FIELD: wastewater treatment.
SUBSTANCE: invention relates to a method for fractional separation of valuable substances from aqueous multicomponent mixtures, such as wastewater, sediments and sewage sludge, under supercritical conditions. The invention also includes fractions of valuable substances that are enriched by the method in accordance with the invention, in particular phosphorus-containing, as well as phosphorus- and ammonium-containing compounds, such as fertilizers and synthesis gas, as an energy source and as a valuable substance for the chemical industry. The invention includes devices for the implementation of these methods. The method for fractional separation of valuable substances from an aqueous multicomponent mixture includes compression of an aqueous multicomponent mixture to 25-35 MPa, heating of a compressed aqueous multicomponent mixture to 200-300°C and removal of the first fraction (41) of a valuable substance in which solids are enriched, further heating of a compressed aqueous multicomponent mixture to 300-400°C and removal of the second fraction (42) of a valuable substance in which metal salts are enriched, further heating of the compressed aqueous multicomponent mixture to 400-550°C and removal of the third fraction (43) of the valuable substance, in which phosphate and ammonium are enriched. The device according to the first variant for implementing the method contains a storage tank (1) for receiving an aqueous multicomponent mixture, a feed line (12) for directing an aqueous multicomponent mixture, a cutting device (2) for grinding components of an aqueous multicomponent mixture, a pump (3) for compressing an aqueous multicomponent mixture, at least three heat exchangers (4) for heating a compressed aqueous multicomponent mixture in at least three stages up to 550°C, at least three separators (5) for separating the first-third fractions’ (41), (42), (43) valuable substances, valves (6) for separating fractions of valuable substances, a pump (3) and a line (18) for supplying a precipitating agent for adding a precipitating agent (32) to the third separator (5). The device according to the second variant for implementing the method contains a storage tank (1), a feed line (12) connected to the storage tank (1) for transporting an aqueous multicomponent mixture with the exclusion of oxygen, the pump (3) connected to the feed line (12) for compressing raw materials (31) to 25-35 MPa and the direction of the feed line (12) through a heat exchanger (4) for heating compressed feed materials (31) to 200-300°C and the subsequent direction of the feed line (12) through a separator (5) for separating the first isolated fraction (41) of a valuable substance, the direction of the feed line (12) through the second heat exchanger (4) to heat the compressed feedstock (31) to 300-400°C and the subsequent direction of the feed line (12) through the second separator (5) to separate the second separated fraction (42) of the valuable substance, the direction of the feed line (12) through the third heat exchanger (4) to heat the compressed feedstock (31) to 400-550°C and the subsequent direction of the feed line (12) through the third separator (5) to separate the third separated fraction (43) of the valuable substance. By means of a method and devices in accordance with the invention, valuable substances can be completely extracted from waste, sediment and sewage sludge and provided for new use.
EFFECT: these methods and devices are suitable for the extraction of phosphorus and ammonium in the form of fertilizers available to plants, the extraction of metals and heavy metals, the production of synthesis gas and the extraction of hydrogen from synthesis gas, for example, for portability.
22 cl, 3 dwg
