Environmental pitfalls and associated human health risks and ecological impacts from landfill leachate contaminants: Current evidence, recommended interventions and future directions.

The improper management of solid waste, particularly the dumping of untreated municipal solid waste, poses a growing global challenge in both developed and developing nations. The generation of leachate is one of the significant issues that arise from this practice, and it can have harmful impacts on both the environment and public health. This paper presents an overview of the primary waste types that generate landfill leachate and their characteristics. This includes examining the distribution of waste types in landfills globally and how they have changed over time, which can provide valuable insights into potential pollutants in a given area and their trends. With a lack of specific regulations and growing concerns regarding environmental and health impacts, the paper also focuses on emerging contaminants. Furthermore, the environmental and ecological impacts of leachate, along with associated health risks, are analyzed. The potential applications of landfill leachate, suggested interventions and future directions are also discussed in the manuscript. Finally, this work addresses future research directions in landfill leachate studies, with attention, for the first time to the potentialities that artificial intelligence can offer for landfill leachate management, studies, and applications.

Novel CRISPR/Cas technology in the realm of algal bloom biomonitoring: Recent trends and future perspectives.

In conjunction with global climate change, progressive ocean warming, and acclivity in pollution and anthropogenic eutrophication, the incidence of harmful algal blooms (HABs) and cyanobacterial harmful algal blooms (CHABs) continue to expand in distribution, frequency, and magnitude. Algal bloom-related toxins have been implicated in human health disorders and ecological dysfunction and are detrimental to the national and global economy. Biomonitoring programs based on traditional monitoring protocols were characterised by some limitations that can be efficiently overdone using the CRISPR/Cas technology. In the present review, the potential and challenges of exploiting the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas technology for early detection of HABs and CHABs-associated toxigenic species were analysed. Based on more than 30 scientific papers, the main results indicate the great potential of CRISPR/Cas technology for this issue, even if the high sensitivity detected for the Cas12 and Cas13 platforms represents a possible interference risk.

SARS-CoV-2 in Atmospheric Particulate Matter: An Experimental Survey in the Province of Venice in Northern Italy.

Analysis of atmospheric particulate matter (PM) has been proposed for the environmental surveillance of SARS-CoV-2. The aim of this study was to increase the current knowledge about the occurrence of SARS-CoV-2 in atmospheric PM, introduce a dedicated sampling method, and perform a simultaneous assessment of human seasonal coronavirus 229E. Thirty-two PM samples were collected on quartz fiber filters and six on Teflon using a low- and high-volumetric rate sampler, respectively, adopting a novel procedure for optimized virus detection. Sampling was performed at different sites in the Venice area (Italy) between 21 February and 8 March 2020 (n = 16) and between 27 October and 25 November 2020 (n = 22). A total of 14 samples were positive for Coronavirus 229E, 11 of which were collected in October-November 2020 (11/22; positivity rate 50%) and 3 in February-March 2020 (3/16 samples, 19%). A total of 24 samples (63%) were positive for SARS-CoV-2. Most of the positive filters were collected in October-November 2020 (19/22; positivity rate, 86%), whereas the remaining five were collected in February-March 2020 at two distinct sites (5/16, 31%). These findings suggest that outdoor PM analysis could be a promising tool for environmental surveillance. The results report a low concentration of SARS-CoV-2 in outdoor air, supporting a scarce contribution to the spread of infection.

Intrinsic sustainability assessment at technosphere level by adapting entropy based ecologic indicators. A preliminary analysis for some main waste treatment processes.

