Azo　dyes　are　very　resistant　to　light-induced　fading　and　biodegradation.　Existing　advanced　oxidative　pre-treatment　methods　based　on　the　generation　of　non-selective　radicals　cannot　efficiently　remove　these　dyes　from　wastewater　streams,　and　post-treatment　oxidative　dye　removal　is　problematic　because　it　may　leave　many　byproducts　with　unknown　toxicity　profiles　in　the　outgoing　water,　or　cause　expensive　complete　mineralization.　These　problems　could　potentially　be　overcome　by　combining　photocatalysis　and　biodegradation.　A　novel　visible-light-responsive　hybrid　dye　removal　agent　featuring　both　photocatalysts　(g-C3N4-P-25)　and　photosynthetic　bacteria　encapsulated　in　calcium　alginate　beads　was　prepared　by　self-assembly.　This　system　achieved　a　removal　efficiency　of　94%　for　the　dye　reactive　brilliant　red　X-3b　and　also　reduced　the　COD　of　synthetic　wastewater　samples　by　84.7%,　successfully　decolorized　synthetic　dye-contaminated　wastewater　and　reduced　its　COD,　demonstrating　the　advantages　of　combining　photocatalysis　and　biocatalysis　for　wastewater　purification.　The　composite　apparently　degrades　X-3b　by　initially　converting　the　dye　into　aniline　and　phenol　derivatives　whose　aryl　moieties　are　then　attacked　by　free　radicals　to　form　alkyl　derivatives,　preventing　the　accumulation　of　aromatic　hydrocarbons　that　might　suppress　microbial　activity.　These　alkyl　intermediates　are　finally　degraded　by　the　photosynthetic　bacteria.