Abstract:
In Jaffna peninsula, groundwater is the primary water source for domestic agricultural and
industrial purposes. However, increased water hardness and contamination by nitrates are
two major water quality problems prevalent in this area, The present study was conducted
with the aim of assessing the efficacy of powdered mature leaves of Terminalia arjuna
(Kumbuk) to improve the water quality in terms of nitrate concentration and total hardness.
Water samples with three replicates were collected from randomly selected 15 domestic
wells located in the Kondavil area, Jaffna peninsula. The nitrate-N, and total hardness (TH)
were measured using standard analytical methods. The water samples were filtered in a
column filter using powdered mature leaves of Terminalia arjuna and these water quality
parameters were measured in filtered water samples as well. The water quality parameters
were compared with the standard water quality parameters for safe drinking water
established by the Sri Lanka Standards Institution (SLSI). The variation of water quality
parameters before and after filtration were compared by paired t test using MINITAB 14
software. The mean TH of the sampled wells ranged from 644.15 mg/L CaC03 and The mean
nitrate N ranged from 12.07 mg/L. All the the wells exceeded the SLSI standard (250 mg/ L)
for TH and 60 % of the wells exceeded the SLSI standard (11.3 mg/ L) for nitrate. After
filtration through the powdered mature leaves of Terminalia arjuna, the TH and nitrate N
were reduced significantly (Paired t test, 0.05). The mean TH and nitrate N of the filtered
water were 635.8 mg/L CaC03 and 9.49 mg/L respectively. Percentage reduction of TH and
nitrates after filtration were 1.3 % and 21.36% respectively. Therefore, results of the present
study showed that Terminalia arjuna leaf powder can be used as an effective low cost
household treatment method to improve the water quality in terms of TH and nitrate N.