The present study was developed on the following evidence: "what is considered to be environmentally sustainable in the technosphere has to be in compliance with the development tendency of the ecosphere". Starting from this hypothesis, two entropy-based indicators were proposed: the specific entropy per amount of exergy gained (SEEG); the specific entropy per amount of exergy exploitable in the technosphere (SEEE). These were retrieved from the specific entropy (SE) indicator largely exploited for assessing the health status and the development tendency of ecosystems. Entropy based indicators SEEG and SEEE were used for assessing the environmental sustainability of incineration, anaerobic digestion and composting of waste. The aim of these indicators was to support already available methodologies for environmental impact assessment for better understating the intrinsic sustainability of specific processes, since the only quantification of the emission appears not enough informative for this goal. Concerning the ecosphere, SE minimization follows the Darwinian principle "survival of the fittest", being the fittest ecosystems those able to make the most efficient and effective use and storage of energy and materials, at the lower relative entropy generation. Consequently, the lower are SEEG and SEEE the fittest is the analysed system (i.e. sustainable). Main findings indicate SEEG ranging from 2.471 to 3.705, for incinerator, from 0.007 to 0.106 for anaerobic digestion whereas resulted constant = 0.266 for composting. The SEEE ranged from 0.433 to 0.484 for incinerator, from <0.001 to 0.008 for anaerobic digestion and resulted constant = 0.014 for composting. These preliminary results indicates that processes and system able to return chemicals and materials exploitable at technosphere level were characterized by higher ability in returning exergy flows at the lower entropy increase compared to hose returning only energy.

Environmental and energy performances of the Italian municipal solid waste incineration system in a life cycle perspective.

The environmental and energy performances of the Italian municipal solid waste incineration (MSWI) system was investigated by a life cycle assessment approach. On average the 39 MSWIs operating in Italy in 2018 treated about 6,000,000 Mg of residual municipal solid waste (RMSW) recovering on average from 448 kWh Mg-1 RMSW to 762 kWh Mg-1 RMSW of electricity and from 732 kWh Mg-1 RMSW to 1102 kWh Mg-1 RMSW of heat. The average quantity of CO2eq Mg-1 RMSW emitted ranged from about 800 up to about 1000 depending on the size and on the energy recovery scheme of the facility. Avoided impacts (i.e., negative values) were detected for the kg PM2,5eq Mg-1 RMSW and for human health (disability-adjusted life year Mg-1 RMSW). The determination of the hybrid primary energy index (MJ Mg-1 RMSW) indicated that mainly large size facilities and those operating according to a power and heat energy recovery scheme are effectively able to replace other primary energies by the exploitation of the lower heating values of the RMSW.

Environmental and human health impact of different powertrain passenger cars in a life cycle perspective. A focus on health risk and oxidative potential of particulate matter components.

Different powertrains passenger cars, homologate in compliance with Euro 6 standard, were compared in a life cycle perspective for assessing both environmental and human health impacts. For this latter aspect, some correlation between the emission of heavy metals, elemental carbon, organic carbon, the oxidative potential of particulate matter and the adverse effect on human health were also analyzed and discussed. Battery electric vehicle (BEV) showed the lower greenhouse gases emissions, from 0.1 kgCO2eq/km to 0.2 kgCO2eq/km but were charged by the higher emissions of freshwater eutrophication and freshwater ecotoxicity, about 6 × 10-6 kgPeq/km and 4 CTUe/km, respectively. Lower resource depletion was detected for cars powered by internal combustion and hybrid powertrains. Amount of particulate matter (PM) emitted resulted lower for petrol-hybrid electric vehicles (Petrol-HEV), of about 5 × 10-5 kgPM2.5eq/km. BEV were charged by the higher values of human toxicity cancer, from about 2 × 10-5 CTUh/km to about 5 × 10-5 CTUh/km whereas Petrol-HEV were credited by the lower impact on human health (DALY/km). The large contribution to PM emission from all the analyzed cars was from tyre and brake wear. Main PM components were elemental (ElC) and organic carbon (OC) compounds. ElC is also a specific marker of PM emitted from traffic. Both ElC and OC were characterized by a strong correlation with the oxidative potential of PM, indicating a threat for human respiratory tract only marginally decreased by the transition from conventional to electric poweretrains vehicles.

Integrated hybrid architecture of metal and biochar for high performance asymmetric supercapacitors.

