Pollution Abatement Research Articles

Biochar alters the selectivity of MnFe2O4-activated periodate process through serving as the electron-transfer mediator

Constructing green and sustainable advanced oxidation processes (AOPs) for the degradation of organic contaminants is of great importance but still remains big challenge. In this work, an effective AOP (MnFe2O4-activated periodate, MnFe2O4/PI) was established and investigated for the oxidation of organic contaminants. To avoid the severe aggregation of MnFe2O4 nanoparticles, a hybrid MnFe2O4-biochar catalyst (MnFe2O4-BC) was further synthesized by anchoring MnFe2O4 nanoparticles on chemically inert biochar substrate. Intriguingly, MnFe2O4-BC/PI exhibited different selectivity towards organic contaminants compared with MnFe2O4/PI, revealing that biochar not only served as the substrate, but also directly participated into the oxidation process. Electron-transfer mechanism was comprehensively elucidated to be responsible for the abatement of pollutants in both MnFe2O4/PI and MnFe2O4-BC/PI. The surface oxygen vacancies (OVs) of MnFe2O4 were identified as the active sites for the formation of high potential complexes MnFe2O4-PI*, which could directly and indirectly degrade the organic pollutants. For the hybrid MnFe2O4-BC catalyst, biochar played multiple roles: (i) substrate, (ii) provided massive adsorption sites, (iii) electron-transfer mediator. The differences in selectivity of MnFe2O4/PI and MnFe2O4-BC/PI were determined by the adsorption affinity between biochar substrate and organics. Overall, the findings of this study expand the knowledge on the selectivity of PI-triggered AOPs.

Can green credit policy increase corporate pollution abatement efforts? Evidence from China

Based on the green credit policy enacted in China since 2012, our study examines the monitoring role of banks in promoting corporate pollution abatement. The results show that the green credit policy has a significantly positive effect on corporate green innovation for polluting firms. Furthermore, we find that the positive effect is more pronounced when banks substitute institutional investors and media to monitor corporate environmental performance, in the product market of intense peer competition, and in regions where environmental regulatory enforcement is strong. These results suggest that the green credit policy strengthens the monitoring force of banks, thus promoting corporate green transformation and development.

Who will Spend more Pollution Abatement Costs: does Size Matter?

This paper looks at the relationship between enterprise size and pollution abatement costs using firm-level datasets in China, where size-dependent distortions may exist in the distribution of enterprises of different sizes. We find that the pollution abatement costs decrease with enterprise size. Compared to the smallest size, the magnitudes of marginal decreases in pollution abatement costs per 1000 CNY of industrial output in the largest size are 3.29 CNY, 0.54 CNY and 2.60 CNY for gas, SO2 and dust, respectively. Moreover, we further explore the potential mechanisms for the decrease of pollution abatement costs from three perspectives: environmental protection-related investment, regulation intensity, and technological capability. Our findings suggest that the decrease in the intensity of environmental protection-related investment for large enterprises may be directly reduce the intensity of pollution abatement costs. Although large enterprises have low intensity of pollution abatement costs, this does not mean that they are subject to weaker environmental regulation. More importantly, we find that large enterprises may have more adoption of abatement technologies. For SO2 and dust, the pollutant removal efficiency of the largest enterprises is 4.92% and 1.82% higher than that of the smallest enterprises, respectively. Our results are robust to different specifications. These findings help us enact appropriate policies for enterprises based on their size, thereby improving the efficacy of pollution abatement and achieving the optimal level of pollution abatement for the entire society.

Electron shuttle of carboxyl boosted Fe(III)-anchored carboxylated cellulose activating sodium perborate for organic pollutant abatement

The traditional Fenton application is limited by the disproportionation of hydrogen peroxide (H2O2) and the tardy reduction of Fe(III). To conquer these issues, we construct an enhanced Fenton-like process using a composite of citric acid-carboxylated microcrystalline cellulose complexing with Fe(III) (CA-Fe(III)@MCC) to activate sodium perborate (SPB), which can effectively eliminate antibiotic sulfamethoxazole (SMX, 89.2%, 0.035 min-1). The CA-Fe(III)@MCC composite significantly enhances the circulation of Fe(III)/Fe(II), leading to the generation of hydroxyl radicals and perboric radicals with excellent structural stability and minimal Fe leaching during CA-Fe(III)@MCC/SPB process. Systematic investigations reveal that the introduced carboxyl groups not only anchor Fe(III) to prevent its deactivation and leaching, but also regulate the coordination environment and serve as electron shuttles, driving the formation of reactive species and reduction of Fe(III). This process presents a novel, environmentally friendly, and sustainable strategy for utilizing natural cellulose and its industrial biomass product in advanced oxidation processes.

