Decomposition And Settlement Behaviour Of Municipal Solid Waste

Understanding the behavior of municipal solid waste settlement and decomposition is critical in managing a good landfill system. This study was conducted in order to develop understanding on MSW as it undergoes settlement and decomposition process through observation of individual waste behaviour in laboratory. The examination into the behaviour of individual waste was carried out due to the fact that real wastes are very heterogeneous and complex if it was to be analyzed at once. Eight types of waste namely Spinach, Rice, Fish, Meat, Spinach and Fish, Rice and Fish, Rice and Spinach, and Municipal mix were experimented

Assessment Of Fluctuational And Critical Transformational Behaviour Of Ground Level Ozone

Ground level ozone (O3) is a noxious air pollutant that imposed adverse effects to human health, crop yield and the environment. Hence, it is important to understand their fluctuation and transformation characteristics in Malaysia in order to design abatement and control strategies properly. Therefore, this study aimed at investigating the characteristics of O3 fluctuation and transformation from its precursors as well as to introduce the critical conversion point (CCP) of O3 formation in 18 monitoring stations across Malaysia from 1999 to 2010. The next hour O3 prediction models during daily, daytime, nighttime and critical conversion time were also developed using multiple linear regression (MLR) and principal components regression (PCR) to predict O3 concentrations in different groups of monitoring stations. Groups of monitoring stations were based on the Department of Environment, Malaysia in terms of classification and newly developed groups using ranking of means and cluster analysis. Although majority of the recorded data was below 100 ppb, total of 1,995 hour of exceedances have been recorded, with Shah Alam contributed 885 hour or 44.5%. O3 diurnal cycles suggested a uni-modal peak between 12 p.m. to 4 p.m., while minimum concentrations were consistently measured at 8 a.m.. Results of PCA showed the contributions to O3 variation by NO2, NO, temperature and UVB up to 80%, whereas the composite diurnal plots confirmed that variation is highly influenced by NO2 and NO concentrations. The CCP of O3 formation were identified to occur between 8 a.m. to 11 a.m.. The MLR model based on cluster group during daily exhibited optimal performance in terms of coefficient of determination, prediction accuracy, and index of agreement with values of 0.9351, 0.9671 and 0.9831,respectively

Diurnal variation of secondary air pollutant concentrations during movement restriction orders in Johor

Secondary air pollutants are those that are formed through chemical reactions between primary pollutants and other substances in the atmosphere. Diurnal variations in secondary air pollutants can occur due to changes in sunlight, temperature, and the presence of other chemicals in the atmosphere. Ground-level ozone is created when sunlight interacts with nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the air. This study focused on secondary air pollution levels during movement restriction orders (MCOs)using hourly average ozone data acquired from the Department of Environment Malaysia in 2020 and 2021 in Batu Pahat station. The data were analyzed using descriptive statistics, time series analysis, and diurnal plot. The diurnal pattern of ozone concentrations showed a consistent trend in the location, with the highest levels observed from noon to evening and the lowest levels at night. Additionally, the study found that ozone levels were highest during the movement control order (MCOs) compared to the conditional movement control order (CMCO) and restricted movement control order (RMCO) with mean values of 18.1 ppb, 14.5 ppb and 17.4 ppb, respectively due to increased sunlight during the summer months. The study findings can be used to identify and study the best conditions to decrease ozone air pollution

Transformational characteristics of ground-level ozone during high particulate events in urban area of Malaysia

Observations of ground-level ozone (O3), nitric oxide (NO), nitrogen dioxide (NO2), particulate matter (PM10) and meteorological parameter (temperature, relative humidity and wind speed) fluctuations during high particulate event (HPE) and non-HPE in Malaysia have been conducted for 2 years (2013 and 2014). The study focuses on urban areas, namely, Shah Alam, Petaling Jaya and Bandaraya Melaka. The diurnal variations of ground-level O3 concentration were higher during HPE than those during non-HPE in all urban areas. The concentration of O3 fluctuated more in 2014 than 2013 due to the higher incidences of HPE. Temperature and wind speed fluctuated with higher PM10, NO2 and NO concentrations during HPE than those during non-HPE in all urban sites. Relative humidity was lower during HPE than that during non-HPE. Positive correlations were found between PM10 and ozone during HPE for Shah Alam and Petaling Jaya with 0.81 and 0.79, respectively. Meanwhile, negative correlation (− 0.76) was recorded for Bandaraya Melaka. The non-HPE correlation of PM10 and O3 showed negative values for all locations except Petaling Jaya (0.02). Temperature and wind speed shows a strong positive correlation with ozone for all locations during HPE and non-HPE with the highest at Shah Alam (0.97). Inverse relationships were found between relative humidity and O3, in which the highest was for Shah Alam (− 0.96) in 2013 and Shah Alam (− 0.97) and Bandaraya Melaka (− 0.97) in 2014. The result of the ozone best-fit equation obtained an R2 of 0.6730. The study parameters had a significant positive relationship with the ozone predictions during HPE

