Improvement of water treatment pilot plant with Moringa oleifera extract as flocculant agent

Abstract

Moringa oleifera extract is a high‐capacity flocculant agent for turbidity removal in surface water treatment. A complete study of a pilot‐plant installation has been carried out. Because of flocculent sedimentability of treated water, a residual turbidity occured in the pilot plant (around 30 NTU), which could not be reduced just by a coagulation‐flocculation‐sedimentation process. Because of this limitation, the pilot plant (excluded filtration) achieved a turbidity removal up to 70%. A slow sand filter was put in as a complement to installation. A clogging process was characterized, according to Carman‐Kozeny’s hydraulic hypothesis. Kozeny’s k parameter was found to be 4.18. Through fouling stages, this k parameter was found to be up to 6.36. The obtained data are relevant for the design of a real filter in a continuous‐feeding pilot plant. Slow sand filtration is highly recommended owing to its low cost, easy‐handling and low maintenance, so it is a very good complement to Moringa water treatment in developing countries.

Keywords:

• Moringa oleifera
• flocculation
• natural coagulants
• slow sand filtration
• Kozeny

Acknowledgements

This investigation has been supported by the Programa de Iniciación a la Investigación, Universidad de Extremadura, oriented modality, SANTANDER, S.A. subprogram. The authors thank also the Oficina Universitaria de Cooperación al Desarrollo de la Universidad de Extremadura, for its support in previous research stages and the Comisión Interministerial de Ciencia y Tecnología (CICYT) CTQ 2007‐60255/PPQ project as well as to Junta de Extremadura under the PRI‐07A031 project.