Methods for making activated carbon-supported transition metal-based nanoparticles include (a) impregnated activated carbon with at least one transition metal-containing compound, and (b) heating the impregnated activated carbon at a temperature and for a time sufficient to carbothermally reduce the transition metal-containing compound. Also disclosed are activated carbon-supported transition metal-based nanoparticles produced by such methods. Further disclosed are methods for treating water and waste streams that include contacting the water or waste streams with the activated carbon-supported transition metal-based nanoparticles.

Various embodiments provide methods for removing a PFC by concentration and separation. In an exemplary method, a PFC in an aqueous solution or in a mixed water-organic solvent solution can be adsorbed onto a surface of a floc generated by electroflocculation, to form sludge. The sludge containing the PFC can be centrifuged to separate the PFC from the sludge and to form a concentrated PFC solution. Eelectroflocculation provides a simple process that is easy to operate. Reaction conditions are mild. Energy consumption is low. Treatment effect is desirable, stable, and reliable. Industrial application can be easy to implement. Further, the centrifugal separation technology used for the harmless treatment of the generated PFC-containing sludge is novel and does not need to use chemicals. Further, dewatering of the sludge is achieved at the same time during the harmless treatment. The needed equipment is simple and can be automatically operated.

A magnetic filtration device (105) configured to entrap magnetically susceptible material and non-magnetically susceptible material. An array of magnetic columns (703, 704) of alternating north and south polarity are positioned within a plurality of chambers (308, 309) that direct the fluid flow in an extended flowpath through a magnetic field circuit created by the columns of magnets (703, 704). A separator flange (305) acts to entrap nonferrous particles for subsequent removal and isolation from a fluid network in which the device (105) maybe installed.

A device for preparing washing water, belonging to the technical field of electro-chemical and membrane filtration water treatment. The device comprises a water container which is respectively provided with a water inlet and a water outlet; at least one pair of a cathode and an anode are arranged within the water container; a water-permeable porous membrane is clamped between the coupled cathode and anode with no gaps, and the area of the inside of the water-permeable porous membrane opposite the cathode or the anode is smaller than the area of the inside of the cathode or the anode opposite the water-permeable porous membrane. The device can generate washing water which contains a large a number of ultra-micro bubbles and strong oxidation factors and has excellent reducibility.

A conditioning method for deep dewatering of sludge from municipal wastewater treatment plants is provided. The method includes following steps: firstly, concentrated sludge is conditioned with polyhexamethylene biguanide to form polyhexamethylene biguanide conditioned sludge, subsequently, a pupa shell powder slurry, formed by treating hermetia illucens pupae shells with sulfuric acid, is added to the polyhexamethylene biguanide conditioned sludge to form a combined pupa shell powder slurry-polyhexamethylene biguanide treated sludge, finally, polydimethyldiallylammonium chloride is added to obtain the conditioned sludge, after mechanical dewatering of this conditioned sludge, deeply dewatered sludge is obtained.