1. Introduction
The first reported use of the household septic tank was in
France in 1860 when John Louis Mouras discovered a ‘box’
set between the house and the cesspool effectively trapped
excrement, reduced the amount of solids and produced a
clarified liquid which more quickly entered the soil.[1] The
main purpose of conventional septic tanks was to physically
remove suspended solids (SSs) and biologically remove
dissolved organic compounds. Septic tanks have been popular
in China in the past 20–30 years, and such systems
are still in use in most parts of the country. However, with
the development of municipal sewage treatment systems
in China and the inherent disadvantages of conventional
septic tanks, such as risk of explosion, inefficiency