Biological Problems Encountered in Water Supplies

Abstract

Although none of the organisms found in surface waters may be injurious to health, domestic water supplies must be free of such organisms, since they, or their by‐products, may interfere with filtration and cause customer complaints. The authors have compiled various reports and surveys and their results will be of interest to all concerned with water quality.

Notes and Comments—Analysis of Unaccounted‐for‐Water

“…Usually 5-50 mg/1 of C12 is adequate for iron bacterial destruction, but concentra tions over 100 mg/1 are used at times to control bacterial infestations in wells. 2 Another possible method which has been investigated is the use of biological control. Venosa attempted to use the bacterial para site Bdellevibrio bacteriovorus to control the growth of Sphaerotilus natans.…”

L’Etat des Ressources En Eau au Maghreb En 2009

“…En effet, l'accumulation des matières en suspension sur la surface et dans les pores contribue à réduire le seuil de coupure de la membrane. C'est dans ce sens que plusieurs études (Mackenthun et Keup, 1970 ;Narkis et Rebhun, 1975 ;Safe Drinking Water Committee et National Research Council, 1977 ;Kay et al, 1980) Les résultats obtenus montrent que la membrane PSf/PAA 89/11 permet d' éliminer totalement les matières organiques et inorganiques en suspension, alors que la membrane PSf/PAA 92/08 laisse passer une très petite quantité, surtout dans les premières étapes de la filtration. La différence de comportement est due essentiellement à la taille des pores et à la densité des charges membranaires.…”