G. MacFarlane and M. Burchett, "Cellular distribution of copper, lead and zinc in the grey mangrove, Avicennia marina (Forsk.) Vierh," Aquatic Botany, vol. 68, pp. 45-59, 2000. Available at: https://doi.org/10.1016/s0304-3770(00)00105-4.
 G. M. Alaa and W. K. Osman, "Water quality and heavy metal monitoring in water, sediments, and tissues of the African Catfish Clarias gariepinus (Burchell, 1822) from the River Nile, Egypt," Journal of Environmental Protection, vol. 1, pp. 389-400, 2010.
 M. Storelli, A. Storelli, R. D'addabbo, C. Marano, R. Bruno, and G. Marcotrigiano, "Trace elements in loggerhead turtles (Caretta caretta) from the Eastern Mediterranean Sea: Overview and evaluation," Environmental Pollution, vol. 135, pp. 163-170, 2005. Available at: https://doi.org/10.1016/j.envpol.2004.09.005.
 M. Tüzen, "Determination of heavy metals in fish samples of the middle Black Sea (Turkey) by graphite furnace atomic absorption spectrometry," Food Chemistry, vol. 80, pp. 119-123, 2003. Available at: https://doi.org/10.1016/s0308-8146(02)00264-9.
 M. Canli and G. Atli, "The relationships between heavy metal (Cd, Cr, Cu, Fe, Pb, Zn) levels and the size of six Mediterranean fish species," Environmental Pollution, vol. 121, pp. 129-136, 2003. Available at: https://doi.org/10.1016/s0269-7491(02)00194-x.
 A. Ahmad and M. Shuhaimi-Othman, "Heavy metal concentrations in sediments and fishes from lake Chini, Paliang, Malaysia," Asia Network for Scientific Information, vol. 10, pp. 93-100, 2010. Available at: https://doi.org/10.3923/jbs.2010.93.100.
 M. Demlie, T. Ayenew, and S. Wohnlich, "Comprehensive hydrological and hydrogeological study of topographically closed lakes in highland Ethiopia: the case of Hayq and Ardibo," Journal of Hydrology, vol. 339, pp. 145-158, 2007. Available at: https://doi.org/10.1016/j.jhydrol.2007.03.012.
 APHA (American Public Health Association), American water works association, water environment federation, standard methods of the examination of water and wastewater, 20th ed. New York: American Public Health Association, APHA, AWWA, and WPCF, 1999.
 K. Salnikow and E. Denkhaus, "Nickel essentiality, toxicity, and carcinogenicity," Critical Reviews in Oncology/hematology, vol. 42, pp. 35-56, 2002. Available at: https://doi.org/10.1016/s1040-8428(01)00214-1.
 O. Awofolu, Z. Mbolekwa, V. Mtshemla, and O. Fatoki, "Levels of trace metals in water and sediment from Tyume River and its effects on an irrigated farmland," Water Sa, vol. 31, pp. 87-94, 2005. Available at: https://doi.org/10.4314/wsa.v31i1.5124.
 S. Kocak, O. Tokusoglu, and S. Aycan, "Some heavy metal and trace essential element detection in canned vegetable foodstuffs by differential pulse polarography (DPP)," Electronic Journal of Environmental, Agricultural and Food Chemistry, vol. 4, pp. 871-878, 2005.
 A. M. Balba and G. El Shibiny, "Effect of lead increments on the yield and lead content of tomato plants," Water, Air, and Soil Pollution, vol. 57, pp. 93-99, 1991. Available at: https://doi.org/10.1007/bf00282872.
 A. Abayneh, W. Taddese, and B. Chandravanshi, "Trace metals in selected fish species from lakes Awassa and Ziway, Ethiopia," Sinet, vol. 26, pp. 103-114, 2003. Available at: https://doi.org/10.4314/sinet.v26i2.18206.
 ATSDR, Agency for toxic substances and disease registry, toxicological profile for cadmium United State department of health and humans services, public health service centers for diseases control. Atlanta, GA: ATSDR, 2003.
 Y. Zenebe, "Accumulation of certain heavy metals in Nile Tilapia (Oreochromisniloticles) fish species relative to heavy metal concentrations in the water of Lake Hawassa," M.Sc. Thesis, Addis Ababa University, Ethiopia, 2011.
 Y. Wang, Z. Zhang, S. Kuang, G. Wu, Y. Li, Y. Li, and W. Liao, "Selective extraction and recovery of copper from chloride solution using cextrant 230," Hydrometallurgy, vol. 181, pp. 16-20, 2018. Available at: https://doi.org/10.1016/j.hydromet.2018.08.007.
 S. H. Chang, A. A. A. Wahab, and A. M. Som, "Extraction behaviour of Cu 2+ Ions with used cooking oil-based organic solvent," in International Proceedings of Chemical, Biological and Environmental Engineering, 2016.
 A. Chmielewski, T. Urbański, and W. Migdał, "Separation technologies for metals recovery from industrial wastes," Hydrometallurgy, vol. 45, pp. 333-344, 1997. Available at: https://doi.org/10.1016/s0304-386x(96)00090-4.
