Carbon-modified titanium dioxide nanoparticles and the photocatalytic remediation of aqueous sources systems and methods thereof

A closed-loop system for remediation of an aqueous solution comprising a polychlorinated biphenyl, the system comprising:

• a vessel comprising an aqueous solution comprising a first amount of at least one polychlorinated biphenyl and carbon modified titanium dioxide nanoparticles having a Ti:C atomic ratio in the range of 3:1 to 6:1 and a bandgap in the range of 1.4-1.8 eV dispersed in the aqueous solution;
• a pump;
• a tray oriented at a tilt angle from the horizontal comprising a distributor end and an opposing collector end located at a lower vertical height than the distributor end;
• and
• wherein the vessel is configured to deliver the aqueous solution through the pump to the distributor end of the tray;
• wherein the tray is configured to flow the aqueous solution along the tray via entirely gravity from the distributor end to the collector end while exposing the aqueous solution to a light source thereby forming a remediated aqueous solution comprising a second amount of the at least one polychlorinated biphenyl;
• wherein the collector end is configured to return the remediated aqueous solution to the vessel;
• and
• wherein the first amount of the at least one polychlorinated biphenyl is greater than the second amount of the at least one polychlorinated biphenyl.