Heavy metal pollution leads to human health problems and represents a constant threat to the environment. Pollutant
clean-up using conventional methods are often hampered by high cost and ineffective pollutant removal. Phytoremediation
technique is a preferable alternative due to its minimal side effects to the environment in addition to reasonable treatment
cost. In this study, we investigated the potential of Centella asiatica and Orthosiphon stamineus as phytoremediation
agents. Both species were grown in contaminated soil obtained from industrial land. Plant growth response and their
ability to accumulate and translocate zinc, copper and lead were assessed. From this study, root growth of C. asiatica
was compromised when grown in contaminated soil. Copper was highly accumulated in C. asiatica roots while the
leaves were more concentrated with zinc and lead. Conversely, all three tested metals were highly detected in the roots
of O. stamineus, although the root elongation was not adversely affected. Low amount of metals in the stems of both
species permits longer stem length. Correlation study showed that the accumulation of zinc, copper and lead in plant
tissues varies depending on plant species and the type of metals. Based on the bioaccumulation, translocation and
enrichment factor, our study showed that C. asiatica was tolerant towards zinc, copper and lead; hence suitable for
phytoextraction. By contrast, O. stamineus acted as a moderate accumulator of the tested metal elements.
Historically, there is evidence to suggest that communities in the developing countries
are still using plant-based materials as one of the strategies for purifying drinking
water. In this review, the coagulant properties of Moringa oleifera seeds extract were
quantitatively evaluated toward suitable wastewater treatment and examining its
coagulation mechanism. The seeds are rich in bio-active components and also used as
a natural coagulant for effective water treatment. The seeds extract operates
predominantly by bridging coagulation mechanism and operates through charge
neutralization. This natural ingredient of an organic polymer is essential as it contains
acrylamide monomers that are harmless to human’s health and lesser expensive as
compared to conventional chemicals since they are available in most rural
communities. The application of this readily available natural product as part of pointof-use
in water treatment technology may offer a practical, cheap, appropriate and
sustainable solution for producing potable water in some developing nations.