 T. A. Kurniawan, G. Y. Chan, W.-H. Lo, and S. Babel, "Physico–chemical treatment techniques for wastewater laden with heavy metals," Chemical Engineering Journal, vol. 118, pp. 83-98, 2006. Available at: https://doi.org/10.1016/j.cej.2006.01.015.
 S. H. Chang, T. T. Teng, and N. Ismail, "Extraction of Cu (II) from aqueous solutions by vegetable oil-based organic solvents," Journal of Hazardous Materials, vol. 181, pp. 868-872, 2010. Available at: https://doi.org/10.1016/j.jhazmat.2010.05.093.
 P. K. Kuipa and M. A. Hughes, "Diluent effect on the solvent extraction rate of copper," Separation Science and Technology, vol. 37, pp. 1135-1152, 2002. Available at: https://doi.org/10.1081/ss-120002246.
 I. Komasawa and T. Otake, "The effects of diluent in the liquid-liquid extraction of copper and nickel using 2-hydroxy-5-nonylbenzophenone oxime," Journal of Chemical Engineering of Japan, vol. 16, pp. 377-383, 1983. Available at: https://doi.org/10.1252/jcej.16.377.
 T. T. Tow, Y. Yusup, and L. W. Low, "Heavy metal Ion extraction using organic solvents: An application of the equilibrium slope method." Stoichiometry and Research - The Importance of Quantity in Biomedicine, Dr Alessio Innocenti (Ed.), in Tech. Available: http://www.intechopen.com/books/stoichiometry-and-research-the-importance-of-quantity-in-biomedicine/stoichiometry-of-metal-complexes-extracted-using-organic-solvents, 2012.
 B. Han, B. Altansukh, K. Haga, Y. Takasaki, and A. Shibayama, "Copper recovery from silicate-containing low-grade copper ore using flotation followed by high-pressure oxidative leaching," Resources Processing, vol. 64, pp. 3-14, 2017. Available at: https://doi.org/10.4144/rpsj.64.3.
 J. B. A. Paulo and J. Y. P. Leite, "A comparison of LIX984® and non-conventional reagents as copper extractants," Developments in Mineral Processing, vol. 13, pp. C6-70-C6-76, 2000. Available at: https://doi.org/10.1016/s0167-4528(00)80049-6.
 N. Rice, "Recent developments and potential uses for carboxylic acid extractants—a review," Hydrometallurgy, vol. 3, pp. 111-133, 1978. Available at: https://doi.org/10.1016/0304-386x(78)90015-4.
Marye Mulugeta , Dessie Tibebe
 U. T. Un and S. E. Ocal, "Removal of heavy metals (Cd, Cu, Ni) by electrocoagulation," International Journal of Environmental Science and Development, vol. 6, p. 425, 2015.Available at: https://doi.org/10.7763/ijesd.2015.v6.630.
 E. Bazrafshan, A. Mahvi, S. Nasseri, A. Mesdaghinia, F. Vaezi, and S. Nazmara, "Removal of cadmium from industrial effluents by electrocoagulation process using iron electrodes," Journal of Environmental Health Science & Engineering, vol. 3, pp. 261-266, 2006.
 E. Bazrafshan, L. Mohammadi, A. Ansari-Moghaddam, and A. Mahvi, "Heavy metals removal from aqueous environments by electrocoagulation process-a systematic review," Journal of Environmental Health Science & Engineering, vol. 13, pp. 1-16, 2015.Available at: https://doi.org/10.1186/s40201-015-0233-8.
 Z. Gebre-Mariam and Z. Desta, "The chemical composition of the effluent from Awassa textile factory and its effects on aquatic biota," SINET: Ethiopian Journal of Science, vol. 25, pp. 263-274, 2002.Available at: https://doi.org/10.4314/sinet.v25i2.18084.
 D. Diriba, S. Till, S. Feyera, V. P. Steven, and A. Hossein, "Environmental and health impacts of effluents from textile industries in Ethiopia: The case of Gelan and Dukem," Oromia Regional State College of Social Science and Humanities, vol. 189, pp. 11-18, 2008.
 L. Jihyun, H.-M. Kang, L.-H. Kim, and S.-O. Ko, "Removal of heavy metals by sawdust adsorption: Equilibrium and kinetic studies," Environmental Engineering Research, vol. 13, pp. 79-84, 2008.Available at: https://doi.org/10.4491/eer.2008.13.2.079.
 L. M. Beshir, "Determination of cadmium, chromium and lead from industrial wastewater in Kombolcha Town, Ethiopia Using FAAS," Journal of Environmental Analytical Chemistry, vol. 5, pp. 1-5, 2018.
 S. Solomon, C. Yadessa, T. Girma, and F. Daniel, "Heavy metal concentrations and physicochemical characteristics of effluent along the discharge route from Hawassa textile factory, Ethiopia," Journal of Environmental & Analytical Toxicology, vol. 5, pp. 1-7, 2015.
 Ethiopian Environmental Protection Authority, Provisional standards for industrial pollution control in Ethiopia. Addis Ababa, Ethiopia: Prepared Under the Ecologically Sustainable Industrial Development (ESID) Project -US/ETH/99/068/Ehiopia, EPA/UNIDO, 2003.