Environmental protection is being given more and more attention in whatever projects. Some corporation in the business of river and later cleaning has a main business is to make the polluted river and lake clean again. The method they are always using is the separate the solids out from the water step by step, then the produced water would be clean enough to flow back to the river or lake.
The dredging boat is the most used to get the slurry out from the bottom of the river or lake. That is the very first step. Then the slurry would be guided to a pool or tank. There a coarse screen would be located to separate the very large size is the slurry like the tree remains, beer cans and something else.
Then the treated slurry would be pumped into a solids and liquid separation system. Simpler than the oil gas drilling mud solids control system, the mud system is designed with the coarse shaker which is fixed with gap screens. As we know, the solid separation is a step by step procedure, after separation by the shaker screen, the slurry would also be fed to the desander unit and desilter unit. After treated by the desilter, the solids with size large than 20 microns would be removed out.
The separation procedure after the desilter is much difficult as the solids is really fine. The operator always need add flocculate agent into the slurry to make a flocculation block which could be easily separate out. A machine with name filter press is always be used to remove the flocculation block out from the slurry. The capacity of the filter press is really small, so, in one project, always several units filter press would be used. The mud cake out from the filter press would be very dry.
In general condition, after separation by the filter press, the water can be guide back to the river and lake.