Microwave enhanced advanced oxidation process for treating dairy manure at low pH

This study investigated the treatment of dairy manure using the microwave enhanced advanced oxidation process (MW-AOP) at pH 2. An experimental design was developed based on a statistical program using response surface methodology to explore the effects of temperature, hydrogen peroxide dosage and heating time on sugar production, nutrient release and solids destruction. Temperature, hydrogen peroxide dosage and acid concentration were key factors affecting reducing sugar production. The highest reducing sugar yield of 7.4% was obtained at 160°C, 0 mL, 15 min heating time, and no H₂O₂ addition. Temperature was a dominant factor for an increase of soluble chemical oxygen demand (SCOD) in the treated dairy manure. The important factors for volatile fatty acids (VFA) production were microwave temperature and hydrogen peroxide dosage. Temperature was the most important parameter, and heating time, to a lesser extent affecting orthophosphate release. Heating time, hydrogen peroxide dosage and temperature were significant factors for ammonia release. There was a maximum of 96% and 196% increase in orthophosphate and ammonia concentration, respectively at 160°C, 0.5 mL H₂O₂ and 15 min heating time. The MW-AOP is an effective method in dairy manure treatment for sugar production, nutrient solubilisation, and solids disintegration.     

Degradation of rizazole in water–sediment systems

This study investigated the degradation of rizazole in water-sediment systems (West Lake system, WL; Beijing–Hangzhou Grand Canal system, BG) with two different types of sediments under aerobic and anaerobic conditions. The half-lives of rizazole in the WL water phase (14.59–15.13 d) were similar to those in the BG water phase (15.90–16.46 d). Within 3–7 d, the rizazole concentration in the sediments reached the maximum values, i.e., equilibrium. Rizazole dissipation was faster in the WL sediment phase with higher organic matter content (T_1/2 = 18.99–19.09 d) compared with the BG sediment phase (T_1/2 = 31.08–33.32 d). Rizazole degradation was slightly faster in the West Lake water-sediment system (WL system) (T_1/2 = 17.11–18.05 d) than in the Beijing–Hangzhou Grand Canal water—sediment system (BG system) (T_1/2 = 20.51–25.02 d). The aerobic degradation of rizazole was similar to its anaerobic degradation in the water-sediment system. The findings are useful to understand the behavior of pesticide in environment.     

高压实新疆阿尔泰膨润土微观结构随吸力变化特征

采用压汞法(MIP)和扫描电镜(SEM)法,在自由和侧限状态下,试验研究了高压实新疆阿尔泰膨润土在不同吸力条件下的微观结构变化特征。吸力的控制采用了气相法和渗析(液相)法。研究结果表明:(1)低吸力范围内,自由膨胀和侧限条件下的高压实膨润土土水特征存在明显差异;(2)膨润土在自由和侧限状态下的水化过程中呈现出了截然不同的微结构变化特征。自由膨胀条件下,土的吸水膨胀量主要来自土中大孔隙的逐渐膨胀。侧限状态下,随着控制吸力的降低,膨润土的大孔隙逐渐被压缩,较小孔隙的数量不断增加,土中孔隙分布变得更加均匀。     

PPP机制在城市污水处理行业中的应用

PPP模式作为公共部门与私人企业合作的一种模式,可以有效地缓解基础设施建设资金紧张的状况,是一种基于双赢或多赢理念基础上而形成的模式,目前已被许多国家广泛采用。在我国推行公用事业市场化改革的背景下,该模式具有广阔的应用前景。本文分析了该模式在我国城市污水处理行业中应用的主要形式,以及该模式在我国现实环境下面临的风险、存在的问题和相应的解决办法,并为政府推进PPP模式的应用提供了相关的建议。     

浅谈深圳市环境监督管理全覆盖移动执法系统的建设和应用

环境监督管理全覆盖移动执法系统,是利用现代无线通信技术、计算机技术等先进技术手段,利用手持终端(PDA)、手提电脑等设备,通过无线数字通信网的支持,实现在任何执法地点都可从后台业务系统中获取所需的业务数据、文字、图片、视频等信息,同时将现场执法的信息及时回传至后台系统中。本文介绍了移动执法系统的建设以及应用的情况。     

重庆市道路交通空气监测现状及控制对策

分析重庆市道路交通空气质量自动监测站的各项参数监测数据的变化趋势,并对机动车尾气对大气环境的影响进行了分析与评估。同时结合一些先进的预防、控制和处理汽车尾气污染的方法,提出了一些意见和建议来防止机动车尾气污染进一步蔓延。     

南充市城郊农村居民的环境法律意识调查与分析

本文通过采用问卷调查和走访调查的方法,对南充市两县三区的城郊农村居民进行了抽样调查。调查结果发现,当地城郊农村居民环境法律“知”的水平中等、个体差异较大,环境法律“行”的水平偏低,“知”与“行”之间存在脱节现象。这与当地城郊农村居民的文化程度和所处地域有关。为此,提出了从“知”和“行”上加强当地城郊农村居民的环境法律知识教育和环境维权意识教育的建议,这也是提高城郊农村居民环境法律意识的途径所在。     

公路项目竣工环境保护验收调查中的重点与难点

公路项目是生态影响类建设项目,本文以达渝高速公路三期工程(大竹城西至重庆段)竣工环境保护验收调查为例,以验收调查的技术路线、方法、工程建设对生态环境的影响及声环境的影响为重点进行调查,对在公路项目竣工环境保护验收调查中存在的问题和重点进行总结。     

水利旅游吸引力评价模型与实证研究

水利旅游是水利经济的新兴增长点,吸引力评价是旅游开发的基础性研究。借鉴引力理论,构建了由25个指标组成的水利旅游吸引力评价指标体系,运用AHP—PCA—Borda主客观组合评价法,对我国水利旅游吸引力进行了实证评价。结果表明,水利旅游吸引力地区不平衡,江苏、广东、山东、湖北、河南、浙江、湖南、北京和江西等省水利旅游吸引力较强,西部省份和处于我国版图中轴线附近的省份水利旅游吸引力较弱。     

羧酸盐型双子表面活性剂的合成及性能研究

以月桂酰氯、乙二胺与丁二酸酐为原料合成了一种羧酸盐型双子(gemini)表面活性剂。采用IR、1 HNMR对中间产物和目标产物进行结构表征,并考察了合成所得羧酸盐型gemini表面活性剂的表面活性。结果表明:合成产物即为目标产物。合成产物的临界胶束浓度为0.027mmol/L,比普通单链表面活性剂低2～3个数量级,表面张力最低可降至29.5mN/m。