Remediation System Research Articles

Evaluating two multi-model simulation–optimization approaches for managing groundwater contaminant plumes

Addressing conceptual model uncertainty using multi-model approaches has become an important topic in groundwater hydrology. Model uncertainty is of practical importance when designing a pump-and-treat system for groundwater remediation, as inappropriate consideration of model uncertainty may ultimately lead to ineffective system designs. This study introduces two multi-model approaches for addressing model uncertainty at a site contaminated by chlorinated hydrocarbons and BTEX compounds. We use a multi-objective simulation–optimization method to design a multiple-well pump-and-treat system to contain contaminant plumes within the site perimeter, while minimizing the pumping rate. The design parameters include the coordinates of the pumping well locations and pumping rates. We consider four groundwater models to address uncertainty in conceptualizing site geology, boundary condition, and recharge. Using two multi-model approaches, we evaluate different design concepts. The first approach is a model selection approach that identifies the critical models, which particularly govern the design process, within the multi-model ensemble. The second approach is a model aggregation approach that identifies system designs that meet the remediation objectives for all models of the ensemble. Results show that the model aggregation approach is a more conservative option, which results in reliable designs at the expense of higher pumping rates. This study evaluates these two approaches within the context of multi-model simulation–optimization, providing insights on multi-model simulation–optimization in groundwater management.

Triblock copolymer-assisted synthesis of Z-scheme porous g-C3N4 based photocatalysts with promoted visible-light-driven performance

The challenge strategy for construction of the Z-scheme heterostructures including porous g-C3N4 based materials employing triblock copolymer and MCM-41 templates-assisted synthesis is to obtain stable photocatalysts with high charge-separation during photocatalysis application utilizing visible light. In this contribution, synthesis of mesoporous α-Fe2O3, CuO and CoFe2O4 nanoparticles (NPs) on porous g-C3N4 for promoted Hg(II) photoreduction efficiency have been evaluated compared with pristine g-C3N4. A Z-scheme system of mesoporous CuO, CoFe2O4 or Fe2O3-/g-C3N4 heterostructures provides an enhanced photocatalytic Hg(II) reduction, yielding a rate of 628.7, 472.2 and 424.1 μmolg−1h−1, respectively, which is ~7.77, 5.84 and 5.24 times greater than that pristine g-C3N4 (80.85 μmolg−1h−1). The photocatalytic efficiency was improved up ~100, 76.5, and 68.6% over mesoporous CuO, CoFe2O4 and Fe2O3-/g-C3N4, respectively, however, it was 12% over pristine g-C3N4 through 50 min illumination time. The enhanced photoreduction using Z-scheme CuO, CoFe2O4 and Fe2O3-/g-C3N4 heterostructures was attributed to its superb characteristics to expedite the photoreduction of Hg(II), involving: (i) 3D mesostructure and more suitable active sites which improves the Hg(II) adsorption, (ii) high surface area (188 m2 g-1) and narrow bandgap (1.93 eV) and (iii) the superior Z-scheme heterostructures characteristic efficiently enhances the electron-hole pairs separation. This research work creates new windows for mesoporous metal oxides and perovskites/g-C3N4 -based Z-scheme system for wastewater remediation, air purification and clean energy generation.

Practice and Consideration on Restoration of Sandbar-Lagoon Geomorphology: A Case Study on Fudu Estuary Sandbar

With the development and construction of the coastal economic belt, the marine ecological environment is under great pressure. The typical river mouth sandbar - lagoon hydro-geomorphological system is facing unprecedented threats, and it is extremely urgent to restore this typical geomorphological system. Taking the Fudu River Mouth Sandbar as a case study, combining with the characteristics of surrounding marine resources and the current situation of exploitation and utilization of sea area, this paper puts forward various ecological restoration measures including the construction of landscape ecological corridor, sandbar maintenance, demolition of reclamation works and structures, landscape park construction, on-line water quality monitoring, fisherman wharf reconstruction, etc. to solve the major problems in this area. This paper also suggests that, during the implementation of marine ecological restoration, the following measures should be taken, including to establish a library of coastline remediation and restoration projects within the study area, give full play to the technological advantages of universities and research institutes at the national and provincial levels, strengthen scientific and technological support, and implement the target-oriented responsibility system for marine ecological remediation and restoration by taking marine ecological remediation and restoration targets as indicators to assess cadres’ performance

