探讨了自制重金属捕集絮凝剂ATX对铜离子的捕集机理,研究了其处理含铜离子废水的处理条件,并研究了其他物质和离子对铜离子去除效果的影响。研究结果表明,在p H 7~14范围内,快速搅拌时间2min,慢速搅拌3min,ATX对含铜离子的污水处理后其...探讨了自制重金属捕集絮凝剂ATX对铜离子的捕集机理,研究了其处理含铜离子废水的处理条件,并研究了其他物质和离子对铜离子去除效果的影响。研究结果表明,在p H 7~14范围内,快速搅拌时间2min,慢速搅拌3min,ATX对含铜离子的污水处理后其上清液中所含铜离子为0.64mg/L,对铜离子的去除率达到87.2%,完全达到国家排放标准。展开更多
The effects of Zn content on strength and wear performance of Al-12Si-3 Cu alloy synthesized by gravity casting were systematically investigated.The microstructure and mechanical properties of the alloys were evaluate...The effects of Zn content on strength and wear performance of Al-12Si-3 Cu alloy synthesized by gravity casting were systematically investigated.The microstructure and mechanical properties of the alloys were evaluated using OM,XRD,SEM as well as hardness,tension,compression and Charpy impact tests.Their dry sliding wear tests were carried out with a ball-on-disk tester.Microscopic examinations revealed that the microstructure of the base alloy consisted of theα(Al)dendrites,needle-type and coarse Si particles,and CuAl2(θ)phase.The addition of Zn to this alloy resulted in the formation ofα-solid solution phase and the increase of coarse Si particles.The hardness,yield,tensile and compressive strengths,elongation to fracture and impact toughness of the Al-12Si-3 Cu-Zn alloys increased with increasing Zn content,but tendency in the tensile and compressive strengths and ductility reversed after adding 1.5%-2%Zn.In addition,the friction coefficient and volume loss of the Al-12Si-3 Cu-Zn alloys decreased with increasing Zn content.The study showed that the addition of Zn to Al-12Si-3 Cu alloy can improve its potential applications as tribological material.展开更多
This work evaluated the complexation capacity, exchange constants and availability of micronutrients for plants and humic substances extracted from peat samples. Samples of humic substances extracted from two tropical...This work evaluated the complexation capacity, exchange constants and availability of micronutrients for plants and humic substances extracted from peat samples. Samples of humic substances extracted from two tropical peats （HS-P1 and HS-P2） were enriched with the micronutrients Cu（II）, Co（II）, Fe（II）, Mn（II）, Ni（II） and Zn（II） and the parameters for formation of the complexes （HS-N） were evaluated at different pH. The Scatchard model was used to calculate the maximum complexation capacity and the nutrient availability was studied using exchange capacity experiments based on ultrafiltration procedure. The optimum pH for complexation was 4.5 and the order of affinity was： Fe（II） 〉 Cu（II） 〉 Co（II） 〉 Mn（II） = Ni（II） 〉 Zn（II）. The maximum complexation capacity reached 56.8 mg·g-1 Fe of HS-P1 （the highest） and 1.7 mg.g1 Zn of HS-P2 （the slightest）. The exchange experiments showed that HS-P-Fe complexes were formed preferentially. The least stable complex was formed with Zn, which was therefore, more easily available. The results contribute to understand the behavior and availability of some nutrients in soils.展开更多
文摘探讨了自制重金属捕集絮凝剂ATX对铜离子的捕集机理,研究了其处理含铜离子废水的处理条件,并研究了其他物质和离子对铜离子去除效果的影响。研究结果表明,在p H 7~14范围内,快速搅拌时间2min,慢速搅拌3min,ATX对含铜离子的污水处理后其上清液中所含铜离子为0.64mg/L,对铜离子的去除率达到87.2%,完全达到国家排放标准。
文摘The effects of Zn content on strength and wear performance of Al-12Si-3 Cu alloy synthesized by gravity casting were systematically investigated.The microstructure and mechanical properties of the alloys were evaluated using OM,XRD,SEM as well as hardness,tension,compression and Charpy impact tests.Their dry sliding wear tests were carried out with a ball-on-disk tester.Microscopic examinations revealed that the microstructure of the base alloy consisted of theα(Al)dendrites,needle-type and coarse Si particles,and CuAl2(θ)phase.The addition of Zn to this alloy resulted in the formation ofα-solid solution phase and the increase of coarse Si particles.The hardness,yield,tensile and compressive strengths,elongation to fracture and impact toughness of the Al-12Si-3 Cu-Zn alloys increased with increasing Zn content,but tendency in the tensile and compressive strengths and ductility reversed after adding 1.5%-2%Zn.In addition,the friction coefficient and volume loss of the Al-12Si-3 Cu-Zn alloys decreased with increasing Zn content.The study showed that the addition of Zn to Al-12Si-3 Cu alloy can improve its potential applications as tribological material.
文摘This work evaluated the complexation capacity, exchange constants and availability of micronutrients for plants and humic substances extracted from peat samples. Samples of humic substances extracted from two tropical peats （HS-P1 and HS-P2） were enriched with the micronutrients Cu（II）, Co（II）, Fe（II）, Mn（II）, Ni（II） and Zn（II） and the parameters for formation of the complexes （HS-N） were evaluated at different pH. The Scatchard model was used to calculate the maximum complexation capacity and the nutrient availability was studied using exchange capacity experiments based on ultrafiltration procedure. The optimum pH for complexation was 4.5 and the order of affinity was： Fe（II） 〉 Cu（II） 〉 Co（II） 〉 Mn（II） = Ni（II） 〉 Zn（II）. The maximum complexation capacity reached 56.8 mg·g-1 Fe of HS-P1 （the highest） and 1.7 mg.g1 Zn of HS-P2 （the slightest）. The exchange experiments showed that HS-P-Fe complexes were formed preferentially. The least stable complex was formed with Zn, which was therefore, more easily available. The results contribute to understand the behavior and availability of some nutrients in soils.
