Pollutants In Industrial Wastewater Research Articles

Multifunctional property of N,N-bis (carboxymethyl) glutamic acid modified biomass material: adsorption and degradation removals of cationic dyes in wastewater

As a common type of pollutants in industrial wastewater, cationic dyes have attracted great attentions. Using biodegradable N,N-di (carboxymethyl) glutamic acid (GLDA) as ligand and corn stalk (CS) as matrix, a novel and green biomass modified material GLDA-CS was successfully prepared. The multifunctional property of GLDA-CS for removing methylene blue (MB), malachite green (MG) and alkaline red 46 (R-46) from wastewater was evaluated. The dyes were removed by the electrostatic adsorption based on the cationic adsorption properties of GLDA-CS. The removal rates of MB, MG and R-46 can quickly reach 90.4%, 96.8% and 94.8% in short time. especially for MG and R-46 even only 20 min. The adsorption capacities of the dyes still remain more than 86.5% of the initial values after 5 cycles. In a heterogeneous system, the dyes were removed by Fenton-like degradation based on the metal chelating property of GLDA-CS. 100% degradation rates of the dyes can be achieved in 35 min under the acidic region. Even if at pH 7, degradation rates are 44.1%, 47.1% and 56.6% higher than those under the conventional homogeneous system, and the degradation rate remained at 83.7% after 5 cycles. Regardless of the adsorption or degradation, GLDA-CS shows strong anti-anion interference ability. The potential mechanisms of adsorption and degradation for the dyes by GLDA-CS were deduced by quantization calculation. It is concluded that the adsorption removal of the dyes by GLDA-CS follows MG > R-46 > MB, and mainly depends on the electrostatic interaction between -COOH in GLDA-CS and -N- in the dye molecules. Based on the degradation mechanism of Fenton-like reaction, the possible active sites of the dyes attacked by free radicals and their possible degradation intermediates were predicted by the calculations of Fukui function.

Activation mechanism of persulfate by Fe3C-based materials for efficient benzo-a-pyrene abatement in wastewater: The reversed direct electron transfer from persulfate to contaminants

Herein, an unusual reserved direct electron transfer (r-DET) process from persulfate (PS) to contaminants was observed on the surface of Fe3C with N-doped C shell supported on carbon nanotubes (Fe3C@CN-CNTs). The Fe3C-based materials were synthesized via a facile sol–gel method employing melamine, glucose, FeCl3, and commercial multi-walled CNTs. The activation mechanisms were fully explored with a comparison of Fe3C@CN-CNTs and other Fe3C-based materials for the effective abatement of benzo-a-pyrene (BaP), a typical persistent organic pollutant in industrial wastewater. Electrochemical measurements, zeta potential monitoring, and Mössbauer spectroscopy indicated that the lack of CN shell result the relatively large particle size of Fe3C on Fe3C-CNTs, leading to more negatively charged surface and abundant OH during PS activation. Nevertheless, the superparamagnetic fraction with a fine particle size on the surface of Fe3C@CN and Fe3C@CN-CNTs potentially leads to a more positively charged surface, enhancing the zeta potential of surface adsorbed BaP and benefiting the r-DET. Through r-DET, oxidized PS and reduced BaP formed as intermediates, accelerating the overall degradation of BaP in Fe3C@CN-CNTs/PS. The degradation pathways, cytotoxicity, and operation conditions of BaP degradation by Fe3C@CN-CNTs/PS were thoroughly investigated. Additionally, Fe3C@CN-CNTs were found to promote the nucleophilic reaction between Cl− and PS, producing free chlorine and enhancing BaP degradation efficiency in chloride-containing wastewater. Overall, this study presents a new insight for the PS-based r-DET process and offers a promising approach for treating organically-contaminated wastewater.

