Researchers from Sweden have developed a simple method to extract and purify coagulating proteins from Moringa oleifera (MO) seeds [1]. The research stems from an attempt to find a low-cost locally available alternative to expensive commercial coagulants used in a water treatment plant in Asmara, Eritrea. The single step ion exchange purification process developed will allow scaling-up for large-scale water treatment applications. Moringa oleifera trees, also called horseradish or drumstick trees, are indigenous in many tropical countries [2].

The purified coagulant protein showed both flocculating and antibacterial effects of 1.1–4 log reduction. With samples of high turbidity, the MO extract showed similar coagulation activity as alum. Cecropin A and MO extract were found to have similar flocculation effects for clay and microorganisms.

In an earlier project [3] on large-scale application of MO, unpurified crushed seeds were used. According to Kebreab Ghebremichael, this has several disadvantages as long hydraulic retention times in the distribution system as the organic material could become septic, lead to the growth of microorganisms and the formation of harmful disinfection-by-products after chlorination.

[1] Ghebremichael, K.A. … [et al.]. (2005). A simple purification and activity assay of the coagulant protein from Moringa oleifera seed. Water Research, vol. 39, no. 11, p. 2338-2344. Abstract

See also:
Ghebremichael, K.A (2004). Moringa seed and pumice as alternative natural materials for drinking water treatment : a case study for Eritrea. Stockholm, Sweden, Dept. of Land and Water Resources Engineering, Royal Institute of Technology (KTH). ISRN KTH/LWR/PHD 1013-SE. PDF file

For an e-discussion on the thesis see: PHYTO-P1: Moringa seed and pumice in drinking water treatment (13-24 June) - web site

[2] Trees for Life – The Moringa Tree -

[3] Trees for Life – Large Scale Water Purification

Contact: Dr. Kebreab A. Ghebremichael, KTH Dept. of Dept. of Land and Water Resources Engineering, Sweden, kebreab@kth.se, personal web page

Tags: water quality