Physicochemical factors and sources of particulate matter at residential urban environment in Kuala Lumpur

Long-term measurements (2004–2011) of PM₁₀ (particulate matter with an aerodynamic diameter <10 μm) and trace gases (carbon monoxide [CO], ozone [O₃], nitrogen oxide [NO], oxides of nitrogen [NO_x], nitrogen dioxide [NO₂], sulfur dioxide [SO₂], methane [CH₄], nonmethane hydrocarbon [NMHC]) have been conducted to study the effect of physicochemical factors on the PM₁₀ concentration. In addition, this study includes source apportionment of PM₁₀ in Kuala Lumpur urban environment. An advanced principal component analysis (PCA) technique coupled with absolute principal component scores (APCS) and multiple linear regression (MLR) has been applied. The average annual concentration of PM₁₀ for 8 yr is 51.3 ± 25.8 μg m^?3, which exceeds the Recommended Malaysian Air Quality Guideline (RMAQG) and international guideline values. Detail analysis shows the dependency of PM₁₀ on the linear changes of the motor vehicles in use and the amount of biomass burning, particularly from Sumatra, Indonesia, during southwesterly monsoon. The main sources of PM₁₀ identified by PCA-APCS-MLR are traffic combustion (28%), ozone coupled with meteorological factors (20%), and windblown particles (1%). However, the apportionment procedure left 28.0 μg m^?3, that is, 51% of PM₁₀ undetermined.

Implications: Air quality is always a top concern around the globe. Especially in the South Asian regions, measures are not yet sufficient; as revealed in our studies, the concentrations of particulate matters exceed the tolerable limits. Long-term data analysis and characterization of particular matters and their sources will aid the policy makers and the concerned authority to adapt measures and policies according to the circumstances. Additionally, similar intensive studies will give insight about future implications of air quality management.     

Use of fungi for the bioconversion of rice straw into cellulase enzyme

Cellulase production was carried out by solid state bioconversion (SSB) method using rice straw, a lignocellulosic material and agricultural waste, as the substrate of three Trichoderma spp. and Phanerochaete chrysosporium in lab-scale experiments. The results were compared to select the best fungi among them for the production of cellulase. Phanerochaete chrysosporium was found to be the best among these species of fungi, which produced the highest cellulase enzyme of 1.43 IU/mL of filter paper activity (FPase) and 2.40 IU/mL of carboxymethylcellulose activity (CMCase). The “glucosamine” and “reducing sugar” parameters were observed to evaluate the growth and substrate utilization in the experiments. In the case of Phanerochaete Chrysosporium, the highest glucosamine concentration was 1.60 g/L and a high concentration of the release of reducing sugar was measured as 2.58 g/L obtained on the 4th day of fermentation. The pH values were also recorded. The range of the pH was about 5.15 to 5.56 in the case of Phanerochaete Chrysosporium.     

Capital and Operating Costs of Selected Air Pollution Control Systems—IV

Previous articles in this series discussed the equipment costs of control devices, gas conditioning equipment, hoods, ductwork, and dampers. In this article, the discussion will concern the fans and associated components required to convey the gas stream from the initial pollutant source to the control device.     

Urbanisation and greening of Indian cities: Problems,practices, and policies

Progress of the Indian economy is threatened by the impact of climate change. Generation of urban heat islands (UHIs), waning of urban green cover, increase in carbon emissions and air pollution deteriorate the living environment. Rise in urban temperatures and heat stress induced mortality remain major concerns. Although the National Action Plan on Climate Change emphasises the national missions of ‘enhanced energy efficiency’, and ‘green India’, little research has been devoted to explore the passive cooling potential of urban greenery in India, thus lending uniqueness to this study. The manifestations of unplanned urban development (UHIs, escalated carbon emissions, air pollution) are discussed and corroborated with identification of contributory factors. Contemporary greening practices and bye-laws in four major Indian cities (New Delhi, Pune, Chennai, and Visakhapatnam) are analysed and compared with global best practices. The findings are used to propose planning guidelines which are expected to assist in consolidating natural sustainability of emerging economies.     

The challenges of reducing greenhouse gas emissions and air pollution through energy sources: evidence from a panel of developed countries

The objective of the study is to investigate the long-run relationship between climatic factors (i.e., greenhouse gas emissions, agricultural methane emissions, and industrial nitrous oxide emission), air pollution (i.e., carbon dioxide emissions), and energy sources (i.e., nuclear energy; oil, gas, and coal energy; and fossil fuel energy) in the panel of 35 developed countries (including EU-15, new EU member states, G-7, and other countries) over a period of 1975–2012. In order to achieve this objective, the present study uses sophisticated panel econometric techniques including panel cointegration, panel fully modified OLS (FMOLS), and dynamic OLS (DOLS). The results show that there is a long-run relationship between the variables. Nuclear energy reduces greenhouse gases and carbon emissions; however, the other emissions, i.e., agricultural methane emissions and industrial nitrous oxide, are still to increase during the study period. Electricity production from oil, gas, and coal sources increases the greenhouse gases and carbon emissions; however, the intensity to increase emissions is far less than the intensity to increase emissions through fossil fuel. Policies that reduce emissions of greenhouse gases can simultaneously alter emissions of conventional pollutants that have deleterious effects on human health and the environment.     