Two state-of-the-art electrodes were successfully synthesized and used to assemble both symmetric and asymmetric type supercapacitors. 3DFAB was fabricated by direct pyrolysis of green macroalgae in the presence of NaOH. Possible NaOH activation mechanisms are proposed, which explains the formation of oxygen functional groups through quick penetration of OH- and NaOH into the vacancies. To obtain CoTLM, the tile-like architecture of cobalt oxides was introduced to the 3D interconnected functional algal biochar (3DFAB) by a simple one-pot hydrothermal method under mild conditions. For the symmetric supercapacitors, the maximum specific capacitance of RAB, 3DFAB, and CoTLM were 158, 296, and 445 F g-1 at the current density of 1 A g-1. Regarding cobalt-based asymmetric systems, the maximum capacitance for the 3DFAB//CoTLM was 411 F g-1. This asymmetric supercapacitor device also retained 100.9% of its initial capacitance after 4000 cycles at the current density of 4 A g-1. Unbuffered aqueous electrolyte and the unique morphological structure used in this study might catapult forward commercialization of such advanced energy storage devices.

The life cycle approach for assessing the impact of municipal solid waste incineration on the environment and on human health.

The impact of municipal solid waste incineration (MSWI) on the environment and on human health was assessed by a life cycle assessment (LCA) approach. Even if risk assessment and epidemiologic analyses are specifically indicated for the investigation of the health outcomes, they resulted costly, time intensive and generally focused only on the effects caused by pollutant compounds directly emitted by the facility. Differently, LCA approaches are less time and cost intensive and able to account also for other indirect and direct emission of MSWI. However, results returned by LCA are based on average pollutant diffusion and individual exposure models limiting their representativeness for the specific context investigated. Furthermore, LCA is not able to return information about the final health outcomes caused by the pollutants emitted. The LCA performed for the Italian MSWI detected avoided impacts of about -0.11 kgPM2,5eq/tonne of MSW and of about -2.5 × 10-3 kgSbeq/tonne MSW for particulate matters and resource depletion, respectively. Positive impacts of about 900 kgCO2eq/tonne MSW and about 15,000 CTUe/tonne MSW were detected for global warming and freshwater ecotoxicity indicators, respectively. Avoided impacts of about -1 × 10-6 CTUh/tonne MSW and of about -2 × 10-4 DALY/tonne MSW were also detected for human toxicity cancer and human health indicators, respectively. Epidemiologic studies referred to different Italian and EU reported some correlations among MSWI and some specific cancer and non-cancer health outcomes. By the way, these resulted affected by some methodological limitation preventing the definitive identification of causal nexus. In any case, a general coherence between LCA and epidemiologic approaches was detected. Furthermore, a particular correspondence was found between LCA results and biomonitoring studies concerning the concentration of heavy metals in blood and urinary samples of exposed individuals. All this highlighted the important role that LCA can have in supporting health impact assessment of MSWI in combination with epidemiologic approaches.

A review of the presence of SARS-CoV-2 RNA in wastewater and airborne particulates and its use for virus spreading surveillance.

According to the WHO, on October 16, 2020, the spreading of the SARS-CoV-2, responsible for the COVID-19 pandemic, reached 235 countries and territories, and resulting in more than 39 million confirmed cases and 1.09 million deaths globally. Monitoring of the virus outbreak is one of the main activities pursued to limiting the number of infected people and decreasing the number of deaths that have caused high pressure on the health care, social, and economic systems of different countries. Wastewater based epidemiology (WBE), already adopted for the surveillance of life style and health conditions of communities, shows interesting features for the monitoring of the COVID-19 diffusion. Together with wastewater, the analysis of airborne particles has been recently suggested as another useful tool for detecting the presence of SARS-CoV-2 in given areas. The present review reports the status of research currently performed concerning the monitoring of SARS-CoV-2 spreading by WBE and airborne particles. The former have been more investigated, whereas the latter is still at a very early stage, with a limited number of very recent studies. Nevertheless, the main results highlights in both cases necessitate more research activity for better understating and defining the biomarkers and the related sampling and analysis procedures to be used for this important aim.

Environmental consequences of the treatment of corn contaminated by aflatoxin B1 with co-digestion and co-composting in a life cycle perspective.

