Constructing the ecological sanitation: a review on technology and methods

Abstract

a b s t r a c tWastewater often contains valuable resources (e.g. organic matter and nutrients). Different from conventional sanitation approaches, the ecological sanitation (Eco-San) system is based on the closure of material flow cycles to recover resources with minimized demands on other resources. The review comprehensively summarized the main components of the Eco-San system (user interface, collection and conveyance, storage and primary treatment, and reuse/disposal), the frequently-used evaluation methods, and the framework of evaluation index system. Some typical practical cases were discussed to demonstrate the managerial implications and popularize the applications of the Eco-San system. The results show that the Eco-San systems are beneficial to resource efficiency, agricultural use of the organic matters and nutrients, and energy recovery although some shortages exist (e.g. high cost, cultural constraints, and complex operation and management). The evaluation methods can help to identify the restriction factors, contributing factors and measures to improve the efficiency of the future Eco-San system. The setting, selection and quantification are three critical steps when using the evaluation indices to complete the evaluation process. This study not only provides the methods for both developing novel Eco-San systems (combinations of the components) and improving the Eco-San systems (evaluation of the combinations) to solve the wastewater problem in rural areas. Considering the challenges or limitations in the Eco-San research, the recommendations for future research may mainly focus on the combination of different components, methods for sustainability assessment, quantification of the evaluation index, and implementation of more real Eco-San cases.

Get in sanitation 2.0 by opportunity of rural China: Scheme, simulating application and life cycle assessment

“…The government has kept on attaching great importance to the rural water supply and hygiene, which are shown in Figure 1 (National Health and Family Planning Commission of the People"s Republic of China, 2013). The rural household is subsidized to install six types of toilets, including two types of water-flush toilet (septic tank toilet and sewer-connected toilet), and four types of waterless toilet (dual-urn funnel toilet, biogas toilet, urine diverting dehydration toilet and alternating dual-pit toilet) (Hu et al, 2016). Additionally, the "other toilets" in Figure 1 are elementally certain primitive waterless toilets of the local context too.…”

“…Vacuum toilet is widely employed in airplanes, ships and trains, and vacuum sewer is also a regular municipal wastewater collection technology especially being adopted where gravity sewer is inapplicable (Zeeman et al, 2007). A testing system of rural sanitation system basing on vacuum source-separation was built at Hehuageng Settlement, Guli Town of Changshu in 2011 (Hu et al, 2016). This is the first practical rural sanitation system using vacuum source-separation in China.…”

“…Sanitation refers to remove and treat the wastes-generated by human settlements to create hygienic conditions and prevent disease (Flores, 2010). Fast-forward 100 years, the conventional sanitation (Con-San) symbolizes with water-flush toilet, mixed-wastewater collection and energy-intensive wastewater treatment technology (Hu et al, 2016). However, Con-San always views wastewater as "waste" that requires complex technology and expertise to dispose, which consuming enormous amounts of energy and resources.…”

“…There is currently about 700 million rural residents, of which 90% percent haven"t got sewage systems complying with environmental requests, and about a quarter even without toilets in accordance with modern standards (Hu et al, 2016). The upcoming huge demands provide opportunities to develop San-2 in rural China; especially, the modern sanitation needs have become intensive and elementally affordable along with the recent rapid progress in socio-economy and serious deterioration in eco-environment.…”

Economic Aspects of Sustainable Sanitation in Rural Settlements

“…40%) lives without access to the sound environmental sanitation, especially in the developing countries (e.g. [8,12]). Moreover, the coverage of sanitation systems is usually significantly lower in rural areas then in urban ones and huge disparities between access to water supply and sanitation were reported [13,14].…”