**3.10 Manganese (Mn2+)**

The concentrations of Mn2+ from the study range from 0.01 mg/l – 0.17 mg/l in the sampled water sites as shown in **Table 7**. All the values obtained from the sample sites except for sites BR1 (0.12 mg/l), SB2 (0.15 mg/l) and TA3 (0.17 mg/l) are within the WHO [25] permissible levels of 0.1 mg/l to 0.5 mg/l. The mean concentration of Mn2+ ranged from(0.003–0.063) mg/l in all the sample sites as reported in **Table 6**. The


**Table 7.**

*Ions from water in Jalingo Metropolis during rainy season.*

highest value of 0.17 mg/l was recorded for site TA3, which is higher than the value of (0.057–0.010)mg/l reported by Ayeki, Asikhia and Ojeh [26] in the study of seasonal and spatial variation in physicochemical & biological quality of rainwater in Benin City, Edo State. All the mean values obtained from the locations were within the WHO [27] permissible levels of (0.1 to 0.5)mg/l.

**Manganese (Mn2+):** The concentration of manganese from the study range from (0.00–0.17)mg/l in the sampled water as shown in **Table 2** with mean value of 0.01 0.02 – o.6 0.09 as shown in **Table 8** during the dry season and value range of (0.01–0.19)mg/l as shown in **Table 7** with the mean value range of 0.02 0.02–- 0.09 0.09 mg/l as show in **Table 6** during the rainy season were all within the WHO permissible levels of 0.1 mg/l to 0.5 mg/l. The highest value of 0/17 mg/l recorded for site TA3 and 0.19 mg/l in dry season and rainy season respectively are higher than the value of (0.10–0.57)mg/l.

#### **3.11 Fluoride(F- )**

The fluoride concentration recorded in this study range from(0.01–0.82)mg/l. The high levels were recorded in sample sites TB1 (0.4 mg/l), KS1 (0.4 mg/l) and TB2 (0.82 mg/l). The permissible range of fluoride by WHO is(0.5 to 1.5)mg/l. The fluoride concentrations found in the study are within the permissible WHO standards. Therefore, the fluoride found in the drinking water in the study area is not detrimental to life.

#### **3.12 Nitrate (NO3 )**

The nitrate (NO3 ) levels obtained in the study range from 0.01–38.5 mg/l for the sample sites. The high values of (6.2 mg/l),(l4.4mg/l) and (38.5 mg/l were observed at site TB3, TB2 and MD3, respectively. This is higher than the range of 0.33 and 2.37 mg/L reported by Popoola, Yusuf and Aderibigbe [24] in assessment of natural groundwater physico-chemical properties in major industrial and residential locations of Lagos metropolis. All the nitrate values obtained in the study are lower than the WHO [27] recommended guideline value of 50 mg/l. This implies that the nitrate concentrations obtained in the study are within the permissible standards and might not pose any health risk.

**Nitrate (NO3 )**The nitrate levels obtained in this study range from 0.01–38.5 mg/l as shown in **Table 9** with mean value range of 0.06 0.03–7.4 6.48 as shown in **Table 8** during the dry season and the value range of 0.02–38.8 mg/l as shown in **Table 7** with mean value of range of 0.09 0.04–13.56 21.88 as shown in **Table 6** during the rainy season.

The high values of TB3 (6.7), TB2+ (14.8) and MD3 (38.8) during thee rainy season and TB3 (6.2 mg/l) TB2 (14.4 mg/l) and MD3 were higher than the range of 0.33 and 2.37 mg/l reported by Popoola, Yusuf and aderigbe [24] in assessment of natural groundwater physicochemical properties in major industries and residential locations of Lagos metropolis.

All the Nitrate values obtained during the dry and rainy season are lower than the WHO [27] recommended guidelines value of 50 mg/l which implies that the nitrate concentrations obtained in the study were within the WHO standard and might not cause any health risk (**Tables 10** and **11**).

#### **3.13 Nitrite (NO2 )**

The nitrite (NO2 ) levels obtained in this study range from 0.01 mg/l – 0.09 mg/ l for all the sampled sites. The highest value of 0.09 mg/l was observed at site TB2 and MD3. This is lower than the value of 0.27 0.005 mg/l reported by Bolarinwa,


#### **Table 8.**

*Mean values of selected ions in water in Jalingo during dry season.*
