SBR中运用不同操作步骤去除生物营养

出水营养浓度：

为了达到满意的出水标准，最后操作的营养浓度标准及合适的操作更为重要。图３表明不同出水中的营养浓度。

表２中描述了各操作进水和出水中营养浓度和去除率。三步、四步和五步操作中出水COD浓度为28 mg L^-1。明显的，四步操作的COD的去除率最低。三步和五步操作同样受到出水标准的限制。出水三步操作NH₄-N的去除率最低(3.2 mg L^-1)。但是，出水五步操作NH₄-N的去除率最高(5.6 mg L^-1)。最后NH₄-N(0.9 mg L^-1)和PO₄-P的浓度(3.2 mg L^-1)明显低于其他操作。因此，运用五步操作明显优于其它操作。

五步操作中的营养浓度数据：

五步操作在10.5-h中的营养浓度COD, NH₄-N，NO₃-N和PO₄-P的数据见图４。COD浓度随着时间从632 mg L^-1最后降到37 mg L^-1。大多数COD是在最初的六小时期间降解的。最后两个操作过程中相对于COD，主要去除N和P。

NH₄-N在最初的2.5 h (an和ax阶段)保持不变，在第一个好氧阶段由于同化和硝化作用而明显下降。NH₄-N浓度在后两个过程中基本不变，操作在最后浓度为5.6 mg L^-1。

COD, NH₄-N，NO₃-N不同变化，说明了不同操作中的变化趋势。NO₃-N的降低是因为前两个阶段NO₃-N的反硝化作用，但是在第一好氧阶段由于NH₄-N的硝化作用而升高。在第二个间氧阶段，NO₃-N的反硝化使得NO₃-N浓度降到操作最后水平0.9 mg L^-1。

P的去除主要在厌氧和间氧阶段去除，因此PO₄-P在前两个操作阶段明显降低。但是在第一个和第二个好氧阶段有所上升。最后，PO₄-P浓度接近于3.2 mg L^-１低于比以前报道的7.4 mg L^-１。

结论：

在运用不同SBR操作步骤来实现从模拟废水中去除营养。三步－(An/Ax/Ox)、四步- (An/Ox/

Ax/Ox) 五步 (An/Ax/Ox/Ax/Ox)操作在不同的操作时间下，并对其去除结果进行测定和比较。对COD和 NH₄-N在不同的操作过程中进行比较，三步操作明显最好。这是因为大部分COD和 NH₄-N在最初的三个步骤中去除的。但是，PO₄-P和NO₃-N的去除效果，五步操作高于其他操作。反硝化作用发生在第二个间氧阶段，多余的P是在第二个好氧阶段吸收，NO₃-N和PO₄-P在五步操作中明显高。最后，五步操作包括An/Ax/Ox/Ax/Ox阶段，操作时间分别为1/1.5/4/1.5/2 h，COD，NH₄-N，NO₃-N和PO₄-P浓度降到37 mg L^-1，5.6 mg L^-1，0.9 mg L^-1 和 3.2 mg L^-1，去除了94%的COD、90%的NH₄-N、64%NO₃-N和PO₄-P57%。

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