Relationship between common air pollutants with risk of cardio-respiratory hospitalization in urbanized areas in Kelantan

A high concentration of air pollution can lead to health problems which are the cardiovascular and respiratory systems (WHO, 2014). A study has been conducted to know the relationship between five criteria air pollutants with hospitalization related to cardiovascular and respiratory diseases in two cities in Kelantan. The secondary data from 2000 until 2015 analyzed in the study were obtained from DOE and MOH for the air pollutants concentration and hospitalization, respectively. This study shows that the mean concentration of all pollutants in the study area is below the RMAAQS. Significant Relative Risk (RR) values were found for cardiovascular hospitalization associated with SO2 (RR = 1.537, 95% CI = 2.970, 7.956), NO2 (RR = 1.212, 95% CI = 1.156, 1.272), and O3 (RR = 4.873, 95% CI = 2.768, 8.578). In contrast, significant RR for respiratory hospitalization was found to be associated with SO2 (RR = 1.952, 95% CI = 1.013, 3.762), NO2 (RR = 2.021, 95% CI = 6.170, 6.620), O3 (RR = 1.128, 95% CI = 4.427, 2.874), and PM10 (RR = 1.008, 95% CI = 1.007, 1.008). The highest value of Relative Risk is O3 and NO2 for hospitalization related to cardiovascular and respiratory diseases, respectively. In conclusion, the value of RR associated with air pollutants proves that air pollutants are associated with cardiovascular and respiratory-related hospitalization risk

Time effects of high particulate events on the critical conversion point of ground-level ozone

Particulate matter (PM), especially those with an aerodynamic particle size of less than 10 μm (PM10), is typically emitted from transboundary forest fires. A large-scale forest fire may contribute to a haze condition known as a high particulate event (HPE), which has affected Southeast Asia, particularly Peninsular Malaysia, for a long time. Such event can alter the photochemical reactions of secondary pollutants. This work investigates the influence of PM on ground-level ozone (O3) formation during HPE. Five continuous air quality monitoring stations from different site categories (i.e., industrial, urban and background) located across Peninsular Malaysia were selected in this study during the HPEs in 2013 and 2014. Result clearly indicated that O3 concentrations were significantly higher during HPE than during non-HPE in all the sites. The O3 diurnal variation in each site exhibited a similar pattern, whereas the magnitudes of variation during HPE and non-HPE differed. Light scattering and atmospheric attenuation were proven to be associated with HPE, which possibly affected O3 photochemical reactions during HPE. Critical conversion time was used as the main determining factor when comparing HPE and non-HPE conditions. A possible screening effect that resulted in the shifting of the critical transformation point caused a delay of approximately of 15–30 min. The shifting was possibly influenced by the attenuation of sunlight in the morning during HPE. A negative correlation between O3 and PM10 was observed during the HPE in Klang in 2013 and 2014, with −0.87. Essentially, HPE with a high PM concentration altered ground-level O3 formation

Investigation of relationship between particulate matter (PM2.5 and PM10) and meteorological parameters at roadside area of first Penang bridge