The potential of coupled water electrolysis with electrochemical wastewater treatments

The coupled water electrolysis is a promising strategy for green hydrogen production. Pollutants are attractive feedstocks for the fungible anode reactions of the sluggish oxygen evolution reaction, with the advantages of trash-to-treasure and cost reduction. There is an urgent need for real waste sample tests from the view of both contaminant abatement and electrochemical hydrogen production. This work offers a systematic evaluation of the coupled water electrolysis with real wastewater, where four real wastewater with sulfur element compounds in different states are taken as examples. The technical and economic potentials are evaluated particularly based on the coupled water electrolysis performances, including cell voltage, current density, hydrogen production rate, hydrogen electricity consumption, and pollution abatement. The coupled water electrolysis with the refractory wastewater, e.g. the desulfurization wastewater from coal-fired power plants and the H acid wastewater, does not show advantages from the view of hydrogen production, due to the high overpotential and limited current density. Nevertheless, hydrogen is a high-value-added byproduct for operation cost reduction from the view of wastewater treatment. The readily oxidizable pollutants, e.g. sulfite and sulfide, exhibit notable potentials for anodic depolarization and electricity consumption reduction of hydrogen production. However, the coupled water electrolysis adopting the sulfide spent caustic stream may suffer a low hydrogen production rate for sulfide to sulfur. The coupled water electrolysis adopting sulfite wastewater indicates excellent potential for both space-time yield and electricity consumption for hydrogen production. This work may offer a reference for the systematic evaluation and selection of coupled water electrolysis with real wastewater.

Political ‘Colour’ and Firm Behaviour: Evidence from U.S. Power Plants’ Pollution Abatement

We ask whether firms behave differently depending on the political party in charge, above and beyond responding to any actual differences in policy. We use the pollution abatement behaviour of U.S. Steam Electric Power Plants under the Clean Water Act as our case study. Exploiting the variation provided by the outcome of tightly contested gubernatorial elections, we provide causal evidence that large firms respond to the political ‘colour’ of the governor in the state they operate, even when neither the stringency nor the enforcement of the rules depend on it. Within a theoretical model of the interaction between the regulator and the regulated firms, we show that multiple equilibria arise, and the outcomes of the election provide an effective coordination device. This unexpected behaviour has real-world consequences and leads to significant differences in pollution levels.

Synergistic emission reductions and health effects of energy transitions under carbon neutrality target

China's climate and environmental problems remained prominent. Energy transition was the key to improve climate and pollution, and it was at a critical period. Previous studies mostly focused on the impact of climate policies on the reduction of air pollutants and the environmental health impacts of individual sector or pathway policies. Thus, focusing on the synergistic abatement of CO2 and air pollutants and health effects of energy transition in carbon neutrality was significant for building beautiful and healthy China. LEAP-HEA model was constructed to project energy demand, CO2 and air pollutants, and assess energy transition's environmental health effects from 2020 to 2060. LMDI model was adopted to decompose the abatement contribution. Synergistic assessment index was used to estimate the coordinated abatement effects. Cost-effectiveness of energy transition and regional heterogeneity of PM2.5 toxicity were not considered. The results indicated: (1) energy demand would decrease and structure would be optimized significantly under deep energy transition scenario. (2) Deep energy transition could promote earlier realization of carbon neutrality. It would contribute significantly to CO2 and air pollutants abatement with strong synergistic effects. (3) Energy transition would reduce health risks with large economic benefits. Recommendations were proposed based on the conclusions.

