The present invention relates to an exhaust gas purifying and heat recovering system and method for sludge treatment. The system comprises: a first heat exchange flow path including a first heat exchanger, and a second heat exchanger and a third heat exchanger arranged downstream of the first heat exchanger, a first heat exchange medium is circulated in the first heat exchange flow path, to heat process gas for sludge treatment in the first heat exchanger; a second purification and heat exchange flow path including a heat exchange tank containing a second liquid heat exchange medium, the exhaust gas after sludge treatment is discharged into the heat exchange tank; and a third dirty liquid separation flow path including a dirty liquid separation tank provided between a dirty of the heat exchange tank and a clean liquid inlet of the heat exchange tank, for separating the dirty liquid after purging the exhaust gas, and the separated liquid is again directed to the clean liquid inlet of the heat exchange tank.

Systems and processes for purifying and concentrating a liquid feed stream are disclosed. In the systems, the concentrated liquid output from the high pressure side of a reverse osmosis stage is used as the draw solution in the low pressure side of the reverse osmosis stage in a configuration called osmotically assisted reverse osmosis. This reduces the osmotic pressure differential across the membrane, permitting high solute concentrations to be obtained, hastening the purification of the liquid. Reduced system pressures are also obtained by arranging multiple osmotically assisted reverse osmosis stages in a cross-current arrangement. Overall system energy consumption is reduced compared to conventional thermal processes for high concentration streams.

Disclosed is a one-way pressure exchange device (1) for reverse osmosis desalination plants of the type comprising a pair of pumping circuits (2, 3) for pumping a low-pressure inflow of seawater in contact with another high-pressure inflow of reject brine. The device comprises: a first selector valve (11) for selecting an alternative inlet into the pumping circuits (2, 3), which is connected to an inlet collector (5) for collecting reject brine from the osmosis device (100); a second selector valve (12) for selecting an alternative outlet from the pumping circuits (2, 3), which is connected to an outlet collector (6) for collecting low-pressure reject brine for discharge to the sea; and retention valves (21, 22, 23, 24), wherein the phases of the first selector valve (11) and the second selector valve (12) are arranged crosswise.

Systems and methods for treating a raw wastewater feed stream using a low energy ejector, which works as a heat pump to increase the pressure and temperature of a two-phase distillate stream used, in part, to heat the raw wastewater feed stream. The systems and methods utilize heat from a liquid distillate stream and a concentrated liquid wastewater stream to pre-heat the raw wastewater feed stream and produce a liquid distillate product stream.

Described herein are systems and methods for the efficient desalination and electrolysis of water to form hydrogen and oxygen gas. The systems include a desalinator, an electrolyzer, and a coolant loop. The coolant loop transfers heat produced by the electrolyzer to the desalinator, thereby reducing the energy inputs required for the desalinator to function. The methods generally include desalinating water in a desalinator, electrolyzing the desalinated water, and transferring heat generated by the electrolyzing to the desalinator.

Disclosed is a method for the treatment and resource utilization of acidic organic wastewater, comprising: (1) performing activated sludge treatment on acidic organic wastewater; and (2) performing microalgae treatment on the acidic organic wastewater treated in step (1). By means of the combination of activated sludge treatment and microalgae treatment, the present invention can significantly reduce the COD of the acidic organic wastewater. In some embodiments, the use of acclimated activated sludge or activated sludge having a specific microbial flora structure can not only improve the treatment efficiency while shortening the treatment time, but also omit a pH value adjustment step without causing sludge accumulation.

A system for recovering ammonia from an ammonia-containing liquid, which system comprises a waste tank (10) for receiving ammonia-containing liquid entering the system; a filtration unit (14) comprising an ultrafiltration unit for receiving the ammonia-containing liquid from the waste tank (10) and filtering the ammonia-containing liquid to remove solids; an ammonia concentrating unit comprising a reverse osmosis unit (18) for receiving ammonia-containing liquid from the filtration unit (14) and concentrating the ammonia within the liquid; and an ammonia-recovery unit (100) for receiving concentrated ammonia-containing liquid from the ammonia concentrating unit (18) and recovering ammonia therefrom, wherein the ammonia-recovery unit (100) comprises a rectifier (102) for separating ammonia from the concentrated ammonia-containing liquid and recovering the ammonia as ammonia-containing gas; and wherein the system does not comprise an ammonia stripper.

A water vending apparatus is disclosed. The water vending system includes a water vapor distillation apparatus and a dispensing device. The dispensing device is in fluid communication with the fluid vapor distillation apparatus and the product water from the fluid vapor distillation apparatus is dispensed by the dispensing device.

A method of operating a pressure-retarded osmosis plant, the plant comprising at least one osmosis element having a semi-permeable membrane, the semi-permeable membrane defining a feed side and a permeate side of the osmosis element, the method comprising, in a first mode of operation, supplying a feed stream having a relatively high concentration of solute to the feed side, supplying a permeate stream having a relatively low concentration of solute to an inlet of the permeate side, and receiving a feed outlet stream from the feed side wherein permeate has passed through the semi-permeable membrane from the permeate side to the feed side, in a second mode of operation, supplying a backwash stream having a relatively low concentration to the feed side of the osmosis element such that water passes through the semi-permeable membrane, and receiving a permeate outlet stream from an outlet of the permeate side, the method further comprising alternately performing the first mode of operation, to perform a production step, and performing the second mode of operation, to reduce fouling of the semi-permeable membrane.

A method including anaerobically biotreating an anaerobic biotreatment feed comprising wastewater to produce an anaerobically biotreated product, and aerobically biotreating an aerobic biotreatment feed comprising wastewater to produce a treated water, wherein the anaerobic biotreatment feed, the aerobic biotreatment feed, or both comprise wastewater from a POSM process. A method including producing, via an incinerator/boiler combination operated without utilizing a refractory lining and via dry technology and, a flue gas and steam from an incinerator feed comprising wastewater, and producing a treated water by biotreating a biotreatment feed comprising wastewater, wherein the incinerator feed, the biotreatment feed, or both comprise wastewater from a POSM process. Systems for carrying out the method are also provided.