title: Impact of Tannery Effluent on the Self-purification Capacity and Biodiversity Level of a River.
abstract: The present study investigates the impact of tannery effluents on the self-purification capacity and the local macroinvertebrate community of one natural stream. As the concentration of chromium and sulfide increased from up- to downstream sites, the reduction of suspended solids, 5-days biological oxygen demand (BOD5), chemical oxygen demand and nitrification capacity decreased by 61 %, 21 %, 30 % and 74 %, respectively. Similarly, the share of Ephemeroptera, Plecoptera, and Trichoptera on the macroinvertebrate community decreased from 24 % to 0 %. Also the diversity (Simpson's) index and the correlation between the physicochemical parameters, BOD5 reduction, the macroinvertebrate abundance and the chromium concentration underpin the importance of the contamination by tannery effluents for the degradation of the stream habitat quality. In conclusion, although the physicochemical parameters indicate that the self-purification of the river can be maintained for a certain stream section, the biodiversity of the river is severely compromised.
authors.affiliation: Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, 3001, Louvain, Belgium. embiallemengistie.beyene@cit.kuleuven.be.
authors.forename: Embialle
authors.identifier: http://orcid.org/0000-0002-0790-9087
authors.initials: E
authors.lastname: Mengistie
authors.affiliation: Department of Environmental Health Sciences and Technology, Jimma University, P. O. Box: 378, Jimma, Ethiopia.
authors.forename: Argaw
authors.initials: A
authors.lastname: Ambelu
authors.affiliation: Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, 3001, Louvain, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Van Gerven
authors.affiliation: Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, 3001, Louvain, Belgium.
authors.forename: Ilse
authors.initials: I
authors.lastname: Smets
mesh_terms: D000818:Animals; D044822:Biodiversity; D002857:Chromium / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D007448:Invertebrates / Q000187:drug effects*; D045483:Rivers / Q000737:chemistry*; D013440:Sulfides / Q000032:analysis*; D013633:Tanning; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D013440:Sulfides; D014874:Water Pollutants, Chemical; D002857:Chromium
keywords: Chromium; Macroinvertebrate; Self-purification; Sulfide; Tannery effluent