Chromate fate and effect in bioelectrochemical systems for remediation of chlorinated solvents

A continuous-flow bioelectrochemical reactor was developed in a previous study to address the bioremediation of groundwater contaminated by trichloroethene (TCE). The present report investigated the applicability of the same system in the presence of Cr(VI) and its possible inhibitory effect on dehalorespiring bacterial populations. Preliminary batch tests were performed at the optimal cathodic reducing potential for the reductive dechlorination (RD) of TCE (-0.65 V vs. the standard hydrogen electrode) with two different dechlorinating microorganism consortia. The results demonstrated that Cr(VI) removal efficacy was increased by microorganisms that had been previously acclimatised to Cr(VI). Specifically, Cr(VI) was completely reduced only in the presence of acclimated microorganisms. The presence of chromate negatively affected RD performance, by either (i) limiting the TCE transformation to cis-dichloroethene at lower concentrations, or (ii) completely inhibiting RD at higher concentrations. In contrast, after the acclimation period, RD was extended down to vinyl chloride, which is the main TCE daughter product. Finally, the continuous flow reactor was fed by synthetic groundwater contaminated with TCE (50 μM) and Cr(VI) (45 μM), and the experimental results showed that Cr(VI) was completely reduced under RD conditions. Moreover, TCE removal was complete, with vinyl chloride and ethene as the main intermediates, thus indicating that chromate inhibition was decreased by Cr(VI) removal.

Reliability-Based Multi-Objective Optimization of Groundwater Remediation

In-situ bioremediation of groundwater is relatively low cost and has high efficiency in remediating groundwater contaminated with petroleum hydrocarbons under suitable hydrogeologic settings. This work develops a multiobjective simulation-optimization (S-O) model for the design of an in-situ bioremediation system for petroleum-hydrocarbon contaminated groundwater. Minimizing the cost of the remediation system (installation and operation) and maximizing its reliability are the two objectives of the developed S-O model. The BIO PLUME II software simulates the remediation process and the non-dominated sorting genetic algorithm (NSGA) II optimizes remediation. The reliability objective measures the effect of uncertainty in the estimate of the initial contaminant concentration on the performance of bioremediation design, and is evaluated under five scenarios of initial contaminant concentration in an example case study illustrating this paper’s methodology. The S-O model for optimal remedation calculates Pareto fronts reflecting the best tradeoff between cost and system reliability that can be obtained. Remediation managers choose remediation strategies from the calculated Pareto front that best serve their cost preferences and remediation requirements. The calculated remediation demonstrates the effectiveness of the remediation system is sensitive to the magnitude of the initial contaminant concentration.

Compliance of Judgments of the Inter-American Court of Human Rights

Compliance is particularly challenging in International Law and extremely puzzling in International Human Rights. Although a large amount of research has endeavored to explain the process of incorporation, execution, and compliance of certain paradigmatic judgments of the Inter-American Court of Human Rights (IACtHR), only a few quantitative and multidisciplinary approaches to compliance have been developed. This paper contributes to this effort by describing and explaining the current state of compliance of the judgments of the IACtHR. The first section provides a general overview of the literature related to compliance with the judgments of the IACtHR, including theories such as realism, liberalism, institutionalism, and constructivism. The second section introduces the Inter-American System of Human Rights, the different and particular remedies that have been developed by the Court throughout its case-law, and a set of descriptive data about the work in the IACtHR. Finally, the third section develops a quantitative model for testing the compliance of judgments of the IACtHR according to the different International Relations theories.

Ultrasonic-electrochemical treatment for effluents of concrete plants

Huge quantities of water are consumed by the construction industry, and consequently huge amount of polluted wastewater is discharged from this industry to the surrounding environment. For example, it was reported that a single 8000 L capacity concrete mixer requires 1,500 litters of water per each shift for washing process and 1,600 litters for concrete preparation. This huge consumption of water results in substantial production of wastewater, which is generally highly contaminated with various contaminates and high pH (≥ 11). Consequently, it exerts serious influence on quality of freshwater and marine lives. Therefore, this research was devoted to examine the efficiency of a new method of wastewater treatment, which combines and applies electrocoagulation and ultra-sonication systems (UL-EC) for remediation of concrete plants’ effluents from chemical oxygen demand (COD) from. The electrocoagulation cell was based on four aluminum electrodes, while ultrasonic treatment was applied using ultrasonic bath. The effect of other major parameters, including initial pH of wastewater (IPHW) (4, 7 and 10), current densities (CDS) (1, 3 and 5 mAcm−2), and electrodes spacing (ES) (5, 10 and 15 mm) on the efficiency of UL-EC were optimized using Box–Behnken Design (B-BD). The results of the present experiments confirmed that 68.14% COD removal was gotten by the electrocoagulation unit, while, the UL-EC removed 87.8% of COD. The optimum removal of COD was achieved at IPHW of 7, CDS of 5 mA.cm−2 and ES of 5mm.

