbacks. As an alternative, No effect concentrations (NEC) as a parameter in a process-based model, offer great potential in risk assessment.     

天山哈密榆树沟6号冰川积雪化学特征及环境意义

本研究基于2017年8月和2018年8月在天山榆树沟6号冰川采集的雪坑和表层雪实测资料,通过海盐示踪法、相关分析法、HYSPLIT后向轨迹等方法,对冰川积雪的主要阴阳离子的化学特征进行了分析,并探讨了离子的来源及环境指示意义.研究发现,冰川积雪中平均离子浓度顺序为Ca2+ ＞SO42-＞Cl-＞Na+ ＞NO3-＞NH...     

Effectiveness of Fish Habitat Compensation in Canada in Achieving No Net Loss

Fish habitat loss has been prevalent over the last century in Canada. To prevent further erosion of the resource base and ensure sustainable development, Fisheries and Oceans Canada enacted the habitat provisions of the Fisheries Act in 1976. In 1986, this was articulated by a policy that a “harmful alteration, disruption, or destruction to fish habitat” (HADD) cannot occur unless authorised with legally binding compensatory habitat to offset the HADD. Despite Canada’s progressive conservation policies, the effectiveness of compensation habitat in replicating ecosystem function has never been tested on a national scale. The effectiveness of habitat compensation projects in achieving no net loss of habitat productivity (NNL) was evaluated at 16 sites across Canada. Periphyton biomass, invertebrate density, fish biomass, and riparian vegetation density were used as indicators of habitat productivity. Approximately 63% of projects resulted in net losses in habitat productivity. These projects were characterised by mean compensation ratios (area gain:area loss) of 0.7:1. Twenty-five percent of projects achieved NNL and 12% of projects achieved a net gain in habitat productivity. These projects were characterised by mean ratios of 1.1:1 and 4.8:1, respectively. We demonstrated that artificially increasing ratios to 2:1 was not sufficient to achieve NNL for all projects. The ability to replicate ecosystem function is clearly limited. Improvements in both compensation science and institutional approaches are recommended to achieve Canada’s conservation goal.     

聊古一井数字化氡影响因素分析

对聊古一井数字化氡观测资料进行分析研究的结果显示,科学合理的气水分离装置对于获得真实可靠的观测结果具有重要作用;保障仪器的正常工作状态,是数字化氡观测的重要环节之一。聊古一井数字化氡的变化特征主要受气温、气压和井压的影响,分析和排除这些因素的影响是数字化观测资料分析应用的基础。     

Chemical contamination and the ecological quality of surface water

In the assessment of the quality of surface waters, the typical procedure is that the concentration of contaminants in the surface water is monitored and subsequently compared with their respective Maximum Permissible Concentrations (MPCs). If the MPCs are not exceeded the water quality is considered to be safe. But can we be certain that this is true?We compared MPCs to observed and calculated effects of measured contaminants in Dutch surface waters and showed that effects of mixtures can cause a daphnid population to go extinct within 30 h of exposure even when MPCs are not exceeded. We conclude that there are shortcomings underlying the concepts of the MPCs. And that the MPCs aim to protect 95% of all species is not met.     

Assessing the Effectiveness of a Constructed Arctic Stream Using Multiple Biological Attributes

Objective assessment of habitat compensation is a central yet challenging issue for restoration ecologists. In 1997, a 3.4-km stream channel, designed to divert water around an open pit diamond mine, was excavated in the Barrenlands region of the Canadian Arctic to create productive stream habitat. We evaluated the initial success of this compensation program by comparing multiple biological attributes of the constructed stream during its first three years to those of natural reference streams in the area. The riparian zone of the constructed stream was largely devoid of vegetation throughout the period, in contrast to the densely vegetated zones of reference streams. The constructed stream also contained lower amounts of woody debris, coarse particulate organic matter (CPOM), and epilithon; had lower coverage by macrophytes and bryophytes; and processed leaf litter at a lower rate than reference streams. Species richness and densities of macroinvertebrates were consistently lower in the constructed stream compared to natural streams. This contributed to differences in macroinvertebrate assemblage structure throughout the period, although assemblages showed some convergence by year 3. The effectiveness of the constructed stream to emulate natural streams varied somewhat depending on the biological attribute being evaluated. Assessments based on individual attributes showed that minimal to moderate levels of similarity between the constructed stream and natural streams were achieved. A collective assessment of all biological and ecosystem attributes suggested that the constructed stream was not a good surrogate for natural streams during these first years. Additional time would be required before many characteristics of the constructed stream would resemble those of reference streams. Because initial efforts to improve fish habitat in the constructed stream focused on physical structures (e.g., weirs, vanes, rock, groins), ecological factors limiting fish growth were not considered and likely constrained success. We suggest that a greater focus on organic characteristics and vegetation within the stream and its riparian zone could have accelerated compensation. The addition of woody debris and CPOM, combined with planting of shrubs and herbs along the stream, should provide a source of allochthonous matter for the biotic community while large cobble and boulders should improve the physical stability of stream system, protecting its organic components.     

铅、锌催干剂废水的处理

介绍了铅催化剂废水通过全部循环使用,不仅提高产品质量而且废水实行零排放,锌催化剂通过改进生产工艺,废水的排放量少,水质基本无污染,从生产源头上解决了废水排放问题。     

基于面向对象的北京市区城市内部用地信息提取

选取北京市四环以内为研究区域,以资源三号卫星遥感影像为数据源,针对类型多样、特征易混淆的城市内部用地以及高分辨率遥感影像海量信息、人工提取费时费力等特点,论文基于面向对象分类方法,探讨城市内部用地自动提取方法,并对分类结果进行精度评估.结果表明:利用不同地物的光谱、形状、纹理和空间关系等特征,通过多尺度分割和隶属度函数法,构建合理的分类层次,不仅精确提取出研究区内水体、绿地、建设用地和待开发用地,更独具创新地区分了城市建设用地内部各种地物类型,包括工业生产用地、低密度和高密度生活用地以及交通用地.该方法有效地利用了资源3 号卫星影像的光谱、纹理及空间信息特征,总体精度可达到87.00%,Kappa系数达到0.853 9,取得较好的分类效果.     

含灰含水烟气的脉冲放电脱除NO和NOx的研究

脉冲放电脱除ＮＯ和ＮＯｘ（ＮＯ＋ＮＯ２）的实验表明,烟气中的飞灰对ＮＯｘ具有２％－４％的吸附脱除作用,对脉冲放电又有抑制作用,使ＮＯ和ＮＯｘ脱除具有降低的趋势,增加烟气含水量增强了飞灰粒子表面的化学吸附能力,使得在烟气含水量为１５％和单位体积烟气注入能量小于３Ｗ．ｈ／Ｎ,＾３时,ＮＯ和ＮＯｘ脱除率提高５％－１５％。