PHOSPHORUS AND ORGANIC MATTER REMOVAL FROM SYNTHETIC WASTEWATER USING ALUM AND ALUMINUM HYDROXIDE
PHOSPHORUS AND ORGANIC MATTER REMOVAL FROM SYNTHETIC WASTEWATER USING ALUM AND ALUMINUM HYDROXIDE
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使用明矾和氢氧化铝去除合成废水中的磷和有机物
DOI：
10.30955/gnj.000348
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
H. Grigoropoulou
中科院分区：
文献类型：
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作者：
Dimitris Α Georgantas;H. Grigoropoulou
目前，化学方法被广泛用于从水或废水中去除磷和有机物，作为唯一的深度处理方法或作为生物处理的预处理阶段，并且铝盐传统上被用作混凝剂。在本研究中，使用两种铝源：明矾[Al 2（SO 4）3·18 H2O]和氢氧化铝[Al（OH）3（s）]去除正磷酸盐或溶解性有机物的废水处理过程进行了研究。选择无定形氢氧化铝是因为它是明矾的水解（氧化）产物，并且是土壤中无机和有机物质的重要吸附剂，因为三羟铝石、三水铝石和勃姆石含有大部分氢氧化铝。使用正磷酸盐溶液（10 mg l-1）或鞣酸溶液（50 mg l-1）作为模拟废水进行实验室瓶试验研究，并研究了诸如混凝剂剂量（在明矾的情况下高达15 mg Al l-1，在Al（OH）3的情况下高达90 mg Al l-1）和pH（2-12）等参数的影响。这些参数的值是基于对雅典一家废水处理厂一级处理输入的城市废水的测量。正磷酸盐已被选为P替代品，因为它们是在废水中发现的总P的主要部分，单宁酸溶液被用作可溶性有机物的替代品。事实证明，明矾比氢氧化铝更有效地去除磷和单宁酸。在明矾和氢氧化铝这两种情况下，最佳pH值都是5-6，尽管明矾在更宽的pH范围（4-7）内是有效的，并且提出了解释这些结果的机制。在pH值小于6时，Al与单宁酸或磷酸盐形成不溶性络合物，而在pH值较大时（6-8），Al与固体Al（OH）3发生吸附。氢氧化铝和磷酸盐在25 ℃时的吸附符合Freundlich吸附等温式，其KF值为49.1，N值为0.19，表明吸附是不均匀的。这项工作的结果可能不仅有助于更好地了解化学废水处理的化学过程，从而改善该过程，而且还对磷和有机物固定在土壤中含有很大一部分的氢氧化铝。
At present, chemical processes are widely used to remove phosphorus and organic matter from water or wastewater either as the only advanced treatment method or as a pre-treatment stage to biological treatment, and aluminium salts have been traditionally used as coagulants. In the present study removal of orthophosphate or dissolved organic matter with the use of two aluminium sources: alum [Al2(SO4)3•18H2O] and aluminium hydroxide [Al(OH)3(s)] is examined for the wastewater treatment process. Amorphous aluminium hydroxide was chosen because it is the hydrolyzed (olated) product of alum and an important adsorbent of inorganic and organic substances in soils since bayerite, gibbsite and boehmite contain a large portion of aluminium hydroxides. Laboratory jar test studies were carried out using either an orthophosphate solution (10 mg l -1 ) or a tannic acid solution (50 mgC l -1 ) as simulated wastewater and the effect of parameters such as coagulant dose (up to 15 mg Al l -1 in the case of alum and up to 90 mg Al l -1 in the case of Al(OH)3) and pH (2-12) is investigated. The values of these parameters were based upon measurements on municipal wastewaters from the input of the primary treatment of a wastewater plant in Athens. Orthophosphates have been chosen as a P surrogate as they are the major portion of the total P found in wastewater and tannic acid solution was used as a surrogate for soluble organic matter. It was proven that alum is much more efficient in phosphorus and tannic acid removal than aluminium hydroxide. The optimal pH values are 5-6 in both cases, alum and aluminium hydroxide, although alum is efficient in a wider pH range (4-7) and a mechanism was proposed to interpret these results. In pH values less than 6 the mechanism proposed was chemical bonding between Al species and tannic acid or phosphates creating insoluble complexes while in bigger pH values (6-8) adsorption on solid Al(OH)3. Freundlich isotherm was proven to fit satisfactorily the experimental data for aluminium hydroxide and orthophosphate at 25 0 C suggesting heterogeneous sorption, with KF and N values 49,1 and 0,19 respectively. The findings of this work may not only contribute to a better understanding of the chemistry of chemical wastewater treatment and therefore to an improvement of the process but also on phosphorus and organics fixation in soils that contain a large portion of aluminium hydroxides.