Package Plant for Wastewater Treatment

Package Plant generally refers to a pre-engineered treatment plant made to serve medium sized communities and small-scale industrial areas. The capacity for the plant design can be as high as 3000 cubic meters per day while there are some smaller package plants with capacity that go as low as 50 cubic meters per day. Provided that it is well maintained and the wastewater amount doesn’t go beyond the treatment capacity, it should be able to its function as per requirement providing satisfactory results.

There are basically few different types of commonly employed package plants. The most commonly in use is the Extended Aeration type whereby it has all the typical schematic configuration of a normal wastewater plant like the aerobic digester, secondary sedimentation and aeration tank except that it doesn’t has the primary clarification. Overall, the aeration system should have sufficient agitation in order to keep the solids in suspension.

Rotating Biological Contactor type is another typical example of a standard package plant. It usually has a primary settling unit preceding the RBC system so that buildup of solids in the disk compartment can be avoided. For best performance, the unit should also has a proper cover to prevent complete wash off of the biological growth and to protect the whole setup from exposure to extreme weather conditions which can cause damage.

Contact Stabilization is another setup whereby the application is mostly towards treatment of wastewater in which the large percentage of BOD is contributed by suspended particles. The process is mainly used in package plants to reduce the volume of aeration tanks and also since the contact time is quite less, averaging only about 30 minutes, the system should be employed in conjunction with presence of an equalization facilities. As in all other wastewater treatment plants, it is best that the influent should first be subjected to grit removal in a Grit Chamber before going further forward to the next step.

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