Completely clear filtrate cannot be obtained using belt press filters except in rare circumstances. Thus further treatment may be required for the filtrate before it is reused or discharged as waste. If the filter is downstream of a clarifier or thickener the filtrate (and wash water) can be recycled back into the clarifier to reduce the required filtrate clarity and allows for the use of more durable cloths. If recycling or reuse is not an option the filtrate should be discharged subject to legislation and license requirements. Further treatment of clarified water (filtration or chemical treatment) may be required before discharge.
The filter cake usually has a high enough solid concentration to allow for all types of disposal methods without further treatment including recycling back into the process, landfill/composting and incineration. The polymer content makes filter cake from a belt press filter more suited to the aforementioned disposal methods than a cake conditioned with ferric chloride and lime which can occur with other dewatering processes.