Abstract: Disclosed is a process for clarifying an algae-laden waste water stream wherein the waste water stream is deaerated and passed through a substantially light-free environment before coagulating aids are added to the water stream and the water stream is clarified in a coagulated solids settling step. The deaeration and light-free travel allow the algae to be more easily settled.

Abstract: This is a process for recovering bromine from a waste liquid formed in the production of an aniline derivative by ammonolysis of a nuclear substituted bromobenzene derivative with a halogen atom or a functional group. The waste liquid is first subjected to chlorine treatment in alkaline region to remove most part of ammonia and aniline derivatives, and then it is subjected to chlorine treatment in acidic region to recover bromine. The process does not involve danger of explosion accidents and can be smoothly operated.

Abstract: Ground water containing ferrous compounds is first treated with aluminum sulfate before aeration followed by lime addition after aeration to produce an iron-aluminum sludge possessing an oxidative capacity. Portions of the sludge are recycled back to utilize the oxidative capacity of the sludge. Chlorine is added after the oxidative capacity of the sludge has been utilized. An improved oxidation and removal of iron is obtained, yielding a treated water low in iron content with decreased requirements for chlorine.

Abstract: In a process for the treatment of water with ozone a partial current of treated water is contacted under pressure in a packed column with an oxygen-ozone mixture from an ozonizer to oxidize water contaminants and to improve their flocculation. The portion of oxygen which has not dissolved in the water in the packed column is recycled into the ozonizer and the treated partial water current is mixed again with water to be treated. The pressure in the column is adjusted in dependence on the nitrogen content of the water to be treated. By this measure is ensured that the quantity of nitrogen escaping from the water and contained in the cycle oxygen permits an optimum operation of the ozonizer. The nitrogen content in the cycle oxygen is preferably kept below 10% by volume.

Abstract: Water containing dissolved compounds is preheated, and is then pressurized in stages of water pressure, while receiving a quantum of steam. Scale-forming compounds in the water are thermally precipitated, and clarified post-thermal water is formed. This is flash vaporized in stages corresponding to the stages of water pressure, and the flashed vapors are compressed to form each said quantum of steam. Alternately, the flashed vapors themselves comprise each said quantum of steam, by being induced into the water as it flows through an eductor means. Flash-cooled, post-thermal water, substantially devoid of scale-forming compounds, is employed as such, or more generally is evaporated to form fresh water and an end concentrate of dissolved compounds.