Bio-SR工艺去除硫化氢气体的研究

采用Bio-SR工艺,利用铁盐吸收与氧化亚铁硫杆菌的联合作用对H2S进行脱除实验。通过改进微生物的培养条件,减少了83.9%的沉淀量,一定程度上解决了挂膜后生物填料塔易堵塞的问题,保证了填料塔的连续运行。在实验选取工况下,硫化氢脱除率可达到98.4%以上,当吸收液中Fe3+浓度为5.5～6 g/L、H2S进气浓度为1 g/m3、通气量为0.08～0.12 m3/h时效果最佳,反应器可持续高效地运行。此外,对进气浓度、通气量与硫化氢去除率之间的相关性进行了进一步研究,其结果有利于反应器及运行参数的优化设计。     

气氛含氧量对DDT热处理特性的影响

滴滴涕属于有机氯农药,其所含成分DDTs在环境中难以降解,并具有生物毒性。利用高温管式炉研究气氛中含氧量对滴滴涕热处理特性的影响,为研发废弃滴滴涕高温热处理技术提供理论依据。实验结果表明,在600℃时,滴滴涕去除率最高为含氧量21%时的70.48%;在900℃条件下,当含氧量为21%时DDT去除率≥99%;在1 200℃条件下,当含氧量≥12%时DDT去除率≥99.9%。在滴滴涕热处理残渣中,o,p’-DDT占DDTs总量的比例在3个温度段中都随含氧量的增加而增长,DDT则都随含氧量增加而减少,且上述变化随温度升高而幅度加大。在尾气中,p,p’-DDE占DDTs总量的比例在3个温度段中都随含氧量增加而递增,在1 200℃条件下尤为明显。     

耐盐石油降解菌性能及降解条件优化

从冀东油田钻井废液中筛选分离出耐盐石油降解菌Virgibacillus sp.(简称SJ菌),其在高含盐条件下对石油具有较好的降解效果,高达56.12%左右。考察了pH值、盐度、不同N和P形态等因素对SJ菌降解石油效果的影响。结果表明:SJ菌有较宽的pH值适应范围(pH值为6～10)和较好的耐盐能力(0.5%～20%),在pH值为9及NaCl质量浓度为5%时对石油类降解效果最好,其最佳利用N源和P源分别为(NH2)2CO和KH2PO4,该研究为油田高含盐含油废液处理提供了一条新途径。     

环境适应性试验项目的选择

介绍低气压试验、高低温试验、湿热试验、IP防护等级试验、振动试验、冲击和碰撞试验、盐雾试验等试验项目的考核目的和相应试验参数,分析上述试验项目的适用范围。并根据当前产品的发展状况,简单介绍环境试验项目的组合和试验顺序。     

旅游概念规划内容体系创新研究——以重庆市璧山千亩荷园乡村旅游概念规划为例

在界定旅游概念规划的基础上,对其内容体系进行了研究,创新性地提出了一种新的旅游概念规划内容体系,即它由背景环境解析、理念融合创新、目标定位、发展战略确定、关键策略选择五大板块组成,内容涉及到发展背景认知、区域特征分析、特殊理念识别、特有思想梳理、关键概念提取、规划目标界定、发展战略选择、主题形象提升、空间构架部署、概念分区支撑、意象设计解码、发展模式生成、旅游策略选择等13个方面,并以《重庆市千亩荷园旅游概念规划》为例,在理论和实证双重层面上证实了这套新内容体系的实践价值和存在意义.     

Molten salt oxidation: a versatile and promising technology for the destruction of organic-containing wastes

Molten salt oxidation (MSO), a robust thermal but non-flame process, has the inherent capability of destroying organic constituents in wastes, while retaining inorganic and radioactive materials in situ. It has been considered as an alternative to incineration and may be a solution to many waste disposal problems. The present review first describes the history and development of MSO, as well as design and engineering details, and then focuses on reaction mechanisms and its potential applications in various wastes, including hazardous wastes, medical wastes, mixed wastes, and energetic materials. Finally, the current status of and prospects for the MSO process and directions for future research are considered.     

