Remediation and recycling of chromium from tannery wastewater using combined chemical-biological treatment system

Our findings indicate that the maximum Cr(III) precipitation (98%) was achieved using 2 g/100 mL of lime and 2 h of settling rate. On the other hand, microcosm columns using sand that was inoculated with induced culture (OD600 = 2.43) and flow rate (2 mL/min) gave the maximum recovery (99%) of Cr(VI). The experimental Cr(III) was successfully recycled in the tanning process and the experimental leathers showed comparable properties as same as the leathers tanned with commercial Cr(III). Thus, we concluded that using combined chemical-biological treatment system for Cr remediation from tanning wastewater together with recycling process for the recovered Cr(III) is a promising strategy for economic and environmental friendly tanning industry.