Bio-mediated treatment of organic soil with fungal strain Penicillium Chrysogenum and wood fly ash

有机土壤是加拿大发现的最脆弱的土壤类型之一，占加拿大陆地总面积的近18%。这种土的一些特点是抗剪强度和压缩性能较差，蠕变性能较高。在这种土壤上进行的建筑工程会导致这些结构的破坏。因此，在进行上面的任何开发工作之前，必须对它们进行改进。改良这些土壤最常见的方法是使用水泥和其他化合物进行化学处理。碳排放量(约占总碳排放量的5%)的增加，气候变化，以及水泥和其他传统胶凝材料生产带来的野火，增加了开发替代材料的必要性。生物土工技术是一项不断发展的环境友好型技术，它使用各种微生物来稳定土壤。下面的研究目标是利用一种名为产黄青霉的真菌和木材飞灰(加拿大造纸和纸浆工业的副产品)的生物胶结技术来稳定这种有问题的土壤。生物胶结过程主要有细菌和真菌两种，其中真菌生物胶结作用的研究较少。将进行各种小规模实验，以检查将微生物与飞灰和有机土壤混合形成生物复合材料的可能性。此外，还将进行一些模拟现场条件的试验台标尺。与细菌生物粘结相比，所形成的生物复合材料有望具有更好的均匀性和分布，从而获得更高的力学性能、更好的压缩性能和更大的适用性。此外，添加木质飞灰有望缩短处理周期，减少向环境释放的铵的数量。该项目的成功将导致该技术在加拿大建造地基、高速公路和其他在有问题的有机土壤上建造的结构。

Organic soil is one of the vulnerable kinds of soil found in Canada which occupies almost 18% of its total landmass. Poor shear strength and compressibility properties and high creep behaviour are some of the characteristics of such soil. Construction works done above such soil lead to the failure of those structures. Therefore, they must be improved before performing any developmental works above them. The most common approach to improving those soils is the chemical treatment using cement and other chemical compounds. The hike in carbon emission (i.e., about 5% of total carbon emissions), climate change, and wildfires with the production of cement and other conventional cementing compounds have increased the necessity of exploring alternative materials. Bio geotechnics is an evolving environmentally friendly technology that employs various microorganisms to stabilize the soil. The following research targets to stabilize such problematic soil with the help of bio cementation technique using a type of fungi called Penicillium Chrysogenum and wood fly ash (a by-product of the Canadian paper and pulp industry). There are mainly two types of bio cementation processes i.e., bacterial, and fungal among which the fungal bio cementation is less explored. Various bench-scale experiments will be conducted to check the possibility of forming a biocomposite material by blending the microbe with fly ash and organic soil. Also, some trial bench scales replicating the field conditions will be performed. The biocomposite material formed is expected to have better uniformity and distribution resulting in higher mechanical behaviour, better compressibility behaviour and applicability to a larger area compared to bacterial bio cementation. Also, the addition of wood fly ash is expected to reduce the cycles of treatment reducing the amount of ammonium released to the environment. Success of the project will lead to application of the technology for the construction of foundations, highways and other structures constructed on problematic organic soils in Canada.