Global environmental performances of anaerobic co-digestion and co-composting of aflatoxin B1 (AFB1) contaminated corn were investigated by a life cycle assessment approach. Anaerobic co-digestion of pig slurry and corn with 25 µgkg-1 ww AFB1 concentration resulted able to generate 627 NLkgVS-1 of biogas with a reduction of the AFB1 concentration in the digestate of 44%. At AFB1 concentration of 100 µg kg-1 ww, the process resulted strongly inhibited with a biogas generation of 122 NLkgVS-1 and AFB1 concentration reduction in the digestate of 25%. Co-composting of 100 µg kg-1 dw AFB1 contaminated corn with other substrates as organic fraction of municipal waste, pig slurry, and other lignin-cellulosic residues showed a removal efficiency of AFB1 ranging from about 80 up to 95% depending on the different mixtures adopted. Environmental consequences associated to the removal of 1 mg of AFB1 in different scenarios investigated, including also the use on land of the digestate and of the compost, indicated that global warming was affected equally by co-digestion and co-composting, about 95 kgCO2eq. Co-digestion showed also the possibility of achieving avoided emissions of about - 0.007 kgNMVOCeq, - 2.5E-3 kgPeq, and - 30CTUe. Benefits concerning resource depletion resulted higher for co-composting due to the high amount of mineral fertilizer replaced. Contribution of AFB1 in the determination of human health (DALY) resulted lower than about 4% for co-digestion and practically negligible for co-composting.

Management of the biodegradable fraction of residual waste by bioreactor landfill.

The performances of an integrated system based on mechanical biological treatment and bioreactor landfill with leachate recirculation for managing the mixed municipal solid waste generated in a given Italian district were investigated. In the mechanical biological treatment the municipal solid waste was mechanically sorted into two main streams: a dry and a mechanically sorted organic fraction consisting of 45,000 tonnes year-1. After being sorted the mechanically sorted organic fraction was aerobically pretreated before being disposed of in the 450,000 m3 bioreactor landfill. Experimental runs showed that an aerobic pretreatment period ranging from 15 to 30 days was able to maximize the methane generated by the mechanically sorted organic fraction once landfilled up to 10 Nm3 tonne-1. The aerobic pretreatment leads to a significant volatile solids reduction in the first 30 days, after which the volatile solids concentration remained quite constant. Similarly the potential dynamic respirometer index was significantly reduced in the first 15 days of the aerobic pretreatment decreasing from about 5,000 to about 3,500 mgO2kgVS-1h-1. The whole amount of electrical energy producible by the landfill ranged from 18.5 kWh tonne-1 to 21 kWh tonne-1, depending on the strategies adopted for the activation in bioreactor mode of each landfill cell by the leachate recirculation.

Minimization of spreading of SARS-CoV-2 via household waste produced by subjects affected by COVID-19 or in quarantine.

Currently available evidence supports that the predominant route of human-to-human transmission of the SARS-CoV-2 is through respiratory droplets. Indirect hands contact with surfaces contaminated by infectious droplets subsequently touching the mouth, nose or eyes seems to be another route of an indirect contact transmission. Persistence of the virus on different surfaces and other materials has been reported in recent studies: SARS-CoV-2 was more stable on plastic and stainless steel than on copper and cardboard. Viable virus was detected up to 72 h after application to different surfaces, although infectivity decay was also observed. This evidence suggests the likelihood that waste generated from patients affected by COVID-19 or subjects in quarantine treated in private houses or in areas different from hospitals and medical centres could be contaminated by SARS-CoV-2. Consequently, waste streams may represent a route for viral spreading being a potential risk also for the operators directly involved in the different phases of waste management. To address this concern, a specific multidisciplinary working group was settled by the Italian National Institute of Health (ISS) during the COVID-19 emergency, in order to establish guidelines related to solid waste collection, delivering, withdrawal, transport, treatment and disposal. Temporary stop of waste sorting, instructions for the population on how to package waste, instructions for Companies and operators for the adoption of adequate personal protection equipment (PPE), the use and sanitation of proper vehicles were among the main recommendations provided to the community by publications of freely downloadable reports and infographics in layman language. Incineration, sterilization and properly managed landfills were identified as the facilities to be preferentially adopted for the treatment of this kind of waste, considering the main inactivation strategies of SARS-CoV-2 (e.g. treatment length > 9 days and temperature > 70 °C for more than 5 min).

