Seasonal Dynamics in Bacteriological and Physicochemical Water Quality of the Southern Gulf of Lake Tana

Table 4

Mean and standard deviation of physicochemical parameters measured at the Southern Gulf of Lake Tana (N = 3), 2021.

Site	Par. Sea.	pH	Temp (°C)	Turb(NTU)	E.C(µS/cm)	TDS(ppm)	NH4 (mg/l)	NO3 (mg/l)	PO4 (mg/l)	DO (mg/l)	BOD5(mg/l)
S1	Dry	7.8 ± 01	25 ± 2	27.7 ± 3	203 ± 10.7	88 ± 13.1	0.2 ± 0.1	39.7 ± 5.2	0.06 ± 0.01	6.1 ± 0.5	4.5 ± 0.5
	Wet	7.9 ± 0.05	22.7 ± 1	11 ± 0.4	285 ± 1.5	148 ± 4	0.5 ± 0.2	36.3 ± 3.1	0.38 ± 0.05	4.7 ± 0.2	11.7 ± 3.1
S2	Dry	7.9 ± 0.32	22.8 ± 0	23 ± 0.8	141 ± 11	71 ± 8.4	0.15 ± 0.2	33.2 ± 3.6	1.4 ± 1.2	6.4 ± 0.4	4 ± 1.3
	Wet	8.7 ± 0.1	25.3 ± 1.1	23.1 ± 2	167 ± 0.8	84 ± 0.1	0.16 ± 0.1	13.9 ± 1.7	0.14 ± 0.1	6.7 ± 0.15	13
S3	Dry	8.2 ± 0.6	24.9 ± 0.7	22.9 ± 6	174 ± 22	81 ± 6.1	0.1 ± 0.07	26.7 ± 3.7	1.6 ± 0.5	6.2 ± 0.4	4.7 ± 1.5
	Wet	9.3 ± 0.06	24 ± 1.2	19.4 ± 1	146 ± 3.4	73 ± 0.1	0.37 ± 0.02	33 ± 2.5	0.31 ± 0.1	7.7 ± 0.3	11 ± 1.7
S4	Dry	8.4 ± 0.4	25.6 ± 0.5	24.8 ± 4	193 ± 16	86 ± 13.1	0.16 ± 0.07	57.2 ± 8.6	0.58 ± 0.95	6.5 ± 0.5	5
	Wet	8.6 ± 0.2	21.9 ± 1.5	16 ± 0.3	146 ± 0.5	73 ± 0.1	0.59 ± 0.3	27 ± 2.5	0.47 ± 0.1	6.8 ± 0.5	23 ± 2.6
S5	Dry	7.4 ± 0.2	23.5 ± 0.8	16.3 ± 3	123 ± 7.7	61 ± 4.9	0.12 ± 0.03	15 ± 13	0.02 ± 0.02	6.1 ± 0.5	2.8 ± 1.4
	Wet	9.3 ± 0.06	21.3 ± 0.6	18.7 ± 1.5	131 ± 0.1	66 ± 0.4	0.2 ± 0.27	8.1 ± 6	0.04 ± 0.04	7.6 ± 0.5	5.7 ± 1.5
S6	Dry	7.4 ± 0.1	23 ± 0.7	14.9 ± 2	122 ± 9.9	71 ± 14.6	0.08 ± 0.07	4.5 ± 3.9	0.02 ± 0.02	6.7 ± 0.5	2.3 ± 0.6
	Wet	8.99 ± 0.1	22	27 ± 0.5	146.9 ± 3	74 ± 0.3	0.39 ± 0.15	30 ± 1.5	0.32 ± 0.95	7.9 ± 0.5	17 ± 2.5
S7	Dry	7 ± 0.6	25 ± 0.7	18.4 ± 1.2	134 ± 9.6	58 ± 15.6	0.07 ± 0.06	6.1 ± 0.8	0.03 ± 0.03	6.3 ± 0.5	2.3 ± 0.6
	Wet	8.9 ± 0.2	21 ± 1	24.9 ± 0.2	139 ± 1.9	71 ± 0.1	0.32 ± 0.11	17 ± 1.5	0.12 ± 0.05	7.5 ± 0.5	22 ± 2
S8	Dry	7.3 ± 0.9	24 ± 1.3	11.8 ± 1.7	116 ± 6.9	62 ± 6.7	0.03 ± 0.03	4.5 ± 3.9	0.02 ± 0.02	6.9 ± 0.6	4.0±0.5
	Wet	8.9 ± 0.02	20.7 ± 0.6	26.8 ± 0.6	157 ± 47	70.6	0.56 ± 0.01	34 ± 1.5	0.28 ± 0.04	6.7 ± 0.9	20.5 ± 3

Note. Par. = parameters; Sea. = season; Temp = temperature; EC = electrical conductivity; Turb = turbidity; TDS = total dissolved solids; DO = dissolved oxygen; BOD = biological oxygen demand; NO₃ = nitrates; PO₄ = phosphate; NH₄ = ammonium; EPA 2001: PO₄ 0.5; NO₃ = 50, conductivity = 1000, BOD₅ = 5, pH = 5.5 to 8.5 for surface water.