Comparative study of mineral nitrogen in sediment of Lagos lagoon and Ibeshe river.

Abstract

Analysis of mineral nitrogen comprising ammonium and nitrate nitrogen in sediment of Lagos lagoon and Ibeshe river shows a nitrate record range of 9.51 mg/g low and 84.44 mg/g high  in Ibeshe river with a mean value of 25.12 ± 4.73 mg/g. A low value of 13.46 mg/g and a high of 54.09 mg/g was observed in sediment of Lagos lagoon with a population mean of  31.05 ± 4.48. The ammonium value in Ibeshe river range from 0.39 to 6.97 mg/g with a mean value of 2.76 +/- 0.83 mg/ g while that of the lagoon range from 1.58 to 33.09 mg/g with a mean value of 9.54 ± 2.45 mg/g. A DO value of 5.51±0.28 mg/l, B.O.D value of 23.36±2.44 mg/l and a slightly acidic pH value  of 6.64+/-0.12 were obtained in Lagos lagoon. A DO value of 24.73±6.17 mg/l, B.O.D value of 114.83±22.80 mg/l and a similar pH value of 6.50±0.10 were obtained in Ibeshe river. The one-way ANOVA shows a significant difference in the mineral nitrogen data when comparing variance of ammonium and nitrate level in Lagoon with Ibeshe river.  A probability value of 0.000005 was obtained, while a p value of 0.000039 was observed when dissolved oxygen and B.O.D values were compared. A double beam ultraviolet visible spectrophotometer was used to determine nitrate nitrogen using salicylate method of analysis at 420 nm while ammonium was determined using indophenol method at 630 nm. Keywords: mineral nitrogen, nitrate, ammonium, sediment, Lagos lagoon, and Ibeshe river, ammonium nitrogen and nitrate nitrogen.