Microbial contamination of drinking water in Pakistan—a review

Water pollution with pathogenic microorganisms is one of the serious threats to human health, particularly in developing countries. The main objective of this article is to highlight microbial contamination of drinking water, the major factors responsible for microbial contamination, and the resulting health problems in Pakistan. Furthermore, this study will be helpful for researchers and administrative agencies to initiate relevant studies and develop new policies to protect further deterioration of water supply with pathogenic microbes and ensure clean and safe drinking water to the public in Pakistan. In Pakistan, water at the source, in the distribution network, and at the consumer tap is heavily polluted with coliforms and fecal coliforms all over the country. An overview of more than 7,000 water samples reviewed here reveals that an average of over 71 and 58 % samples in the country was contaminated with total coliforms and fecal coliforms, respectively. Drinking water contamination accounts for 20 to 40 % of all diseases in the country, which causes national income losses of Rs 25–58 billion annually (US$0.25–0.58 billion, approximately 0.6–1.44 % of the country’s GDP). Improper disposal of industrial and municipal wastes is the most important factor responsible for water pollution in the country followed by cross-contamination due to old and leaking pipes and lack of water filtration and disinfection facilities. There is an urgent need for emergency steps to stop further deterioration of water quality and improve the existing water quality so as to protect the public from widespread waterborne diseases.     

UV–visible light-activated Ag-decorated,monodisperse TiO2 aggregates for treatment of the pharmaceutical oxytetracycline

Noble metal Ag-decorated, monodisperse TiO₂ aggregates were successfully synthesized by an ionic strength-assisted, simple sol–gel method and were used for the photocatalytic degradation of the antibiotic oxytetracycline (OTC) under both UV and visible light (UV–visible light) irradiation. The synthesized samples were characterized by X-ray diffraction analysis (XRD); UV–vis diffuse reflectance spectroscopy; environmental scanning electron microscopy (ESEM); transmission electron microscopy (TEM); high-resolution TEM (HR-TEM); micro-Raman, energy-dispersive X-ray spectroscopy (EDS); and inductively coupled plasma optical emission spectrometry (ICP-OES). The results showed that the uniformity of TiO₂ aggregates was finely tuned by the sol–gel method, and Ag was well decorated on the monodisperse TiO₂ aggregates. The absorption of the samples in the visible light region increased with increasing Ag loading that was proportional to the amount of Ag precursor added in the solution over the tested concentration range. The Brunauer, Emmett, and Teller (The BET) surface area slightly decreased with increasing Ag loading on the TiO₂ aggregates. Ag-decorated TiO₂ samples demonstrated enhanced photocatalytic activity for the degradation of OTC under UV–visible light illumination compared to that of pure TiO₂. The sample containing 1.9 wt% Ag showed the highest photocatalytic activity for the degradation of OTC under both UV–visible light and visible light illumination. During the experiments, the detected Ag leaching for the best TiO₂-Ag photocatalyst was much lower than the National Secondary Drinking Water Regulation for Ag limit (0.1 mg L^?1) issued by the US Environmental Protection Agency.     

How much could a tanker spill cost British Columbians?

Ocean-based industries provide employment for nearly 30 % of the population in the North Coast region of British Columbia. Marine resource dependence has raised concerns about the possible economic impacts of a tanker spill along the proposed Enbridge Northern Gateway shipping route, which would export 525,000 barrels (bbls) per day of oil, bitumen, and condensate from Kitimat, British Columbia, to international markets. This study uses current and projected future values of four ocean-based industries and the Enbridge Northern Gateway project to estimate total (i.e., direct, indirect, and induced) economic effects on total output, employment, and gross domestic product (GDP) and impacts on the regional economy over a 50-year period under three potential spill scenarios: no impact (no spill), medium impact (a 63,000-bbl spill), and high impact (a 257,000-bbl spill). The proposed Enbridge Northern Gateway project could produce total positive economic effects of $600 million in output, 5,700–8,400 person years (PYs) of employment, and $300 million in GDP in the North Coast region. A medium impact tanker spill could cause losses of $40–$190 million in output, 400–1,500 PYs of employment, and $20–$100 million in GDP, and a high-impact spill could cause losses of $90–$300 million in output, 1,650–4,500 PYs of employment, and $70–$200 million in GDP.     

Evidence for a warm and humid Mid-Holocene episode in the Aegean and northern Levantine Seas (Greece,NE Mediterranean)

Marine and terrestrial biological and biogeochemical proxies in three sediment cores from North and SE Aegean and northern Levantine Seas record continuous warm and humid conditions between 5.5 and 4.0 ka BP related to the establishment of relatively stratified conditions in the upper water column. These conditions may have resulted from the concordant albeit weak Mid-Holocene South Asian monsoon forcing, combined with lighter Etesian winds. During this interval, sea surface temperatures fluctuate in the Aegean Sea, although exhibiting a strong positive shift at ~4.8 ka BP. The warm and humid climatic conditions triggered upper water column stratification and enhancement of the deep chlorophyll maximum (DCM), leading to dysoxic conditions and the deposition of a sapropel-like layer, but only in the SE Aegean site. In contrast to the shallow water SE Aegean, the deeper North Aegean and the northern Levantine sites, although experiencing stratification in the upper parts of the water column, did not achieve bottom-water dysoxia. Thus, a top–bottom mechanism of stratification–DCM development accompanied by fast transport and burial of organic matter is a likely explanation for the preservation of productivity signal in the shallow sites of the SE Aegean and establishment of sapropelic conditions during the warm and humid Mid-Holocene. The termination of the Mid-Holocene warm and humid phase coincides with the “4.2 ka” climate event. Our data exhibit an N–S time transgressive aridification gradient around the Aegean Sea, most probably associated with the reorganization of the general atmospheric circulation during the Mid-Holocene.