A combined process for algae-laden water treatment based on hydroxyl radical

我国水体的富营养化问题日益严重，导致大量水源地出现季节性的藻类爆发现象。由于藻类爆发的水体中藻细胞浓度急剧增加、有机物含量升高，传统饮用水处理工艺已无法满足处理要求。因而，需要改造原有处理工艺以解除高藻水引发的饮用水供水卫生安全威胁。本文依托国家科技支撑计划项目“高藻水源地供水卫生保障羟基自由基氧化技术研发与示范”(NO.2013BAC06B00)，利用大气压强电离放电制备羟基自由基(•OH)技术，以厦门市水源地高藻水为研究对象，构建了高藻水•OH处理系统，探索了高藻水预处理条件，完成了•OH和ClO2处理高藻水的中试对比实验，取得的主要成果有： (1)结...In recent years, eutrophication has affected more and more fresh water Lakes. Algae-laden water contains a high concentration of algae cells and organisms. In conventional process of drinking water treatment, algal blooms may cause negative influence and difficulties for water treatment. In order to treat algae-laden water, we must upgrade the progress of drinking water treatment. This paper based...学位：工学硕士院系专业：环境与生态学院_环境工程学号：3332013115175

Treatment of algae bloom water using ·OH based on conventional drinking water process

我国水体的富营养化日益严重,水源地出现季节性藻类爆发现象,严重威胁饮用水安全。以厦门市莲坂水厂各工艺段出水为研究对象,采用大气压强电离放电产生羟; 基自由基(·OH),分别对水源水、混凝沉淀出水、砂滤出水进行处理,处理时间为4.5 s。当注入总氧化剂浓度为1.8 mg·; L~(-1)时,高藻浓度从25.3*10~4 cells · mL~(-1)降到800 cells ·; mL~(-1);对混凝沉淀出水注入总氧化剂0.6 mg· L~(-1)、砂滤出水注入0.2 mg·; L~(-1)时,藻细胞都未检出;·OH处理后CODMn、TOC及UV254均有明显降低,砂滤出水三卤甲烷小于8; mug·L~(-1);检测的各项指标均达到国家《生活饮用水卫生标准》(GB; 5479-2006)。因此,·OH可快速有效安全地杀灭高藻,为我国高藻水源地饮用水卫生安全保障提供技术支撑。Due to the increasing eutrophication in China, harmful algae blooms; often occur in water body periodically, which poses serious threats to; drinking water safety. Using a strong ionization discharge technology at; atmosphere pressure, ·OH was used to remove algae bloom. Other; conventional process such as coagulation, sedimentation and sand; filtration were applied respectively in the Lianban Water Plant in; Xiamen (China). The total reaction time required in the three water; processes was only 4.5 s. When the total reactive oxidant (TRO); concentration injected to algae bloom water was 1.8 mg·L~(-1), the algae; content was decreased by ·OH from 25.3*10~4 cells·mL~(-1) to 800; cells·mL~(-1). When the TRO that was injected into coagulation,; sedimentation and sand filtration water achieved 0.6 mg·L~(-1) and 0.2; mg·L~(-1), respectively, the algae contents were not detected (ND) in; treated effluents. At the same time, water quality in CODMn, TOC and; UV254 were decreased and the disinfection by-products(DBPs) such as,; trihalomethanes (THMs) concentration was lower than 8 mug·L~(-1) in; treated effluents. The treated effluent, resulting from this technology,; met the requirement of the National Drinking Water Standards (GB; 5479-2006). Therefore, ·OH was effective and safe to remove freshwater; algae without further treatment being required.国家科技支撑计划项目; 国家重大科研仪器研制项目; 科技部创新人才推进计划重点领域创新团

尼日利亚农林业发展与荒漠化防治探析/Analysis on Agriculture & Forestry Development and Desertification Combating in Nigeria[J]

尼日利亚南部紧邻几内亚湾,为热带雨林气候,北部与撒哈拉沙漠接壤,为稀树干草原.历史以来,有多条沙垄深入该国北部100～200 km,风沙土遍布,生态环境脆弱.近年来,森林因砍伐和烧荒以每年1.36％的速度消失,而沙化土地每年以35万hm2的速度增加,荒漠化发展迅速,生态安全堪忧,气候旱化、人口增加、沙质地表及农林牧资源过度开发利用为主因.尼日利亚通过采取减少木材依赖型能源与工业、控制人口、草畜平衡、禁止开垦、环境意识与法制结合等对策与措施,提高土地生产力,逐步恢复稀树干草原,促进社会经济可持续发展和生态环境的良性循环.文中介绍了尼日利亚农林业发展现状、荒漠化与沙产业发展、荒漠化防治中存在的问题与对策,认为长期开展气候周期性变化对生物多样性与荒漠化关系影响研究以及成功地采用林木引种驯化、育苗造林、流沙垄固定、防护林营造、沙产业开发、适地适树等技术值得我国学习与借鉴