Enhanced photocatalytic degradation activity of titanium dioxide by adsorbing aromatic amines through N-bonding

Narrowing the wide band gap of TiO2 (∼3.2 eV) to enhance its visible light efficiency is crucial for advancing photocatalytic degradation of organic pollutants in industrial wastewater. In this study, we achieved band gap reduction and slowed recombination rates by adsorbing some aromatic amines, like aniline and its electron-donating derivatives, onto TiO2. The predominantly present N-bonded amine species reduced the band gap and decelerated charge carriers’ recombination, enhancing photocatalytic degradation under visible light. In contrast, the amine with electron-withdrawing group is adsorbed as only H-bonded species, which showed no improvement in photocatalytic activity, performing similarly to pristine TiO2. This surface modification strategy offers potential for creating visible light-driven photocatalysts for effective degradation of organic pollutants in water.

Facile fabrication of Cu/kaolin nanocomposite as highly efficient heterogeneous catalyst for 4-nitrophenol reduction in aqueous solution

Hazardous organic pollutants in industrial wastewaters are becoming a major global challenge that threatens life on earth and particularly poses a serious health risk to human beings. 4-Nitrophenol (4-NP) is a highly hazardous organic contaminant that has been extensively utilized across multiple industries, and their wastewater disposal into water streams leads to a higher accumulation of 4-NP. It is therefore important for both academia and industry to make catalysts that are cheap, very effective, good for the environment, easy to recover, and can be used more than once for reducing 4-NP in normal conditions. This paper reports the synthesis, characterization, and application of Cu/kaolin nanocomposite (NC) as an efficient heterogeneous catalyst for decomposing 4-NP, a model organic molecule. The catalyst was synthesized by incorporating a copper precursor into layered kaolin clay and directly reducing the metal precursor using sodium borohydride (NaBH4). The morphology, structure, surface property, and interaction of the resulting Cu/kaolin NC were characterized by ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron spectroscopy/energy-dispersive X-ray spectroscopy, selected area electron diffraction, X-ray diffraction, and N2 adsorption/desorption, and the results clearly demonstrated the growth of copper nanoparticles on the kaolin surface. It was discovered that the Cu nanoparticles (NPs) on the kaolin surface had a crystallite size of about 23.6 nm. The significance of Cu NPs and the high catalytic activity of the synthesized Cu/kaolin NC toward 4-NP reduction by NaBH4 were evaluated by the catalytic reduction experiments. Among the different nanocomposites synthesized, 30-Cu/kaolin showed the highest catalytic activity for 4-NP reduction, with a reduction efficiency of over 99 % within 4 min with a pseudo-first-order rate constant, kapp, of 1.23 min−1. Furthermore, the reusability test indicated that Cu/kaolin NC can be reused for up to six runs efficiently without significant decrease in its catalytic performance, indicating the nanocomposite has excellent stability and great potential applications in industrial and agricultural wastewater treatment.

Catalytic conversion of soluble aniline into insoluble N-phenylphenazine for wastewater treatments

Aniline, a common pollutant in industrial wastewater, requires an effective treatment method with minimal chemical usage. In this study, a two-stage catalytic oligomerization process has been developed to address this issue by converting soluble aniline into insoluble oligomers for wastewater treatment. In the first stage, aniline is oxidized using hydrogen peroxide (H2O2) and a green catalyst, iron tetraamido macrocyclic ligand (Fe-TAML) to form aniline tetramers or pentamers. In the second stage, these oligoanilines undergo further oxidation with H2O2 alone at a higher temperature, resulting in the formation of N-phenylphenazine or its derivatives. These macrocyclic compounds precipitate from the wastewater due to π− π stacking, allowing easy separation through decantation or gravity filtration. After process optimization, only 3 mg/L of Fe-TAML and 2 g/L of H2O2 are required to treat 1 g/L of aniline, achieving a remarkable 96.8% aniline removal efficiency and a 62.5% precipitate yield. This two-stage oxidation approach shows promise for treating aniline and similar aromatic compounds in real industrial wastewater.

