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Peat is known as problematic ground with low bearing capacity and extensively high compressibility. Ordinary Portland cement (OPC) and lime were usually used to tackle unfavourable characteristics of peat by improving it with its cementation effect. However, little was known of the effect of bio-cementation towards peat improvement. Bio-cementation or commonly known as Microbial-induced calcite precipitation (MICP) has been recently introduced as a ground improvement alternative for geotechnical engineering application. MICP performed by utilising metabolic pathways of non-pathogenic urealytic bacteria that precipitates calcium carbonate (CaCO3) crystal as cementation binder that seal soil particles together increasing soil strength. MICP of inorganic soil was extensively explored, and only limited was done for organic soil. This study explores on the effect of different surcharge preloading of 18kPa, 36kPa and 48kPa towards Microbial-Induced Calcite Precipitation (MICP) treatment of tropical peat. Fibrous peat studied were obtained from Miri, Sarawak and cured under a submerged condition with different vertical preload for seven days. Laboratory study including unconfined compression test, quantification of carbonates precipitated, and moisture content of stabilised specimens was observed to evaluate the performance of stabilisation effort. Unconfined compressive strength (UCS) of treated specimens was observed to be higher than untreated specimens with the highest increase of UCS up to 469%. However, CaCO3 precipitation amount for this study was observed to decrease with increasing surcharge preload.

Sludge treatment in vertical flow constructed wetlands (VFCWs) is a promising alternative to conventional treatment, which provides adequate treatment at low-cost, while being energy efficient. They may dewater and mineralize various kinds of sludge, including surplus sludge from activated sludge systems, agricultural slurries, and septage and faecal sludge effectively. This paper presents a review of the state-of-the-art of VFCWs treating sludge. The effects of varying design and operational parameters, as well as environmental factors on treatment performance are discussed. The paper also summarizes the performance of various pilot- and full-scale systems in terms of final dry matter content and degree of mineralization. In order to understand the governing processes and predict its performance, modelling of VFCWs in sludge treatment is suggested.

With the growth of economy and population, there is an increase in infrastructure construction projects. As such, it is unavoidable to have construction projects on soft soil. Without proper risk management plan, construction projects are vulnerable to different types of risks which will have negative impact on project's time, cost and quality. Literature review showed that little or none of the research is focused on the risk assessment on the infrastructure project in soft soil. Hence, the aim of this research is to propose a risk assessment framework in infrastructure projects in soft soil during the construction stage. This research was focused on the impact of risks on project time and internal risk factors. The research method was Analytical Hierarchy Process and the sample population was experienced industry experts who have experience in infrastructure projects. Analysis was completed and result showed that for internal factors, the five most significant risks on time element are lack of special equipment, potential contractual disputes and claims, shortage of skilled workers, delay/lack of materials supply, and insolvency of contractor/sub-contractor. Results indicated that resources risk factor play a critical role on project time frame in infrastructure projects in soft soil during the construction stage.