The effects of sulfate on the physical and chemical properties of actively treated acid mine drainage floc

被引:2
作者
Lenter C.M. [1 ]
McDonald Jr. L.M. [1 ]
Skousen J.G. [1 ]
Ziemkiewicz P.F. [2 ]
机构
[1] Div. of Plant and Soil Sciences, West Virginia Univ., Morgantown, WV 26506-6108
[2] National Mine Land Reclamation Ctr., West Virginia Univ.
关键词
Chemical treatment; Imhoff cone; Iron; Settling rate; Sludge; Water quality;
D O I
10.1007/s102300200032
中图分类号
学科分类号
摘要
It is important to consider floe properties when designing acid mine drainage treatment (AMD) systems. Relatively few studies have evaluated the effects of neutralizing base, neutralization pH, and sulfate in solution on floe properties in active treatment systems. We used NaOH and NH4OH as neutralizing bases, 0:1, 2.5:1, and 5:1 SO4:Fe molar ratios, and neutralization pH of 7, 8, and 9 in laboratory studies. Neutralizing cation, sulfate content, and neutralization pH had significant effects on floe mass and volume, but SO4:Fe ratio was the most important parameter. Settled floe volumes were slightly larger in the sodium system. Floe mass and volume both decreased with increasing pH. Floe generated in the presence of sulfate required significantly more time to reach a total suspended solids discharge limit of 70 mg L-1, had slower initial settling rates, and smaller settled volumes than floe generated without sulfate. The systems we studied were less complicated than actual AMD, but understanding the effects of sulfate, neutralizing cation, and neutralization pH on floc properties may help to design more efficient treatment systems. Choosing the appropriate treatment chemical and designing adequate pond sizes will ultimately increase treatment efficiency and improve stream water quality. © IMWA Springer-Verlag 2002.
引用
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页码:114 / 120
页数:6
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