The scientists studied how bromate forms in water treated with ozone and ultraviolet light. They compared three methods: ozone alone, ozone with UV light, and ozone with vacuum UV light. They tested different pH levels, ozone amounts, and UV power levels. They found that ozone with vacuum UV light produced the least bromate. Increasing ozone amount and UV power led to more bromate formation. It was hard to remove both bromate and organic matter from the water at the same time.