Present study was focusing to characterize the particulate matter (PM2.5 and PM10) at the roadside of First Penang Bridge and the associated meteorological parameters influence such as precipitation, temperature, and relative humidity. The study was conducted by focusing on the roadside area of First Penang Bridge (N05°21.375’; E100°23.584’). A total of 12 samples thrice per month for each particulate matter sizes were collected starting from June 2015 to September 2015. Meteorological data were obtained from the Meteorological Department of Penang on daily basis and 24-hours averages. Descriptive statistical analysis was conducted in characterizing the relationship between particulate matter concentrations and the target meteorological parameters. Result showed that PM2.5 and PM10 concentrations ranged between 18.06 – 79.51 µg/m³ and 22.38 – 130.90 µg/m³ with the overall mean concentration of 39.35 µg/m³ for PM2.5 and 45.24 µg/m³ for PM10. For the PM2.5, weak negative correlation was obtained between PM and precipitation (r = -0.462), strong negative correlation with relative humidity (r = -0.799) and weak positive correlation between temperature (r = 0.456). PM10 showed weak negative correlation between PM with temperature (r = -0.061) and precipitation (r = -0.022), and strong positive correlation between PM and relative humidity (r = 0.130)

Time effects of high particulate events on the critical conversion point of ground-level ozone

Particulate matter (PM), especially those with an aerodynamic particle size of less than 10 μm (PM10), is typically emitted from transboundary forest fires. A large-scale forest fire may contribute to a haze condition known as a high particulate event (HPE), which has affected Southeast Asia, particularly Peninsular Malaysia, for a long time. Such event can alter the photochemical reactions of secondary pollutants. This work investigates the influence of PM on ground-level ozone (O3) formation during HPE. Five continuous air quality monitoring stations from different site categories (i.e., industrial, urban and background) located across Peninsular Malaysia were selected in this study during the HPEs in 2013 and 2014. Result clearly indicated that O3 concentrations were significantly higher during HPE than during non-HPE in all the sites. The O3 diurnal variation in each site exhibited a similar pattern, whereas the magnitudes of variation during HPE and non-HPE differed. Light scattering and atmospheric attenuation were proven to be associated with HPE, which possibly affected O3 photochemical reactions during HPE. Critical conversion time was used as the main determining factor when comparing HPE and non-HPE conditions. A possible screening effect that resulted in the shifting of the critical transformation point caused a delay of approximately of 15–30 min. The shifting was possibly influenced by the attenuation of sunlight in the morning during HPE. A negative correlation between O3 and PM10 was observed during the HPE in Klang in 2013 and 2014, with −0.87. Essentially, HPE with a high PM concentration altered ground-level O3 formation

Does light pollution affect nighttime ground-level ozone concentrations?

Ground-level ozone (O3) is mainly produced during daytime in the presence of ultraviolet (UV) light and later destroyed by nitrogen oxides during nighttime. However, light pollution caused by the excessive use of artificial lights may disrupt the chemistry of night-time ground-level O3 by providing enough energy to initiate nighttime ground-level O3 production. In this study, nighttime (7 p.m. to 7 a.m.) ground-level O3, nitrogen oxide (NO), and nitrogen dioxides (NO2) concentrations were observed for three years (2013, 2014, and 2015). The existence of O3 was found during nighttime, especially in urban areas with a concentration range of 8–20 ppb. The results suggested that nighttime variations of ground-level O3 concentrations were higher in urban areas than in suburban areas. The mean nighttime O3 concentration at urban sites varied, possibly because the distribution of anthropogenic lights around the urban sites is brighter than in suburban locations, as indicated by the data from the light-pollution map. This anthropogenic light has not caused the suspected nighttime photolysis processes, which directly slowed nighttime oxidation. The photochemistry rate of JNO2/k3 was supposed to be near zero because of the absence of photochemical reactions at night. However, the minimum concentration in all urban and suburban sites ranged from 2–3 ppb, indicating that O3 might also form at night, albeit not due to light pollution

Identification of cation elements in PM10 concentration in industrial area of Penang

This study aims to investigate the concentrations of particulate matter with aerodynamic diameter less than 10 micron (PM10) and their associated cation elements in PM10. The sample of PM10 were collected at Royal Malaysian Customs Department (N5° 22’ 012”; E100° 23’589”) located in Perai Industrial Area, Penang, from June to September 2015. The sampling was carried out during the southwest monsoon and a total of 12 samples were collected using low volume sampler (LVS). Result suggested that there are five elements that commonly identified from PM sampled which are ammonium, sodium, potassium, calcium and magnesium. The concentrations of the cation from all four months in the industrial area shows the order of NH4 + > Ca+ > K+ > Mg2+ > Na+ . The lowest nand highest concentrations calculated both were ammonium (0.012 µg/m³) in July and (0.873 µg/m³) September, respectively