Wastewater Toxicity of Tannin- Versus Chromium-Based Leather Tanneries in Marrakesh, Morocco

• Published in: Archives of environmental contamination and toxicology 2007-10, Vol.53 (3), p.321-328
• Main Authors: De Nicola, E, Meriç, S, Della Rocca, C, Gallo, M, Iaccarino, M, Manini, P, Petruzzelli, D, Belgiorno, V, Cheggour, M, Di Gennaro, A, Moukrim, A, Tünay, O, Pagano, G
• Format: Article
• Language: English
• Subjects: Algae; Algal growth; Animal, plant and microbial ecology; Animals; Applied ecology; Applied sciences; Bioassays; Biological and medical sciences; Biological Assay; Chromium; Chromium - toxicity; Daphnia - drug effects; Daphnia - physiology; Daphnia magna; Dunaliella tertiolecta; Echinoidea; Ecotoxicology, biological effects of pollution; Embryo, Nonmammalian - drug effects; Embryos; Eukaryota - drug effects; Eukaryota - growth & development; Exact sciences and technology; Female; Fertilization; Fundamental and applied biological sciences. Psychology; General aspects; Growth rate; Immobilization; Leather; Male; Marine; Offspring; Paracentrotus lividus; Pollution; Sea urchins; Sea Urchins - embryology; Sperm; Tanneries; Tanning; Tanning industry; Tannins; Tannins - toxicity; Toxicity; Toxicity testing; Trends; Vegetable tannins; Waste Disposal, Fluid; Wastewater; Wastewaters; Water Pollutants, Chemical - toxicity; Water treatment and pollution
• ISSN: 0090-4341; 1432-0703
• DOI: 10.1007/s00244-006-0181-5

The toxicity of leather tanning wastewater from a traditional tannery (TT), which is based on vegetable tannin (VT), was compared with wastewater from a tannery combining the use of chromium-based tanning (CT) with VT-based tanning operations. Wastewater samples from a TT and a CT plant as well as from five sewer sampling points were collected in Marrakesh, Morocco, and the concentrations of VT and some selected inorganics were measured. A set of bioassays were used to test wastewater toxicity in sea urchin (Paracentrotus lividus) embryos and sperm, in Daphnia magna, and in marine microalgae (Dunaliella tertiolecta). Toxicity end points included: (1) developmental defects, embryonic mortality, sperm fertilization success, and offspring damage in sea urchins; (2) D. magna immobilization; and (3) algal growth rate inhibition. Toxicity tests on TT and CT effluents (TTE and CTE) were run at dilutions ranging from 0.1% to 2% (sea urchins and algae) or up to 12% in D. magna. Parallel bioassays were run on VT extract (VTE) at nominal tannin concentrations ranging from 0.1 to 10 mg l-¹. The results showed higher toxicity of CTE compared with TTE. CTE toxicity in sea urchins and algae showed concentration-related trends, whereas TTE exerted hormetic effects at levels of 0.1% to 0.2% and toxic effects at levels >=1%. The same trends were observed for VTE, suggesting a prevailing role of tannin in TTE-associated effects. The moderate wastewater toxicity of VT-based tanneries might prompt interest in the VT tanning process.