Le traitement et le recyclage de l'eau dans les industries agro-alimentaires

Water treatment and recycling in the agricultural and food industries

D.E.S.T., Ingénieur C.N.A.M., Chef du Secteur Centre à l'Agence Financière de Bassin Seine-Normandie

Abstract

The contents of this paper relate to pollution control as envisaged in a law on water management adopted by French Parliament w.e.f. 16.12.64, implementation of which has taken the form of definite forms of action with a view to both quantitative and qualitative improvement of available water supplies. It is submitted with the following objects in view : - To examine the amount of pollution caused by effluent from agricultural and food factories in the Seine-Normandy region above Paris ; -To review the purification methods most frequently applied. The limitations, requirements and "trump cards" associated with factory positions in the considered region are described (especially in relation to local natural outlets), also how this policy stands with regard to the European market. Emphasis is laid upon the original features and limitations of the proposed pollution control methods, especially the following :-Recycling of water to reduce effluent discharge ; -Storage facilities ; -Natural self-cleaning action during storage (re-aeration). - Recent artificial re-aeration methods ; -Effluent-spreading methods. The basic role of natural self-purification is considered from the two following angles :- Reduction of effluent volume by recycling ; -Rational storage capacity management based on "modulation" of effluent discharge in keeping with water quality improvement during the year. Author concludes with a discussion of French Government contract clauses shortly to be agreed upon with the various sectors of the agricultural and food industry concerned, which lay down the main guidelines for pollution control policies to be applied in years to come.