Pressure vessels are used to pump water through treatment plants. One of the most important inventions in the history of water treatment was the continuously pressurized water system, which kept water flowing continuously as opposed to in regular intervals. A new pressure vessel invention has to store pressurized water more efficiently than anything on the market today. One idea is to design materials for a pressure vessel that can withstand more pressure than anything currently on the market. This would require testing different materials to see how much pressure they can take per square inch.
Water quality checkers are used in water treatment plants to check for the presence of different particles in water. Different devices serve different purposes. For example, some devices can measure the total number of particles in a water sample, while others measure electrical conductivity in a water sample. An invention in particle measurement would either measure something that cannot currently be measured, or measure more different types of particles than any current device measures. One idea is a quality checker that measures water quality holistically, using an algorithm to identify which particles are dangerous to humans.
Particle removal is the key challenge of water treatment. Water treatment plants typically use several machines to remove different types of particles from water. One obvious invention for particle removal would be a single machine that can remove all types of unwanted particles. This machine would need to employ several different filters, since contaminant particles come in all shapes and sizes.
Water treatment systems use disinfectants to cleanse water of known pathogens. The disinfection process involves introducing chemicals to the water that will kill pathogens from fecal matter and other sources, and then filtering out these chemicals. A possible invention in disinfection is a chemical compound that can be used to kill all known contaminants, from fecal bacteria to e. coli bacteria. This compound would need to disrupt the chemical structures of pathogenic microorganisms, so much so that it could be used against all known water-based pathogens. It would likely be a chlorine compound, since these compounds are known for strong disinfectant properties.