Cd²+-Adsorption Properties in Wastewater of Composite Modified Maifan Stone

Abstract

A new kind of Cd 2+ adsorption material was prepared using maifan stone by composite modification with chemical and heat treatment methods. The modified maifan stones were characterized by SEM and EDS. Effects of the modified maifan stone content, contact time and the initial pH of the solution on the adsorption of Cd 2+ were studied. The research results show as follows: 1) The composite modified maifan stone was prepared with heat treatment for 1 h at 340 ℃ after the chemical dipping for 24 h with 2 mol/L CaCl 2 solutions; 2) The composite modified maifan stone had even more obvious poor porosity holes and more contact area for ion exchange and adsorption of Cd 2+ ; 3)In the condition of the initial Cd 2+ concentration=50 mg/L, the maifan stone content=50 g/L, the contact time=40 min and pH=8, the adsorption of Cd 2+ was up to 87.6 %. Keywords-water treatment; cadmium ion pollution; adsorption; water purification material; maifan stone I.Supported by the national key disciplines (cultivation) construction project of mineralogy, petrology and mineral deposit geology (No.SZD0407) 978-1-4244-4713-8/10/$25.00 ©2010 IEEE

Preparation and Electromagnetic Shielding Effectiveness of a New Kind of Electromagnetic Shielding Composite Coatings

“…2 showed that when the content of Ni-Cu-coated glass fibers was less than 6 wt %, the coating resistivity decreased significantly as the amount of the fibers was added; when the fiber content reached 6 wt %, the resistance of the coating had a minimum value; and continue to increase the fiber content, the resistivity of coating increased. This is because the conductivity of the coatings mainly depends on the fillers and polymer binders together form the close-grained degree of the electrical conductivity of the network at this point [8]. So, the appropriate adding amount of Ni-Cu-coated glass fibers was 6 wt %, the composite coating resistivity had a minimum value of 1.13 cm ⋅ Ω .…”

“…Table 1 1 showed that the shielding effectiveness of the coatings containing 6 wt% Ni-Cu-coated glass fibers had dramatically increased. This was because the completeness and closely knit degree of the conductivity network in the coatings achieved the best when the mass fraction of Ni-Cu-coated glass fibers reaches a critical value [8]. The close electrical conductivity network of the shielding coatings significantly improved the attenuation degree of the incident electromagnetic wave energy to enhance the shielding effectiveness.…”

“…But because of the traditional glass fiber reinforced brittle and poor wear resistance and electric conductivity, these restrict to a certain extent the application range of the glass fiber. As a new surface-treatment method, electroless Ni-Cu plating is a simple, effective and low-cost method and is commonly used to make surface metallized materials with good conducting and magnetic-inductive properties [6][7][8]. In order to improve the conductive performance of glass fiber and to enlarge the use of glass fiber, the research team developed a new kind of nickel-copper-coated glass fiber using glass fiber as substrate and by chemical plating technology.…”