高声能密度超声波破碎污泥细胞效能的研究

采用超声波在较高声能密度下处理SBR的剩余污泥,主要考察了含固率、声能密度和作用时间对污泥细胞破碎效果的影响。结果表明,在声能密度0.5～3 W/mL内,含固率1%～1.5%的剩余污泥经超声波作用后,上清液SCOD随作用时间呈线性升高;在声能密度1～3 W/mL内,含固率0.25%～0.5%的剩余污泥经超声波作用后,上清液SCOD随作用时间呈平缓缓慢升高。高声能密度超声波更适合对较高含固率污泥的细胞破碎;此情况下,上清液SCOD增幅、NH4＋-N、TN及TP升幅均与声能密度正相关。经超声波作用6 min后,污泥形态结构已破坏。     

Energy resource reallocation in Daphnia schodleri (Anomopoda: Daphniidae) reproduction induced by exposure to hexavalent chromium

Cladocerans are able to store energy in the form of macromolecules such as proteins, lipids and carbohydrates. However, their ability to do so depends to a large extent on their physiological and reproductive condition as well as their age. These macromolecules constitute the total caloric reserves of the body and may be modified as a result of environmental stress conditions by either physical or nutritional factors or by exposure to toxic compounds. Neonates of the freshwater cladoceran Daphnia schodleri were exposed to 0.0064, 0.032 and 0.064 mg L⁻¹ of hexavalent chromium - Cr(VI) - up to age 5, 7, 14, 21 or 28 d. Survival and fecundity of parthenogenetic females was evaluated for 28 d (maximum exposure period). Body length and maximum width were determined in specimens of all ages. Caloric content was evaluated in progeny and females within each age group. Female survival was significantly lower with exposure to 0.064 mg L⁻¹ of Cr(VI) than with other treatments, and negative effects on reproduction were observed from the lowest concentration on. Largest adult size was attained by control specimens towards the end of the observation period, but no significant differences in neonate size occurred between concentrations. Energy content decreased in adults as toxicant concentration increased, but these females allocated a larger amount of energy reserves to their progeny as a possible compensation aimed at ensuring neonate survival in an adverse environment due to toxicant presence. Sublethal concentrations of Cr(VI) modified energy content in D. schodleri, affecting to varying degrees its survival, growth and reproduction.     

城市绿地生态系统合理供水辨识分析

城市绿地因具有美化环境、降低空气污染、控制城市热岛等作用而日益得到重视。合理的城市生态供水不仅有益于植被的正常生长,对城市水资源合理配置同样具有积极意义。为统筹城市生态与国民经济发展,保证绿地健康,需要合理的绿地供水管理。本文以土壤含水量为标准,根据田间持水量、临界土壤含水量和凋萎系数三个土壤含水量值划分不同等级的绿地需水量,将供水量分为四个等级,建立了城市绿地供水合理性评价模型,为有效辨识供水合理性提供了参照依据。以2009年北京市城市绿地供水为例,进行了供水合理性分析,结果表明,从全年来看,供水基本合理,虽然绿地蒸散发受到一定抑制,但不影响植被生长;从逐月供水来看,个别月份存在供水过少或过多现象,影响植被生长,且不利于水资源合理利用。     

利用盐泥制取轻质氧化镁

采用二氧化碳法提取盐泥中的镁,研究了使之转化为轻质氧化镁的影响因素以及主要反应的动力学性质。实验确定的最佳条件为固液比1∶15、二氧化碳通入时间90min、水解温度90℃、水解时间25min,在此条件下,盐泥中镁的总提取率为75%;采用微分法求得氢氧化镁与二氧化碳反应的反应级数和活化能分别为1.7和68.1kJ/mol。