Nondestructive characterization of municipal-solid-waste-contaminated surface soil by energy-dispersive X-ray fluorescence and low-Z (atomic number) particle electron probe X-ray microanalysis

The long-term environmental impact of municipal solid waste (MSW) landfilling is still under investigation due to the lack of detailed characterization studies. A MSW landfill site, popularly known as Dhapa, in the eastern fringe of the metropolis of Kolkata, India, is the subject of present study. A vast area of Dhapa, adjoining the current core MSW dump site and evolving from the raw MSW dumping in the past, is presently used for the cultivation of vegetables. The inorganic chemical characteristics of the MSW-contaminated Dhapa surface soil (covering a 2-km stretch of the area) along with a natural composite (geogenic) soil sample (from a small countryside farm), for comparison, were investigated using two complementary nondestructive analytical techniques, energy-dispersive X-ray fluorescence (EDXRF) for bulk analysis and low-Z (atomic number) particle electron probe X-ray microanalysis (low-Z particle EPMA) for single-particle analysis. The bulk concentrations of K, Rb, and Zr remain almost unchanged in all the soil samples. The Dhapa soil is found to be polluted with heavy metals such as Cu, Zn, and Pb (highly elevated) and Ti, Cr, Mn, Fe, Ni, and Sr (moderately elevated), compared to the natural countryside soil. These high bulk concentration levels of heavy metals were compared with the Ecological Soil Screening Levels for these elements (U.S. Environment Protection Agency) to assess the potential risk on the immediate biotic environment. Low-Z particle EPMA results showed that the aluminosilicate-containing particles were the most abundant, followed by SiO2, CaCO3-containing, and carbonaceous particles in the Dhapa samples, whereas in the countryside sample only aluminosilicate-containing and SiO2 particles were observed. The mineral particles encountered in the countryside sample are solely of geogenic origin, whereas those from the Dhapa samples seem to have evolved from a mixture of raw dumped MSW, urban dust, and other contributing factors such as wind, precipitation, weather patterns, farming, and water logging, resulting in their diverse chemical compositions and the abundant observation of carbonaceous species. Particles containing C and P were more abundant in the Dhapa samples than in the countryside soil sample, suggesting that MSW-contaminated soils are more fertile. However, the levels of particles containing potentially toxic heavy metals such as Cr, Mn, Ni, Cu, Zn, and/or Pb in the Dhapa samples were significant, corroborated by their high bulk concentration levels (EDXRF), causing deep concern for the immediate environment and contamination of the food chain through food crops.     

Determination of six anti-infectives in wastewater using tandem solid-phase extraction and liquid chromatography-tandem mass spectrometry

A rugged and specific method based on tandem solid-phase extraction and liquid chromatography-tandem mass spectrometry for the determination of anti-infectives in raw sewage and wastewater plant effluents was developed. Analyte recoveries from spiked effluents ranged from 68 to 104%. Two specific selected reaction monitoring transitions and their peak area ratios were used to avoid false positives and confirm the presence of the targeted substances. Detection limits allowed low nanogram per litre detection (0.3-22 ng L(-1)). The method was successfully applied to real samples from the Montréal wastewater treatment plant. All the studied anti-infectives were found in the wastewater samples in concentrations ranging from 39 to 276 ng L(-1). Mean flows of anti-infectives were estimated from effluent concentrations and it was found that large amounts (>118 g day(-1) up to 830 g day(-1)) are discharged in the receiving waters of the St Lawrence River.     

Propolis efficacy on SARS-COV viruses: a review on antimicrobial activities and molecular simulations

Environmental Science and Pollution Research - This current study review provides a brief review of a natural bee product known as propolis and its relevance toward combating SARS-CoV viruses....     

Consequences of manganese compounds: a review

Manufacturing of manganese (Mn) compounds, their industrial applications as well as mining overburden, has generated a potential environmental pollutant. Occupational exposure to elevated levels of Mn occurs during mining, welding, smelting and other industrial anthropogenic sources. Chronic and acute exposure of this metal pollutant leads to adverse consequences and is clinically categorized by various symptoms of neurotoxicity including cognitive, psychiatric symptoms, Parkinson's disease, extra pyramidal signs, manganism, dystonia, and motor system dysfunction. The aim of this review is to summarize the possible mechanism underlying Mn compounds-mediated neurotoxicity leading to neurodegenerative diseases. Our review endeavours to examine recent advances in research on Mn-related environmental pollution, Mn-induced poisoning, molecular mechanisms underlying Mn-induced neurotoxicity with case studies as well as current approaches employed for treatment and prevention of Mn exposure.     

Baseline requirements can hinder trades in water quality trading programs: Evidence from the Conestoga watershed

The U.S. Environmental Protection Agency (USEPA) and the U.S. Department of Agriculture (USDA) are promoting point/nonpoint trading as a way of reducing the costs of meeting water quality goals. Farms can create offsets by implementing management practices such as conservation tillage, nutrient management and buffer strips. To be eligible to sell offsets or credits, farmers must first comply with baseline requirements. USEPA guidance recommends that the baseline for nonpoint sources be management practices that are consistent with the water quality goal. A farmer would not be able to create offsets until the minimum practice standards are met. An alternative baseline is those practices being implemented at the time the trading program starts, or when the farmer enters the program. The selection of the baseline affects the efficiency and equity of the trading program. It has major implications for which farmers benefit from trading, the cost of nonpoint source offsets, and ultimately the number of offsets that nonpoint sources can sell to regulated point sources. We use a simple model of the average profit-maximizing dairy farmer operating in the Conestoga watershed in Pennsylvania to evaluate the implications of baseline requirements on the cost and quantity of offsets that can be produced for sale in a water quality trading market, and which farmers benefit most from trading.     

Performance assessment of the indigenous ceramic UF membrane in bioreactor process for highly polluted tannery wastewater treatment

Environmental Science and Pollution Research - The present study evaluates the performance of an indigenously developed ceramic ultrafiltration (UF) membrane in a lab-scale membrane bioreactor...     

Competitive Adsorption of Pb(II) and Phenol Onto Modified Chitosan/Vermiculite Adsorbents

Journal of Polymers and the Environment - Many industrial wastewaters are contaminated with both heavy metal ions and organic compounds, posing a major threat to public health and the ecosystem. In...     

Recycling of waste tire by pyrolysis to recover carbon black: an alternative reinforcing filler

Journal of Material Cycles and Waste Management - Thermal pyrolysis of waste tires is an industrially beneficial method for material and energy recovery. Pyrolytic carbon black (CBp) is considered...