Abdulkareem - Anwer: Biosorption of cadmium and lead using microalgae Spirulina sp. isolated from Koya city (Iraq) - 2657 - APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 18(2):2657-2668. http://www.aloki.hu ● ISSN 1589 1623 (Print) ● ISSN 1785 0037 (Online) DOI: http://dx.doi.org/10.15666/aeer/1802_26572668 © 2020, ALÖKI Kft., Budapest, Hungary BIOSORPTION OF CADMIUM AND LEAD USING MICROALGAE SPIRULINA SP. ISOLATED FROM KOYA CITY (IRAQ) ABDULKAREEM, P. M. 1* – ANWER, S. S. 2 1 Department of Biology, Health and Sciences Faculty, Koya University, Erbil, Iraq 2 Department of Clinical Biochemistry, College of Health Sciences, Hawler Medical University, Erbil, Iraq (phone: +964-750-494-3730) *Corresponding author e-mail: parween.mohsin@koyauniversity.org; phone: +964-750-441-2402 (Received 25 th Aug 2019; accepted 8 th Jan 2020) Abstract. The alternative to the traditional method for heavy metal uptake is biosorption. The potential of Spirulina sp. for biosorption of waste effluent was examined. In this study, morphology and molecular features of microalgae Spirulina sp. isolated from Koya city were identified on. The rate of biosorption of cadmium (Cd +2 ) and lead (Pb +2 ) were studied by using a spectrophotometer. The optimum uptake for both metals Cd +2 and Pb +2 showed at low metal concentration of 100 mgl -1 88.8% and 93.6%, respectively. Spirulina sp. showed the ability to remove metals at all pH values 38.1% and 85.8% for Cd +2 and 34.6% and 88.4% for the Pb +2 with maximum uptake at 30 °C 85.7% for Cd and Pb optimum uptake was 88.4%. Optimum removal showed at agitation rate 150 rpm 87.1) in Cd +2 , and Pb +2 optimum adsorption at 150 rpm was 89.9%. Both metals showed optimum adsorption at 1.5 g l -1 of algal biomass, Cd +2 removed 86.7%, and Pb +2 89.2%. Pb +2 showed the best performance for metal biosorption. Keywords: metal uptake, algal biomass, temperature, agitation rate, pH Introduction Microalgae include those chlorophyll-bearing organisms that are thalloid (Vashishta et al., 2002). Nearly 75% of algal species are microalgae that contribute 30-40% of oxygen to the atmosphere (Ponuswamy et al., 2013). They are the primary producers who switch water and carbon dioxide into carbohydrates and oxygen in the presence of the sun (Chisti, 2008). Microalgae biomass is often measured with a concentration of chlorophyll and can provide a useful index of potential production. Cadmium (Cd +2 ) is a chemical element that involves different machinery to induce its harmful effect on many biological activities in humans, animals, and various other organisms. In humans, the adverse effect of Cd +2 is not only limited to the kidney and bone, but it includes nearly every organ and tissue where it accumulates, which argues the need for public health measures aimed at reducing exposure. There are many ways in which this heavy metal can be suppressed in its activities, forming the prospect for reduced metal toxicity involving Cd +2 (Hogan, 2010; Sharma et al., 2015). Lead (Pb +2 ) is number two on the “Top 20 List” of toxic and hazardous substances of the ATSDR. Pb +2 accounts for the majority of pediatric heavy metal poisoning (Roberts, 1999). Pb +2 occurs in many forms worldwide in natural sources and is one of the most commonly and uniformly distributed trace metals (Jackson et al., 2005). Pb +2 creates several adverse effects in both males and females on the reproductive system. Common impacts shown in males involve decreased libido, unusual spermatogenesis (decreased motility and number), chromosomal harm, infertility, abnormal prostatic function, and