Moringa seed and pumice as alternative natural materials for drinking water treatment

In developing countries treatment plants are expensive, the ability to pay for services is minimal and skills as well as technology are scarce. In order to alleviate the prevailing difficulties, approaches should focus on sustainable water treatment systems that are low cost, robust and require minimal maintenance and operator skills.
Locally available materials can be exploited towards achieving sustainable safe potable water supply.
This thesis presents an investigation on the suitability of pumice and the Moringa oleifera (MO) seeds as alternative natural materials for drinking water treatment. It is based on problems identified at the Stretta Vaudetto water treatment plant in Eritrea.
Moringa oleifera seeds treat water on two levels, acting both as a coagulant and an antimicrobial agent. Lab and pilot scale studies showed that pumice was a suitable alternative material for dual media filtration. Conversion of the sand filters at Stretta Vaudetto to pumice-sand media would significantly improve the performance of the filtration units.
In this research, the coagulation protein from the MO seed was purified in a single-step ion exchange purification method. The parameters for batch purification were optimized to be readily scaled up. A small volume coagulation assay method was developed that simplified and expedited the coagulation activity experiments. MO coagulants protein (MOCP) possessed considerable coagulation and sludge conditioning properties as alum. It also showed antimicrobial effects against bacteria, some of which were antibiotic resistant. The coagulation and antimicrobial properties of MOCP render it important in water treatment.