In this era of globalisation and modernisation, the proliferation of machineries and alarming city noises have created detrimental effect to the health of the human. The issue has received the attention from world and therefore noise reduction has been a critical problem that cannot be side-lined. For an ergonomic indoor workplace especially in the manufacturing plants, noise pollution shall be controlled and mitigated. Various noise control techniques have been proposed up-to-date, and the objective of current paper is to provide a short yet comprehensive review on the available noise attenuation strategies nowadays

Microalgae is a type of microscopic organisms that are high in lipid with rapid biomass production, which is suitable to be used as biofuel for renewable energy. The aim of this study is to conceptually design a floating platform for microalgae cultivation on the sea and to determine the structural motion of floating platform subject to Malaysia wave. ANSYS Aqwa simulation was carried out to simulate the heave and pitch motion of the floating platform under Malaysia wave condition. From the ANSYS Aqwa simulation, design of the floating platform by increased the elevation angle of design, the stability of the increased from the stability of the floating platform. Cultivation of microalgae required greater movement speed in water to enhance high efficiency in biomass production. Based on the result of the simulation, the design of the floating platform which has greater elevation angle is the most suitable for cultivation of microalgae.

In the present study, Opuntia cactus, an environmentally friendly bio-coagulant that is locally available, was used for the first time for the treatment of Palm oil mill effluent (POME). The optimum conditions for applying Opuntia in the POME treatment process were identified by performing jar test experiments. Parameters tested were chemical oxygen demand (COD), total suspended solids (TSS) and turbidity. The results of the work indicate that Opuntia is an effective bio-coagulant, which can remove 91.2% COD, 94.4% TSS and 90.7% turbidity. Okra solution which was introduced as a bioflocculant in the experiment resulted in slightly better performance. The reduction of COD, TSS and turbidity by Opuntia with okra solution improved to 93.9%, 96.1% and 93.6%, respectively. This was achieved at an Opuntia powder dosage of 8 g/L, pH 9 and reaction time of 240 minutes. The main mechanism involved in the treatment process was determined to be the polymeric bridge mechanism. From the study, it can be deduced that Opuntia has great potential to be used as a low-cost bio-coagulant for the treatment POME.