of the filter media. This will cause an increase in pressure drop of the system. In situations where the filter media is clogged and pressure drop continually increases it is common that waste particles and streams may seep through the zones within the cartridge and pass through the outlet stream resulting in no purification To minimize the effects of clogging and particle build-up a back flushing system must accommodate approximately 1-5% of the bulk flow as back flush, operating at approximately 6-8 bar. Beyond this range particulates may become fragmented making them difficult to be removed from the system, and potentially cause fluidization of the system. Post treatment systems and waste stream production The main purpose of a depth filter is to act as a clarifier, separating suspended solids from a bulk flow liquid stream and as a result is employed within the final stage of a separation process. By convention, depth filters consist of a single outlet stream of a purified liquid retaining the waste particles within its system. Due to its length it has greater residue holding capabilities than standard filters. In terms of a waste stream, often the outlet stream may be recycled into a subsequent filter in order to ensure that the stream is free from particulates. A waste stream may also be produced when cleaning the filter media as the water passes in the opposite direction residue caught within the filter media or media particles that have been displaced may emerge from the unit before it is adequately disposed. New developments With the ongoing advancements in process technologies, depth filters have been modified to improve its feasibility within a range of industrial sectors. References Filters