托盘式烟气脱硫喷淋塔空塔冷态流场数值模拟

以600MW机组多孔合金托盘喷淋塔为研究对象,利用国际流行的商用CFD(ComputationalFluidDynamics)软件Fluent及其前处理软件Gambit对烟气脱硫立式喷淋空塔的流场进行二维数值模拟。计算中选用模型作为计算模型,用SIMPLE算法进行计算。计算结果表明,喷淋塔的烟气入口角度以及多孔合金托盘的安装高度对塔内流场分布有一定的影响,安装托盘后气速明显均匀化,斜切式烟气进口流场分布较直进式均匀,还获得了合适的托盘安装高度。     

两相厌氧消化工艺的研究进展及其应用

两相厌氧消化工艺因产酸相和产甲烷相的分离而具有一系列的特点和优势。针对该工艺的理论依据和运行机理进行了阐述，讨论了两相厌氧消化工艺的相分离以及相分离的实现对整个工艺的影响，着重剖析了两相厌氧消化工艺的影响因素，并对该工艺的应用范围及存在的问题进行了论述，说明了工艺的先进性和可行性。     

Database-driven models of the world's Large Marine Ecosystems

We present a new methodology for database-driven ecosystem model generation and apply the methodology to the world's 66 currently defined Large Marine Ecosystems. The method relies on a large number of spatial and temporal databases, including FishBase, SeaLifeBase, as well as several other databases developed notably as part of the Sea Around Us project. The models are formulated using the freely available Ecopath with Ecosim (EwE) modeling approach and software. We tune the models by fitting to available time series data, but recognize that the models represent only a first-generation of database-driven ecosystem models. We use the models to obtain a first estimate of fish biomass in the world's LMEs. The biggest hurdles at present to further model development and validation are insufficient time series trend information, and data on spatial fishing effort.     

Decadal changes in a NW Mediterranean Sea food web in relation to fishing exploitation

We analysed changes in the ecological roles of species, trophic structure and ecosystem functioning using four standardized mass-balance models of the South Catalan Sea (North-western Mediterranean). Models represented the ecosystem during the late 1970s, mid 1990s, early 2000s, and a simulated no-fishing scenario. The underlying hypothesis was that ecosystem models should quantitatively capture the increasing exploitation in the ecosystem from the 1970s to 2000s, as well as differences between the exploited and non-exploited scenarios. Biomass showed a general decrease, while there was an increase in biomass at lower trophic levels (TL) from the 1970s to 2000s. The efficiency of energy transfer (TE) from lower to higher TLs significantly increased with time. The ecosystem during the 1990s showed higher biomass and flows than during the 1970s and 2000s due to an increase in small pelagic fish biomass (especially sardines). Exploited food webs also showed similarities in terms of general structure and functioning due to high intensity of fishing already in the 1970s. This intensity was highlighted with low trophic levels in the catch, high consumption of production by fisheries, medium to high primary production required to sustain the catches and high losses in secondary production due to fishing. Significant differences on ecosystem structure and functioning were highlighted between the exploited and no-fishing scenarios. Biomass of higher TLs increased under the no-fishing scenario and the mean trophic level of the community and the fish/invertebrate biomass ratios were substantially lower in exploited food webs. The efficiency of energy transfer (TE) from lower to higher TLs was lower under the no-fishing scenario, and it showed a continuous decrease with increasing TL. Marine mammals, large hake, anglerfish and large pelagic fish were identified as keystone species of the ecosystem when there was no fishing, while their ecological importance notably decreased under the exploited periods. On the contrary, the importance of small-sized organisms such as benthic invertebrates and small pelagic fish was higher in exploited food webs.     

工业区群环境影响评价初探

阐述了开展工业区群环境影响评价的意义,比较了单个工业园区和工业区群环评的异同,以广州番禺区工业区群环评项目为例,简述了该环评的主要内容和特点,并提出了建议。     

六箱一体化工艺处理城市污水周期设置的试验

介绍了智能型六箱一体化活性污泥脱氮除磷工艺的运行方式及原理,并研究了周期设置对污染物去除的影响。中试研究表明,在泥龄13d和水力停留时间13h的条件下．当周期时间为16h时．工艺取得良好的脱氮除磷效果．出水水质可达国家一级A排放标准。     

混凝法在滇池蓝藻暴发期净水除藻的可行性研究

采用精制硫酸铝为混凝剂,L93^4正交法安排滇池蓝藻暴发期混凝沉降除藻除净水工艺实验。结果表明,混凝剂种类、水样pH值对蓝藻去除率有很大影响。研究确定了混凝剂除藻最佳操作条件,为混凝法去除蓝藻的工业化提供了理论和实际操作依据。     

生活污水为主要补给源的城郊排水沟渠氮磷滞留特征

为揭示生活污水补给影响下排水沟渠氮、磷滞留特征,以合肥市城郊结合部的关镇河支渠为对象,以NH₄Cl和KH₂PO₄为添加营养盐,以NaCl为保守型示踪剂,开展5次现场示踪试验. 在此基础上,利用OTIS(one-dimensional transport with inflow and storage)模型估算D(扩散系数)、A(渠道过水断面面积)、A_s(暂态存储区断面面积)、α(暂态存储交换系数)、λ(主流区溶质一阶吸收系数)和λ_s(暂态存储区吸收系数);并利用营养螺旋原理,计算营养盐的S_w(吸收长度)、V_f(吸收速度)和U(吸收速率)等. 结果表明:①A_s/A具有随流量减小而增大的变化特征,平均值为0.35;5次试验得到的α均处在10-3数量级水平,平均值为2.49×10-3 s-1. ②S_w-NH₄和S_w-PO₄(分别表示NH₄-N和PO₄-P的S_w,下同)均较大,最大值分别达934 020、47 518 m,意味着关镇河支渠已基本不具备氮、磷滞留能力;而S_w-NH₄和S_w-PO₄均不同程度地出现负值,表明该支渠还具有“源”的作用. ③V_f-NH₄与河水平均深度、渠道流量均呈显著负相关,V_f-PO₄和U-PO₄与渠道水面宽度均呈显著正相关. ④NH₄-N和PO₄-P的营养螺旋指标与其相应质量浓度背景值无明显相关性.      

湿法脱硫系统优化分析

分析了运用烟塔合一等技术对现有湿法脱硫系统简化的可行性.在湿法脱硫系统中,利用冷却塔排烟气代替烟囱排烟,取消烟囱和GGH换热器,将增压风机和引风机合二为一,可提高能源的利用效率,减少设备的投资,降低系统运行及维护费用.     

有关有限边界岸边排放稳态二维混合模式的几个问题的探讨

针对目前我国环境影响评价领域普遍采用的有限边界岸边排放稳态二维混合模式的局限性和不精确性,本文对由河流二维稳态水质模型的基本方程推求出的有限边界岸边排放的二维稳态混合模式的解析解的各项进行分析比较。同时针对费休的混合长度公式进行了计算比较。