Dear Rosemary,​ Thank you for ​your answer. Grey water is ​not available. ​My problem ​deals with an ​area where is ​no fresh water ​at all and the ​fresh one (from ​rains) is being ​expensive and ​used for ​cooking and ​drinking (if ​any surplus for ​washing). There ​is but a plenty ​of sea water. ​Instead of ​sending it back ​to the ocean (I ​consider it too)​ think if an ​active sludge ​process could ​be applied for ​such a "waste ​sea water" ​similarly like ​for sewage of ​fresh ​water, or the ​presence of ​salt unable ​it.

Published by Piotr Grzybowski, Ph.D. at Warsaw University of Technology

Dear Rosemary,​ Thank you for ​your answer. Grey water is ​not available. ​My problem ​deals with an ​area where is ​no fresh water ​at all and the ​fresh one (from ​rains) is being ​expensive and ​used for ​cooking and ​drinking (if ​any surplus for ​washing). There ​is but a plenty ​of sea water. ​Instead of ​sending it back ​to the ocean (I ​consider it too)​ think if an ​active sludge ​process could ​be applied for ​such a "waste ​sea water" ​similarly like ​for sewage of ​fresh ​water, or the ​presence of ​salt unable ​it.