Metagenomic landscape of sediments of river Ganga reveals microbial diversity, potential plastic and xenobiotic degradation enzymes

The Ganga is the largest river in India, serves as a lifeline for agriculture, drinking water, and religious rites. However, it became highly polluted due to the influx of industrial wastes and untreated sewages, leading to the decline of aquatic biodiversity. This study investigated the microbial diversity and plastic-xenobiotic degrading enzymes of six sediment metagenomes of river Ganga at Prayagraj (RDG, TSG, SDG) and Devprayag (KRG, BNG, BRG). The water quality parameters, higher values of BOD (1.8–3.7 ppm), COD (23–29.2 ppm) and organic carbon (0.18–0.51%) were recorded at Prayagraj. Comparative analysis of microbial community structure between Prayagraj and Devprayag revealed significant differences between Bacteroidetes and Firmicutes, which emerging as the predominant bacterial phyla across six sediment samples. Notably, their prevalence was highest in the BRG samples. Furthermore, 25 OTUs at genus level were consistent across all six samples. Alpha diversity exhibited minimal variation among samples, while beta diversity indicated an inverse relationship between species richness and diversity. Co-occurrence network analysis established that genera from the same and different groups of phyla show positive co-relations with each other. Thirteen plastic degrading enzymes, including Laccase, Alkane-1 monooxygenase and Alkane monooxygenase, were identified from six sediment metagenomes of river Ganga, which can degrade non-biodegradable plastic viz. Polyethylene, Polystyrene and Low-density Polyethelene. Further, 18 xenobiotic degradation enzymes were identified for the degradation of Bisphenol, Xylene, Toluene, Polycyclic aromatic hydrocarbon, Styrene, Atrazene and Dioxin etc. This is the first report on the identification of non-biodegradable plastic degrading enzymes from sediment metagenomes of river Ganga, India. The findings of this study would help in pollution abatement and sustainable management of riverine ecosystem.

Assessing leachate contamination and groundwater vulnerability in urban dumpsites: a case study of the Ipata Area, Ilorin, Nigeria

This study explores the extent of leachate contamination and groundwater vulnerability in urban dumpsites, with a specific focus on the Ipata area in Ilorin, Nigeria. The study employs a combination of 2D Electrical Resistivity Tomography (ERT), soil classification, and physicochemical analyses to investigate the percolation of leachate into groundwater and its potential environmental and health implications. The ERT data unveiled subsurface layers, highlighting the presence of decomposed topsoil down to approximately 1.2m. Beneath this layer, a low-resistivity zone (6.53 to 10.7 ?m) indicated the potential risk of leachate percolation into groundwater. Soil classification revealed a shallow topsoil layer with insufficient clay content to hinder leachate penetration, emphasizing the need for enhanced containment measures. Physicochemical analysis of leachate, well water, and soil displayed variations in key parameters such as pH, electrical conductivity, total dissolved solids, and anion concentrations. Leachate exhibited high pH and electrical conductivity, suggesting elevated total dissolved solids, while well water remained within acceptable pH limits for drinking water. Heavy metal concentrations exceeded permissible WHO limits in topsoil, leachate, and well water, with cadmium presenting a high ecological risk. The absence of persistent organic pollutants (POPs) in the samples indicates a current focus on heavy metals as a primary concern. In conclusion, this study underscores the urgent need for proactive pollution abatement measures in urban dumpsites like Ipata. Regular monitoring of surface and groundwater quality is essential to safeguard public health and the environment.

Review Paper: A Quarter of a Century of the European Water Framework Directive — The Slow Path Towards Sustainable Water Management

The European Water Framework Directive (WFD) is one of the most analyzed environmental legislations in the scientific literature, influencing the water management in some non-European countries. The WFD has the strong ambition of achieving a good ecological status of water bodies across all river basins in Europe. However, the advances towards sustainable management are falling far behind the planned schedule. The emphasis of the Directive is focused on water quality rather than on water quantity. The advances during the last quarter of the century since its inception have been strong on urban and industrial point pollution, but not on agricultural non-point pollution that remains high and even increases in major basins. Water quantity aspects have been mostly left aside in the Directive, despite the fact that water scarcity is a serious problem in Southern European countries, and will become more critical with climate change in most basins across Europe. Some policy measures of the WFD need to be reformed, in particular measures for abating agricultural pollution, and new measures for addressing water scarcity. The narrow focus of the WFD on water pricing to solve at the same time issues of financing, water allocation and efficiency, environment, opportunity costs and pollution abatement, should be broadened. The challenge is giving more emphasis to command & control and collective action instruments, and designing combinations of instruments adapted to sectoral and spatial locations in basins. This overhaul of the water policy instruments by the European Commission will be needed to advance in the sustainable management of river basins in Europe.

