Real-time bias-adjusted O3 and PM2.5 air quality index forecasts and their performance evaluations over the continental United States

The National Air Quality Forecast Capacity (NAQFC) system, which links NOAA’s North American Mesoscale (NAM) meteorological model with EPA’s Community Multiscale Air Quality (CMAQ) model, provided operational ozone (O₃) and experimental fine particular matter (PM_2.5) forecasts over the continental United States (CONUS) during 2008. This paper describes the implementation of a real-time Kalman Filter (KF) bias-adjustment technique to improve the accuracy of O₃ and PM_2.5 forecasts at discrete monitoring locations. The operational surface-level O₃ and PM_2.5 forecasts from the NAQFC system were post-processed by the KF bias-adjusted technique using near real-time hourly O₃ and PM_2.5 observations obtained from EPA’s AIRNow measurement network. The KF bias-adjusted forecasts were created daily, providing 24-h hourly bias-adjusted forecasts for O₃ and PM_2.5 at all AIRNow monitoring sites within the CONUS domain. The bias-adjustment post-processing implemented in this study requires minimal computational cost; requiring less than 10 min of CPU on a single processor Linux machine to generate 24-h hourly bias-adjusted forecasts over the entire CONUS domain.The results show that the real-time KF bias-adjusted forecasts for both O₃ and PM_2.5 have performed as well as or even better than the previous studies when the same technique was applied to the historical O₃ and PM_2.5 time series from archived AQF in earlier years. Compared to the raw forecasts, the KF forecasts displayed significant improvement in the daily maximum 8-h O₃ and daily mean PM_2.5 forecasts in terms of both discrete (i.e., reduced errors, increased correlation coefficients, and index of agreement) and categorical (increased hit rate and decreased false alarm ratio) evaluation metrics at almost all locations during the study period in 2008.     

NiO/AC催化臭氧氧化去除水中的苯酚

采用低温湿式浸渍法制备了负载氧化镍/活性炭(简称NiO/AC)催化剂。在不同pH、叔丁醇浓度等条件下,对NiO/AC与臭氧联合催化臭氧氧化苯酚的降解效果等进行了研究。用XRD、SEM及BET技术分析了活性炭与催化剂的组成、形貌及结构变化。结果表明,镍以棒状氧化镍的形式负载在活性炭表面,与AC相比,NiO/AC比表面积减少了47.9%。在O3/NiO/AC与苯酚的反应体系中,反应遵循羟基自由基(HO.)机理,苯酚的去除率比单独臭氧氧化提高了29%,且与溶液pH呈正相关。NiO/AC催化性能较稳定,镍离子最大析出浓度仅为7 mg/L,可重复使用。     

Biodegradability of leathers through anaerobic pathway

Leather processing generates huge amounts of both solid and liquid wastes. The management of solid wastes, especially tanned leather waste, is a challenging problem faced by tanners. Hence, studies on biodegradability of leather become imperative. In this present work, biodegradability of untanned, chrome tanned and vegetable tanned leather under anaerobic conditions has been addressed. Two different sources of anaerobes have been used for this purpose. The effect of detanning as a pretreatment method before subjecting the leather to biodegradation has also been studied. It has been found that vegetable tanned leather leads to more gas production than chrome tanned leather. Mixed anaerobic isolates when employed as an inoculum are able to degrade the soluble organics of vegetable tanned material and thus exhibit an increased level of gas production during the initial days, compared to the results of the treatments that received the anaerobic sludge. With chrome tanned materials, there was not much change in the volume of the gas produced from the two different sources. It has been found that detanning tends to improve the biodegradability of both types of leathers.     

Hydrocarbon Uptake by Roots of Vicia faba (Fabaceae)

Vicia faba was grown in crude oil polluted soil and its roots were extracted for the detection and estimation of hydrocarbons. Saturated and unsaturated Aliphatic Hydrocarbons (AHs) ranging from C₂₂ to C₃₆ were identified in AHs fraction. However, PAHs were not present in the same extract. This could be due to the fact that PAHs being toxic compounds are not accumulated in the plant root extracts of V. faba grown in crude oil polluted soil. Three phytoalexins were identified and estimated by mass spectrometric analysis in the root extracts of V. faba. These three compounds are 2-t-butyl-4-(dimethyl benzyl) phenol, 2, 4-bis (dimethyl benzyl) phenol and 2,4-bis (dimethyl benzyl)-6-butyl phenol. These phenolics in V. faba are being reported for the first time. These compounds are presumably elicited as a direct stress on crude oil hydrocarbons on the roots of this plant.     

Effectiveness of porous covers for control of ammonia, reduced sulfur compounds, total hydrocarbons, selected volatile organic compounds, and odor from hog manure storage lagoons

Anaerobic lagoons are a major source of odor at concentrated animal feeding operations. Seven different kinds of artificial (geotextile and polyethylene foam) and natural (straw and redwood) permeable lagoon covers were evaluated for their potential to reduce odorous emissions generated by anaerobic waste lagoons. A novel floating sampling raft was constructed and used to simultaneously evaluate the effectiveness of lagoon covers on an operating swine waste lagoon. The air collected from the raft was evaluated for odor, total reduced sulfur (TRS) compounds, ammonia, total hydrocarbons, dimethyldisulfide, and trimethylamine. The emission rates from the lagoon were highly variable both temporally and spatially. All of the lagoon covers substantially reduced TRS emissions and odor. Geotextile fabric and a recycled foam cover exhibited the greatest reduction in total hydrocarbon emissions; natural covers were less effective. Because of consistently low emission rates of ammonia, no statistically significant reduction of ammonia emissions were observed from any of the lagoon covers.     