Sustainable Solutions for Industrial Wastewater Remediation by KBiFe2O5 Under Visible‐Light Irradiation

AbstractIndustrial wastewater poses a serious threat to human health and the environment. The rising demand for an easy, efficient, environment‐friendly, and cost‐effective method for wastewater treatment has paved the way for the photocatalytic degradation of wastewater. Organic dyes, which comprise a major portion of organic pollutants in industrial wastewater, are highly toxic and carcinogenic. The hydrothermal method, being economical, easily available, and environmentally friendly, is used to prepare the time‐varying KBiFe2O5 samples. KBiFe2O5 is a lead‐free (nonhazardous), low‐bandgap brownmillerite‐structured crystalline material that can use a wide range of solar spectrum. Their phase purity is also confirmed by powder X‐ray diffraction (XRD), UV–Vis diffuse reflectance spectrophotometer (UV–Vis DRS) is done to confirm the bandgap value and Fourier transform infrared (FTIR) spectroscopy is performed to identify the chemical bonds in the material. Degrading textile organic effluent methylene blue (MB) dye under visible light and comparing its photodegradation performance are conducted to investigate the synthesized samples’ photocatalytic properties. The photocatalytic activity is relatively enhanced by adding H2O2 in a precise amount. So, the synthesized samples effectively demonstrate photocatalytic behavior, which has been used for wastewater remediation purposes.

Nanofiber aerogel with layered array with structure coupled photothermal/magnetothermal effect for continuous seawater desalination

The solar evaporation is susceptible to intermittent solar irradiation as well as salt crystallization deposition on the surface severely limits the evaporation efficiency. In this work, subject to inspiration of the transpiration, groove array structure and antifouling performance of banana leaves, a multifunctional photothermal/ magnetothermal coupled three-dimensional(3D) aerogel evaporator with layer-by-layer array structure was prepared by blow-spun technology which can achieve mass produced. The unique super hydrophilic vertical array structure has multi-scale high-efficiency water transport channels and the SnSe-Fe3O4 evaporation layer realizes super hydrophobic self-cleaning and excellent photothermal and magnetothermal conversion performance, which can achieve all-weather seawater desalination. The vertical array structures facilitate the reflection and refraction of light and promote the seawater convection and salt crystals absorption coupling. It could improve the photothermal conversion efficiency and salt resistance of the evaporator. Which resulted in an evaporation rate of 2.53 kg m−2h−1 under 1 sun, with solar energy conversion efficiency of 105 % and the evaporation rate is about 4.54 kg m−2h−1 at a magnetic field. Furthermore, it could purify organic pollutants in industrial wastewater and use waste heat to generate electricity. This evaporator provides a new economical and environmentally friendly solution for seawater desalination and sewage treatment.

Trace silver doping improved the efficiency of copper-based Fenton-like catalysts cathode for wastewater treatment

The treatment of highly concentrated and recalcitrant organic pollutants in industrial wastewater has garnered significant attention, with Fenton oxidation emerging as a promising approach. However, traditional iron-based Fenton reagents present certain limitations, and copper-based Fenton systems are often less efficient. Thus, it is necessary to develop innovative copper-based Fenton catalytic materials. In this study, Cu₂O and Ag-modified activated carbon fibers (Cu₂O-Ag@ACF) were synthesized via liquid-phase reduction. The composition, structure, and morphology of Cu₂O-Ag@ACF were systematically characterized. The Cu₂O-Ag@ACF was employed as a functionalized cathode in the electro-Fenton process to degrade a highly concentrated organic pollutant solution, with methylene blue serving as a model contaminant. The loading of Cu₂O and Ag not only enhances the electrochemical performance of ACF but also improves its Fenton oxidation efficiency. Cu₂O-Ag@ACF exhibited less than 1 % performance degradation after five cycles of use, highlighting its potential for industrial applications under simulated realistic conditions. Moreover, the electro-Fenton system parameters, including current density, pH, electrode spacing, and solution temperature, were optimized. Under the optimal conditions, the degradation rate of methylene blue by Cu₂O-Ag@ACF reached 92.8 % within 120 minutes. Kinetic analysis indicated that the reaction followed a first-order kinetic model, with a rate constant of 0.253 min⁻¹. Furthermore, this study revealed that trace silver doping significantly accelerated the generation of reactive oxygen species, thereby enhancing the efficiency of the Cu-based Fenton-like catalysts. In conclusion, this work presents a convenient strategy for the sustainable and efficient purification of industrial wastewater, contributing to the improvement of human life quality.