In situ growth of iron incorporated Ni3S2 nanosheet on nickel foam in mediating electron transfer to peroxymonosulfate for pollutant abatement

Catalytic oxidation of organic pollutants is a well-known and effective technique for pollutant abatement. Unfortunately, this method is significantly hindered in practical applications by the low efficiency and difficult recovery of the catalysts in a powdery form. Herein, a three-dimensional (3D) framework of Fe-incorporated Ni3S2 nanosheets in-situ grown on Ni foam (Fe-Ni3S2@NF) was fabricated by a facile two-step hydrothermal process and applied to trigger peroxymonosulfate (PMS) oxidation of organic compounds in water. A homogeneous growth environment enabled the uniform and scalable growth of Fe-Ni3S2 nanosheets on the Ni foam. Fe-Ni3S2@NF possessed outstanding activity and durability in activating PMS, as it effectively facilitated electron transfer from organic pollutants to PMS. Fe-Ni3S2@NF initially supplied electrons to PMS, causing the catalyst to undergo oxidation, and subsequently accepted electrons from organic compounds, returning to its initial state. The introduction of Fe into the Ni3S2 lattice enhanced electrical conductivity, promoting mediated electron transfer between PMS and organic compounds. The 3D conductive Ni foam provided an ideal platform for the nucleation and growth of Fe-Ni3S2, accelerating pollutant abatement due to its porous structure and high conductivity. Furthermore, its monolithic nature simplified the catalyst recycling process. A continuous flow packed-bed reactor by encapsulating Fe-Ni3S2@NF catalyst achieved complete pollutant abatement with continuous operation for 240 h, highlighting its immense potential for practical environmental remediation. This study presents a facile synthesis method for creating a novel type of monolithic catalyst with high activity and durability for decontamination through Fenton-like processes.

Bacterial biodegradation of oil-contaminated soil for pollutant abatement contributing to achieve sustainable development goals: A comprehensive review

Petroleum hydrocarbon-induced environmental degradation has escalated, necessitating immediate remediation due to the ongoing growth of communities and modernization of civilization. Both carbon and energy can be obtained from hydrocarbons of petroleum, which are decomposed by a wide variety of microorganisms found in nature. Many times, remediation of places damaged by oil using biological means is accomplished by using bacteria that have such characteristics. Hence, this review attempt to highlight on the oil contaminated soil, source of oil pollution, the composition of oil, the impact of oil contamination on the living organisms additionally, the destiny of oil in the environment, how bacteria distributed in the soil and the most common degradable bacteria and their role in oil biodegradation with some attention on the impact of their enzymes. Also, considering the mechanism of biodegradation of aliphatic and aromatic oil hydrocarbon compounds, how bacteria taking up oil hydrocarbons and the influence of several elements on the processes of oil biodegradation. Furthermore, it; reducing pollution contributes to achieving sustainable development goals.

Green quality choice in a duopoly

AbstractThis article considers a quantity‐setting duopoly (Cournot rivalry) in which firms adopt an abatement technology as a device to improve the quality of products. Consumer preferences capture vertical product differentiation (quality) towards “green” products. This introduces a trade‐off on the production side, as firms that do not abate, in turn, do not sustain any abatement cost but the demand for their product is low. On the contrary, firms that choose to abate incur abatement costs, but the demand for their product is high. The article aims to study and understand whether this kind of preference may lead firms to strategically invest in green technology and introduces a new, private‐based (that contrasts the well‐known public‐based) mechanism through which pollution abatement can emerge as a sub‐game perfect Nash equilibrium (SPNE) of a non‐cooperative abatement decision game with product quality and complete information. The model is developed in a parsimonious way to pinpoint the main determinants of the endogenous market outcomes ranging from an anti‐prisoner's dilemma in which self‐interest and mutual benefit of non‐abatement do not conflict to an anti‐prisoner's dilemma in which self‐interest and mutual benefit of abatement do not conflict, passing through to an anti‐coordination scenario. Additionally, the welfare analysis reveals the existence of a win‐win solution from a societal perspective. The article shows that the results obtained in the Cournot setting also hold considering a Bertrand duopoly.

