Abstract

The expansion of biofuels produced from cooking oils and vegetal oils is expected to increase, together with the production of exhausted clay used in the refinery process. Clay produced in the process is considered waste as it is not intended for further applications. This study has assessed a sample of clay produced by a vegetal oil refinery plant and tested it for environmental applications with two types of vegetal species. In the experiment, the oily clay was added to a sandy loam soil in different percentages in order to modify the soil texture and assess the effect on the hydrological and chemical properties. The results demonstrated that on the one hand, oily clay does not change the pH in the soil mixture and it enriches the elemental composition (in terms of Mg, Cu and Zn), but, on the other hand, there are counteracting effects. Even if oily clay did not have toxic effects on seed germination, when applied to the soil, the presence of Ni did affect the plants’ growth. The results thus suggest the need for phytoremediation prior to any application of such clay in soil.

Graphic abstract

中文翻译：

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检查生物柴油提炼过程中产生的膨润土，作为排水良好的土壤中的土壤改良剂

摘要

预计从食用油和植物油生产的生物燃料的增加以及炼油过程中使用的废粘土的生产将增加。该过程中产生的粘土被认为是浪费，因为它不打算进一步应用。这项研究评估了植物油提炼厂生产的粘土样品，并测试了两种植物种类在环境中的应用。在实验中，将油性粘土以不同百分比添加到沙质壤土中，以改变土壤质地并评估其对水文和化学性质的影响。结果表明，一方面，油性粘土不会改变土壤混合物中的pH值，并且可以丰富元素成分（以Mg，Cu和Zn的形式），但另一方面却具有抵消作用。即使将油性粘土对种子发芽没有毒性作用，但将其施于土壤后，镍的存在也会影响植物的生长。因此，结果表明在将这种粘土施用于土壤之前需要进行植物修复。

图形摘要