How collection efficiency and legal constraints on digestate management can affect the effectiveness of anaerobic digestion of bio-waste: An analysis of the Italian context in a life cycle perspective.

The influence of collection efficiency and of legal regulations on both the technology and the effectiveness of energy and fertilizer recovery from the anaerobic digestion (AD) of bio-waste was investigated in a life cycle perspective for the Italian context. Concerning collection efficiency, some correlation was detected to both the AD technology and the amount of energy and fertilizer recovered. Nine out of 31 CE plants were based on solid anaerobic digestion batch located in those areas with collection efficiency <65%, recovering about 100 kg and 125 kWh of fertilizer and electricity, respectively, per Mg of bio-waste. The 17 plants adopting wet technologies were implemented in areas with collection efficiency ranging from 50% up to >85% able to recover on average about 130 kg of fertilizer and 275 kWh of electricity per each Mg of bio-waste. Wet AD was also the only adopted for larger size plants from 60,000 Mg/year up to 600,000 Mg/year. Legal constraint on the direct use on land of the digestate caused an average increase of main impacts such as global warming (kgCO2eq), freshwater eutrophication (kgPeq) and human health (DALY) of about 300%. The effect of the quality of the bio-waste returned after the collection showed lower incidence on the overall impacts of about 20%, and mainly limited to global warming (kgCO2eq) and photochemical ozone formation (kgNMVOCeq).

Is the policy of the European Union in waste management sustainable? An assessment of the Italian context.

The sustainability of the waste management system imposed by EU legislation was assessed using the Italian context as a case study by analysing the period from the year 2007 to the year 2016. An integrated sustainability indicator (ISI) based on environmental, social and economic life cycle approach was used. Since the earlier directives the EU waste management policy was strongly oriented to the implementation of the higher levels of the hierarchy, i.e. preparation for reuse and recycling, and a contemporary ban of disposal activities and in particular of landfill. All this was stated in legal quantitative targets to be achieved within a given scheduled time, demonstrated by continuous implementation of a reliable economic, legal and political framework including, among others, penalties, economic support and extended producer responsibility. Noticeable increase of the amount of waste moved to recycling led to a decrease of main environmental burden due to kgCO2eq and kgPeq. The same activity led to avoided impacts detected for both kgPMeq and human health (DALY). A relevant role related to these benefits was also played by the waste to energy sector. Opposite trend was found for the whole average management costs that change from about 146 €/inhabitant in 2007 to about 218 €/inhabitant in 2016. A general decrease of the ISI of about 10% was also detected indicating an increase of the overall sustainability of the system.

Economic and environmental consequences of implementing an EU model for collecting and separating wastes system in Lebanon.

In this study, we examine the economic and environmental significance associated with the implementation of an EU waste-separated collection scheme in a developing context - Lebanon. Two scenarios, S1 and S2, representing different intensities of source segregation were analysed. In S1, the average source segregation intensity reached 25% and 13% for the Italian test area and Lebanese test area, respectively. In S2, source segregation intensity increased to 48% and 68% for the Italian and Lebanese test areas, respectively. Passing from S1 to S2 increased collection costs significantly, up to 44% with greater increases in the Italian test area where labour cost is higher. In both areas, environmental impacts decreased with greater source segregation intensity. Savings in the climate change impact and stratospheric ozone depletion potential were lower under the Lebanese test area in comparison with the Italian test area. In contrast, savings in freshwater eutrophication and acidification impact were lower for the Italian test area. The increase in the source segregation intensity resulted in maximum savings for the depletion of abiotic resources, 74% to 77% and 79% to 80% in a developing and developed context, respectively.

A sustainability assessment for use on land or wastewater treatment of the digestate from bio-waste.

The sustainability of use on land or by processing in a wastewater treatment plant of the digestate from bio-waste was investigated. Sustainability was assessed following a triple bottom line approach entailing environmental, social and economic consequences. A methodology for developing an integrated sustainability indicator was also defined. Global warming and acidification were about 40 kgCO2eq/m3 and 0.7 molcH+eq/m3 and 90 kgCO2eq/m3 and 1.1 molcH+eq/m3 for wastewater treatment and use on land, respectively. The impact on human health for use on land was about 3.5 × 10-4 (DALY), six times higher than wastewater treatment but quite negligible when compared to the DALY associated with other diseases in the same area. Costs calculated for wastewater treatment ranged from about 18 €/m3 up to 35 €/m3, about ten times higher than those related to use on land. The integrated sustainability indicator that was developed indicated higher sustainability for use on land and the relevant influence of such finding with respect to the environmental consequences.