The Definition of National Court within the Meaning of European Union Law. Considerations in the Context of the Polish Reform of the Judicial System

The article deals with two main problems. The first concerns the interpretation of the concept of “court” within the meaning of the provisions of Art. 47 CFR and Art. 267 TFEU. The second part is devoted to the analysis of judgements of the Court of Justice regarding the reform of the Polish judicial system. It enables one to draw several conclusions. Firstly, the Court of Justice found that Poland had violated its Treaty obligations by introducing the provisions that determine the retirement age of judges and establish the procedure enabling the extension of active service by virtue of the discretion of the President of the Republic of Poland. Secondly, the Court of Justice analysed the concept of “court” from the perspective of Art. 19, para. 1, subpara. 2 TEU. It emphasised that these provisions obligate the Member States to establish a system of legal remedies and procedures ensuring effective judicial protection in areas covered by EU law. It also stressed that this concerns a body that can only potentially settle cases with an EU element. Thirdly, the Court of Justice clarified the concept of judicial independence in the context of irremovability of judges and judicial impartiality. It formulated a certain test of judicial independence that should be conducted by the referring court.

Application of Administrative Law in the Time of Reforms in the Light of the Scope of Judicial Review in Hungary

<p class="Default">The Hungarian legal system and especially the administrative law is in the state of permanent change. This constantly transforming environment is a challenge for the rule of law. Every significant field of administrative law is impacted by these changes – even the judicial review model of the administrative decisions. The author analyzes the impact of these changes – especially from the last three years – on the application of administrative law. The issues raised in the article are focused on the transformation of the procedural rules, in particular on the impact of the new Act I of 2017 – Code of Administrative Court Procedure and its amendment in 2019. Two major institutions are analyzed further. First, the work analyzes the impact of the reform on the system of legal remedies in the administrative law, i.e. the reduction of the intra-administration remedies, the administrative appeal. Secondly, the extent of the judicial review was examined, in particular debates, codifications and amendments of the cassation and reformatory jurisdiction of the courts. The courts are currently the major interpreter of administrative law, whose change can be interpreted as a paradigm shift of the approach of the application of administrative law.</p>

Remediation of a Petroleum Hydrocarbon-Contaminated Site by Soil Vapor Extraction: A Full-Scale Case Study

Spills, leaks, and other environmental aspects associated with petroleum products cause hazards to human health and ecosystems. Chemicals involved are total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAHs), solvents, pesticides, and other heavy metals. Soil vapor extraction (SVE) is one of the main in-situ technologies currently employed for the remediation of groundwater and vadose zone contaminated with volatile organic compounds (VOCs). The performance of an SVE remediation system was examined for a petroleum hydrocarbon-contaminated site with attention to remediation targets and final performance. The study assessed: (1) the efficiency of a full-scale remediation system and (2) the influence of parameters affecting the treatment system effectiveness. Results showed how VOC concentration in soil was highly reduced after four year treatment with a global effectiveness of 73%. Some soil samples did not reach the environmental threshold limits and, therefore, an extension of the remediation period was required. The soil texture, humidity, permeability, and the category of considered pollutants were found to influence the amount of total extracted VOCs.

The Structural Change of the Autonomy Litigation and Rebuilding the Remedy System for Violation of Autonomous Right of Local Government

The Structural Change of the Autonomy Litigation and Rebuilding the Remedy System for Violation of Autonomous Right of Local Government

Migration of heavy metals and migration-degradation of phenanthrene in soil using electro kinetic-laccase combined remediation system

