Pilot-Plant Study of the Tertiary Filtration of Wastewater Using Local Sand

Abstract

Local sand with E.S. of 2.4 mm, U.C. of 1.21, and size range of 2.0 to 3.36 mm was studied using a field-scale pilot-filter, which has a cross-section of 30 cm x 30 cm. Three filter runs were performed using filtration rates of 4, 8 and 18 m3/m2/hr. The three runs were continued up to 40,100 and 53 hours, respectively. In Run # 1, the headloss build-up was minimum (about 25 cm), while in Runs 2 and 3, the maximum available headloss (about 2.25 m) was reached. The effluent turbidity, TSS, COD and BOD were all found to be within the acceptable limits. Neither turbidity nor solids breakthrough were reached using a filtration rate as high as 18 m3/m2/hr. Being more economical and suitable for the use in the tertiary filtration of wastewater treatment, local sand is recommended for utilization in the Wastewater Treatment Plants.