Development of ecological sanitation approaches for integrated recovery of biogas, nutrients and clean water from domestic wastewater

Access to adequate sanitation services and the treatment of domestic wastewater becomes a critical problem in developing countries. Domestic wastewater treatment based on conventional sanitation concept is the most common approach, which is neither ecological nor economical sound to realize sustainable sanitation solution. Therefore, there is a need to block the sanitation-linked concerns and limitations of the conventional systems through the development of an alternative sustainable sanitation systems. With the rising demand to improve the existing sanitation system for environmental protection and resources conservation (energy, nutrient, and water), ecological sanitation approach appealed the attention of scientific communities. This paper presents the comprehensive review of domestic wastewater characteristics, conventional sanitation systems and its sustainability challenges; ecological sanitation technologies, process conditions and their performances in terms of resource recovery efficiency (i.e. biogas, struvite-based nutrients and clean water). The outcome of these approaches are resource oriented and closed-loop systems, which promotes the sustainable sanitation by overwhelmed the limitations of conventional systems. Moreover, the application of these technologies to treat domestic wastewater also helps to improve public health by reducing the introduction of disease causing pathogens in to the water cycle and minimizes the negative environmental impacts. Accordingly, the applications of ecological sanitation technologies to treat domestic wastewater would be a viable option to solve the existing sanitation problems; and simultaneously promoting energy–food–water–health nexus, especially in developing country.