Method and system for purifying liquid using waste heat

A method of purifying waste water, saline water, or sewage water, the method comprising:

• performing a first precipitation of foreign objects from the waste water, saline water, or sewage water by mixing the waste water, saline water, or sewage water with an anti-scalant agent in an inlet container of a filtering unit to form a liquid mixture, wherein the anti-scalant agent comprises one of a nitrate, a glycerin and a salt, and receiving the foreign objects in a waste container connected to the inlet container of the filtering unit as the foreign objects settle;
• heating the liquid mixture received from the inlet container to generate a stream of steam in concentric pipes connecting the inlet container and at least one steam container;
• trapping foreign objects from the stream of steam by directing the stream of steam obtained from the heated liquid mixture through louvers in the at least one steam container, the louvers creating a zig-zag path for the stream of steam to retard movement of the foreign objects and to trap the foreign objects;
• and
• condensing the steam of steam in an outer pipe of the concentric pipes to obtain purified water while applying a heat energy derived from the condensing to said heating the liquid mixture received from the inlet container.