Wastewater treatment by infiltration percolation process using fine sand and activated carbon

Abstract

This study was conducted to find an efficient and inexpensive wastewater treatment system in poor regions and countries. For this purpose, two filtration systems were used to treat wastewater from a WWTP in Morocco, the first one is the intermittent sand filter (ISF) based on fine sand, and the second one is called the modified infiltration percolation (MIP) based on activated carbon. Physico-chemical and bacteriological analyses were carried out before and after passing the water through the filters. The results showed a significant decrease in the physicochemical parameters such as Suspended matter (SM) with an abatement rate of 99.6% for ISF and 99.4% for MIP, Chemical oxygen demand (COD) with an abatement rate of 17.7% for ISF and 55% for MIP, Biochemical oxygen demand (BOD5) with an abatement rate of 7.14% for the first filter, and a significant decrease with an abatement rate of 100% by MIP. These two filters decreased the concentration of fecal coliforms with a respective removal rate of 98.2% for ISF and 99% for MIP, except that this concentration exceeds the standards. The physicochemical analyses were within the norms, and the filtration systems showed an important efficiency, contrary to the bacterial load of coliforms which exceeded the standards. To this effect, another treatment is necessary to reduce the bacterial load of the wastewater.