Seeds from
Moringa oleifera(辣木) trees can be used to purify water. Uppsala University leads a research group which has discovered that seed material can give a more efficient purification process than conventional
synthetic1 materials in use today. Clean water is essential for good health. In many countries it is still difficult to obtain clean water. Even developed countries can benefit from a process that treats waste water without addition of further synthetic chemicals.
In a project lead by UppsalaUniversity, scientists from several countries have investigated how an extract from seeds of Moringa trees can be used to purify water. A protein in the seeds
binds2 to
impurities3 causing them to
aggregate4(集合) so that the clusters can be separated from the water.
The study recently published in the journal Colloids and Surfaces A takes a step towards optimisation of the water purification process. Researchers in Uppsala together with colleagues from Lund as well as Namibia, Botswana, France and the USA have studied the
microscopic5 structure of
aggregates6 formed with the protein. The results show that the clusters of material (flocs) that are produced with the protein are much more tightly packed than those formed with conventional
flocculating agents(絮凝剂). This is better for water purification as such flocs are more easily separated.
The new study compares protein from the seeds of different varieties of Moringa trees that are grown in different countries. It also allows estimates of the optimum amount of seed extract that should be used to minimise
residues7 in treated water.
The work used research facilities at the Institut Laue-Langevin in France and the NIST Center for
Neutron8 Research in the USA. Powerful research tools such as those for neutron
scattering9 are important to tackle challenges facing developing countries as well as industrialised regions.
There is a broad interest in new, sustainable methods for water treatment. The research group has already presented results to government agencies and public bodies, particularly in Namibia and Botswana. There are now discussions on best use of Moringa seeds, both to substitute conventional materials in large water treatment plants and in small scale units.
"We can
envisage10 that similar materials could be used in Europe both to produce drinking water and to treat wastewater," says Professor Adrian Rennie.
"
Neutrons11 are an ideal tool for understanding the internal structure of these complex organic aggregates thanks to a contrast matching technique that only highlights the protein
components12 absorbed to the particles," says Dr Lionel Porcar from the Institut Laue-Langevin. "Additionally the use of Ultra Small Angle Neutron Scattering allowed the
mechanism13 of
aggregation14 of these large flocs the to be followed non-invasively."