CARPATHIAN JOURNAL OF EARTH AND ENVIRONMENTAL SCIENCES, vol.9, no.1, pp.69-80, 2013 (Journal Indexed in SCI Expanded)
The presence of heavy metals in wastewater is major concern of public health and environment. Industrial wastewaters usually contain high levels of heavy metals and treatment is needed before disposal, in order to avoid water pollution. Adsorption process is one of the most promising technologies in water pollution control in terms of low cost, simple design and operation. The most popular and widely used adsorbents in wastewater treatment applications have high cost; and unfortunately regeneration costs of these adsorbents limits their large-scale applications for the removal of metals. As a result, researchers started to look for alternative low-cost adsorbents utilizing natural material and industrial wastes. They were thought to use as a replacement for current costly methods of removing metals from aqueous solutions. In this study, the use of micritic limestone as low-cost adsorbent was investigated. From the results, the micritic limestone had the merits of high specific surface area, significant adsorption sites and functional groups. Copper-adsorption significantly depends on the pH, adsorbent dosage, temperature and contact time. The maximum adsorption capacity was 237.05 mg/g for 1 hour and 1 g dosage. The experimental investigation results show that powdered micritic limestone has a high level of copper ions adsorption capacity. Adsorption data was correlated with Langmuir and Freundlich isotherm models. It was found that Langmuir and Freundlich isotherms fitted well to the data. Consequently, it is determined that powdered micritic limestone can be successfully used for removing copper ions from aqueous solutions.