Investigating the environmental costs of utilizing graphene-based adsorbents and pulsed power oxidation for the removal of emerging contaminants from urban wastewater

Tricks and tracks of prevalence, occurrences, treatment technologies, and challenges of mixtures of emerging contaminants in the environment: With special emphasis on microplastic

This paper aims to emphasize the occurrence of various emerging contaminant (EC) mixtures in natural ecosystems and highlights the primary concern arising from the unregulated release into soil and water, along with their impacts on human health. Emerging contaminant mixtures, including pharmaceuticals, personal care products, dioxins, polychlorinated biphenyls, pesticides, antibiotics, biocides, surfactants, phthalates, enteric viruses, and microplastics (MPs), are considered toxic contaminants with grave implications. MPs play a crucial role in transporting pollutants to aquatic and terrestrial ecosystems as they interact with the various components of the soil and water environments. This review summarizes that major emerging contaminants (ECs), like trimethoprim, diclofenac, sulfamethoxazole, and 17α-Ethinylestradiol, pose serious threats to public health and contribute to antimicrobial resistance. In addressing human health concerns and remediation techniques, this review critically evaluates conventional methods for removing ECs from complex matrices. The diverse physiochemical properties of surrounding environments facilitate the partitioning of ECs into sediments and other organic phases, resulting in carcinogenic, teratogenic, and estrogenic effects through active catalytic interactions and mechanisms mediated by aryl hydrocarbon receptors. The proactive toxicity of ECs mixture complexation and, in part, the yet-to-be-identified environmental mixtures of ECs represent a blind spot in current literature, necessitating conceptual frameworks for assessing the toxicity and risks with individual components and mixtures. Lastly, this review concludes with an in-depth exploration of future scopes, knowledge gaps, and challenges, emphasizing the need for a concerted effort in managing ECs and other organic pollutants.

Bibliometric analysis of Advanced Oxidation Processes studies with a focus on Life Cycle Assessment and Costs

Advanced oxidation processes (AOPs) are wastewater treatment technologies that stand out for their ability to degrade Contaminants of Emerging Concern (CECs). The literature has extensively investigated these removal processes for different aqueous matrices. Once technically mature, some of these systems have become accredited to be applied on a large scale, and therefore, their systemic performances in the environmental and cost spheres have also become essential requirements. This study proposed corroborating this trend, analyzing the available literature on the subject to verify how experts in the AOP area investigated this integration during 2015-2023. For this purpose, a sample of publications was treated by applying the Systematic Review (SR) methodology. This resulted in an extract of 83 studies that adopted life-cycle logic to estimate environmental impacts and process costs or evaluated them as complementary to the technical dimension of each treatment technology. This analysis found that both dimensions can be used for selecting or sizing AOPs at the design scale. However, the appropriate choice of the impact categories for the environmental assessment and establishing a methodology for cost analysis can make the approach still more effective. In addition, a staggering number of processes would broaden the reality and applicability of the estimates, and adopting multicriteria analysis methodologies could address essential aspects of decision-making processes during the design of the arrangements. By meeting the original purposes, the study broadened the requirements for designing AOPs and disseminating their use in mitigating the discharge of CECs.

How do energy technology innovation, financial inclusion, and digital trade help to achieve carbon neutrality targets?

The ultimate goal of carbon neutrality objectives is to bring greenhouse gas emissions down to a point where they are no longer a factor in escalating climate change and global warming. Adopting sustainable habits, technologies, and investments may be facilitated and accelerated by energy technology innovation, digitalization trade, and financial inclusion, which can substantially influence reaching carbon neutrality objectives. However, none of the past studies have examined the role of energy technology innovation, financial inclusion, and digital trade on the carbon neutrality targets in top polluted economies. To fill this vacuum, this study aims to investigate the effect of energy technology innovation, financial inclusion, and digital trade on carbon neutrality in the top 40 polluted economies across Asia, America, and Europe from 2004-2021. Two renowned econometric techniques are used for empirical analysis, including Two Stage Least Square (2SLS) and Generalized Method of Moments (GMM). The estimates of energy innovation, ICT trade, digital financial inclusion, foreign direct investment, and research and development spending highlight the adverse influence on carbon emissions in global, Asian, American, and European samples. Conversely, the per capita income and foreign direct investment cause carbon emissions to increase in Asia, America, and Europe. Thus, policy experts in top polluted economies should target an integrated policy with a central focus on energy innovation, digital trade, and financial inclusiveness to achieve carbon neutrality.

The fate of aggregated graphene oxide upon the increasing of pH: An experimental and molecular dynamic study

Given the possible ecological dangers of graphene oxide (GO), a thorough understanding of its aggregation behavior is essential. During industrial applications, GOs may be used as multi-layered, and there is some possibility that GOs are released into the water environment in the aggregated state. Thus, elucidating the fate of aggregated GO is valuable for evaluating their environmental fate. In this work, the effect of pH on the fate of aggregated graphene oxide (GO) was explored using experimental measurements and molecular dynamic simulations and promoted aggregation of GO upon the increase of pH was observed. Additional investigations show that the presence of oxidation debris (ODs) on GO served as the primary driver of the unanticipated trend in aggregation behavior. GO consists of lightly oxidized functionalized graphene sheets and highly oxidized ODs. Upon the increase of pH and the deprotonation of functional groups, ODs are stripped from GO due to electrostatic repulsions and steric hindrance of water molecules. The stripping of ODs decreased the zeta potential and increased the hydrophobicity of GO, thus accelerating the aggregation. Additionally, the stripped ODs may recombine to GO edges and bridged GOs, which also contribute to further aggregation. Functional group deprotonation, ODs stripping, OD bridging, double layer compression, and charge neutralization all worked together to promote aggregation, resulting in the formation of FG-water-OD aggregates. Overall, the presence of ODs complicates the structures and properties of GO and should be considered during the development of GO-related nanomaterials and the evaluation of their environmental impact.

Comparative Life-Cycle Cost Analysis of Alternative Technologies for the Removal of Emerging Contaminants from Urban Wastewater

Emerging contaminants (ECs) continue to threaten our fragile ecosystem, yet their mitigation remains limited by economic factors. Meanwhile, a relatively expensive material, Graphene Oxide (GO), has shown promise as a solution for EC removal following further development into three graphene-based materials (GBMs): Porous graphene adsorbent (PGa), Graphene-oxide foam adsorbent (GOFa), and the hybrid filter. Due to the nuances of each synthesis process, financial costs will differ throughout the GBMs’ life cycle which have been quantified and compared in the present work at a range of possible breakthrough times. Finally, economic and environmental costs have been combined for each technology to compare eco-efficiency. Results demonstrated a substantial economic advantage of the GBMs when compared to alternative technologies, most notably the GOFa filter that incurred the lowest life-cycle costs at $1.73 ± 0.09/m3. This was mainly attributed to the lower demand of GOFa on the most expensive material required for material synthesis, hydrazine. In addition, the material demands of GOFa were more evenly distributed which suggest a higher resilience of the overall costs to price hikes of individual materials required for synthesis. In terms of eco-efficiency the GOFa filter also demonstrated the greatest improvement when compared to the reference technology These results have provided robust total investment costs for several technologies that can now offer contrast to other EC-removal solutions.