Trade liberalization and the choice of pollution abatement

AbstractIt is well known that a consumer price-neutral reform of consumption taxes and import tariffs is welfare-improving. This paper shows that such price controls are inferior to quantity controls in terms of welfare improvement. The paper next turns to a comparison of different abatement strategies. Whether or not policy changes should fix private abatement or public abatement relates to the level of earmarking, and depends on the relationship between private production and public abatement. There are cases in which increased public abatement only improves welfare by more than both increased private and public abatement together. The paper recommends that environmental earmarking in the form of public abatement should be delivered to cushion price hikes and sustain private energy consumption.

Modeling Environmental Impacts of Intensive Shrimp Aquaculture: A Three-Dimensional Hydrodynamic Ecosystem Approach

Already a multibillion-dollar global industry, shrimp aquaculture, is growing all the time. The intensive method, which is the most common method in shrimp aquaculture, remains commercially challenged due to the expenditures associated with environmental pollution abatement. Although the comprehensive understanding of this intricate aquaculture environment has been advanced using mathematical modeling, recent attempts to improve the model’s structure have not yielded enough results. This work upgraded the previous method to a three-dimensional hydrodynamic ecosystem model with the effects of shrimps being replaced by approximation equations for the environmental assessment of a shrimp aquaculture pond in Kyushu District, Japan. Our approach was successful, as demonstrated by the high consistency of the simulation results when compared to observation data and the previous results. Additionally, we first revealed the impacts of stratification and confirmed the notable daily variation in the water quality. Our case study offers significant practical information on the characteristics of intensive shrimp aquaculture, implications for long-term sustainable operations, and future research priorities on local-scale ecosystem modeling.

Trace Elements and Water-Soluble Ionic Species Associated with Ambient Particulate Matter over Lucknow City, India

Clean air is the foremost essentiality to ensure a good life on our planet. Nonetheless, escalating air pollution levels in urban spaces have caused an increase in morbidity and mortality. The air pollution predicament requires a comprehensive understanding of the local scale. In this perspective, the present study was carried out to assess the load of PM10, PM2.5, SO2, NO2, O3 and associated chemical profiles, including trace elements and ionic species of the commercial, industrial and rural areas over Lucknow city during winter months of 2022–23. The average 24-hour PM2.5 concentrations (Avg ± SD) in the commercial, industrial, and rural areas were recorded to be 189.1 ± 57.6, 177.7 ± 36.5, and 141.6 ± 23.0 μg/m3, respectively, with a percentage exceedance over national ambient air quality standards (NAAQS) of 224 to 215, 196, and 136%. Similarly, the concentrations of PM10 were 337.9 ± 109.2, 285.6 ± 53.1, and 234.9 ± 43.0 μg/m3, with 238, 186, and 135% exceedance, respectively. SO2 level ranged from 8.7 to 23.9 μg/m3, whereas NO2 level ranged from 16.8 to 45.7 μg/m3 for the study period. Based on the air quality index (AQI) values, commercial (353), industrial (344), and rural (317) areas fell in the “very poor” category of AQI. 12 studied elemental species in descending order were Al>Fe>Mg>Zn>Pb>Mn>Cr>Cu>Ni>Co>Cd>Mo while the sequence of 8-ionic species was SO4 2->Cl- >K+>NH4 +>NO3 ->Ca2+>Na+>F–. Residents of Lucknow city have been found to be frequently exposed to particulate pollution and related chemical elements, particularly during haze and inversion occurrences in the winter. It is, therefore, imperative to assess and develop pollution abatement strategies to combat urban air pollution.

Remediation of mine overburden and contaminated water with activated biochar derived from low-value biowaste

BackgroundMines can be regarded as the economic backbone of India with a contribution of 10–12 % towards the gross domestic production with industrial demand. It gives rise to environmental problems like soil, water and air pollution. The active mines generate lots of waste rock and wastewater that contaminate nearby soil and water bodies with heavy metals. MethodsThe elimination of heavy metals by suitable amendments is emerging as a potential solution to such problems. Biochar, a carbon rich, stable, alkaline and porous product of thermo-chemical conversion of biomass has emerged as a promising adsorbent of heavy metals. Conversion of these biowastes into biochar is a sustainable approach as it fulfills multiple objectives of waste utilization, and pollution abatement. Significant findingsDue to its large surface area, biochar can restrain heavy metals while modified biochar has an increased potential for adsorption with an increased surface area. The review emphasizes the type of mines, overburden generation, their impact on soil and water, and the utility of different biowastes available to be mobilized into biochar for remediation of contaminated water and soil. It also bridges the gap in the current knowledge on the activation techniques of biochar with heavy metals remediation.