Industrial park wastewater treatment using a combined sono-pulsed electrochemical-coagulation process

Maintaining sustainable water management practices, preserving ecosystems, and safeguarding public health has depend on the treatment of wastewater. It has a significant impact on reducing water pollution and protecting the water supplies. Sono-pulsed electrochemical oxidation (S-PEO) process is a wastewater treatment method that uses ultrasound (US) waves and electrochemistry to enhance the pollutant removal efficiency. This study aim is to investigate the mineralization of industrial park wastewater by using pulsed electrochemical oxidation (PEO) and a combination of sonolysis and pulsed electrochemical oxidation (S-PEO) processes. The research focuses on the percentage elimination of chemical oxygen demand (COD) and color, as well as the assessment of power consumption. The study considers the influence of experimental parameters like initial pH, electrolysis time, and current to find the optimum conditions for maximum percentage removal efficiency with minimization of power consumption. According to the study, the optimum values of responses for the S-PEO process were obtained at pH=7, electrolysis time=40 min, and current =0.5 Amp. The optimum values for the maximum removal percentages of the responses COD and color were 97.04 %, and 99.70 %, respectively. The minimum of power consumption for S-PEO was 0.19 kWh/m3. These results demonstrate that, the superior efficiency of the S-PEO process and its feasibility in the removal of industrial wastewater pollutants. Optimizing parameters like pH, time, and current intensity is crucial for optimal performance, reducing energy consumption and operational costs. The S-PEO technique eliminates pollutants from wastewater efficiently and effectively, making it the suitable process when compared to the others.

Nucleic acid-functionalized upconversion luminescence biosensor based on strand displacement-mediated signal amplification for the detection of trivalent chromium ions

BackgroundRapid industrial development has generated serious pollution, including the presence of toxic and harmful heavy metal ions. Among them, trivalent chromium ion (Cr3+) is a very important element that poses a threat to life and health in our industrial wastewater pollution. Thus, it is important to develop efficient fluorescence methods for Cr3+ detection. In this study, an upconversion luminescence biosensor for detecting Cr3+ was constructed based on a DNAzyme, strand displacement reaction (SDR), and DNA-functionalized upconversion nanoparticles (UCNPs). ResultsThe sulfonate-rich poly (sodium 4-styrene sulfonate) (PSS) was modified onto the surface of UCNPs, forming UCNPs@PSS. Then, NH2-Capture probe DNA (NH2-Cp) was further modified onto the UCNPs@PSS surface through sulfonylation, resulting in UCNPs@PSS@NH2-Cp. The DNAzyme activated by Cr3+ triggered the release of the primer probe (Pp), which initiated the SDR system cycle, thereby releasing a tetramethylrhodamine (TAMRA)-modified signal probe (TAMRA-Sp). Finally, UCNPs@PSS@NH2-Cp bound to TAMRA-Sp through complementary base pairing, causing UCNPs and TAMRA to approach each other. Because of the luminescence resonance energy transfer (LRET) mechanism, the upconversion luminescence (UCL) signal of the UCNPs was quenched by TAMRA, enabling the detection of Cr3+ by the change of I585/I545 ratio. This biosensor has good stability, selectivity, and sensitivity, with a linear range of 0.5–75 nM and a detection limit of 0.135 nM for Cr3+. Significance and noveltyFirstly, based on LRET between UCNPs and TAMRA, the quantitative analysis of Cr3+ is achieved through the changes of ratio fluorescence. Secondly, the specificity of the biosensor is improved by utilizing the specific recognition of DNA enzymes. Thirdly, the signal amplification technology of the SDR cycle greatly improves the sensitivity of biosensor. This biosensor will be useful for future environmental safety monitoring and biopsy of biological fluids.

Atomically dispersed ternary FeCoNb active sites anchored on N-doped honeycomb-like mesoporous carbon for highly catalytic degradation of 4-nitrophenol

In the last decades, 4-nitrophenol is regarded as one of highly toxic organic pollutants in industrial wastewater, which attracts great concern to earth sustainability. Herein, atomically dispersed ternary FeCoNb active sites were incorporated into nitrogen-doped honeycomb-like mesoporous carbon (termed FeCoNb/NHC) by a two-step pyrolysis strategy, whose morphology, structure and size were characterized by a set of techniques. Further, the catalytic activity and reusability of the as-prepared FeCoNb/NHC were rigorously examined by using 4-NP catalytic hydrogenation as a proof-of-concept model. The influence of the secondary pyrolysis temperature on the catalytic performance was investigated, combined by illuminating the catalytic mechanism. The resultant catalyst exhibited significantly enhanced catalytic features with a normalized rate constant (kapp) of 1.2 × 104 min-1g−1 and superior stability, surpassing the home-made catalysts in the control groups and earlier research. This study provides some constructive insights for preparation of high-efficiency and cost-effectiveness single-atom nanocatalysts in organic pollutants environmental remediation.

