An innovative magnetic bar separator for removal of chromium ions in tanning wastewater

An innovative magnetic separator was designed to capture chromium ions in tanning wastewater through magnetic nanoparticles. The effect of Fe3O4 magnetic particle concentrations, magnetic bar spacing and liquid flow velocities on the capture efficiency of the magnetic separator on magnetic nanoparticles in a simulated system was investigated. When the concentration of the magnetic particles is less than 400mg/L, the flow velocity is lower than 18L/hr, and the spacing of the magnetic bar is less than 30mm, the capture efficiency of Fe3O4 magnetic nanoparticles could keep more than 99.4 % within 3h. The magnetic separator was applied to treat chromium-containing tanning wastewater. The initial chromium concentration of the wastewater is 127mg/L. The capture efficiency could keep 99.7 % during 5 h, the wastewater treatment capacity is 18 L/hr and the outlet Cr<0.5mg/L. Amino Fe3O4 can be regenerated and reused 9 times, the chromium capture rate is above 99.6 %, and the outlet Cr<0.5mg/L. The magnetic separator is suitable for large-scale heavy metal wastewater treatment.

Automated summary

A novel magnetic separator was designed to capture chromium ions in tanning wastewater using magnetic nanoparticles. The efficiency of the separator was investigated by studying the effects of Fe3O4 magnetic particle concentrations, magnetic bar spacing, and liquid flow velocities in a simulated system. The results showed that under certain conditions, the capture efficiency of the Fe3O4 magnetic nanoparticles could exceed 99.4%, making it suitable for large-scale heavy metal wastewater treatment.