Effectiveness of municipal solid waste incinerators in replacing other fuels. A primary energy balance approach for the EU28.

The latest European Union legislation introduced the possibility of considering high efficiency incineration of waste as a recovery operation, that is, to use waste as a means of producing energy and hence able to replace other fuels. This possibility has been further investigated by expanding the boundaries for the mass and energy balance of municipal solid waste incinerators operating in the EU28. An energetic analysis based on a hybrid primary energy (MJ Mg-1) approach was performed also using the cumulative energy demand index. Average results showed a net hybrid primary energy >0 for those municipal solid waste incinerators recovering only electricity, indicating that no primary energies can be replaced. For those operating in combined heat and power mode, an average hybrid primary energy ranging from about -200 MJ Mg-1 to about -4800 MJ Mg-1 was detected for large-size municipal solid waste incineration facilities (>200,000 Mg y-1). The value of hybrid primary energy for medium and small facilities ranged from about +3000 MJ Mg-1 to -4000 MJ Mg-1. Furthermore, in some operating conditions landfill had a lower hybrid primary energy than those of small-size municipal solid waste incinerators. To some degree, these results are not in agreement with the classification of municipal solid waste incinerators based on the energy efficiency formula, particularly for those recovering only electrical energy.

Impact of different schemes for treating landfill leachate.

Different technological schemes for treating the leachate generated by an existing landfill were compared in a life cycle perspective. On-site advanced processes based on reverse osmosis and evaporation were compared to conventional off-site co-treatment with civil sewage in wastewater treatment plant (WWTP). The inventories of the different scenarios were built by both direct observation of existing facilities and by retrieving data from the literature and similar equipment. Particular care was given for evaluating the energetic and chemical needs for operating the on-site advanced treatments. The evaporation system required 40 kW h/m3 of electricity and 18.5 kW h/m3 of heat, whereas reverse osmosis needed only 8.5 kW h/m3 of electricity. On the other hand the amount of liquid concentrate returned by the evaporation system was only about 0.03 m3/m3 instead of about 0.30 m3/m3 returned by reverse osmosis. The evaporation system also consumed the highest amount of chemicals. Life cycle analysis showed that the impact categories most affected by the different options were human toxicity, both non-cancer and cancer, together with freshwater ecotoxicity. The uncertainty analysis highlighted the major contribution associated with direct emissions from the processes. On the basis of mean values, the qualitative trends were substantially confirmed.

Solid anaerobic digestion batch with liquid digestate recirculation and wet anaerobic digestion of organic waste: Comparison of system performances and identification of microbial guilds.

Solid anaerobic digestion batch (SADB) with liquid digestate recirculation and wet anaerobic digestion of organic waste were experimentally investigated. SADB was operated at an organic loading rate (OLR) of 4.55kgVS/m3day, generating about 252NL CH4/kgVS, whereas the wet digester was operated at an OLR of 0.9kgVS/m3day, generating about 320NL CH4/kgVS. The initial total volatile fatty acids concentrations for SADB and wet digestion were about 12,500mg/L and 4500mg/L, respectively. There were higher concentrations of ammonium and COD for the SADB compared to the wet one. The genomic analysis performed by high throughput sequencing returned a number of sequences for each sample ranging from 110,619 to 373,307. More than 93% were assigned to the Bacteria domain. Seven and nine major phyla were sequenced for the SADB and wet digestion, respectively, with Bacteroidetes, Firmicutes and Proteobacteria being the dominant phyla in both digesters. Taxonomic profiles suggested a methanogenic pathway characterized by a relevant syntrophic acetate-oxidizing metabolism mainly in the liquid digestate of the SADB. This result also confirms the benefits of liquid digestate recirculation for improving the efficiency of AD performed with high solids (>30%w/w) content.