7 results about "SALT RETENTION" patented technology

The application relates to a high-flux positively charged acid-resistant nanofiltration membrane, a preparation method and application thereof. The preparation method comprises the following steps: immersing an ultrafiltration base membrane into a prepared aqueous phase solution to react, drying to obtain an ultrafiltration base membrane I; immersing the ultrafiltration base membrane I into an oil phase solution to react, obtaining an ultrafiltration base membrane II; and heat treating the ultrafiltration base membrane II to obtain the high-flux positively charged acid-resistant nanofiltration membrane. The nanofiltration membrane prepared by the application has the advantages of 100%-250% flux increase under the premise of ensuring acid resistance and salt retention rate, the preparation method is simple and easy to realize industrial production, and has wide application prospects; the high-flux positively charged acid-resistant nanofiltration membrane prepared by the application improves the retention rate of multivalent cations and the acid permeation rate.

The application discloses a ZIF-8-NH2 doped bridge organic silicon reverse osmosis membrane and a preparation method thereof. The membrane is prepared by doping ZIF-8-NH2 metal organic framework material into polymeric organic silicon sol, and forming a ZIF-8-NH2 / organic silicon hybrid membrane on the surface of a prefabricated ceramic support by a rubbing coating method. The ZIF-8-NH2 / bridge organic silicon membrane prepared by the application has high water permeability and high salt retention rate (NaCl retention rate is greater than 99.2%) in reverse osmosis desalination application, and the membrane structure is stable in the process of treating high-salt wastewater with TDS greater than 7 wt%.

The invention discloses a rhizosphere microbial agent putting control method for saline-alkali soil improvement, relates to the technical field of microbial agent putting control, and aims to solve the problem that the survival rate and improvement effect of microbial agents are reduced. The method comprises the following steps: extracting microbial agent data of different labeled species of rhizosphere microbial agents; evaluating salt tolerance indexes of the labeled species of rhizosphere microbial agents; performing equal-area division on a to-be-put region; detecting conductivity and calculating a water content index, adjusting division and labeling according to the water content index, detecting root system and height data of each division region, and calculating a salt retention index. During putting, the corresponding fungicide salt tolerance index and the salt retention index are called to calculate the putting blending proportion, the default putting amount is obtained, putting regulation and control are conducted on all the marked division areas in combination with the putting blending proportion, the survival rate and the improvement effect of the fungicide in the saline-alkali soil are improved, and putting accuracy, putting equalization and efficient resource utilization are achieved.

The application discloses a preparation method of a BaTiO3@CNTs composite nanofiltration membrane with high dielectric property, and belongs to the field of filtration membranes. The application aims at solving the problem that the water flux and salt retention rate of the existing commercial polyamide nanofiltration membrane are difficult to be simultaneously improved. In the application, high-dielectric barium titanate (BaTiO3) nanoparticles are loaded on the surface of carbon nanotubes (CNTs) to form a heterostructure, and then the heterostructure is embedded into a polyamide (PA) active layer to construct a nanofiltration membrane with high water flux, strong dielectric repulsion and stability. The design breaks through the limitation of single material modification, and cooperatively utilizes the rapid water channel effect of CNTs and the dielectric repulsion effect of BaTiO3, so that the selective separation performance for monovalent / divalent ions is significantly improved. The application is applied to low-cost desalination treatment suitable for high-salt brackish water.

The application discloses a method for cleaning the surface pollution of a polyamide composite membrane and simultaneously repairing the water flux and salt retention rate of the polyamide composite membrane, and the method comprises the following steps: step 1, under normal temperature conditions, immersing a polyamide composite membrane damaged by oxidation of active chlorine substances into a repairing solution, wherein the repairing solution is composed of a methoxyamine salt and a metal catalyst; the methoxyamine salt is one or a combination of two or more of methoxyamine hydrochloride, methoxyamine sulfate, methoxyamine phosphate, methoxyamine acetate, methoxyamine trifluoroacetate, methoxyamine formate, methoxyamine methanesulfonate, methoxyamine trifluoromethanesulfonate and methoxyamine p-toluenesulfonate; and step 2, after 2-5 hours of repairing, taking out the polyamide composite membrane and washing away the residual repairing solution with water. The method can clean and remove the inorganic scaling, organic matter and other pollutants on the surface of the polyamide composite membrane while repairing the water flux and salt retention rate of the polyamide membrane damaged by sodium hypochlorite oxidation.

The utility model relates to the technical field of water environment ecological restoration, in particular to a curtain type periphyton biofilm culturing device for improving nitrogen and phosphorus retention capacity of a small and micro water body, which comprises four support columns respectively arranged at two ends of two PVC (polyvinyl chloride) plastic steel rods, and a biofilm culturing component used for creating periphyton attachment conditions is arranged between the two PVC plastic steel rods. The film hanging assembly comprises a plurality of thin plastic steel rods which are arranged between the two PVC plastic steel rods at equal intervals, a plurality of nylon ropes which are distributed at equal intervals are further arranged on the two PVC plastic steel rods, and a plurality of suspension balls which are distributed at equal intervals penetrate through the nylon ropes. Compared with natural carriers in small rivers, river channels, lakes, reservoirs and ponds, the elastic biological filler is more beneficial to attachment of periphyton and increase of biomass, the contact probability of nutrient salts such as nitrogen and phosphorus in water and periphyton biological membranes is increased, the interaction between the nutrient salts and active sites of the biological membranes is enhanced, and the biomembrane activity is improved. The nutritive salt retention process is influenced, so that the nitrogen and phosphorus retention capacity of the surface water body is improved.

The application belongs to the technical field of reverse osmosis membrane in water desalination and purification, and discloses a high-flux reverse osmosis composite membrane and a preparation method thereof. The preparation method comprises the following steps: adding a monoamine with a non-planar flexible aliphatic ring structure to a m-phenylenediamine aqueous solution in an interfacial polymerization; on the basis of not changing the rigid main body crosslinking structure of a reverse osmosis membrane separation layer, a non-planar flexible ring structure is introduced, the chain segment arrangement of the membrane material is optimized at a molecular scale, a plurality of sub-nanometer free volumes formed in the membrane material are obtained, and a plurality of water transmission channels are created, so that the water permeation and salt retention of the reverse osmosis membrane are simultaneously improved. The preparation process of the reverse osmosis composite membrane provided by the application is simple, the continuity of the interfacial polymerization process can be maintained, the process is compatible with an industrial process, the cost is low, and the reverse osmosis composite membrane can be used in many fields such as seawater / brackish water desalination, pure water / ultra-pure water preparation, sewage purification and reclaimed water reuse.