Table 2.
Central tendency data of pH values and BOD5, COD, ammonium nitrogen, and total phosphorus parameters of ponds M5 (module I: treatment of domestic sewage) and M10 (module II—treatment of domestic wastewater combined with landfill leachate) and the results of the Mann–Whitney test, tested at a 95% confidence level (α = 0.05).
| Parameters | Pond | n | Average | St. deviation | Median | p value |
|---|---|---|---|---|---|---|
| BOD5 (mg/L) | M5 | 59 | 42.28 | 22.98 | 40.00 | 0.049 |
| M10 | 59 | 49.69 | 27.24 | 46.00 | ||
| COD (mg/L) | M5 | 60 | 148.45 | 59.24 | 139.00 | 0.027 |
| M10 | 60 | 172.25 | 64.94 | 155.00 | ||
|
Ammonium Nitrogen (mg N/L) |
M5 | 60 | 1.04 | 1.11 | 0.69 | 0.322 |
| M10 | 60 | 1.63 | 3.83 | 0.72 | ||
| Total phosphorus (mg/L) | M5 | 61 | 1.97 | 0.63 | 2.03 | 0.108 |
| M10 | 61 | 2.28 | 0.87 | 2.08 | ||
| pH | M5 | 62 | 9.15 | 1.07 | 9.45 | 0.570 |
| M10 | 62 | 9.00 | 1.05 | 9.10 |
The parameters that presented a significant difference in the Mann–Whitney test, tested at a 95% confidence level (α = 0.05), were highlighted in bold and underlined.