2results about How to "Continuous and stable release" patented technology

A water-reducing agent for coal-based solid waste concrete and its preparation method are disclosed. The water-reducing agent comprises 40-60 parts of a polycarboxylate-based main agent, 15-25 parts of a slump retainer, 10-20 parts of a crack-resistant reinforcing agent, 5-10 parts of a dispersing agent, 2-5 parts of a stabilizer, and 10-20 parts of deionized water. The slump retainer is a modified polyetheramine prepared by block copolymerization of ethylenediamine with ethylene oxide and propylene oxide; the crack-resistant reinforcing agent is a composite of nano-calcium carbonate and modified lignin sulfonate. This invention reduces the adsorption loss of the water-reducing agent by coal-based solid waste particles through the synergistic effect of the polycarboxylate-based main agent and the modified polyetheramine slump retainer, achieving a slump loss rate of ≤15% after 2 hours. The nano-calcium carbonate fills interfacial voids, and the modified lignin sulfonate alleviates hydration thermal stress, resulting in a lower 28-day drying shrinkage rate and higher crack resistance of the concrete. This invention solves the problems of poor adaptability, short slump retention time, and insufficient crack resistance of traditional water-reducing agents in high-volume coal-based solid waste concrete.

This invention discloses a zoned permeable reactive barrier (PRB) for groundwater denitrification using a combination of zero-valent iron / slow-release carbon and zeolite, and its operating process. The PRB's structure comprises: (1) a quartz sand water distribution zone; (2) Fe... 0 / C-Denitrifying bacteria reaction zone; (3) Zeolite adsorption zone. This invention uses a mixture of biomass slow-release carbon and artificial slow-release carbon as a slow-release carbon source, and adds zero-valent iron to construct Fe 0 The / C system, using a mixed denitrifying bacteria agent for rapid start-up, and a zoned permeable reactive barrier (PRB) operation process for groundwater denitrification have been developed. This includes: filling processes based on different media permeability coefficients, reaction zone packing material compatibility based on different slow-release rates, and operating parameters based on different groundwater nitrogen pollutant concentrations. This invention improves the adaptability of the PRB process to hydrogeological conditions, accelerates the start-up of the denitrification process, ensures denitrification effectiveness during the start-up phase, improves denitrification efficiency during operation, and extends remediation time.