Journal of Environmental Management ( IF 8.7 ) Pub Date : 2020-06-26 , DOI: 10.1016/j.jenvman.2020.110884 Qadeer Alam 1 , Thomas Dezaire 1 , Florent Gauvin 1 , A C A Delsing 1 , H J H Brouwers 1
This paper focuses on the functionalization of heterogeneous and highly contaminated waste material, namely bottom ashes (BA) with a particle size ≤ 125 μm that cannot be recycled with conventional treatments. The main goal of this study is to modify this waste into a valuable material that can be used in various applications, especially in the building sector. The complex mineralogical nature of this material was investigated with quantitative XRD, which confirms the presence of crystalline and amorphous phases such as silicates, carbonates, metallic oxides and amorphous glass. A hydrophobic modification was performed by using a fluorosilane grafting agent that utilizes the reactive surface sites of these minerals to form silanol bonds. Results showed that the 2.5% (m/m) of silane made the BA hydrophobic. Moreover, a thorough characterization showed that fluorosilane was well-grafted at the surface of the BA, with more than 60% of the fluorosilane chemisorbed on the surface. Additionally, the hydrophobic modification led to a significant decrease of the leaching of the contaminants (Cr, Cu, Mo and Sb) from the BA particles. Following this methodology, fine fraction of BA could be eventually used as a building material, preventing the landfill of this toxic waste.
中文翻译:
通过表面功能化来平衡底灰的细度,以减少有害污染物的浸出。
本文着眼于异质性和高度污染的废料的功能化,即粒度≤125μm的底灰(BA),传统处理无法回收利用。这项研究的主要目的是将这种废物改性为有价值的材料,可用于各种应用,尤其是建筑领域。用定量XRD研究了这种材料的复杂矿物学性质,证实了结晶相和无定形相的存在,例如硅酸盐,碳酸盐,金属氧化物和无定形玻璃。通过使用氟硅烷接枝剂进行疏水改性,该氟硅烷接枝剂利用这些矿物的反应性表面位点形成硅烷醇键。结果表明,2.5%(m / m)的硅烷使BA疏水。此外,彻底的表征表明,氟硅烷在BA的表面接枝良好,超过60%的氟硅烷化学吸附在表面上。另外,疏水改性导致从BA颗粒中浸出的污染物(Cr,Cu,Mo和Sb)显着减少。按照这种方法,可以将细微的BA最终用作建筑材料,从而防止将这种有毒废物掩埋。