The value of water as a production factor
The availability of water for industrial production has been taken for granted for many years and in most countries . Climate change is putting an end to this . Even though water is still cheap compared to its value , it becomes precious as soon as production output is affected due to shortages .
The current situation : in many cases industrial effluents have to be treated before being discharged into the sewage system . Reusing water is often not economical for factories because the specific costs per cubic metre of treated wastewater is higher than for fresh water .
However , this calculation is not entirely correct for several reasons :
1 . Industrial effluents must be treated in any case , so these costs already exist . For a cost comparison with fresh water , only the additional costs to achieve the required water quality should be 48 FDPP - www . fdpp . co . uk
Reusing water is often not economical for factories because the specific costs per cubic metre of treated wastewater is higher than for fresh water .
considered , not the full treatment costs . To complete the picture , the risk of pro-duction losses due to water scarcity must also be taken into account .
2 . The quality of fresh water is often higher than what is really needed in production . Many production processes do not require potable water . It is also a waste to use potable water for sanitary purposes . Therefore , it may not even be necessary for a water recycling process to achieve potable water quality .
3 . Instead of an end-of-the-pipe full stream effluent treatment , it may be more economical to treat only single side streams . The treated effluent from one production line may be sufficient for another process or at least for cleaning trucks or for sanitation . This reduces the invest-ment costs for effluent treatment as well as the operation costs because the hydraulic load is reduced .
4 . Another side effect may be material recovery from treatment residues or concentrates . This may reduce material purchasing costs or become another source of income .
5 . Industrial effluent treatment and utilisation can be done with compact , customised side stream plants that offer all flexibility production lines and effluent characteristics demand for . Ideally , these plants are modular and can easily be extended as the production grows .
www . wehrle-env . co . uk