A process to produce an enrichment feed, said process comprising: (a) subjecting a solvent rich stream to a solids concentration zone to form a concentrated solvent rich stream; wherein said solvent rich stream comprises at least one solvent, at least one carboxylic acid, and at least one oxidation byproduct; wherein said solvent rich stream has a solids content of less than 5% by weight; wherein the quantity of solids in said concentrated solvent rich stream is higher than the quantity of solids from said solvent rich stream on a weight basis; (b) subjecting said concentrated solvent rich stream to a concentrated solid-liquid-separation zone to form a mother liquor stream and said enrichment feed; wherein said concentrated solid-liquid-separation zone comprises at least one solid liquid separation device; and (c) recycling at least a portion of said enrichment feed to any point in a TPA production process after a primary oxidation zone and before a drying zone: wherein said at least one carboxylic acid is terephthalic acid; and wherein the enrichment compound(s) of said enrichment feed comprises at least one compound selected from the group consisting of isophthalic acid, phthalic acid, benzene-tricarboxylic acid isomers, benzoic acid, hydroxybenzoic acid isomers, hydroxymethylbenzoic acid isomers, dicarboxybiphenyl isomers, dicarboxystilbene isomers, tricarboxybiphenyl isomers, tricarboxybenzophenone isomers, dicarboxybenzophenone isomers, dicarboxybenzil isomers, form-acet-hydroxybenzoic acid isomers, acet-hydroxymethylbenzoic acid isomers, a-bromo-toluic acid isomers, bromo-benzoic acid, bromo-acetic acid, tolualdehyde isomers, and phtalaldehyde isomers; wherein said solid liquid separation device is a candle filter, and wherein 5 % by weight of said enrichment feed is recycled such that an increase of b* in the TPA product is less than 2 compared to a TPA production process with no enrichment feed or wherein 10 % by weight of said enrichment feed is recycled such that an increase of b* in the TPA product is less than 4 compared to a TPA production process with no enrichment feed. (a) subjecting a solvent rich stream to a solids concentration zone to form a concentrated solvent rich stream; wherein said solvent rich stream comprises at least one solvent, at least one carboxylic acid, and at least one oxidation byproduct; wherein said solvent rich stream has a solids content of less than 5% by weight; wherein the quantity of solids in said concentrated solvent rich stream is higher than the quantity of solids from said solvent rich stream on a weight basis; (b) subjecting said concentrated solvent rich stream to a concentrated solid-liquid-separation zone to form a mother liquor stream and said enrichment feed; wherein said concentrated solid-liquid-separation zone comprises at least one solid liquid separation device; and (c) recycling at least a portion of said enrichment feed to any point in a TPA production process after a primary oxidation zone and before a drying zone: wherein said at least one carboxylic acid is terephthalic acid; and wherein the enrichment compound(s) of said enrichment feed comprises at least one compound selected from the group consisting of isophthalic acid, phthalic acid, benzene-tricarboxylic acid isomers, benzoic acid, hydroxybenzoic acid isomers, hydroxymethylbenzoic acid isomers, dicarboxybiphenyl isomers, dicarboxystilbene isomers, tricarboxybiphenyl isomers, tricarboxybenzophenone isomers, dicarboxybenzophenone isomers, dicarboxybenzil isomers, form-acet-hydroxybenzoic acid isomers, acet-hydroxymethylbenzoic acid isomers, a-bromo-toluic acid isomers, bromo-benzoic acid, bromo-acetic acid, tolualdehyde isomers, and phtalaldehyde isomers; wherein said solid liquid separation device is a candle filter, and wherein 5 % by weight of said enrichment feed is recycled such that an increase of b* in the TPA product is less than 2 compared to a TPA production process with no enrichment feed or wherein 10 % by weight of said enrichment feed is recycled such that an increase of b* in the TPA product is less than 4 compared to a TPA production process with no enrichment feed. wherein said at least one carboxylic acid is terephthalic acid; and wherein the enrichment compound(s) of said enrichment feed comprises at least one compound selected from the group consisting of isophthalic acid, phthalic acid, benzene-tricarboxylic acid isomers, benzoic acid, hydroxybenzoic acid isomers, hydroxymethylbenzoic acid isomers, dicarboxybiphenyl isomers, dicarboxystilbene isomers, tricarboxybiphenyl isomers, tricarboxybenzophenone isomers, dicarboxybenzophenone isomers, dicarboxybenzil isomers, form-acet-hydroxybenzoic acid isomers, acet-hydroxymethylbenzoic acid isomers, a-bromo-toluic acid isomers, bromo-benzoic acid, bromo-acetic acid, tolualdehyde isomers, and phtalaldehyde isomers; wherein said solid liquid separation device is a candle filter, and wherein 5 % by weight of said enrichment feed is recycled such that an increase of b* in the TPA product is less than 2 compared to a TPA production process with no enrichment feed or wherein 10 % by weight of said enrichment feed is recycled such that an increase of b* in the TPA product is less than 4 compared to a TPA production process with no enrichment feed.