In order to solve the problem of heavy metal-organic compound soil pollution, in this paper, we developed a highly efficient electro kinetic-laccase combined remediation (EKLCR) system. The results showed that the EKLCR system had an obvious migration effect on heavy metals (copper and cadmium) and good migration-degradation effect on phenanthrene. The migration rates of copper and cadmium were 48.3% and 40.3%, respectively. Especially, with the presence of laccase, the removal rate of phenanthrene on Cu2+-contaminated soil was higher than that of Cd2+-contaminated soil due to the significant effect of heavy metals on the enzymatic activity of laccase. The average migration-degradation rate of phenanthrene by EKLCR system was 45.4%. Finally, gas chromatography-mass spectrometry (GC/MS) was used to analyze the degradation intermediates of phenanthrene in the soil, which included 9,10-Phenanthrenequinone, phthalic acid, and 2,2-Biphenyldicarboxylic Acid. In addition, we give the possible degradation pathways of phenanthrene, 2,2-Biphenyldicarboxylic Acid is further degraded to produce phthalic acid. The products of the phthalic acid metabolic pathway are protocatechuic acid, pyruvic acid or succinic acid, the final products of these organic acids are carbon dioxide and water.

Visible light responsive photoactive polymer supported on carbonaceous biomass for photocatalytic water remediation

Polymers have emerged as a new group of photoactive materials owing to their excellent optical and electronic properties. In this work, we report the synthesis and application of novel conjugated polymer for photocatalytic water remediation. The photoactive polymer was fabricated via the heat polymerization of Tris(4-carbazoyl-9-ylphenyl)amine (TCTA) into the Polyvinylpyrrolidone (PVP) host polymer (with mass ratio of 98%). TCTA is an electron rich with high lying LUMO and band gap of Eg = 3.4 eV, however, its polymerization with PVP results in higher visible light response until 900 nm. Two conjugated polymer samples were prepared with low and high TCTA contains, namely CP1 and CP2, respectively. The as-prepared photoactive samples were used as photoredox catalysts for the photocatalytic reduction of Cr(VI) and oxidation of MB under visible light (420 nm). CP2 showed higher visible light response, better electrochemical activity and excellent photocatalytic activity compared to CP1. In terms of Cr(VI) photoreduction, CP2 (0.25 g/L) can totally reduce Cr(VI) (20 ppm) at pH ranging from 3 to 8 under visible light. A total reduction of 40 ppm of Cr(VI) was found within 60 min using 0.75 g/L of CP2. 98% of MB was oxidized within 90 min using 0.25 g/L of CP2 under visible light. The photoactive polymer was supported into lignocellulosic biomass for higher surface area and better stability. As a result, this latter composite showed an enhanced adsorption capacity and photocatalytic efficiency towards Cr(VI) and MB compared to bare photoactive polymer. The main compounds used to fabricate this composite including PVP and natural biomass are eco-friendly, safe and low-cost which make it economically feasible photocatalyst for water remediation or other photoredox systems.

Characterizing the Reactivity of Metallic Iron for Water Treatment: H2 Evolution in H2SO4 and Uranium Removal Efficiency

Metallic iron (Fe0) has been demonstrated as an excellent material for decentralized safe drinking water provision, wastewater treatment and environmental remediation. An open issue for all these applications is the rational material selection or quality assurance. Several methods for assessing Fe0 quality have been presented, but all of them are limited to characterizing its initial reactivity. The present study investigates H2 evolution in an acidic solution (pH 2.0) as an alternative method, while comparing achieved results to those of uranium removal in quiescent batch experiments at neutral pH values. The unique feature of the H2 evolution experiment is that quantitative H2 production ceased when the pH reached a value of 3.1. A total of twelve Fe0 specimens were tested. The volume of molecular H2 produced by 2.0 g of each Fe0 specimen in 560 mL H2SO4 (0.01 M) was monitored for 24 h. Additionally, the extent of U(VI) (0.084 mM) removal from an aqueous solution (20.0 mL) by 0.1 g of Fe0 was characterized. All U removal experiments were performed at room temperature (22 ± 2 °C) for 14 days. Results demonstrated the difficulty of comparing Fe0 specimens from different sources and confirmed that the elemental composition of Fe0 is not a stand-alone determining factor for reactivity. The time-dependent changes of H2 evolution in H2SO4 confirmed that tests in the neutral pH range just address the initial reactivity of Fe0 materials. In particular, materials initially reacting very fast would experience a decrease in reactivity in the long-term, and this aspect must be incorporated in designing novel materials and sustainable remediation systems. An idea is proposed that could enable the manufacturing of intrinsically long-term efficient Fe0 materials for targeted operations as a function of the geochemistry.

