The evaluation of low‐cost biosorbents for removal of an azo dye from aqueous solution

There is a need to develop innovative and alternative technologies that can remove dyes from wastewater. In this study, low‐cost and locally available two renewable biosorbents (cotton stalk and apricot seed) were investigated to remove of Astrazone Black from aqueous solution. The effects of various experimental parameters such as dye concentration, adsorbent amount, adsorbent particle size and initial pH were tested, and optimal experimental conditions were examined. The results showed that as the amount of adsorbent was increased, the percentage of dye removal increased accordingly. The ratios of dye sorbed increased as the adsorbent particle size decreased. In addition, antibacterial effect of untreated and treated (decolourized) dye on a soil bacterium, Pseudomonas aeruginosa, was determined. The removal of this dye with agricultural wastes reduced the toxic effect on P. aeruginosa. This reduction in toxic effect is important both in respect of environmental biotechnology and waste detoxification.     

Boron pollution in the Simav River,Turkey and various methods of boron removal

The present study was undertaken to investigate various methods for boron removal from the drainage waters of the Bigadic boron mines of Turkey. α-Cellulose, magnesium oxide and boron-specific resin Amberlite IRA-743 (Rohm & Haas Co.) were selected for the present work. Experimental results show that both the adsorption method using magnesium oxide and the ion-exchange operations are effective in removing boron from the drainage waters. Cellulose as an adsorbent has a minimum efficiency. MgO can be used effectively at a Mg/B mol ratio of 20 for three cleaning cycles with 85% removal efficiency but must be discharged and refreshed after the third cycle. Consumption of 18,100 tons of MgO per year in the removal system makes this process uneconomical. Boron-specific resin Amberlite IRA-743 in free-amine form is also uneconomical due to expensive regeneration steps. The capacity of this resin in salt-form was found to be 1.5 mg boron ml^?1 resin at 10% boron leakage and at a flow rate of 161 h^?1l^?1. The possibility of reuse of 90% of the regenerant and production of 4400 tons of boric acid in the removal system with salt-form boron-specific resin, compensate the annual cost of chemicals and also bring in some profit.