Comparison of bacteriological quality and bacterial challenge study; physicochemical quality parameters of control and solar pasteurization treated water samples (pond, lake and river) with standard valuea
| Bacteriological quality . | Non-treated water samples (as control) . | Treated water samples . | USEPA std for drinking water . | BSTI std for drinking water . | ||||
|---|---|---|---|---|---|---|---|---|
| indicators . | Pond . | Lake . | River . | Pond . | Lake . | River . | (log CFU/ml) . | (log CFU/ml) . |
| Mean value of bacterial populations (log CFU/ml) | ||||||||
| Environmental samples | ||||||||
| Total aerobic bacterial count | 4.8 ± 0.4 | 4.1 ± 0.3 | 4.5 ± 0.1 | 1.3 ± 0.1 | 2.6 ± 0.2 | 0.8 ± 0.1 | TT3 | 1,000 |
| Total coliform count | 4.20 ± 0.1 | 3.8 ± 0.2 | 3.8 ± 0.2 | <1.0 | <1.0 | <1.0 | NR | NR |
| E. coli count | 3.8 ± 0.1 | 3.6 ± 0.1 | 3.1 ± 0.2 | <1.0 | <1.0 | <1.0 | NR | NR |
| E. coli O157:H7 count | 3.4 ± 0.1 | 3.5 ± 0.1 | <1.0 | <1.0 | <1.0 | <1.0 | NR | NR |
| Salmonella count | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 | NR | NR |
| Vibrio count | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 | NR | NR |
| Bacterial challenge test | ||||||||
| E. coli on TSAR | 5.5 ± 0.3 | 4.5 ± 0.4 | 6.8 ± 0.2 | <1.0 | <1.0 | <1.0 | NR | NR |
| E. coli on SMACR | 5.3 ± 0.2 | 4.4 ± 0.2 | 6.7 ± 0.1 | <1.0 | <1.0 | <1.0 | NR | NR |
| Physicochemical parameters . | ||||||||
| Parameters . | Mean value of control samples . | Mean value of treated samples . | US EPA standard for drinking water . | BDS standard . | ||||
| Color | Gray to yellowish (16–19 color unit) | 15 (color unit) | 15 (color unit) | 5 (Hazen unit) | ||||
| Odor | Odorous | Odorless | 3 threshold odor number | Unobjectionable | ||||
| Taste | Fishy-sour smelly | Agreeable | Agreeable | Agreeable | ||||
| pH | 6.9–7.7 | 7.1–7.6 | 6.5–8.5 | 6.4–7.4 | ||||
| Salinity (ppt) | 0.1 | 0.1 | 0.1 | 0.1 | ||||
| Turbidity (NTU) | 29.0–31.0 | 5.0–6.0 | 0.5–1.00 | 5.0 | ||||
| TDS | 302–346 | 310–345 | 500 | 500 | ||||
| Conductivity μs/cm | 600–780 | 620–690 | NS | NS | ||||
| BOD (mg/l) | 2.1–2.5 | 2.71–2.76 | 5.0 | 5.0 | ||||
| COD (mg/l) | 2.214–3.195 | 2.27–2.31 | 40 | 40 | ||||
| Iron (mg/L) | 0.04 | 0.04 | 0.3 | 0.30 | ||||
| Manganese (mg/L) | 0.02 | 0.02 | 0.05 | 0.50 | ||||
| Zinc (mg/L) | 0.01 | 0.01 | 5.00 | 3.00 | ||||
| Lead (mg/L) | 0.000 | 0.0004 | 0.015 | 0.01 | ||||
| Arsenic (mg/L) | 0.002–0.003 | 0.002 | 0.01 | 0.05 | ||||
| Cadmium (mg/L) | 0.00 | 0.00 | 0.005 | 0.003 | ||||
| Bacteriological quality . | Non-treated water samples (as control) . | Treated water samples . | USEPA std for drinking water . | BSTI std for drinking water . | ||||
|---|---|---|---|---|---|---|---|---|
| indicators . | Pond . | Lake . | River . | Pond . | Lake . | River . | (log CFU/ml) . | (log CFU/ml) . |
| Mean value of bacterial populations (log CFU/ml) | ||||||||
| Environmental samples | ||||||||
| Total aerobic bacterial count | 4.8 ± 0.4 | 4.1 ± 0.3 | 4.5 ± 0.1 | 1.3 ± 0.1 | 2.6 ± 0.2 | 0.8 ± 0.1 | TT3 | 1,000 |
| Total coliform count | 4.20 ± 0.1 | 3.8 ± 0.2 | 3.8 ± 0.2 | <1.0 | <1.0 | <1.0 | NR | NR |
| E. coli count | 3.8 ± 0.1 | 3.6 ± 0.1 | 3.1 ± 0.2 | <1.0 | <1.0 | <1.0 | NR | NR |
| E. coli O157:H7 count | 3.4 ± 0.1 | 3.5 ± 0.1 | <1.0 | <1.0 | <1.0 | <1.0 | NR | NR |
| Salmonella count | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 | NR | NR |
| Vibrio count | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 | NR | NR |
| Bacterial challenge test | ||||||||
| E. coli on TSAR | 5.5 ± 0.3 | 4.5 ± 0.4 | 6.8 ± 0.2 | <1.0 | <1.0 | <1.0 | NR | NR |
| E. coli on SMACR | 5.3 ± 0.2 | 4.4 ± 0.2 | 6.7 ± 0.1 | <1.0 | <1.0 | <1.0 | NR | NR |
| Physicochemical parameters . | ||||||||
| Parameters . | Mean value of control samples . | Mean value of treated samples . | US EPA standard for drinking water . | BDS standard . | ||||
| Color | Gray to yellowish (16–19 color unit) | 15 (color unit) | 15 (color unit) | 5 (Hazen unit) | ||||
| Odor | Odorous | Odorless | 3 threshold odor number | Unobjectionable | ||||
| Taste | Fishy-sour smelly | Agreeable | Agreeable | Agreeable | ||||
| pH | 6.9–7.7 | 7.1–7.6 | 6.5–8.5 | 6.4–7.4 | ||||
| Salinity (ppt) | 0.1 | 0.1 | 0.1 | 0.1 | ||||
| Turbidity (NTU) | 29.0–31.0 | 5.0–6.0 | 0.5–1.00 | 5.0 | ||||
| TDS | 302–346 | 310–345 | 500 | 500 | ||||
| Conductivity μs/cm | 600–780 | 620–690 | NS | NS | ||||
| BOD (mg/l) | 2.1–2.5 | 2.71–2.76 | 5.0 | 5.0 | ||||
| COD (mg/l) | 2.214–3.195 | 2.27–2.31 | 40 | 40 | ||||
| Iron (mg/L) | 0.04 | 0.04 | 0.3 | 0.30 | ||||
| Manganese (mg/L) | 0.02 | 0.02 | 0.05 | 0.50 | ||||
| Zinc (mg/L) | 0.01 | 0.01 | 5.00 | 3.00 | ||||
| Lead (mg/L) | 0.000 | 0.0004 | 0.015 | 0.01 | ||||
| Arsenic (mg/L) | 0.002–0.003 | 0.002 | 0.01 | 0.05 | ||||
| Cadmium (mg/L) | 0.00 | 0.00 | 0.005 | 0.003 | ||||
aDetection limit: <1.0 log CFU/ml. TT3: treatment technique, a required process intended to reduce the level of contamination in drinking water; NR: not recommended; TSAR: tryptic soy agar with rifampicin (50 μg/ml); SMACR: sorbitol MacConkey agar with rifampicin (50 μg/ml); NS: not specified.