Performance evaluation of sand filter for tertiary treatment of secondary effluent of wastewater: effect of hydraulic loading
Evaluation des performances des filtres à sable pour le traitement tertiaire de l'effluent secondaire des eaux usées: effet de la charge hydraulique
I. Kader Yettefti1, F. Aboussabiq1, S. Etahiri1, M. Mountadar2*, O. Assobhei1
1 Laboratoire de Biotechnologies marine et de l’environnement, Faculté des sciences,
Université Chouaib Doukkali, BP. 20, El Jadida, Morocco.
2 Unité de chimie analytique et sciences de l’environnement, Faculté des sciences,
Université Chouaib Doukkali, BP.20, El Jadida, Morocco.
* Corresponding author. E-mail: email@example.com
Received: 11 September 2012; revised version accepted: 16 March 2013
The aim of this study was to evaluate the feasibility of slow sand filtration as a technique for tertiary treatment of secondary effluent from the anaerobic denitrifying reactor (ADR). The treatment efficiency depends on several parameters like the sand media used, wastewater characteristics and hydraulic loads. One of the most important parameters in relation to treatment efficiency is the hydraulic loading rate. The experimental pilot consisted of a three columns of opaque PVC supplied with three hydraulic loading rates: 0.16m/h, 0.22 m/h and 0.28 m/h. It was found out that 0.16m/h is the hydraulic loading the most effective. It is capable of removing 86% of chemical oxygen demand (COD), 86% of total suspended solids (TSS), 72% of total Kjeldahl nitrogen (TKN), 75% of ammonium nitrogen (NH4-N), 65% of total phosphorus (TP). Therefore, due to excellent effluent quality, it can be reused for irrigation, and for safe discharge.
Keywords: Wastewater; Slow sand filtration; Tertiary treatment; Hydraulic loading rate; Water reuse.