Composting of municipal solid waste by different methods improved the growth of vegetables and reduced the health risks of cadmium and lead

Environmental Science and Pollution Research - Reutilization of putrescible municipal solid wastes (MSW) in agriculture can provide valuable plant nutrients. However, it may pose serious...     

A global perspective on the biology,impact and management of Chenopodium album and Chenopodium murale: two troublesome agricultural and environmental weeds

Environmental Science and Pollution Research - Chenopodium album and C. murale are cosmopolitan, annual weed species of notable economic importance. Their unique biological features, including high...     

Removal of antibiotics from aqueous solutions by nanoparticles: a systematic review and meta-analysis

Environmental Science and Pollution Research - Antibiotics, as one of the emerging pollutants, are non-biodegradable compounds and long-term exposure to them may affect endocrine, hormonal, and...     

Application of 1D and 2D MFR reactor technology for the isolation of insecticidal and anti-microbial properties from pyrolysis bio-oils

Valuable chemicals can be separated from agricultural residues by chemical or thermochemical processes. The application of pyrolysis has already been demonstrated as an efficient means to produce a liquid with a high concentration of desired product. The objective of this study was to apply an insect and microorganism bioassay-guided approach to separate and isolate pesticidal compounds from bio-oil produced through biomass pyrolysis. Tobacco leaf (Nicotianata bacum), tomato plant (Solanum lycopersicum), and spent coffee (Coffea arabica) grounds were pyrolyzed at 10°C/min from ambient to 565°C using the mechanically fluidized reactor (MFR). With one-dimensional (1D) MFR pyrolysis, the composition of the product vapors varied as the reactor temperature was raised allowing for the selection of the temperature range that corresponds to vapors with a high concentration of pesticidal properties. Further product separation was performed in a fractional condensation train, or 2D MFR pyrolysis, thus allowing for the separation of vapor components according to their condensation temperature. The 300–400°C tobacco and tomato bio-oil cuts from the 1D MFR showed the highest insecticidal and anti-microbial activity compared to the other bio-oil cuts. The 300–350 and 350–400°C bio-oil cuts produced by 2D MFR had the highest insecticidal activity when the bio-oil was collected from the 210°C condenser. The tobacco and tomato bio-oil had similar insecticidal activity (LC₅₀ of 2.1 and 2.2 mg/mL) when the bio-oil was collected in the 210°C condenser from the 300–350°C reactor temperature gases. The 2D MFR does concentrate the pesticidal products compared to the 1D MFR and thus can reduce the need for further separation steps such as solvent extraction.     

Application of life cycle assessment for hospital solid waste management: A case study

This study was meant to determine environmental aspects of hospital waste management scenarios using a life cycle analysis approach. The survey for this study was conducted at the largest hospital in a major city of Pakistan. The hospital was thoroughly analyzed from November 2014 to January 2015 to quantify its wastes by category. The functional unit of the study was selected as 1 tonne of disposable solid hospital waste. System boundaries included transportation of hospital solid waste and its treatment and disposal by landfilling, incineration, composting, and material recycling methods. These methods were evaluated based on their greenhouse gas emissions. Landfilling and incineration turned out to be the worst final disposal alternatives, whereas composting and material recovery displayed savings in emissions. An integrated system (composting, incineration, and material recycling) was found as the best solution among the evaluated scenarios. This study can be used by policymakers for the formulation of an integrated hospital waste management plan.

Implications: This study deals with environmental aspects of hospital waste management scenarios. It is an increasing area of concern in many developing and resource-constrained countries of the world. The life cycle analysis (LCA) approach is a useful tool for estimation of greenhouse gas emissions from different waste management activities. There is a shortage of information in existing literature regarding LCA of hospital wastes. To the best knowledge of the authors this work is the first attempt at quantifying the environmental footprint of hospital waste in Pakistan.     

Colonized beads as inoculum for marine biodegradability assessment: Application to Linear Alkylbenzene Sulfonate

An innovative biodegradation test system was developed in order to fill the current gap for cost effective and environmentally relevant tools to assess marine biodegradability. Glass beads were colonized by a biofilm in an open flow-through system of seawater with continuous pre-exposure to Linear Alkylbenzene Sulfonate (LAS) (20 μg/L). Thereafter, such colonized beads were added as inoculum in different test systems. [¹⁴C]-LAS (5–100 μg/L) was added and primary and ultimate biodegradation were assessed. The bacterial density collected on the beads (10⁹ bact./mL beads) was ca. 3 orders of magnitude higher than the typical seawater content. The LAS mineralization lag phase duration decreased from 55 to < 1 days and the mineralization extent increased from 53 to 90% as the colonized beads volume increased from 10 to 275 mL. This is the first demonstration of marine bacteria's ability to mineralize LAS. On the opposite, less than 13% LAS was mineralized in seawater only. The colonized beads possibly enhanced the probability to encounter the full degraders' consortium in a low volume of seawater (100 mL).     

Optimal temporal scale for the correlation of AOD and ground measurements of PM2.5 in a real-time air quality estimation system

Aerosol optical depth (AOD), an indirect estimate of particulate matter using satellite observations, has shown great promise in improving estimates of PM_2.5 (particulate matter with aerodynamic diameter less than or equal to 2.5 μm) surface. Currently, few studies have been conducted to explore the optimal way to apply AOD data to improve the model accuracy of PM_2.5 in a real-time air quality system. We believe that two major aspects may be worthy of consideration in that area: 1) an approach that integrates satellite measurements with ground measurements in the estimates of pollutants and 2) identification of an optimal temporal scale to calculate the correlation of AOD and ground measurements. This paper is focused on the second aspect, identifying the optimal temporal scale to correlate AOD with PM_2.5. Five following different temporal scales were chosen to evaluate their impact on the model performance: 1) within the last 3 days, 2) within the last 10 days, 3) within the last 30 days, 4) within the last 90 days, and 5) the time period with the highest correlation in a year. The model performance is evaluated for its accuracy, bias, and errors based on the following selected statistics: the Mean Bias, the Normalized Mean Bias, the Root Mean Square Error, Normalized Mean Error, and the Index of Agreement. This research shows that the model with the temporal scale: within the last 30 days, displays the best model performance in a southern multi-state area centered in Mississippi using 2004 and 2005 data sets.     

On-line production of ferrate with an electrochemical method and its potential application for wastewater treatment – A review

A number of studies on the oxidation of various organic/inorganic contaminants by ferrate(VI) were reported in the 1980s and 1990s. The exploration of the use of ferrate(VI) for water and wastewater treatment has been well addressed recently. However, challenges have existed for the implementation of ferrate(VI) technology in practice due to the instability of a ferrate solution or high production cost of solid ferrate products. The research has been carried out aiming at the generation and application of ferrate(VI) in situ. This paper thus reviews ferrate chemistry and its overall performance as a water treatment chemical, discusses the factors affecting the ferrate yield efficiency using the electrochemical method, and finally, summarises the work on the production and use of ferrate in situ which is currently under study.