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

Abstract

This study advances a scheme of sanitation 2 system (S2S) basing on vacuum source-separation to manage the rural waste and wastewater of Changshu, China. The advanced San-2 technology system parts the whole regional rural waste and wastewater into three parallel logistic streams, biogenic waste, other waste, and light grey water. A simulating application of S2S in a township area of Changshu is studied and evaluated by using the life cycle assessment method within the proposed framework and assumptions. Both the systems are divided into four parts: collection, treatment, termination and added processes. And the results show that San-2 has extraordinary advantages of environmental performance over conventional sanitation system (CSS), and the damage scores of the former are 27%, 54%, 27% and 37% as those of the latter with regarding the impacts on human health, ecosystem quality, climate change, and resources respectively. The environmental impact of the CSS is mainly sourced from the added processes, while that of the S2S is mainly from collection and treatment process. Sensitivity analysis shows that the ammonia emission rate and canceling biogas production are the key factor for the S2S, and the settlement population is the critical factor for the CSS. Facing the huge demands of the rural China, the S2S and the rural China are an opportunity to each other, and it is urged to setup encouraging policies for S2S to break up the dictatorship of the CSS.

Toilet revolution in China

“…Innovation is especially needed in densely populated areas, where billions of people are only capturing and storing their waste, with no sustainable way to handle it once their on-site storage—such as a septic tank or latrine pit—fills up. Ground-breaking improvements in toilet design, pit emptying, transportation method ( Fan et al., 2017 ), and sludge treatment, as well as new ways to reuse waste, can help governments and their partners meet the enormous challenge of providing quality public sanitation services. There is much technical guidance available free of charge via the internet for designing and improving complete access to environmental sanitation.…”

Technological system

“…For example, septic tanks, currently adjudged as one of the improved facility, have essentially retained their original design from the 1860s (Bradley et al, 2002) and in the global South, the designs are still rudimentary and poorly constructed (Lüthi & Panesar, 2013). There are, however, some pockets of scaled-up technological innovations such as the Chinese three-chamber septic tanks (Cheng et al, 2017;Fan et al, 2017;Hu et al, 2016); the anaerobic baffled reactor (ABR) that uses baffles to optimize treatment could be referred to as an 'improved' septic tank, but is not widely applied (Foxon et al, 2004;Tilley et al, 2014b;Ulrich et al, 2009); the solar septic tank that utilizes solar energy to inactivate the pathogens and increase sludge biodegradability (Koottatep et al, 2014(Koottatep et al, , 2015(Koottatep et al, , 2016Pussayanavin et al, 2015see section Box 3.3) and septic tank effluent drainage/pumped (STED/STEP) infrastructure that provides effluent sewer services treatment in a communal facility to millions of small communities in Australia and USA (Gardner & Sharma, 2013;Lyle, 1994;Orenco System, 2017).…”

“…They noted that waterless technologies based on separation and dehydration have ecological benefits, but may not meet cultural expectations in communities that use water for anal cleansing (see Section 4.2.1.1). NoDT should provide solutions at a scale in sani-sheds that reflect the SES and explore ways to develop sanitation technologies and systems where toilets are viewed from within the SSC and extending to the final point of disposal and/or end use of faecal sludge (Dias, 2015;Lyle, 1994;Mang & Reed, 2012a;Spaargaren et al, 2006;Tilley et al, 2014a, b) The special features of NoDT processes include: reasonably fast technology, not necessarily independent of existing infrastructures but working in synergy (see Section 2.4.4); appropriateness (see Section 2.4.1); end users' preference (see Section 2.4.8); no mixing of human faeces with other waste; no-linear-flow; NToB (see Section 2.4.5); incorporation of resource recovery and reuse (see Section 2.4.9); affordable technologies that are resource-reclaimable (Gretchen, 2012;Fan et al, 2017;Sunita, 2012;van Loosdrecht & Brdjanovic, 2014); support food production, prevent environmental pollution and minimize demand on other resources (Fan et al, 2017;Zhou et al, 2010). The 'place and scale' concept ensures that sanitation infrastructure functions in close concert with the natural processes within a range of local environmental conditions (see Section 2.4.7).…”

The preliminary evaluation of differential characteristics and factor evaluation of the microbial structure of rural household toilet excrement in China

“…As time progresses and paradigms shifts, people have gradually changed their perception of the treatment and use of human excreta. In many regions, source separated toilet wastes have been applied to the soil as crop fertilizers (Fan et al 2017 ).…”