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Treated wastewater for concrete mixing

a mean TSS of 16.62 mg/L, with the median again the median returned to 7.00 mg/L. Overall, the BOD
at 17 mg/L. A significant increase occurred in July, values remained fairly consistent, with a peak observed
where the mean rose to 17.94 mg/L and the median in August and November.
to 18 mg/L. August continued this upward trend, with
a mean of 18.23 mg/L and a median of 18 mg/L. In 3.3.6. F. coli
September, the mean decreased to 17.07 mg/L, and in Figure 9 presents the monthly and median values of F.
October, the mean was 17.16 mg/L while the median coli concentrations from April to November 2023. In
returned to 17 mg/L. Finally, in November, the mean April, the mean was 535 CFU/100 mL and the median
TSS was 16.77 mg/L, with the median still at 17 mg/L. was 525 CFU/100 mL. Both values increased sharply
Overall, while minor fluctuations were observed, the in May, with the mean reaching 567.5 CFU/100 mL
TSS values consistently hovered around 17 mg/L, and the median 565 CFU/100 mL. In June, values
with July and August showing slightly elevated levels decreased to 497.5 CFU/100 mL (mean) and
(18 mg/L). 495 CFU/100 mL (median). In September, the mean
was 550 CFU/100 mL. In October, the mean slightly
3.3.4. Chemical oxygen demand decreased to 540 CFU/100 mL, while the median
Figure 7 presents the monthly mean and median settled at 525 CFU/100 mL. In November, both values
values of COD in treated sewage water from April decreased further, with the mean at 532.5 CFU/100 mL
to November 2023. In April, the mean COD was and the median at 510 CFU/100 mL. These data indicate
40.08 mg/L, and the median was 40 mg/L. A slight general fluctuations in F. coli concentrations, with peaks
increase was recorded in May, with the mean rising to occurring from May to September and relatively lower
40.26 mg/L, while the median remained unchanged. In levels in June – August.
June, values remained stable at 40.04 mg/L (mean) and
40 mg/L (median). A sharp decrease occurred in July, 3.3.7. TKN
with the mean dropping to 39.42 mg/L and the median Figure 10 presents monthly variations in TKN
to 39 mg/L. In August, the mean further decreased to concentrations from April to November 2023. In April,
39 mg/L, while the median remained stable at 39 mg/L. both the median and median TKN values were 3.0 mg/L.
September showed a continued decrease, with a mean In May, the mean increased slightly to 3.25 mg/L, while
of 38.9 mg/L and a median of 39 mg/L. In October, the the median remained at 3.0 mg/L. In June, both values
mean increased slightly to 39.84 mg/L, with the median decreased to 2.5 mg/L. July recorded the highest TKN
remaining unchanged at 39 mg/L. Finally, in November, values of the study period, with both the mean and
the mean and median values were 39.3 mg/L and median at 4.00 mg/L. In August, the mean decreased
39 mg/L, respectively. These results indicate a gradual to 3.4 mg/L, while the median dropped to 3.0 mg/L. In
downward trend in COD levels over the study period, September and October, the mean was 2.75 mg/L, and
with relatively low variation in median values compared the median was 2.5 mg/L. Finally, in November, both
to the mean. values rose again to 3.5 mg/L. Overall, the TKN levels
showed general stability, with moderate fluctuations
3.3.5. Biochemical oxygen demand and a peak observed in July.
Figure 8 presents the monthly mean and median values of
BOD from April to November 2023, showing generally 3.4. Concrete mixed with 100% potable water
stable trends with minor fluctuations. In April, the mean Concrete cubes were prepared using a mixture of
BOD was 7.12 mg/L and the median was 7.00 mg/L. In cement, sand, and aggregate, combined with 100%
May, the mean slightly decreased to 6.89 mg/L, while potable water. The mixture was poured into 150 mm
the median remained stable at 7.00 mg/L. In June, the cube molds and manually mixed. After curing, a load
mean increased to 7.35 mg/L and the median rose to test was performed to obtain baseline strength for
7.5 mg/L. July recorded a slight decrease, with the comparison in future tests (Figure 11 and Table 2).
mean dropping to 7.10 mg/L and the median returning
to 7.00 mg/L. A noticeable increase occurred in August, 3.5. Concrete mixed with primary treated
with the mean reaching 7.48 mg/L and the median wastewater and potable water (60:40 ratio)
increasing to 8.00 mg/L. In September, the mean was Concrete cubes were prepared by combining cement,
7.33 mg/L, and the median remained at 7.5 mg/L. sand, aggregate, and a mixture of 60% primary treated
October saw the mean drop slightly to 7.29 mg/L, while wastewater and 40% potable water. The mixture was

Volume 22 Issue 2 (2025) 121 doi: 10.36922/AJWEP025060033