Geochemical and Geophysical Study in a Degraded Area Used for Disposal of Sludge from a Water Treatment Plant

Table 5

Results of water analysis.

Parameters	Unit	Upstream well (𝑛=12)		Downstream well (𝑛=12)		WTS well (𝑛=12)		L. D.
		Average	Standard deviation	Average	Standard deviation	Average	Standard deviation
Depth	m	15.59	3.85	18.60	3.22	17.91	3.87
pH		5.3	0.5	5.4	0.5	5.8	0.5
Conductivity	μS/cm	31.7	24.2	33.0	18.3	54.0	29.2
TDS	mg/L	21.5	16.4	22.4	12.5	36.7	19.9
Hardness	mg CaCO3/L	7.5	5.3	11.7	8.2	18.5	15.8
Total alkalinity	mg CaCO3/L	6.0	4.5	8.2	7.0	16.1	14.4
Turbidity	NTU	52.0	91.2	365.4	1,105.8	10.1	11.2	0.1
Consumed oxygen	mg/L	2.4	1.1	3.4	1.9	2.9	1.3
Na	mg/L	0.5	0.3	0.4	0.5	0.4	0.4	0.01
K	mg/L	0.3	0.1	0.4	0.2	0.3	0.1	0.01
Mg	mg/L	0.7	0.5	0.9	0.4	1.0	0.5	0.0
Ca	mg/L	1.8	1.8	3.2	3.1	5.8	5.7	0.02
Mn	mg/L	0.033	0.019	0.039	0.013	0.027	0.005	0.015
Fe	mg/L	0.268	0.236	1.371	3.946	0.185	0.103	0.010
Ammonia nitrogen	mg/L	0.029	0.021	0.039	0.050	0.034	0.038	0.020
Ba	mg/L	0.009	0.008	0.023	0.019	0.021	0.018	0.003
Zn	mg/L	0.041	0.026	0.029	0.010	0.036	0.017	0.012
Cu	mg/L	0.004	0.003	0.004	0.002	0.018	0.049	0.001
Cl	mg/L	0.7	0.4	0.7	0.2	0.8	0.5	0.1
SO4^2−	mg/L	L 1.0	—	L 1.0	—	L 1.0	—	1.0
NO3^−	mg/L	0.125	0.064	0.273	0.152	0.052	0.033	0.010
HCO3^−	mg/L	7.27	5.55	10.83	8.40	19.68	17.52
Al	mg/L	0.704	1.291	0.396	0.417	0.268	0.200	0.002
P	mg/L	0.032	0.018	0.083	0.067	0.051	0.037	0.002
Free CO2	mg/L	46.75	26.12	63.60	67.06	36.22	18.36
Pb	mg/L	0.194	0.136	0.170	0.115	0.297	0.169	0.004
Thermotolerant coliforms	MPN/100 mL	Abs.	—	Abs.	—	Abs.	—
Total coliforms	MPN/100 mL	54.6	156.6	635.2	1059.6	275.8	690.5

Abs.: absence; L. D.: method limit of detection; MPN: most probable number, L: lower than; G: greater than.