PROJECT DESCRIPTION
BACKGROUND
The MEMCOR CMF process is based on microporous hollow fibre membranes which reject suspended solids, bacteria and viruses. The process is unique in that the retained contaminants are rejected from the soft membrane by a proprietary gas backwash. This backwash ensures the maintenance of filtration rates and final effluent quality. Feed to the system will be raw sewage from the villages of Aberporth and Tresaith and will be predominantly domestic in nature. This sewage is, at present, discharged untreated through short outfalls into Cardigan Bay. The technology is expected to treat effluent to a standard above that required by the EC Bathing Water Directive. Prior to the membrane process the raw feed must be treated to remove large solids and to reduce the suspended solids load; this will be achieved by a preliminary screening step and by a very compact lamella settling process. Settled sewage passes through the screen to the feed tank; screened effluent is then pumped to the microfiltration units. The feed flow passes through the microporous hollow fibres within each membrane module. Solids, bacteria, viruses and precipitated phosphorous are retained at the membrane wall whilst clean filtrate passes through to the centre of the fibres. The total filtrate flow then passes under gravity to the discharge point of the plant.