Efficient abatement of organic pollutants by Fe(III)/Fe(II) cycle activating H2O2 with the assistance of sulfurized manganese-supported graphene

This study develops a novel sulfurized manganese-supported graphene material (S-Mn@GO) designed for promoting Fe(III)/Fe(II) cycling in Fenton treatment. The excellent combination of manganese oxides (MnOx) and graphene oxide (GO), along with subsequent, impart S-Mn@GO with excellent electron transfer capabilities. Selecting Bisphenol A (BPA) as the model compound to evaluate the efficacy of the novel material, the findings indicate that the addition of 0.1 g/L of S-Mn@GO in the Fe(II)/H2O2 system enhanced the removal of BPA from 49.7 % to 98.3 % within 30 min. Results show that the abatement of pollutants in the S-Mn@GO/Fe(II)/H2O2 system was significantly influenced by pH, with the maximum removal efficiency (98.3 %) attained at pH 3.5. And the common coexist substances at environmental concentration levels on pollutant abatement was examined and this system showed excellent tolerance to anions. Quenching experiments and EPR analyses demonstrate that the hydroxyl radicals (HO•) dominates the abatement of BPA and the other reactive species (e.g., FeIVO2+) show negligible contribution. Density Functional Theory (DFT) calculations and other evidences indicate that the rapid cycling of iron species was due to the coupling of GO and manganese/sulfur (Mn/S) species. Moreover, the degradation pathway of BPA was analyzed through DFT calculations and LC-MS detection. Further, cycling experiments and long-term experiments confirm the stability of the material. Herein, using GO-based composite as an accelerator of Fe(III)/Fe(II) cycling provides a new strategy to promote the pollutant degradation in the Fenton process.

Sodium citrate enhancing electrodeposition of metallic arsenic from toxic trivalent arsenic and the mechanism understanding

Electrochemical conversion of hypertoxic trivalent arsenic to value-added metallic arsenic can not only contribute to pollution abatement, but also resources reutilization, therefore being widely explored. Electrochemical reduction of trivalent arsenic as a promising way is widely explored. However, the high efficiency conversion is retarded by the sluggish reduction kinetics of AsO33− and fierce evolution of side products of both H2 and toxic AsH3. Herein, by using the sodium citrate as the additive, the current efficiency for metal arsenic production is increased greatly from 60% to 91%, with the accompanied evolution of hypertoxic AsH3 being restrained from 0.15 Nm3/tAs to 0.022 Nm3/tAs, promising a high-efficiency and green process. The electrochemical tests and electrode surface characterizations as well as DFT calculations indicate that the added sodium citrate promotes both the diffusion of reactive AsO33− towards the cathode and its subsequent adsorption on the Ti cathode, contributing to smoother reduction for generating metal arsenic, with the evolution of toxic AsH3 being hindered at the same time. The results can provide new insights for the high-efficiency and greener conversion of hypertoxic trivalent arsenic to value-added metallic arsenic.

Environmental taxes, environmental outsourcing, and pollution abatement: Evidence from Chinese industrial sewage discharge enterprises

Polluting enterprises purchase technologies, goods, or services from external enterprises to mitigate pollution, which is called environmental outsourcing. This paper examines the effect of environmental taxes (ETs) on pollution abatement when environmental outsourcing is prevalent. We build a novel enterprise-level panel dataset for 2011–2018 and employ staggered difference-in-differences (DID) estimators to investigate the heterogeneous responses of in-house and outsourced abatement enterprises to the environmental tax increments. Our research demonstrates that imposing environmental taxes for pollution control has a significant positive effect. However, the environmental taxes have failed to successfully transmit their impacts on the changes in compliance costs of polluting enterprises through pollution treatment fees in the end-of-pipe treatment process. It has been demonstrated that environmental outsourcing seriously dilutes and even hinders the efficacy of environmental taxes in reducing water pollution. These findings shed fresh insight on the relationship between environmental policies and outsourcing services and highlight the necessity of incorporating environmental outsourcing into the design of environmental policies.