Modeling of water quality downgradient of a mulch biowall

Groundwater treatment biowalls may be located close to a surface water body to prevent contaminant discharge from a groundwater plume into the surface water. Groundwater contaminants passing through the biowall are treated within the biowall or immediately downgradient of the biowall. Biowalls designed and constructed for the treatment of chlorinated solvents typically contain either a solid and/or liquid source of organic carbon to promote contaminant degradation by enhanced anaerobic reductive dechlorination. Common solid organic materials in biowalls include wood mulch or similar waste plant material, and common liquid organic materials are vegetable oil (possibly emulsified) or other long‐chain fatty acids. Such biowalls then develop anaerobic conditions in the constructed biowall volume, and potentially downgradient, as dissolved oxygen originally present in the aquifer is consumed. This groundwater condition can lead to the appearance of sulfide if groundwater influent to the biowall contains moderate to high sulfate concentrations. Other researchers have presented evidence for groundwater conditions downgradient of a biowall or a permeable reactive barrier (PRB) that are altered in relation to groundwater quality, besides the desired effect of contaminant degradation or removal by precipitation. The objective of this work was to investigate with modeling the changes in downgradient groundwater species chemistry as a result of a constructed biowall. This was accomplished with a chemical species model to predict levels of sulfate and sulfide present in groundwater in close downgradient proximity to the biowall. The results indicate that downgradient chemical changes could impact a surface water body to which groundwater discharges. The model described could be enhanced by incorporating additional design variables that should be considered in biowall feasibility assessments.     

The environmental aspects of conventional and clean energy policy in sub-Saharan Africa: is N-shaped hypothesis valid?

Environmental Science and Pollution Research - In the energy-environment literature, a handful of the advanced economies, mostly the European Union countries, have met some of the national...     

Experimental investigation of adsorption capacity of anthill in the removal of heavy metals from aqueous solution

In the present work, the adsorption capacity of anthill was investigated as a low‐cost adsorbent to remove the heavy metal ions, lead (II) ion (Pb²⁺), and zinc (II) ion (Zn²⁺) from an aqueous solution. The equilibrium adsorption isotherms of the heavy metal ions were investigated under batch process. For the study we examined the effect of the solution's pH and the initial cations concentrations on the adsorption process under a fixed contact time and temperature. The anthill sample was characterized using a scanning electron microscope (SEM), X‐ray fluorescence (XRF), and Fourier transform infrared (FTIR) techniques. From the SEM analysis, structural change in the adsorbent was a result of heavy metals adsorption. Based on the XRF analysis, the main composition of the anthill sample was silica (SiO₂), alumina (Al₂O₃), and zirconia (ZrO₂). The change in the peaks of the spectra before and after adsorption indicated that there was active participation of surface functional groups during the adsorption process. The experimental data obtained were analyzed using 2‐ and 3‐parameter isotherm models. The isotherm data fitted very well to the 3‐parameter Radke–Prausnitz model. It was noted that Pb²⁺ and Zn²⁺ can be effectively removed from aqueous solution using anthill as an adsorbent.     

Technological trends in nanosilica synthesis and utilization in advanced treatment of water and wastewater

Environmental Science and Pollution Research - Water and wastewater treatment applications stand to benefit immensely from the design and development of new materials based on silica nanoparticles...     

Recent improvements in oily wastewater treatment: Progress, challenges, and future opportunities

Oily wastewater poses significant threats to the soil, water, air and human beings because of the hazardous nature of its oil contents. The objective of this review paper is to highlight the current and recently developed methods for oily wastewater treatment through which contaminants such as oil, fats, grease, and inorganics can be removed for safe applications. These include electrochemical treatment, membrane filtration, biological treatment, hybrid technologies, use of biosurfactants, treatment via vacuum ultraviolet radiation, and destabilization of emulsions through the use of zeolites and other natural minerals. This review encompasses innovative and novel approaches to oily wastewater treatment and provides scientific background for future work that will be aimed at reducing the adverse impact of the discharge of oily wastewater into the environment. The current challenges affecting the optimal performance of oily wastewater treatment methods and opportunities for future research development in this field are also discussed.     

Pollutant emission effect of tourism,real income,energy utilization,and urbanization in OECD countries: a panel quantile approach

Environmental Science and Pollution Research - Although the Organization for Economic Co-operation and Development (OECD) member countries are largely regarded as a high human development index and...     

The role of partisan conflict in environmental sustainability targets of the United States

The prevailing political atmosphere and partisanship in the United States depict the degree of polarization between the two major political parties of the country. Evidently, the polarization between the Democratic Party (DP) and the Republican Party will expectedly drive the partisan conflict to the higher levels. Considering this motivation, this paper examined the role of partisan conflict in the pollutant emissions in the case of the United States. For sound empirical analysis, the impacts of other environmental quality determinants are being examined over the period 1960–2015. In order to present a decent argument that is viable for policy implementation, the study adopts the combined methodologies of Johansen cointegration; the autoregressive distributed lag (ARDL) of Pesaran et al. J Am Stat Assoc 94(446):621–634 (1999); and the Toda and Yamamoto J Econ 66(1–2):225–250 (1995) Granger causality. Empirical outcomes show (i) the kg oil equivalent per capita energy consumed exercise positive and significant impacts on metric tons of per capita CO2 emissions, and it is the principal determinant of environmental degradation in both the short-run and the long-run (ii) renewable energy consumption and economic growth also exercise negative and significant impacts on metric tons of per capita CO2 emissions. Based on our empirical findings, we conclude that partisan conflict indirectly plays a significant role in environmental sustainability targets of the United States. Thus, we are of the opinion that the government should avoid heightened partisan conflict among the political parties in order to promote sustainable environmental policies that would enhance sound and clean environment for both the immediate and the future generation.     

Environmental aspect of energy transition and urbanization in the OPEC member states

Environmental Science and Pollution Research - More than any other nations, the crude oil–exporting countries and especially the Organization of the Petroleum Exporting Countries (OPEC) are...     

Do natural resources and economic components exhibit differential quantile environmental effects?

In view of the resource curse assumption, the environmental aspects of resource utilization are arguably posing more dangers to human existence. In the Middle East and North Africa (MENA) region, the region that holds more than 60% and 50% of the world's oil and gas reserves respectively, the need to examine the contribution of natural resources to environmental quality among other factors cannot be overemphasized. By leveraging on the novelty of observing the differential impact of natural resources and other economic components such as income and primary energy utilizations across the quantiles of carbon emission, this study implements the quantile regression approach alongside other relevant techniques to analyze data between 1990 and 2018 for selected countries in the MENA region including Saudi Arabia, Iran, Kuwait, Qatar, Algeria, Morocco, Oman, Egypt, and the United Arab Emirates (UAE). The result posits that natural resource utilization generally hampers the environment across the quantiles. However, this negative effect decreases until the 50th quantile before starting to rise again toward the upper quantiles. Additionally, primary energy utilization and globalization respectively worsen and improve environmental quantile, especially toward the upper quantiles while income affirms the inverted U-shaped hypothesis across the entire quantiles. Moreover, there is a statistically significant one-way directional causality from natural resources, economic expansion, primary energy use, and globalization to carbon emission levels. Hence, the study offers environmentally friendly resource utilization policies to the MENA economies and other resource-rich states by extension.