Managing the downstream pollution problems and poverty reduction in the tropical developing world: Relying on the integration of nature's library, traditional knowledge and ecological sanitation

The ecosystem management technologies are low cost, environment-friendly and effective, and are based on the interdependence and symbiotic relationships amongst some components of the ecosystem such as microalgae, probiotics, floating, rooted and marginal weeds, artificial islands, herbivorous fishes, mussels, benthic animals, etc. Due to relatively high toxic tolerance and rapid turnover of high organic loading, the so-called living machines develop self design and regulation in functional processes providing reclamation and ecosystem services. Other innovative methods are bottom raking with benthivorous animals, integrated wastewater management using solar-energy driven biological process like aquaculture and hydroponics. Right selection of species from nature's library, traditional knowledge, wise planning, innovative application and patience to natural functioning of ecosystems are the main attributes of the begin - of - the- pipe approach. It is unique for solving much of the environmental problems related with industrial development. It is now realized that the society may benefit more from the integration of ecological engineering and ecological sanitation. As a sustainable source of materials and energy, ecological sanitation can be profitably integrated with ecological engineering in terms of ecosystem services to the society. Human urine or feces obtained from source separated dry toilet can be profitably recycled into the production of vegetables in agriculture, or algal biomass or fish biomass in aquaculture and, hence, reap double benefits by protecting the environment from excreta-related pollution and by promoting the philosophy of recycling wastes into wealth. The present paper examines the state-of-the-art of the low-cost, nature-based reclamation strategies and economic use of reclaimed wastewater and the integration of ecological engineering and ecological sanitation.