Removal of Boron and Boron Compounds from Wastewaters

Boron is an essential micronutrient for plants and animals. However, it is harmful and poisonous in high doses. This study aimed to conduct studies to remove boron from the wastewater of Eti Mine Works using natural and modified adsorbents such as waste clays, zeolites, walnut shells, waste corn cobs and waste sunflowers. Firstly, adsorption studies were carried out with the wastewater taken from Emet boron operations directorate with waste clays obtained from Emet, Bandırma, Kırka, Bigadiç operations directorates and zeolite obtained from site of the Bigadiç operations directorate in a batch system of shaking, thermostat water bath. Adsorption studies were carried out using different amount of adsorbent, pH and particle size to determine the effects of these parameters on adsorption. The adsorption processes were found to be insufficient to remove boron from wastewater with high boron content as 5883 ppm using natural adsorbents. Therefore, it was decided to apply first chemical precipitation and then adsorption by using natural adsorbents. Secondly, it was aimed to eliminate high boron content in Espey Spring Water with high boron content in the Espey open pit site to improve the quality of irrigation water within the framework of social responsibility. Espey Spring Water’s initial boron value was 3810 ppm. After two-stage pre-treatment with lime, its boron value was 297 ppm (92% removal efficiency). Then, the adsorption studies were carried out at the same conditions as in the first part of this study using HCl modified almond shells as adsorbent. The optimum parameters reached were as 8 g of adsorbent, at pH 10, at 150 rpm mixing speed, at 25 ºC and at 4 hours contact time. The adsorption process consisting all these optimum parameters; 66.7% removal efficiency was reached. Almond shells were found to be effective adsorbents for boron removal from springs waters, having high boron content in the scope of social responsibility considering environment and living health. These results were found to be important from an economic perspective because of evaluating natural wastes, as almond shells, in the adsorption process for boron removal.