Page 281 - Membranes for Industrial Wastewater Recovery and Re-Use

2 50 Menibrunes for bidustrial Wastewater Recowry and Re-use

Figure 5.14 CR mernbranes at Kirkniemi

fouling of suspended solids occurs. This has resulted in cleaning strategies based
on routine maintenance procedures rather than on demand and as such offers
the potential for further reductions in opex as confidence grows about the limits
of the system.

5.7 T. Forsell and Son: dyewaste water recycling plant (UK)

5.7.1 Background
Thomas Forsell and Son Ltd is a family owned and run textile mill founded in the
centre of Leicester in 1850, moving to South Wigston (south of the city) in 1963.
The main basis of the company is the production of dyed and spun woollen and
worsted yarns for the Ministry of Defence. Due to the need for the final product to
retain its colour over prolonged periods the dyes are often highly stable chemical
compounds which are poorly biodegradable. The dyes tend have poor fixation
properties with as much as 50% of the dye being passed to the effluent.
Traditionally, the textile house has discharged the effluent, including the dye, to
the sewer for downstream treatment at the local sewage works at South
Wigston. Dye removal through typical sewage works is low and so the final
effluent typically remains high in colour. In January 1996 the Environment
Agency imposed colour consents on Severn Trent discharges to the river Sense at
sewage works such as South Wigston STW (Table 5.8). The cost of upgrading
South Wigston to comply with the new consents was estimated at €1-2.5 mP3
($1.5 5-3.8 7 m-3). Consequently, Severn Trent passed these consents on to the