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ENCYCLOPEDIA OF ENVIRONMENTAL SCIENCE AND ENGINEERING - NATURAL SYSTEMS FOR WASTEWATER TREATMENT

HỆ THỐNG TỰ NHIÊN CHO XỬ LÝ NƯỚC THẢI GIỚI THIỆU Trong các tìm kiếm liên tục cho một hệ thống xử lý nước thải đơn giản, đáng tin cậy, và không tốn kém, hệ thống tự nhiên là những phát hiện mới nhất. Họ không chỉ cung cấp phương pháp hiệu quả xử lý nước thải, mà còn cung cấp một số sử dụng mang lại lợi ích gián tiếp của các thiết bị chẳng hạn như không gian xanh, môi trường sống của động vật hoang dã, và các khu vực giải trí. Trong môi trường tự nhiên, vật. | N NATURAL SYSTEMS FOR WASTEWATER TREATMENT INTRODUCTION In the continual search for a simple reliable and inexpensive wastewater treatment system the natural systems are the latest discovery. They provide not only efficient methods of wastewater treatment but also provide some indirect beneficial uses of the facility such as green space wildlife habitat and recreational areas. In the natural environment physical chemical and biological processes occur when water soils plants microorganisms and atmosphere interact. To utilize these processes natural systems are designed. The processes involved in the natural systems include sedimentation filtration gas transfer adsorption ion exchange chemical precipitation chemical oxidation and reduction and biological conversions plus other unique processes such as photosynthesis photooxidation and aquatic plant uptake.1 In natural systems the processes occur at natural rates and tend to occur simultaneously in a single ecosystem reactor as opposed to mechanical systems in which processes occur sequentially in separate reactors or tanks in accelerated rates as a result of energy input. Generally a natural system might typically include pumps and piping for wastewater conveyance but would not depend on external energy sources exclusively to maintain the major treatment responses.2 In this paper a general overview of natural systems for wastewater treatment is presented. The constructed wetlands are becoming a viable wastewater treatment alternative for small communities individual homes and rest areas. Therefore in this paper a great deal of information has been presented on site selection design of physical facilities performance expectations hydraulic and organic loading rates and cost of the constructed wetlands. TYPES OF NATURAL SYSTEMS Natural systems for effective wastewater treatment are divided into two major types terrestrial and aquatic systems. Both systems depend on physical and chemical responses as 737 well as on the