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

有机土壤是加拿大最脆弱的土壤类型之一，占加拿大陆地总面积的18%。这种土壤的一些特点是抗剪强度和压缩性能差，蠕变性能高。在这些土壤上进行的建筑工程导致这些结构的破坏。因此，在进行任何开发工作之前，必须对其进行改进。改良这些土壤的最常见方法是使用水泥和其他化合物进行化学处理。碳排放量的增加（即，约占总碳排放量的5%）、气候变化以及生产水泥和其他常规水泥化合物时发生的野火，增加了探索替代材料的必要性。生物土工技术是一种不断发展的环境友好型技术，采用各种微生物来稳定土壤。以下研究的目标是在生物胶结技术的帮助下稳定这种有问题的土壤，这种生物胶结技术使用一种称为产黄青霉菌的真菌和木粉煤灰（加拿大造纸和纸浆工业的副产品）。主要有两种类型的生物胶结过程，即，细菌和真菌，其中真菌生物胶结作用研究较少。将进行各种实验室规模的实验，以检查通过将微生物与粉煤灰和有机土壤混合形成生物复合材料的可能性。此外，将进行一些试验台规模复制现场条件。与细菌生物胶结相比，预期形成的生物复合材料具有更好的均匀性和分布，从而导致更高的机械性能、更好的压缩性能和更大面积的适用性。此外，木粉煤灰的添加预计将减少处理周期，从而减少释放到环境中的铵的量。该项目的成功将导致该技术应用于在加拿大有问题的有机土壤上建造地基、公路和其他结构。

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.