Answer:
The correct option is;
Design sewer treatment plants
Step-by-step explanation:
Chemical engineers, also known as a process engineer, are involved in the design and development of cost beneficial ways of utilizing energy and materials which can mostly be established as a chemical manufacturing process
The chemical engineer works by applying scientific principles to resolve and provide amicable solutions to the production usage, disposal, and waste management, of chemical and other related materials
Chemical engineers conducts research into the usage of materials and production process.