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Differences in thickness variations of activated carbon in decreasing oil and grease levels using modified grease trap on the canteen wastewater

Fikri Elanda, Hanifati Dhaifina, Hidayah Nurul

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

2021

Vol. 30, No. 1

106--116

Wastewater is residual water of industrial activities and domestic wastewater that is derived from daily activities of human life related to water usage, such wastewater should not be discharged into water bodies if it has not met the standards based on the regulation. Oil and grease contained in the water bodies will form a layer on the surface because the density of oil is lower than the density of water. The layer of oil and grease will block the entry of sunlight and cause the inability in the photosynthesis process of aquatic plants. The textile industry facilitates canteens within the company which operates daily at 11.00–13.00 Western Indonesian Time, resulting in the domestic wastewater from the canteen kitchen activities. The purpose of this study was to determine differences in the thickness variations of activated carbon to reduce oil and grease levels using modified grease traps on the canteen wastewater at PT. Sipatex Putri Lestari. The type of study used was categorized as a field experiment with a pretest–posttest research design. The population of the study was the entire canteen wastewater of PT. Sipatex Putri Lestari. The sampling technique used the time composite method. The univariate analysis of the study showed the average number of decreases in oil and grease levels in the treatment as 12.32, 15.98 and

Sound Absorption Characteristics of Pineapple Leaf/Epoxy Composite

Adhika Damar Rastri, Prasetiyo Iwan, Noeriman Abiyoga, Hidayah Nurul, Widayani S.

Archives of Acoustics

2020

Vol. 45, No. 2

233--240

Natural fibres are attractive as the raw material for developing sound absorber, as they are green, eco-friendly, and health friendly. In this paper, pineapple leaf fibre/epoxy composite is considered in sound absorber development where several values of mechanical pressures were introduced during the fabrication of absorber composite. The results show that the composite can absorb incoming sound wave, where sound absorption coefficients αn > 0.5 are pronounced at mid and high frequencies. It is also found that 23.15 kN/m2 mechanical pressure in composite fabrication is preferred, while higher pressure leads to solid panel rather than sound absorber so that the absorption capability reduces. To extend the absorption towards lower frequency, the composite absorber requires thickness higher than 3 cm, while a thinner absorber is only effective at 1 kHz and above. Additionally, it is confirmed that the Delany-Bazley formulation fails to predict associated absorption behavior of pineapple leaf fibre-based absorber. Meanwhile, a modified Delany-Bazley model discussed in this paper is more useful. It is expected that the model can assist further development of the pineapple leaf composite sound absorber.