Conversion regular patterns of acetic acid,propionic acid and butyric acid in UASB reactor

On the basis of continuous tests and batch tests, conversion regular patterns of acetate, propionate and butyrate in activated sludge at different heights of the UASB reactor were conducted. Results indicated that the conversion capacity of the microbe is decided by the substrate characteristic when sole VFA is used as the only substrate. But when mixed substrates are used,the conversion regulations would have changed accordingly. Relationships of different substrates vary according to their locations. In the whole reactor, propionate's conversion is restrained by acetate and butyrate of high concentration. On the top and at the bottom of the reactor, conversion of acetate, but butyrate, is restrained by propionate. And in the midst, acetate's conversion is accelerated by propionate while that of butyrate is restrained. It is proved, based on the analysis of specific conversion rate, that the space distribution of the microbe is the main factor that affects substrates' conversion. The ethanol type fermentation of the acidogenic phase is the optimal acid type fermentation for the two phase anaerobic process.

基于地域三脉优化皖淮旅游景观意象

安徽省淮河流域有着自己独特的地理地貌、历史发展和人文风情,通过考察分析找到皖淮区域的地脉、史脉和文脉,为旅游景观设计奠定基石。寻找皖淮旅游景观的优化策略,形成基于淮河地脉的湿地生态旅游、基于淮河史脉的教育景观游、基于文脉的文化景观游,从而塑造具有优质意向的景观,提升旅游景观社会经济综合价值。

北京春季PM2.5和PM10污染水平及影响因素研究

本文以2013年3月份北京市环境监测中心公布数据为依据,对4个(东城天坛、西直门北大街、昌平镇、京西北八达岭)不同采样点PM2.5和PM10的浓度水平、空间分布、PM10/PM2.5比值和空气质量分指数进行分析。结果表明北京市3月份PM2.5和PM10月日均浓度为109.45±67.81μg·m^(-3)μg·m^(-3)和131.94±61.07μg·m^(-3),分别为国家二级标准的1.46倍和0.88倍,PM2.5和PM10日平均超标率为45.94%和4.87%;PM2.5和PM10的日变化以白天高,夜间低为主,基本呈现双峰型特征;PM2.5和PM10排序均为交通污染控制点>郊区环境评价点>城市环境评价点>对照点及城区点,PM2.5/PM10的比值排序为京西北八达岭(107.59%)>东城天坛(84.87%)>昌平镇(84.79%)>西直门北大街(67.80%);PM2.5和PM10与温度呈正相关关系,温度对PM10的影响更显著,PM2.5和PM10浓度变化与相对湿度和风速呈负相关关系,风速主要清除细粒子,对PM10的影响则较小。PM2.5空气质量指数在110.01~126.19之间,属于三级轻度污染,PM10空气质量分指数为68.75~96.82,属二级良,交通污染控制点的空气质量最差,对照点及城区点空气质量较高。北京市PM2.5和PM10污染不容忽视。