Daniele Di Trapani

Sediments play a crucial role in the marine ecosystem by serving as both a sink for pollutants from human activities and a medium of exchange with aquatic environments and organisms. Chemical contaminants such as heavy metals and hydrocarbons pose significant risks due to their potential for bioaccumulation. As a result, treating marine sediments is often necessary. The present study reports the results of the experimental activities aimed at evaluating the removal performance achievable with a Low-Temperature Desorption Treatment (LTDT) on contaminated marine sediments. An LTDT was simulated by means of a lab-scale plant, with the aim of optimizing recalcitrant organic pollutant removal, evaluated by the analysis of the residual concentration of total petroleum hydrocarbons (TPH) in the sediments by varying the treatment temperature (200, 350, and 500 °C) and contact time (10, 15, and 20 min). The evolved vapors were recovered by means of an off-gas condenser system that allowed mass balances to be performed and the volatile organic compound recovery efficiency to be evaluated. Two different biochars were tested as innovative adsorbent materials, achieving a contaminant removal between 97 and 99%.

Dumpsites represent a major environmental and public health challenge, particularly in low- and middle-income countries (LMICs). Despite increasing global waste generation, many regions still struggle to implement safe and sustainable waste management practices, resulting in significant pollution, greenhouse gas emissions, and health risks due to uncontrolled waste disposal. Dumpsites lack containment measures, allowing pollutants to migrate through environmental matrices and reach different targets (e.g., human receptors). The primary objective of this review was to evaluate existing risk assessment procedures and propose a research direction for a standardized human health risk assessment (HHRA) methodology to prioritize interventions, starting with the most dangerous dumpsites in a given territory. The paper begins by presenting an overview of dumpsites, followed by a discussion on the pathways through which pollutants may migrate from dumpsites to human receptors and the associated health risks. Citing case studies, we explore the available environmental and health risk assessment methodologies, identifying and discussing key characteristics appropriate for dumpsites with a focus on LMICs where such sites are widespread and appropriate approaches are necessary. We identify and further discuss the relative HHRA as the most practical and reliable approach. We conclude with recommendations on research and policy.

Groundwater is a critical resource for drinking and irrigation, particularly in the Blue Nile River Basin, Ethiopia. However, uncontrolled waste disposal and leachate leaching from dumpsites can severely compromise water quality. This issue is not unique to Ethiopia. Globally, leachate from poorly managed landfills poses a serious threat to groundwater. This study investigates the impact of a dumpsite on shallow groundwater contamination in Bahir Dar City, assessing the associated risks to nearby communities. Groundwater and leachate samples were collected and analyzed using standard protocols to determine their chemical and physical properties. The Leachate Pollution Index (LPI) was applied. It quantifies the leachate contamination potential based on the concentration of 18 parameters and can be adopted even if data is not available for all the parameters. Results were compared with national and international water quality standards. Groundwater level maps and subsurface flow directions were generated using Surfer 2.0 software. The LPI value of 42.11 indicates a relatively high pollution risk. Among the heavy metals, chromium emerged as the most concerning contaminant, due to its toxicity and bioaccumulation potential. As expected, W1, being the closest well downstream to the dumpsite, was a hot spot with the highest concentrations of pollutants. Surprisingly, W6, i.e. the closest well upstream the dumpsite, was the second more polluted well. This result suggests complex hydrogeological dynamics or site-specific conditions that deserve further investigations. The study highlights the urgent need for improved waste management and groundwater protection strategies. Its integrated monitoring and inferential approach offers a replicable model for addressing similar challenges in other regions facing rapid urbanization and inadequate waste infrastructure.

This study aims to assess the ecological and human health risks associated with four heavy metals (Cd, Cr, Cu, and Zn) in the soil of a dumpsite in Targuist city, Morocco. In total, 16 surface soil samples were collected from the dumpsite and its nearby areas following leaching drain flows. The pollution load index (PLI), geo-accumulation index (Igeo), and potential ecological risk index (RI) were subsequently determined. In addition, hazard quotient (HQ) and health index (HI) were used to assess the non-carcinogenic and carcinogenic risks associated with the soil heavy metal contents. The PLI indicated significant contamination by the studied heavy metals. On the other hand, the Igeo values suggested no Cr contamination, moderate contamination by Cu and Zn, and severe contamination by Cd. The RI indicated a dominant contribution from Cd, with minor contributions from Cu, Zn, and Cr accounting for 92.47, 5.44, 1.11, and 0.96%, respectively, to the potential ecological risk in the study area. The non-carcinogenic health risks associated with exposure of the nearby population to the soil heavy metals at the dumpsite and burned solid waste-derived air pollution were below the threshold value of 1 for both children and adults. Although carcinogenic risks were observed in the study area, they were acceptable for both children and adults according to the United States Environmental Protection Agency (USEPA). However, carcinogenic risks associated with Cr were unacceptable according to the Italian Legislation. Finally, strategies to mitigate the risks posed by the dumpsite were also discussed in this study.

The direct measurement of volatile compounds is becoming increasingly important in assessing site contamination, particularly in relation to human health risk assessment and the design of remediation procedures. This study assesses the influence of direct measurements on the human health risk assessment conducted at a petroleum-contaminated site. Specifically, it provides contaminated-site risk managers with a quantitative comparison of the assessed risks by using measured and modeled data. A total of 16 monitoring campaigns were conducted at a Site of National Interest (SNI) located in Sicily (Italy), during which the hydrocarbon vapor concentrations in the subsurface soil porosity were measured using nested soil gas probes, while the related emitted fluxes were quantified with dynamic flux chambers. Measured data were compared with those obtained with a non-reactive diffusive model using the concentrations measured in the soil. The results highlighted significant overestimations of the expected outdoor concentrations obtained using non-reactive diffusive models by up to four orders of magnitude. These findings underscore the intrinsic limitation of non-reactive diffusive models, which provide overly conservative and unrealistic risk scenarios. Therefore, direct measurements might represent a cost-effective option to account for natural attenuation phenomena occurring in the subsurface, leading to a more realistic human health risk assessment (HHRA).

Rapid population and economic growth have increased the demand for depleting resources. Nitrogen (N) and phosphorus (P) are mineral elements that perform important functions in plants, but their extraction is not sustainable. In addition, these elements contribute significantly to the eutrophication of water bodies. The recovery of these nutrients from wastewater by adsorption techniques offers a promising solution. Previous studies have demonstrated the adsorption capabilities of materials such as zeolite for ammonium (NH₄⁺) and biochar for P. In addition, these materials can serve as a source of N and P for plants in a circular economy context. In this regard, this study aims to evaluate the recovery of N and P by the adsorption capacities of zeolite and biochar through a column test with treated wastewater. Two columns positioned in series, one filled with 2.7 kg of zeolite and the other with 397 g of biochar, were placed at the outlet of the full-scale sewage treatment plant of Marineo (Italy). The zeolite adsorbed 3.6 g of NH₄⁺ accumulated during the test with a rate of adsorption of 44% and adsorption of 1.33 mg g⁻¹ of NH₄⁺. The biochar adsorbed about 11 g of P accumulated during the test, with an adsorption percentage of 13% and an adsorption of 26.75 mg g⁻¹ of P. Despite some problems related to the effluent used during the test, the tested materials showed good adsorption properties.