One of the challenging tasks faced by scientists and
engineers today is to provide safe water to support healthy
human life. But human activities always generate
wastewaters which contain various pollutants that create
problems to aquatic life and contaminate water resources.
Although wastewaters may come from various sources, it
mostly consists of domestic wastewaters (DWWs).
Currently, domestic wastewater is mostly is normally
treated by aerated biological methods. For example, the
activated sludge, being the most famous biological
method of wastewater treatment, produces high quality
effluent, i.e. 90% biological oxygen demand (BOD) and
suspended solids (SS) removal as in [3]. There are some
disadvantages of applying the biological method for
wastewater treatment, such as requiring continuous air
supply, high operating costs (skilled labor, energy, etc),
sensitivity against shock toxic loads, longer treatment
time and necessary sludge disposal.