Comparative Evaluation of Fenton and Persulfate Processes with UV/H2O2 for Batik Wastewater Treatment: Optimizing Fe2+ and S2O8 2- Ratio by H2O2 for Enhanced Pollutant Degradation

Wastewater generated from industrial processes including the batik industry in Indonesia contains high organic pollutants and dyes. In this study, the advanced oxidation process that will produce hydroxyl radicals was used to degrade pollutants in this batik industry wastewater. This study aims to compare the Fenton and Persulfate processes with the influence of variations in the concentration of Fe2+ and S2O8 2- added. This method is carried out by adding H2O2 as an oxidant which is added to each catalyst, namely Fe2+ and S2O8 2- in the presence of a combination of UV light. Fenton process was carried out in 60 minutes and Persulfate process was carried out in 45 minutes. In this study, there was a tendency to increase the efficiency of COD and color removal along with the increasing concentration of each catalyst added. The highest COD and color removal efficiency occurred at a ratio of H2O2:Fe2+ and H2O2: S2O8 2- of 1: 0.08.

Advancing nanoarchitectures of 2D WO3/MXene photoanode for enhanced photoelectrocatalytic oxidation of phenol and arsenic in synthetic wastewater

The photoelectrocatalytic advanced oxidation process (PEAOP) necessitates high-performing and stable photoanodes for the effective oxidation of complex pollutants in industrial wastewater. This study presents the construction of 2D WO3/MXene heteronanostructures for the development of efficient and stable photoanode. The WO3/MXene heterostructure features well-ordered WO3 photoactive sites anchored on micron-sized MXene sheets, providing an increased visible light active catalytic surface area and enhanced electrocatalytic activities for pollutant oxidation. Phenol, a highly toxic compound, was completely oxidized at an applied potential of 0.8 V vs. RHE under visible light irradiation. Systematic optimization of operational conditions for the photoelectrocatalytic oxidation of phenol was conducted. The phenol oxidation mechanism was elucidated via high-performance liquid chromatography (HPLC) analysis and the identification of intermediate compounds. Additionally, a mixed model of phenol and arsenic (III) in polluted water demonstrated the capability of WO3/MXene photoanode for the simultaneous oxidation of both organic and inorganic pollutants, achieving complete conversion of phenol and As(III) to non-toxic As(V). The WO3/MXene photoanode facilitated water oxidation, generating a substantial amount of O2•– and •OH oxidative species, which are crucial for the concurrent oxidation of phenol and arsenic. Recyclability tests demonstrated a 99% retention of performance, confirming the WO3/MXene photoanode's suitability for long-term operation in PEAOPs. The findings suggest that integrating WO3/MXene photoanodes into water purification systems can enhance economic feasibility, reduce energy consumption, and improve efficiency. This PEAOP offers a viable solution to the critical issue of heavy metal and organic chemical pollution in various water bodies, given its scalability and ability to preserve ecosystems while conserving clean water resources.

Coupled treatment of aniline and phenol in water by electrochemical copolymerization

ABSTRACT Anilines and phenols are recognized as challenging organic pollutants in industrial wastewater. Herein, the coupled treatment of aniline and phenol in water was achieved through electrochemical oxidation-induced copolymerization. After the electrolysis (1,300 mA for 10 h) in the solution of aniline and phenol (200 mL, each at a concentration of 5 g/L), the organic compounds were efficiently precipitated from their mixed solution by copolymerization. These insoluble copolymers could be easily separated by filtration and collected as brown powders, and the average removal rate of aniline and phenol was calculated as 0.6 mol/h m2 in this coupled electrolysis. The chemical oxygen demand (COD) test of the filtrates showed that it reached up to 98% of the COD removal ratio. Moreover, mixed solutions containing multiple aniline and phenol derivatives were also applicable for this coupled treatment strategy, and they were efficiently removed together after electrolysis.