The Intra-EU Investment Dispute Settlement After Achmea: Towards an Integrated Model of Justice

The Achmea judgment marks the culmination of the systemic conflict between international legal system and EU legal system on international investment arbitration. The Court referred to the fundamental principles of autonomy, effectiveness, prevalence and direct effect of EU law, as well as the principle of fair cooperation between Member States and ruled that arbitration clause laid down in intra-EU BITs is incompatible with EU law. As a result, the primaute of European law seems to reserve to the CJEU the role of last authoritative institution for the interpretation and application of all EU law and totally exclude the potestas iudicandi of arbitral tribunals in investment disputes. The paper discusses Achmea’s consequences on the relationship between international and European legal order in intra-EU investment dispute settlement. After a general overview of the substantial and procedural framework of investors’ protection, the paper deals with jurisdictional issues in ISDS system before and after Achmea. It reviews all possible scenarios on arbitration proceedings by analyzing the past and the future of arbitrators’ jurisdiction in the European legal order. It considers the most recent developments in EU legal order, specifically the agreement between Member States on a plurilateral treaty for the termination of all intra-EU BITs. The focus is on the ubi consistam of EU law in international legal order and on how courts could cooperate for an integrated model of justice. The analysis of the current status quo of the ISDS will show that the lack of judicial communication between international courts affects the efficiency of investment arbitration, and specifically, about intra-EU issues, the absence of a mechanism which would allow to settle investment dispute in accordance with EU judicial order. The final part of the paper explores the attempts to reconcile the dispute resolution mechanism provided by investment treaties with the European jurisdictional framework, despite it was defined by the ECJ as “a complete system of legal remedies and procedures designed to ensure review of the legality of acts of the institutions”. Proposals for reforms of investor-State dispute settlement system could follow three different approaches (systemic, based on cross-fertilization communication techniques and integralist) in order to restate the relationship between private and public justice: which future for investment dispute settlement system after Achmea?

Application of iron/aluminum bimetallic nanoparticle system for chromium-contaminated groundwater remediation

When the nanoscale zero valent iron (nZVI) is used for the reduction of hexavalent chromium (Cr6+) to trivalent chromium (Cr3+) in groundwater, the reduction efficiency is decreased due to the passivation of reactive sites by precipitation. The bimetallic nanoparticle (BNP) can be created with the addition of the second metal to achieve a higher activity and reduce the occurrence of the ferrous/ferric hydroxide precipitation. In this study, the iron-coated aluminum (Fe/Al) BNP and aluminum-coated iron (Al/Fe) BNP systems were designed for remediating Cr6+-contaminated groundwater. The chemical liquid-phase deposition and co-reduction method was applied to produce BNPs. Cr6+ removal rate by Fe/Al BNPs was directly proportional to the saturation concentration and reactive sites, which caused a higher Cr6+ removal rate. The pseudo-first-order kinetic model could be used to describe the Cr6+ adsorption mechanism by Fe/Al BNPs. Results show that Fe/Al BNPs and Al/Fe BNPs could reduce Cr6+ to Cr3+, and the removal efficiencies for Cr6+ were 1.47 g/g BNP and 0.07 g/g BNP, respectively. Detection of Cr3+ in the aqueous phase was observed during the Cr6+ removal process. Results from X-ray diffraction (XRD) analysis confirmed that Cr(OH)3 was present on the surface of BNPs. Main mechanisms caused Cr6+ removal included reduction, precipitation, and adsorption. The reduction of Cr6+ produced OH−, which created alkaline environment and facilitated the formation of chromium hydroxide precipitates [Cr(OH)3]. Thus, the migration of Cr3+ was prevented and the environmental risk was reduced. BNP had a higher activity and stability, and it was applicable for Cr6+-contaminated site remediation.

Combined process of biofilm+roots for aquaculture wastewater remediation

The mechanism of aquaculture wastewater remediation by combined process of biofilm+roots was studied based on the aquaculture circulatory system. Results showed that under the remediation system, the removal of COD,TP,NH4-N,TN were 84.59%,57.81%,82.43%and70.96%, respectively. The controllable wastewater treatment which is the coupling of biofilm and roots, was effective and could provide basis and technical support for the implementation of aquaculture wastewater treatment.

