The urban runoff in general, carries organic load along with several
hazardous chemicals which not only spoils the aesthetic sense of
the river but at the same time also degrades the aquatic ecosystem.
Due to high establishment and running cost of a sewage treatment
plant (STP) the majority of urban centers in developing world dispose
urban runoff and sewerage water directly into urban river without
any treatments or with partial treatments. Several mechanical and
chemical approaches are being applied widely for urban wastewater
treatments systems in urban centers mainly by sewage treatment
plants (STPs). Apart to construction costs the operation and maintenance
problems in STPs has raised the question of sustainability [1].
Moreover, excess sewage sludge produced by STPs has been subjected
to increasingly stringent limitations on discharge during the
last few decades [2]. According to Sinha et al. [3] many developing
countries cannot afford the construction of STP and therefore; there
is growing concern over developing some ecologically safe and economically
viable small-scale wastewater treatment technologies for
onsite wastewater treatment. However, at this crucial juncture some
ecologically engineered tools can solve issues related with safe and
cost-effective wastewater treatments technologies. The majority of
present wastewater treatment systems are a “disposal-based liner
system” and they should be transformed into cyclical treatments [4]