The present application relates to a preparation method for recycling inorganic salt in printing and dyeing wastewater and comprises the following process steps: S1, performing impurity removal, softening, COD removal and decoloration on reverse osmosis (RO) membrane concentrated water to obtain pretreated wastewater; S2, performing two-stage electrodialysis on the wastewater obtained in step S1: returning fresh water obtained in a first-stage electrodialysis desalination chamber to a front end of the RO process, and taking saline water obtained in a concentration chamber as raw water of a second-stage electrodialysis desalination chamber and a second-stage electrodialysis concentration chamber; and returning the fresh water obtained by the second-stage electrodialysis desalination chamber to the first-stage electrodialysis concentration chamber; and S3, dealkalizing the concentrated saline water obtained in the step S2 and then adjusting the pH value to obtain concentrated saline water capable of being reused for cloth dyeing in a printing and dyeing mill.

Metal carbon and oxide nanocomposites prepared by a simple, low energy demanding, and high yield method are provided. The metal carbon nanocomposites can be prepared with or without a support such as silica, graphite, silicates, and zeolites. Both metal carbon and metal oxides nanocomposites are more efficient in catalytic reduction and oxidation of p-nitrophenol and azo dyes than other reported materials. They have high rate constants, number of catalytic cycles and catalytic turn over number (TON) compared to currently used materials.

The present application relates to a preparation method for recycling inorganic salt in printing and dyeing wastewater and comprises the following process steps: S1, performing impurity removal, softening, COD removal and decoloration on reverse osmosis (RO) membrane concentrated water to obtain pretreated wastewater; S2, performing two-stage electrodialysis on the wastewater obtained in step S1: returning fresh water obtained in a first-stage electrodialysis desalination chamber to a front end of the RO process, and taking saline water obtained in a concentration chamber as raw water of a second-stage electrodialysis desalination chamber and a second-stage electrodialysis concentration chamber; and returning the fresh water obtained by the second-stage electrodialysis desalination chamber to the first-stage electrodialysis concentration chamber; and S3, dealkalizing the concentrated saline water obtained in the step S2 and then adjusting the pH value to obtain concentrated saline water capable of being reused for cloth dyeing in a printing and dyeing mill.

An efficient photocatalyst nanocomposite comprising reduced graphene oxide, noble metal, and a metal oxide prepared by a one-step method that utilizes date seed extract as a reducing and nanoparticle determining size agent. The photocatalyst of the invention is a more effective sunlight photocatalyst than that prepared by traditional method in the photo decomposition of organic compounds in contaminated water.

The present disclosure provides a synthesis method of a g-C.sub.3N.sub.4/C composite material based on a hollyhock stalk, including the following steps: (1) pretreatment of hollyhock stalks; and (2) fabrication of the g-C.sub.3N.sub.4/C composite material. In this method, with the hollyhock stalk as a carbon skeleton, g-C.sub.3N.sub.4 is spread on a template surface to form a laminated layer, and a composite system with a special structure is constructed. Compared with pure phase g-C.sub.3N.sub.4, the composite material substantially increases specific surface area and has a clear interface; the carbon skeleton not only functions as a rigid support, but also increases the electron transfer efficiency of the composite material, thereby improving the separation efficiency of photogenerated carriers and the utilization rate of visible light. Raw materials used in the method are inexpensive and environmentally friendly, which can be used for industrial production and bulk production of eco-friendly materials for harnessing environmental organic pollutants.

An efficient photocatalyst nanocomposite comprising reduced graphene oxide, noble metal, and a metal oxide prepared by a one-step method that utilizes date seed extract as a reducing and nanoparticle determining size agent. The photocatalyst of the invention is a more effective sunlight photocatalyst than that prepared by traditional method in the photo decomposition of organic compounds in contaminated water.

Disclosed are a device and a method for advanced water treatment, and the device comprises a plate-and-frame membrane reactor having a water inlet pipe and a water outlet pipe, a raw water delivery system communicating with the water inlet pipe of the plate-and-frame membrane reactor, and a clear water reservoir communicating with the water outlet pipe of the plate-and-frame membrane reactor; the advanced water treatment device further comprises an oxidant dosing system communicating with the water inlet pipe of the plate-and-frame membrane reactor or the raw water delivery system, the plate-and-frame membrane reactor further comprises a carbon nano-material composite membrane, the carbon nano-material composite membrane comprises carbon nano-material layers sequentially disposed between the water inlet pipe and the water outlet pipe, and a base membrane layer supporting the carbon nano-material layers, and the raw material of the carbon nano-material layers comprises mono-layer reduced graphene oxide and multiwalled carbon nanotubes.

The invention relates to the field of industrial wastewater treatment, and particularly discloses a nanofiltration membrane for treating printing and dyeing wastewater and its preparation method. The preparation method comprises the following steps: S1, pouring an aqueous solution containing m-phenylenediamine, camphorsulfonic acid and triethylamine onto the surface of a polysulfone ultrafiltration membrane, setting still for 10 s to 30 s, and then removing the excess aqueous solution from the surface; S2, pouring an organic solution containing trimesoyl chloride and an interface auxiliary polymerization agent onto the surface of the membrane obtained in step S1, reacting for 5 s to 20 s, and then removing the excess solution from the surface; and S3, setting the membrane obtained in step S2 still and then carrying out heat treatment and water rinsing on the membrane in sequence, thus obtaining the nanofiltration membrane.

The present invention aims at improving the purification of sewage water in water treatment systems, by the use of enzymes. Thus a filter comprising enzymes and a method for producing said filter are provided, as well as the use of said filter, a module system for comprising said filter, and use of said module system.

The present disclosure relates to a conjugated polyelectrolyte-grafted membrane, which is obtained by fixing a conjugated polyelectrolyte (CPE) capable of generating active oxygen under visible light irradiation to a membrane through crosslinking, and can remove contaminants in water, while reducing bio-fouling on the surface of the membrane, by generating active oxygen through a photocatalytic reaction of the conjugated polyelectrolyte (CPE), as well as to a method for manufacturing the same. The method for manufacturing a conjugated polyelectrolyte-grafted membrane includes the steps of: preparing a conjugated polyelectrolyte (CPE); coating a conjugated polyelectrolyte (CPE) on the surface of a membrane; and carrying out crosslinking of the conjugated polyelectrolyte (CPE) with the surface of the membrane.