The influence of PAX-14 on activated sludge systems and in particular on Microthrix parvicella
The influence of PAX-14 on activated sludge systems and in particular on Microthrix parvicella
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DOI：
10.2166/wst.2002.0521
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发表时间：
2002-01-01
影响因子：
2.7
通讯作者：
Roelandt, F
中科院分区：
文献类型：
--
作者：
Roels, T;Dauwe, F;Roelandt, F
自欧盟指令271/91关于营养物去除的新要求以来，处理固体分离问题的废水处理厂（WWTP）的数量显著增加。在弗兰德斯，许多去除营养物的污水处理厂受到固体分离问题的影响，主要是由于微丝藻是最常见的优势物种。污水处理厂的固体分离问题，特别是因为Microthrix parvicella的剂量聚合氯化铝（PAX-14）对活性污泥的效果说明。在9个生产性污水处理厂中研究了PAX-14对微生物学和微丝菌形态的影响。PAX-14成功地降低了高SVI值，并控制了由Microthrix parvicella引起的发泡问题。实验室试验表明，PAX-14的剂量应小于150穆尔/L或7 g Al 3 +/kg MLSS。在高于250穆尔/L的剂量下，观察到游离细菌的增加和原生动物活性的降低。在全规模中，PAX-14的投加浓度为1.5至4.5 g Al 3 +/kg MLSS。在添加之前，混合液浮渣层（如果存在）应除去。根据我们的经验，给药应持续至少3周。在第一周，没有发生剧烈的变化。在第一周结束时，SS和SVI可能会增加。SVI和浮渣在10至15天后开始减少。在3至32周后，细丝的数量减少。微丝藻的形态特征发生变化，而其他丝状体如泥生念珠藻和诺卡氏菌的形态特征发生变化。没有问题.这项研究证明，PAX-14是有效的控制膨胀和泡沫问题，在污水处理厂时，他们是由于Microthrix parvicella。可以预测SVI何时降低以及何时应该停止添加。
The amount of wastewater treatment plants (WWTP) dealing with solid separation problems has significantly increased since the new requirements of the EU Directive 271/91 on nutrient removal. In Flanders a number of the nutrient removal WWTP are affected by solid separation problems mostly attributed to Microthrix parvicella being the most common dominant species. The effect of dosing polyaluminium chloride (PAX-14) on activated sludge is illustrated for WWTP solids separation problems, in particular because of Microthrix parvicella. The effects of the addition of PAX-14 on the microbiology and the morphology of Microthrix parvicella were studied in 9 full-scale WWTP. PAX-14 succeeded in reducing high SVI-values and controlled foaming problems whenever caused by Microthrix parvicella. Laboratory trials have shown that the dosage of PAX-14 should be less than 150 muL/L or 7 g Al3+/kg MLSS. At a dosage higher than 250 muL/L, an increase of free bacteria and a decrease of the protozoa activity are observed. In full-scale, PAX-14 is dosed at a concentration of 1.5 to 4.5 g Al3+/kg MLSS. Before addition, the mixed liquor scum layer-if present-should be removed. In our experience, the dosing should last for at least 3 weeks. During the first week, no drastic changes occur. At the end of the first week, an increase of SS and SVI is possible. The SVI and scum start to decrease after 10 to 15 days. The amount of filaments is reduced after 3 to 32 weeks. The morphological properties of Microthrix parvicella change, while other filaments such as Nostocoida limicola and Nocardia spp. are not affected. This study proves that PAX-14 is effective in controlling bulking and foaming problems at WWTPs when they are due to Microthrix parvicella. Prediction of when the SVI will decrease and when addition should be stopped is possible.