I imagined taking control of a sewage treatment centre and having a building assembled that causes a vacuum that make the sewage boil at ambient temperatures. The dry sewage would then be sent to an incinerator to be burnt. The ashes of the burnt dry sewage would be a mixture of things gypsum, lime stone fragments, carbon powder and things like that.
The heavy insoluble fragments would be separated from the ashes and droped by the coast from drones. It would help small islands to form that could have wild gardens on them. The islands would help protect the coast during a storm. The rest of the burnt sewage would be mixed with sand and plastic to make bricks and concrete slabs.
This is a common thought I often have in my mind and it causes a peace inside of me.