▎ 摘　　要

NOVELTY - A composition comprises graphene quantum dots having a particle size of 2-20 nm, and a residue of a treatment compound covalently bonded to the graphene quantum dot. The treatment compound is effective for treating a water source. USE - Composition is used for treating water sources e.g. industrial water (claimed) wastewater, injectate, and recycled water. ADVANTAGE - The composition effectively measures chemical dosages and reduces at least 50% turbidity of wastewater. The graphene quantum dot has excellent dispersibility and compatibility in industrial water sources. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for determination of the concentration of a treatment compound in a water source, which involves applying a treatment composition to a water source to form a tagged water source, irradiating the tagged water source with a source of light having a wavelength (W1), and measuring the luminescent emission of the tagged water source at a wavelength (W2). The luminescent emission is measured along with irradiation. The quantum dot has a residue of the treatment compound covalently bonded to it. The concentration of the graphene quantum dot in the tagged water source is at least 0.1 weight ppb and the total concentration of the treatment composition in the tagged water source is 5-5000 weight ppm.