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Water quality and health risks

Table 1. Analytical parameters and methods for laboratory testing
Parameters Analyzer Model and brand Analytical method Standard References
values
Alkalinity Test kit (LR LH2018 and LH2019 Acid-base titration method 20 – 200 64
and HR) (Lohand)
Hardness Test kit LH2013 (Lohand) EDTA titration method 80 – 100
Chloride Test kit LH2015 (Lohand) Silver nitrate titration method 150 – 600
DO DO meter DO-5509 (Lutron) Electrochemical reaction 6
(Acc. ±0.4)
BOD 5 BOD meter BOD-PC02 Respirometric (Incubation) 0.2
(BIOBASE)
COD COD meter LH-C3 (Lohand) Rapid digestion 4
(Acc. ±5%) spectrophotometry
Iron Iron checker HI-721 (Hanna) Colorimetric 0.3 – 1.0
(Acc. ±0.04)
Arsenic Test kit (LR) Test Strip (Hach) Colorimetric 0.05
TDS Multimeter CON30 (CLEAN) Electrochemical reaction 1,000
(Acc.±1%)
EC Multimeter CON30 (CLEAN) Electrochemical reaction 700
(Acc.±1%)
pH Multimeter PH-220 (BIOBASE) Electrochemical reaction 6.5 – 8.5
(Acc.±0.01)
Temperature Multimeter PH-220 (BIOBASE) Electrochemical reaction 20 – 30
(Acc.±0.5°C)
ORP Multimeter PH-220 (BIOBASE) Electrochemical reaction 650 – 700 65
(Acc.±1 mV)
Bacterial Plate count M091A-500G Plate count method (48 h at 37°C) - -
load (CFUs) agar (HiMedia)
Abbreviations: BOD 5: Biochemical oxygen demand; COD: Chemical oxygen demand; DO: Dissolved oxygen; EC: Electrical
conductivity; EDTA: Ethylenediaminetetraacetic acid; HR: High range; LR: Low range; ORP: Oxidation-reduction potential; TDS: Total
dissolved solids.

proportionality (k) by the standard acceptable value (Sn) parameter. For pH, V = 7, for DO, V = 14.6 mg/L,
id
id
of a given parameter: and for all other parameters, V is usually zero [ . The
34
id
calculated 1/Sn, k, and W are represented in Table S2.
W = k Sn/ (III) (iii) Calculation of aggregated WQI
i
n
k was determined using Equation IV: The aggregated WQI was calculated using Equation VI:
k = 1/ ( ∑ 1 ) (IV) WQI = q W /W n (VI)
n
n
S n The WQI values were classified into the following
34
(ii) Calculation of subindex or quality rating categories for drinking water quality assessment :
The subindex (q ) for each water quality parameter Excellent (0 – 25), good (26 – 50), bad (51 – 75), very
n
was calculated using Equation V: poor (76 – 100), and unsuitable for drinking (>100).
V V 2.8. Pollution index
q n id 100 (V)
n
S V id This study used NPI to identify the primary pollutants
n
in the water supply network. The NPI provides
where V is the observed value of the n-th water a comprehensive evaluation of water quality by
n
quality parameter, and V is the ideal value for the n-th prioritizing the most pollutants while accounting for the
id

Volume 22 Issue 1 (2025) 71 doi: 10.36922/ajwep.8163