Use of macroinvertebrate assemblages for assessing performance of stabilization ponds treating effluents from sugarcane and molasses processing

• Published in: Environmental monitoring and assessment Vol. 189; no. 2; p. 79
• Main Authors: Raburu, Phillip Okoth, Masese, Frank Onderi, Tonderski, Karin S.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.02.2017; Springer Nature B.V
• Subjects: Analytical chemistry; Animals; Aquatic ecosystems; Atmospheric Protection/Air Quality Control/Air Pollution; Biochemical oxygen demand; Biological Oxygen Demand Analysis; Biomonitoring; Chemical analysis; Chemical oxygen demand; Developing countries; Diptera - classification; Earth and Environmental Science; Ecology; Ecosystem; Ecotoxicology; Effluent treatment; Effluents; Environment; Environmental Management; Environmental monitoring; Environmental Monitoring - methods; Factories; Food-Processing Industry; Insecta - classification; Invertebrates - classification; Kenya; LDCs; Macroinvertebrates; Molasses; Monitoring/Environmental Analysis; Performance assessment; Performance evaluation; Pollutants; Pollution levels; Ponds; Ponds - analysis; Saccharum; Stabilization ponds; Sugarcane; Syrups & sweeteners; Waste Water - analysis; Wastewater discharges; Wastewater treatment; Water quality; Water treatment; Biomonitoring; Sugarcane effluents; Molasses; Invertebrates; Wastewater; Biotic index
• DOI: 10.1007/s10661-017-5786-9
• ISSN: 0167-6369; 1573-2959

Wastewater discharge from sugarcane processing is a significant pollutant of tropical aquatic ecosystems. For most developing countries, monitoring of the level of pollutants is done mostly through chemical analysis, but this does not reflect potential impacts on aquatic assemblages. In addition, laboratory facilities for accurate concentration measurements are often not available for regular monitoring programs. In this study, we investigated the use of benthic macroinvertebrates for biological monitoring in western Kenya. Benthic macroinvertebrates were sampled in stabilization ponds treating wastewater from sugarcane- and molasses-based processing plants to assess their composition and abundance in relation to different concentrations of chemical variables. Optimum concentrations and tolerance values were identified for various taxa, and a biotic index was developed that combined tolerance values (ranked between 0 and 10) for the various macroinvertebrate taxa. A succession in composition and distribution of macroinvertebrate taxa was observed from the inlet to the outlet of the pond systems. Diptera dominated in the first ponds that had high concentrations of chemical oxygen demand (COD), biological oxygen demand (BOD 5 ), and nutrients, while intolerant Ephemeroptera, Plecoptera, and Trichoptera (EPT) appeared as the concentrations dropped in subsequent ponds. The effluent quality was classified as “good,” “fair,” and “poor,” corresponding with biotic index value ranges 0–3.50, 3.51–6.50, and 6.51–10, respectively. During validation, the index grouped sites with respect to levels of measured environmental variables. The study revealed that the developed biotic index would help in monitoring the quality of sugarcane processing and molasses effluents before release into recipient aquatic ecosystems, replacing the need for costly chemical analyses.