Applied Mechanics and Materials Vol. 802

Abstract: The energy consumption in transportation sector was mostly created by the individual likeness to use private motor vehicle. High dependency on private motor vehicles has contributed not only to the traffic problem but also accounted to carbon emission. This study aims to investigate the psychological factors that influencing the adolescents’ intention to be more pro-environmental. This study found that the behavioural intention was significantly influenced by the adolescents’ awareness towards consequences, attitude towards environment and public transport, the sentiment of moral obligation to change, and the perceived possibilities or difficulty to practice environmental friendly travel behaviour.

Abstract: In this present study, rubber seed-coated activated carbon (RSCAC) was used as a natural adsorbent to remove basic (MB), acid (MR) and reactive (RBV) dyes using batch process. Each dye in the adsorption process was tested at different initial concentration from 50-500 mg/l. Different dyes showed different percentage removals. The highest removal was recorded by MB which was up to 99.9 %. The experimental data was analyzed with Langmuir and Freundlich adsorption models. The data fitted well with Langmuir. The adsorption capacity were 332.99, 210.33 and 155.37 mg/g for MB, MR and RBV, respectively.

Abstract: Five series of silica supported bimetallic oxide (NiCo/SiO₂) catalysts have been synthesized through successive reverse co-precipitation and wet impregnation methods at different metal loadings (i.e. 80Ni20Co/SiO_2,, 60Ni40Co/SiO_2, 50Ni50Co/SiO_2, 40Ni60Co/SiO_2, 20Ni80Co/SiO₂). The catalytic performance of these catalysts were tested for the CO₂ methanation catalysis using microactivity fixed bed reactor. Nickel rich catalyst (80Ni20Co/SiO₂) exhibited the highest catalytic activity in the CO₂ methanation with 47.1% of CO₂ conversion. Meanwhile, the CH₄ selectivity and yield was found to be at 99.9% and 27%, respectively.

Abstract: Palm oil mill effluent (POME) contains high biological oxygen demand (BOD) and chemical oxygen demand (COD) Agra base wastewater is the concern of biodegradable treatment methods. Consequently, the BOD / COD ratio has a significant effect on the biodegradability of wastewaters. This study investigates effects of aerated sequencing batch reactor (SBR) system augmented by zeolite used for treatment of POME. Not only, the BOD / COD ratio increased from 0.11 in raw POME to mean 68.15% increase after aeration in the SBR system, but also, the most obvious finding to emerge from this study is that, aerated SBR could be considered as an effective method for enhancing BOD/COD ratio for qualifying post treatment by biotreatment methods.

Abstract: Animal farming industries is important in Malaysia because its contribution to the economy. The production causes all the major environmental negative impact such as water pollution from waste water and malodours emanating from farms. The current methods of disposing of manures were no longer adequate or suitable for the new, large and intensive animal farming. Inappropriate technologies, poor maintenance and inadequate dimensions and design of the treatment systems in addition to inappropriate production method are causing serious environmental problems especially odorous emissions. Present of Hydrogen Sulphide (H2S) in the air contribute to the odour pollution. Static monitoring has been done and maximum concentration of H2S is 220.6 ppb. Temperature and relative humidity fluctuations were seem to have influence on concentration of H2S. Linear regression analysis was shown that relative humidity has higher influence on correlation gaseous pollution compared to temperature. Correlation coefficient for H2S and relative humidity was in range 0.675 to 0.881 in the morning and 0.417 to 0.729 in the evening, which are in range of strong correlations.

Abstract: Bioretention media composition plays an important role in maintaining hydraulic conductivity within appropriate range and treating stormwater runoff to reduce pollution to receiving water bodies. This study investigated 4 types of bioretention media, 2 of which different types of compost and another 2 using shredded newspaper and crushed cockle shell as additives to modify the bioretention media. The objective of the study was to provide insight on hydraulic performance and media characteristics that control bioretention stormwater treatment performance. Results showed that organic matter content has no effect on hydraulic conductivity and nutrient removal performance of the media. Comparison of hydraulic conductivity and nutrient removal showed that reduced hydraulic conductivity (from 250mm/hr to 159mm/hr) increased total suspended solids (TSS) removal of the media (up to 98.5%) but has no effect on total nitrogen (TN) and total phosphorus (TP). The preliminary pollutant test using natural runoff showed that bioretention media enhanced with 10% shredded newspaper performed the best in TN removal (up to 85.3%) and bioretention media enhanced with 10% crushed cockle shell removed the most TP (up to 95.6%).