Facile and Sensitive Spectrophotometric Determination of Carbosulfan in Formulations and Environmental Samples

Facile, selective and sensitive spectrophotometric method has been developed for the determination of carbosulfan in insecticidal formulations, fortified water, food grains, agriculture wastewater and soil samples with newly synthesized reagents. The method was based on acid and alkaline hydrolysis of the carbosulfan pesticide, and the resultant hydrolysis product of carbosulfan was coupled with 2,6-dibromo-4-methylaniline to give a yellow color product with λ _max of 464 nm or interaction with 2,6-dibromo-4-nitroaniline to produce yellow colored product with λ _max of 408 nm or coupling with 2,4,6-tribromoaniline to form red colored product has a λ _max of 471 nm. Under optimal conditions, Beer’s law range for 2,6-dibromo-4-methylaniline (DBMA) was found to be 0.2–12.0 μg ml⁻¹, 0.6–16.0 μg ml⁻¹ for 2,6-dibromo-4-nitroaniline (DBNA) and 0.4–15.0 μg ml⁻¹ for 2,4,6-tribromoaniline (TBA). The molar absorptivity of the color systems were found to be 3.112 × 10⁴ l mol⁻¹ cm⁻¹ for DBMA, 3.214 × 10⁴ l mol⁻¹ cm⁻¹ for DBNA and 3.881 × 10⁴ l mol⁻¹ cm⁻¹ for TBA. Sandell’s of the color reactions are 0.013 μg cm⁻² (DBMA), 0.012 μg cm⁻² (DBNA) and 0.011 μg cm⁻² (TBA) respectively. The effect of the non-target species on the determination of carbosulfan was studied to enhance the selectivity of the proposed methods. The formation of colored derivatives with the coupling agents is instantaneous and stable for 28, 30, and 26 h. Performance of the proposed methods were compared statistically in terms Student’s F and t-tests with the reported methods. An erratum to this article can be found at     

Environmental impact of plantations in and around the petroleum refinery: a case study

Plantation or green belt (GB) grown around the factories and industrial premises improves the condition of land, mitigates air pollution (as the plants serve as a sink for pollutants and check the flow of dust, etc.), and reduces the level of noise pollution. The software developed by NEERI for the determination of the optimal width of GB in and around an industry is based on the pollution attenuation coefficient of selected plant species of deciduous trees existing in the region. The assessment of the impact of these plantations/green belts of 500-m width in and around a petroleum refinery in the west coast of India is evaluated for reducing/managing various waste generated, and it is observed that the overall efficiency is more than 60%.     

Fluoride in groundwater, Varaha River Basin, Visakhapatnam District, Andhra Pradesh, India

Excess intake of fluoride through drinking water causes fluorosis on human beings in many States of the country (India), including Andhra Pradesh. Groundwater quality in the Varaha River Basin located in the Visakhapatnam District of Andhra Pradesh has been studied, with reference to fluoride content, for its possible sources for implementing appropriate management measures, according to the controlling mechanism of fluoride concentration in the groundwater. The area occupied by the river basin is underlain by the Precambrian Eastern Ghats, over which the Recent sediments occur. Results of the chemical data of the groundwater suggest that the considerable number of groundwater samples show fluoride content greater than that of the safe limit prescribed for drinking purpose. Statistical analysis shows that the fluoride has a good positive relation, with pH and bicarbonate. This indicates an alkaline environment, as a dominant controlling mechanism for leaching of fluoride from the source material. Other supplementary factors responsible for the occurrence of fluoride in the groundwater are evapotranspiration, long contact time of water with the aquifer material, and agricultural fertilizers. A lack of correlation between fluoride and chloride, and a high positive correlation between fluoride and bicarbonate indicate recharge of the aquifer by the river water. However, the higher concentration of fluoride observed in the groundwater in some locations indicates insufficient dilution by the river water. That means the natural dilution did not perform more effectively. Hence, the study emphasizes the need for surface water management structures, with people's participation, for getting more effective results.     

Environmental Modeling and Methods for Estimation of the Global Health Impacts of Air Pollution

Air pollution is increasingly recognized as a significant contributor to global health outcomes. A methodological framework for evaluating the global health-related outcomes of outdoor and indoor (household) air pollution is presented and validated for the year 2005. Ambient concentrations of PM2.5 are estimated with a combination of energy and atmospheric models, with detailed representation of urban and rural spatial exposures. Populations dependent on solid fuels are established with household survey data. Health impacts for outdoor and household air pollution are independently calculated using the fractions of disease that can be attributed to ambient air pollution exposure and solid fuel use. Estimated ambient pollution concentrations indicate that more than 80% of the population exceeds the WHO Air Quality Guidelines in 2005. In addition, 3.26?billion people were found to use solid fuel for cooking in three regions of Sub Saharan Africa, South Asia and Pacific Asia in 2005. Outdoor air pollution results in 2.7?million deaths or 23?million disability adjusted life years (DALYs) while household air pollution from solid fuel use and related indoor smoke results in 2.1?million deaths or 41.6?million DALYs. The higher morbidity from household air pollution can be attributed to children below the age of 5 in Sub Saharan Africa and South Asia. The burden of disease from air pollution is found to be significant, thus indicating the importance of policy interventions.