Sediment and nutrient loads into river Lwiro, in the Lake Kivu basin, Democratic Republic of Congo
This study assessed sediment and nutrient loads in Lwiro river, Lake Kivu basin in the Democratic Republic of Congo. Water discharge was measured and water samples were collected twice a month from 6 sites in Lwiro river system and analyzed for total suspended sediment (SS), temperature, pH, dissolved oxygen (DO), chemical oxygen demand (COD), five-day biological oxygen demand (BOD5), alkalinity and nutrients (P, N, PO43-, NO3- and NH4+) using standard methods. Results show that the concentration of BOD5 was low (1.08 ± 0.83 mg/L); but COD (13.13 ± 6.26 mg/L) and SS (1.15 ± 0.36 mg/L) were high in the industrial effluent than in agricultural effluent (2.7 ± 0.77 mg/L for BOD5; 9.05 ± 3.55 mg/L for COD and 0.81 ± 0.36 mg/L for TSS). It was observed that all these values were low compared to the standard limit proposed by UNECE and Uganda standard. TSS, nutrient and other chemicals parameters load analyzed were high in agriculture effluent than in industrial effluent except for NH4+ load. Temporal variation and site difference between TSS and nutrient load were significantly different (F=5.54, p< 0.005 for SS; F= 8.59, p< 0.005 for TP and F=7.63, p< 0.005 for TN). Techniques for reducing nutrient and TSS loads should be initiated in the microcatchment to protect the Lake Kivu.
Keywords: Sediment; nutrient load; industrial; agriculture effluent; Lwiro river; Lake Kivu.
Submission of a paper for publication implies the transfer of the copyright from the author(s) to the publisher upon acceptance. International Formulae Group is therefore the copyright holder after publication of an article in International Journal of Biological and Chemical Sciences, and published articles should not be used for commercial purpose without the written consent of the Editor-in-Chief. They are licensed under a Creative Commons Attribution-Non Commercial-Share Alike 4.0 International License.