Abstract: At the ambient temperatures, the influence of operating conditions on persulfate (S₂O₈) oxidation of real textile wastewater was investigated for the removal of color, suspended solids (SS) and chemical oxygen demand (COD). The effects of oxidant dosage, initial solution pH and contact time were studied in a series of batch experiments using persulfate (PS) oxidant as sodium persulfate. Oxidant dose was defined by an oxidant/contaminant (PS/COD) molar ratio, varied from 1/1-10/1. Although parameter removals increased with the oxidant dose, especially for color and SS, a PS/COD molar ratio of 4/1 (6720mg/L) was adopted in a bid to use fewer chemicals. The pH was varied from 2-11, with pH of between 2 and 3 being the optimum. At 360minutes contact time, the removals of color, SS and COD were 84%; 71% and 32% respectively. Although relatively effective, especially for color removal, results show that the reactions might have been inhibited at ambient temperatures as shown by the particularly low removal of COD.

Abstract: Several techniques are used for iron and manganese removal from groundwater. Among these treatments, adsorption has been proven to be a very effective in metal removal for groundwater treatment. Thus, limestone has been proposed as adsorption media because of its low cost. In this study, the mineral contents of limestone were detected using X-ray fluorescence (XRF). XRF results showed that limestone contains 97.93% CaCO₃, 0.87% MgO, and 1.2% other elements. Groundwater sample was obtained from USM borehole located at 5° 08’ 50.5”N and 100° 29’ 34.7”E. A batch study was carried out for various dosages of limestone media (5–50 g) in 200 mL of groundwater sample. The highest iron and manganese removal was more than 90% and 70%, respectively, at optimum dosage of 40 g/200 mL sample. Adsorption data were modeled using Langmuir and Freundlich adsorption isotherms. The batch study result shows that monolayer Langmuir isotherm fitted the experimental data better than the Freundlich isotherm. The correlation coefficient (R²) in the Langmuir isotherm for both metals were 0.84 and 0.97, whereas 0.83 and 0.23 in the Freundlich isotherm, respectively. Based on the present results, application of limestone as adsorbent media can be a good alternative of groundwater treatment because of the low cost of the media. Thus, the use of limestone could help to overcome the excessive iron and manganese problem in water treatment plants.

Abstract: As a developing country and one of the tropical tourism industry leaders, Malaysia is faced with environmental problems, such as the conversion of municipal solid waste landfill leachate into hazardous wastewater in mega cities. High concentrations of pollutants, toxic refractory component, and complex composition of landfill leachate have serious environmental impact. This study investigated a novel rapid treatment method to remove turbidity, suspended solid, color, and ammonia nitrogen. Bentonite augmented sequencing batch reactor with miscellaneous aeration (0.5–7.5 L/min) and contact time (1–3 h) is applied via response surface methodology in 13 runs. Results of this study show that in optimum circumstances, 93.63% of turbidity, 90.42% of total suspended solid, 76.33% of ammonia nitrogen (AN), and 45.96% color were removed in only three hours. Furthermore, natural bentonite is a cost effective adsorbent for landfill leachate treatment.

Abstract: Malaysia is one of the world’s largest palm oil exporters, amounting to 39 % of world palm oil production and 44 % of world exports [1]. Palm oil mill usually engaged with odour problem that came from the wastewater treatment pond that released odourous compounds such as ammonia, volatile organic acids, and sulfides. This study was done to investigate odour nuisance from palm oil mill operations and odour emission rate at United Oil Palm (UOP) Mill, Nibong Tebal, Penang, Malaysia. Odour assessment was done on-site at four points and odour sample was taken from four anaerobic treatment ponds. Flux hood method was used and the samples were analysed by using the olfactometry method with six panels. It was found that in the UOP mill, the highest odour emission is from the anaerobic pond 2 with the average specific odour emission rate of 10.88 OU_E/sm², follow by cooling pond, acid pond and anaerobic pond 1. Besides knowing the main source of the odour, this study was run to find the intensity and offensiveness of the palm oil mill odour. A simple questionnaire was asked to the six panels about the odour intensity and odour offensiveness, and the average for both was at 5 (very strong odour) and 3 (definitely offensive odour). Higher level of offensiveness and intensity will increase the odour complaints, but by knowing those levels, it will help in deciding the limit of odour concentration that can be released and the threshold of odour that can be accepted by humans.