PbO2 /graphite and graphene/carbon fiber as an electrochemical cell for oxidation of organic contaminants in refinery wastewater by electrofenton process; electrodes preparation, characterization and performance

The electro-Fenton oxidation process was used to treat organic pollutants in industrial wastewater as it is one of the most efficient advanced oxidation processes. The novel cell in this process consists of a prepared PbO2 electrode by electrodeposition on graphite substrate and carbon fiber modified with graphene as a cathode. X-ray diffraction, fluorescence, analysis system, atomic force microscopy, and scan electron microscopy were used to characterize the prepared anode and cathode. XRD patterns clearly show the characteristic reflection of the mixture of  - and β phases of PbO2 on graphite and carbon fiber, and AFM results for cathode and anode present that PbO2 on graphite substrate and graphene on carbon fiber surface are on a nanoscale. Contact angle measurement was determined for the carbon fiber cathode before and after modification. The anodic polarization curve showed a higher anodic current when utilizing the PbO2 anode than the graphite anode. Phenol in simulated wastewater was removed by electro-Fenton oxidation at 8 mA/cm2 current density, 0.4 mM of ferrous ion concentration at 35 °C up to 6 h of electrolysis. Chemical oxygen demand for the treated solution was removed by 94.02 % using the cell consisting of modified anode and cathode compared with 81.23% using modified anode and unmodified cathode and 79.87 % when using unmodified anode and modified cathode.

Impact of Biosorption Process on Industrial Waste Water Treatment in Panipat District, Haryana

Abstract: In this research paper, I have thoroughy described about the topic “Impact of Biosorption Process on Industrial Waste Water Treatment in Panipat District, Haryana.” The industrial wastewater pollution plaguing Panipat District, Haryana, poses a complex environmental challenge due to the diverse range of industrial activities in the region, including textiles, petrochemicals, and leather processing. This pollution, characterized by the discharge of heavy metals, dyes, organic compounds, and other contaminants into water bodies, threatens both aquatic ecosystems and public health. Conventional physical and chemical treatments have proven inadequate or environmentally harmful, necessitating the exploration of ecofriendly alternatives. Biosorption, a biotechnological method employing live or dead biomass to remove pollutants from wastewater, emerges as a promising solution owing to its cost-effectiveness, efficiency, and low environmental impact. This study explores the efficacy of biosorption techniques in mitigating industrial wastewater pollution in Panipat District, evaluating various biosorbents' performance and efficiency in pollutant removal. Results indicate remarkable reductions in pollutant concentrations, with activated carbon achieving a removal efficiency of 96% for chromium, agricultural residues demonstrating a removal efficiency of 95% for dyes, and microbial biomass exhibiting an 87.5% removal efficiency for organic compounds. Furthermore, biosorption processes contribute to cost savings, regulatory compliance, water quality enhancement, resource recovery, positive public perception, and long-term sustainability, positioning them as integral components of environmentally responsible industrial practices in Panipat. This research bridges scientific inquiry with practical application, advocating for the widespread adoption of biosorption technologies to address industrial wastewater challenges, protect ecosystems, and safeguard communities in Panipat District and beyond.

Numerical Simulation of the Solute Migration Regulated by Vertical Cutoff Wall based on FEFLOW

