Paper industry USES wood, straw, reed, rags and other raw materials, through high temperature and high pressure cooking and separation of cellulose, pulp. In the production process, the non – cellulose part of the final discharge of raw materials into paper black liquor. Black liquor contains lignin, cellulose, volatile organic acid and so on, smelly, pollution is very strong.
Superconducting high gradient magnetism
High gradient magnetic separation and purification technology is a new method for wastewater treatment. Because it does not produce impurities such as flocs, it is feasible to treat a large amount of wastewater in a short time.
Scientists from the department of energy and environmental engineering, Osaka university, Japan, studied the use of magnetic separation system to treat waste water from papermaking plants. The treatment of papermaking wastewater in the test workshop was 2000 t/d, and the chemical oxygen demand (CODCr) in the water was <40 mg/L after the magnetic separation. Superconducting magnetic tube NbTi helical tube length 680 mm, inner diameter 400 mm.
The system is mainly composed of mixing tank (magnetic seed tank for organic matter, pulp and dye), precipitation tank and superconducting magnetic tube. The magnetic particles and organic polymers, such as pulp and pigment, are captured by the superconducting magnetic force in the separation tube, and the magnetic staple fiber and filler are floatated. A part of the magnetic staple fiber and filler is deposited in the sedimentation tank through the action of gravity sedimentation, which helps to reduce the amount of staple fiber and filler when circulating water passes through the magnetic tube. The system has been running successfully for several months with satisfactory results.
Papermaking wastewater treatment
Papermaking wastewater mainly comes from pulp and paper production in papermaking industry. Pulping is the separation of fibers from plant materials to make pulp, and then bleaching, this process will produce a lot of paper wastewater; Paper is the pulp dilution, molding, pressing, drying, into paper, this process is also easy to produce paper wastewater.
The paper wastewater from pulping is the most polluted. When washing pulp, the discharged wastewater is dark brown, known as black water. The concentration of pollutants in black water is very high. BOD is as high as 5-40g /L, which contains a large number of fibers, inorganic salts and pigments. The paper wastewater from bleaching process also contains a lot of acid and alkali substances. The papermaking wastewater discharged by the papermaking machine is called white water, which contains a large number of fibers and fillers and colloids added in the production process.
Papermaking wastewater treatment should focus on improving recycling water use rate, reducing water consumption and wastewater discharge, and actively explore various reliable, economical and useful wastewater treatment methods that can make full use of the useful resources in wastewater. For example, flotation wastewater treatment method can recover fibrous solid substances in white water, with a recovery rate of up to 95%, and the clarified water can be reused. The combustion wastewater treatment method can recover sodium hydroxide, sodium sulphide, sodium sulfate and other sodium salts combined with organic matter in black water. The pH value of wastewater is regulated by neutralization wastewater treatment. The suspended solids in wastewater can be removed by coagulation precipitation or flotation. Decolorization by chemical precipitation; Biological treatment method can remove BOD and is more effective for kraft wastewater. Wet oxidation treatment of pulp sulphuric acid wastewater is more successful. In addition, reverse osmosis, ultrafiltration, electrodialysis and other wastewater treatment methods have been used at home and abroad.
Suitable for paper pump.
Papermaking pump is imported energy-saving non-clog sewage pump, organize the unit technology development, and various performance standard are reaching or higher than the domestic and foreign similar products technology, because of single channel impeller, adopt unique sealing adopts two sets of special material of carbide mechanical seal device type line, with no jam, durable, accurate, use convenient, high efficiency, energy saving significantly, is our country pumps upgrading of new products, welcomed by users. The pump has a variety of models and different types of structure available for selection. Pump by motor and pump two parts, the two through the oil isolation room and mechanical seal components separated, mechanical and electrical integration products, motor and pump with the same shaft (rotor) the entire pump length is short, compact structure.