Pretreatment of lignocellulosic biomass from sugar bagasse under microwave assisted dilute acid hydrolysis for biobutanol production.

Alternative renewable energy sources are the future potential energy that will benefit the country's overall energy shortage and demand. The efficient biofuel production depends on the viability of the raw material used. The holistic approach of this study is to establish an integrated bioprocess from lignocellulosic material for biofuel synthesis. Sugar bagasse as one of the waste material, can be economically process for sugar extraction used in biofuel production. In this study, the optimum saccharification rate obtained was 43.62% when the biomass was pretreated at microwave temperature of 100 °C for 15 min with 2.5 g catalyst concentration. The results attained shows that hydrolysis time reduces to approximately 40-50% in compare with other traditional heating method. The sample was analyzed by using UV spectrophotometer and HPLC and computed by using Response Surface Method in MINITAB 17, whereas the structural changes of the residue was detected by using ATR-FTIR and ESEM.

Conversion of rice husk into fermentable sugar and silica using acid-catalyzed ionic liquid pretreatment.

Rice husk is a bulky byproduct with a high silica content from rice milling. In this study, the application of an acid-catalyzed ionic liquid (IL) pretreatment was studied for processing rice husks with a rugged structure. The pretreatment conditions were 130°C for 30 min with 1.2 wt% HCl. The results of enzymatic hydrolysis demonstrated that cellulose conversion of HCl-BMIMCl-treated at 48 h was increased by 660.05%, 538.81%, and 376.55% compared with the untreated, HCl-treated, and BMIMCl-treated rice husks, respectively. Composition analysis demonstrated that most of the hemicellulose was removed in the acid-IL combined treatment. Moreover, scanning electron microscopy, X-ray diffraction (XRD), and Fourier transform infrared analyses indicated that the crystalline structure and outer silica layer of the rice husks were efficiently broken up. The results revealed that the HCl-catalyzed dissolution is highly favorable for the industrial application of rick husks in the production of fermentable sugar and high-purity silica.

Chemical characterization of PM2.5 emissions and atmospheric metallic element concentrations in PM2.5 emitted from mobile source gasoline-fueled vehicles.

Fine particulate matter with an aerodynamic diameter of <2.5 µm (PM2.5), particularly from the in-use gasoline-fueled vehicles, is a leading air quality pollutant and the chemical composition of PM2.5 is vital to the practical issues of climate change, health effects, and pollution control policies, inter alia. These atmospheric fine particulate matters (PM2.5) emitted from the exhausts of mobile source gasoline-fueled vehicles constitute substantial risks to human health through inhalation, and most importantly, affect urban air quality. Therefore, in order to explicitly determine the inhalation risks of PM2.5 which could potentially contain a significant amount of chemicals and metallic elements (MEs) concentration, we investigated the chemical composition (comprising of carbonaceous species and metallic elements) of PM2.5 emissions from mobile source gasoline-fueled vehicles. To further examine the chemical composition and metallic elements concentration in PM2.5 from the exhausts of mobile source gasoline-fueled vehicles, we systematically investigated PM2.5 emission samples collected from the exhausts of fifteen (15) mobile source gasoline-fueled vehicles. Our study has equally also determined the chemical compositions based on carbonaceous species (organic carbon - OC and elemental carbon - EC). Furthermore, the concentrations of PM2.5 and metallic elements (Ca, Al, Zn, K, Ca, Fe, Mg and Cr) in PM2.5 were analyzed with the help of Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The details of the tested gasoline-fueled vehicles cover the model years, consisting of the vehicles registered from 2000 to 2017 from several vehicle manufacturers (or brands) with various running mileages ranging from 123.4 to 575,844 km (average 123,105 km). Our results established that elemental carbon (EC) and organic carbon (OC) were the most significant concentrations of carbonaceous species. The concentration of metallic elements in PM2.5 and chemical characterization were studied by their relationship with atmospheric PM2.5 and the results showed that the metallic elements concentration in PM2.5 were in descending order as follows: Ca > Al > Zn > K > Fe > Mg > Cr. These results will help us to further understand how PM2.5 emissions from the exhausts of in-use gasoline-fueled vehicles contribute to both chemical and atmospheric metallic elements concentration in the ambient air.

Effect of air pollutants and toxic emissions from various mileage of motorcycles and aerosol related carcinogenicity and mutagenicity assessment.

This research investigates the mileage and the health risk assessment of aerosol carcinogenicity and mutagenicity emitted by ten in-use motorcycles. The total p-PAHs emission factor of ten in-use motorcycles are 676.3 µg km-1 with average of 67.6 ± 13.6 µg km-1. Naphthalene (Nap) shows the largest emission factors, followed by phenanthrene (PA) and fluoranthen (FL). The mileage present high correlation coefficient (Rsp = 0.681) with CO. CO is associated with cumulative mileage leading to bad combustion efficiency, which caused low to high relationship for total p-PAHs (Rsp = 0.388), PM2.5 (Rsp = 0.680) and NOx (Rsp = 0.799). Both PM2.5 and total p-PAHs are generally generated via incomplete combustion and the results expressed the moderate to high correlation (Rsp = 0.578, 0.898) with NOx. Taking into consideration of high-mileage motorcycles (30,001-50,000 km), the toxic equivalent of carcinogenicity and mutagenicity exhaust are about 4.67, 1.99 and 3.89, 2.0 times higher than low (10,001-20,000 km) and middle (20,001-30,000 km) cumulative mileages, respectively. Therefore, in the conclusion of our study in compared with that of other research directed the fact that lower carcinogenicity and mutagenicity emission factor were found at lower cumulative mileages motorcycles however, the impact increases with the high cumulative mileage motorcycles.

Assessment of PM2.5 and PAH content in PM2.5 emitted from mobile source gasoline-fueled vehicles in concomitant with the vehicle model and mileages.

This study investigates the PM2.5 emission and analyses the PAHs content in PM2.5 emitted from gasoline-fueled vehicles. Outflow from the vehicles appear to be the ultimate source of PAHs in metro urban communities since the emission from gasoline vehicle increases the wellbeing hazard due to contiguity of exposure to gasoline exhaust. In this study, fifteen vehicles were randomly taken for sampling, where sixteen priority PAHs concentration were investigated. The study was performed on the vehicles with different Euro standard emission by taking into consideration the European legislative levels for vehicles on the toxic gaseous emission. Among all the PAHs outflow components of PM2.5 radiated in the exhaust of gasoline engines, the average concentration of total PAHs discharged was 0.377ng/L-fuel, while the total BaPeq concentration was 0.00993ng/L-fuel.