Methods and systems for preventing biofouling of membranes utilized in water treatment processes (i.e., water treatment membranes) are described. Methods include X-ray excitation of luminescent materials capable of emitting in the violet to UV range (e.g., from about 180 nm to about 440 nm). X-rays are directed at water treatment modules to contact the luminescent materials within the modules and excite internal violet/UV to prevent biofouling of membranes. The methods can be utilized in conjunction with existing processing equipment and can prevent biofouling of water treatment membranes in high volume treatment processes in an environmentally friendly fashion.