Cutoff wall has been widely used in desalination of coastal aquifers in many coastal regions and remediation of industrial waste water pollution. In recent years, the excessive exploitation of resources in the coastal brine distribution area leads to the salinization of deep soil. At the same time, the mine water pollution caused by improper discharge of industrial waste water into the abandoned mining area is a new form of pollution in Shandong, China. However, due to the complex geological conditions of abandoned mining areas, loose collapse of overlying strata in roadway and gob layer, it is difficult to prevent and control groundwater pollution in deep gob layer. It is a major difficulty in practical engineering to evaluate the cutoff interception performance of vertical cutoff wall on the pollution of gob layer in such mining areas and optimize cutoff interception measures. In this paper, a typical polluted abandoned mining area in Shandong, China is taken as an example, and COD is used as the main simulation factor for numerical simulation. The numerical simulation results show that in the process of groundwater pollution control, the cutoff wall with appropriate thickness and hydraulic conductivity can effectively block the diffusion of solute. The horizontal transport of solute can be significantly weakened when the thickness of the cutoff wall is 90 cm and the hydraulic conductivity is 1.0×10-4 m/d. Compared with increasing the thickness, reducing the hydraulic conductivity of the cutoff wall is more effective in controlling the migration of solute in the site. When the hydraulic conductivity is reduced by an order of magnitude, the diffusion range of solute is reduced by 19.74% compared to before. Therefore, priority should be given to reducing the hydraulic conductivity of the cutoff wall in order to optimize its influence on pollutant migration.

Eficiencia de los bioindicadores de toxicidad sobre contaminantes de aguas residuales industriales

In this paper, we present some important biological factors that modify the efficiency of toxicity bioindicators used to evaluate the harmful effect of industrial wastewater pollutants on biological organisms and processes, such as reproduction, growth and development. The Lactuca sativa model was analyzed and proposal for new biological parameters with fungi, bacteria, plants and animals that can be used as bioindicators of toxicity and ecotoxicity that do not directly compromise the survival of organisms in bioassays and environments contaminated with industrial wastewater effluents.

Double-shell hollow FeCoOx nanozyme-catalyzed colorimetric quantification and discrimination of dihydroxybenzene isomers

Due to the high perniciousness of dihydroxybenzene isomers toward environment and human health, it is imperative to develop simple and rapid strategies for detecting/distinguishing dihydroxybenzene isomers. However, most of the traditional approaches can only respond to single component of dihydroxybenzene isomers, which limits their application in the assay of complex samples. Herein, we develop a colorimetric sensing array based on the peroxidase-like activity of double-shell hollow FeCoOx nanozyme. Since different phenolic substances showed distinct kinetics during the catalytic reaction with the participation of FeCoOx, three different kinds of dihydroxybenzene isomers could be identified by principal component analysis. Moreover, various combinations of mixed dihydroxybenzene isomers with different concentrations can also be completely distinguished within 30 min in tap water and environmental water. The method showed a good linear response to catechol, resorcinol, and hydroquinone in the range of 1.5 to 100 µM, 5 to 100 µM, and 1 to 100 µM, respectively, with corresponding detection limit of 1.37 µM, 2.91 μM, and 0.824 μM. Besides, we have constructed a smartphone-based portable platform for analyzing various combinations of mixed dihydroxybenzene in actual water. This work provides a new idea for distinguishing phenolic substances with similar structures, and is promising to identify and monitor phenolic pollutants in industrial wastewater.

Influence of aeration-induced air–water interfaces on pollutant degradation in water treatment: A theoretical and experimental study

Advanced oxidation processes (AOPs) based on hydroxyl radicals (OH)-dominant pathway are the most important technologies for the removal of bio-recalcitrant organic pollutants in industrial wastewater. Air–water interface formed by aeration is one of the factors that affect the removal efficiency of pollutants in AOPs. In this work, the mechanistic and kinetic insights into the roles of air–water interface on the hydroxylation of three chlorophenols (CPs) in UV/H2O2 process have been investigated via theoretical calculation and experimental methods. Results show that CPs is more prone to accumulate at the air–water interface as the number of chlorine substituents increases. Consequently, the hydration reaction of CPs occurring at the interfacial influence the electron transfer associated with OH, leading to the non-oxidative consumption of OH. This interfacial reaction diminishes degradation efficiency, resulting in the formation of persistent organic pollutants. Herein, in UV/H2O2 degradation of 2,4,6-TCPs, persistent free radical (PFRs), as well as 1,3,7,9-TCDD and 2,3,6-Trichloro-4-(2,4,6-trichlorophenoxy)phenol, were identified using EPR spectroscopy and LC-Q-TOF-MS mass spectrometry, respectively. Altogether, this work provides a comprehensive understanding of the roles of aeration on OH-initiated degradation behavior of chlorinated phenol pollutants.