MATERIALS ANDMETHODSThe experiment

MATERIALS ANDMETHODS
The experiment was conducted in the greenhouse
at the Department of Applied Radiation and Isotopes,
Faculty of Science, Kasetsart University. Three vetiver
ecotypes, Kamphaeng Phet-2, Sri Lanka and Surat
Thani, were hydroponically cultured in four sources of
industrial wastewater. The water was collected from a
milk factory (W1), a battery manufacturing plant (W2),
an electric lamp plant (W3) and an ink manufacturing
facility (W4). The 3 x 4 factorial experiment in
Completely Randomized Design with 3 replications
was performed. The pH values of the four wastewater
sources were adjusted to 7 before using them for vertiver
cultivation. Twenty-centimeter tall vetiver seedlings
from tissue culture propagation were used. One
seedling was planted in a plastic cup filled with sand.
The bottom of each cup was streaky cut across to allow
wastewater to soak the sand. The five cups were fitted
on foam sheet floating in each bucket. The plants were
pruned to 15 cm high before cultivation which lasted
for 120 days. During cultivation, weeds were thoroughly
removed and the solution volume in the buckets was
maintained at 20 liters by weekly the addition of distilled
water