Low-cost Magnetic Seed For The Preparation Of Magnetic Fluid Using In The Treatment Of Printing And Dyeing Wastewater And High Gradient Magnetic Separation Technology

With the development and innovation of printing and dyeing technology, large quantities of printing and dyeing wastewater are discharged into our environment. This situation brings serious threat to humanity. While the printing and dyeing wastewater treatment technology has been a very good development, some of the current printing and dyeing wastewater treatment technology still exist of their respective deficiencies and shortcomings. For example, chemical coagulation and activated carbon adsorption, not only failed to eliminate organic pollutants completely and cost the chemical reagents, but also caused accumulation of waste and secondary pollution. Biological treatment method not only require substantial dilution water and long processing time, but also equipment covers an area of large and treatment effect is not satisfactory and so on.Magnetic separation is a new environmental protection technology, it has been widely used in water treatment. The magnetic fluid treatment of dyeing wastewater as a new printing and dyeing wastewater treatment technology, it has to deal with high efficiency, small size equipment, the advantages of simple structure, but high manufacturing cost of the magnetic fluid can not make the technology widely. Therefore, to reduce the cost of preparation of magnetic fluids is badly needed.In this study, precipitator dust selected from metalworking industries were used to preparative low-cost magnetic fluid. First of all, the impact of factors outside and experimental conditions were studied on the preparation of magnetic fluid in order to determine the process conditions of the preparation of stability magnetic fluid which was suitable for treat printing and dyeing wastewater. At the same time, the amount of magnetic fluid, pH, temperature, mixing time, the magnetic field strength, velocity and other factors were studied on the effect of printing and dyeing wastewater treatment, in order to determine the good process conditions.The main results of this research were as follows:1. Precipitator dust A, B and C were weight 48.5g, 34g, 20g, the amount of surfactant PEG-4000 were 2g, 3.5g and 2.75g, the value of pH was 11, then the better and stronger magnetic fluid could be prepared.2. The best dosages of Magnetic fluid A, B and C to deal with 100mL printing and dyeing wastewater were 6mL, 4mL and 5mL. The efficiency of wastewater treatment was better, and the CODcr removal efficiency was higher, the chroma reduced significantly.3. When the volume ratio of 60mg/mL of the magnetic fluid C to the printing and dyeing wastewater was 1:20, the concentration of PAC was 60mg/L, the velocity of flow was 50mL/min, the extra intensity of magnetic field was 2200 Gauss, the water leakage chroma and CODcr arrived the least, the data were 10 times and 156mg/L respectively.