Injunctions and Hold-up under Weak Patent Protection

This paper analyzes how injunctions relate to patent hold-up problems. To this end, we present a simple model of licensing negotiations between a patent holder and a downstream firm in the shadow of litigation. More specifically, we consider the situation in which an injunction is granted as a matter of course if a patent is found valid and infringed upon in litigation, but the patent holder may be under-compensated due to aspects of the patent remedy system other than injunctions. We show that if the downstream user is unaware of the patent before any investment in initially designing its product, the patent hold-up problems created by injunction threats are worrisome when (i) the redesign process is costly, (ii) the degree of patent protection (by aspects of the patent remedy system other than injunctions) is sufficiently strong and (iii) the injunction is requested not to practice the patented technology exclusively but to collect excessive patent royalties. Even if the downstream user is aware of the patent before the initial investment, the patent hold-up problems do not disappear. The findings here imply that a discretionary approach is required towards denying injunctions against patent infringement. If the degree of patent protection is not sufficiently strong, denying injunctions can exacerbate the under-compensation problem. However, once patent protection improves enough (not necessarily perfectly), we may see a surge of patent hold-up problems, and it would be better to apply alternative patent remedies in place of injunctions when necessary. Lastly, we discuss several possible alternatives to injunctions and their pros and cons.

Exploring recent advances in silver halides and graphitic carbon nitride-based photocatalyst for energy and environmental applications

Engineering visible light active photocatalytic systems for renewable energy production and environmental remediation has always been a promising technology to counter overall energy demands and pollution challenges. As a fascinating conjugated polymer graphitic carbon nitride (g-C3N4) has been developed as a hotspot in the research field as a metal-free semiconducting material with the appealing band gap of 2.7 eV. Recently, g-C3N4 has gained tremendous interest in photocatalytic wastewater abatement as well as for hydrogen (H2) generation, carbon dioxide (CO2) reduction, and pollutant degradation, under exposure to visible light. Plasmonic silver halides (AgX) such as AgCl, AgBr, and AgI as plasmonic photocatalyst have received immense research interest owing to their escalating photocatalytic efficacy and strong surface plasmon resonance effect (SPR). AgX is the photosensitive, broad bandgap semiconducting materials with effectual antimicrobial properties. This review summarizes the heterostructure of carbonaceous g-C3N4 with plasmonic AgX, to reduce the recombination of photo-generated charge carriers, thus enhancing the natural light absorption. g-C3N4 grafted AgX nanoarchitectures can be utilized for several potential applications, for instance, overall water splitting (OWS), CO2 conversion to hydrocarbon fuels, pollutant exclusion, and antibacterial disinfection. This review focuses on the evolution of g-C3N4 as well as AgX, facile, and synthetic routes for fabrication of g-C3N4 tailored AgX, construction of nano-junctions (AgX/g-C3N4) with various photocatalytic applications. Finally, we provided a viewpoint of current hassles and some perceptions of novel trends in this exciting as well as developing research arena.

Environmental remediation by chitosan-carbon nanotube supported palladium nanoparticles: Conversion of toxic nitroarenes into aromatic amines, degradation of dye pollutants and green synthesis of biaryls

Nitroarenes, organic dyes and solvents are recalcitrant pollutants commonly found in industrial effluents. These organic compounds are toxic to aquatic organisms, hence their removal from aquatic systems is of significance. Remediation systems based on metallic nanoparticles are superior to the conventional systems with respect to their efficiency. Biopolymers like chitosan are considered to be suitable support material because biopolymers are capable of forming gel and exhibit affinity for metal cations. Catalysis systems with palladium nanoparticles are efficient in reducing nitroarenes to aromatic amines through hydrogenation, degradation of dye molecules and forming C-C bonds in organic coupling reactions. This study reports the preparation of chitosan-carbon nanotube supported palladium catalyst and the results of characterization studies by FTIR, XRD, TGA and SEM-EDX. The catalyst system was effective in catalytic reduction of 4-nitrophenol, 2-nitroaniline, 4-nitro-o-phenylenediamine and 2,4-dinitrophenol, and in degradation of dyes i.e., Congo red, Methyl orange, Methylene blue and Methyl red. The heterogeneous catalyst system also showed an excellent activity in green and solvent-free synthesis of 18 different biaryl compounds simply by six-minute microwave irradiation. The study demonstrated that chitosan-carbon nanotube supported-Pd(0) nanoparticles can be used for environmental remediation and protection, and for green synthesis of biaryls through Suzuki-Miyaura coupling reactions.