This critique examines a review article in this journal on adsorption techniques for removing metal ions from wastewater. The article is marred by several flaws, including tortured phrases, unsubstantiated quotes, incoherent statements, and factual inaccuracies. These problems weaken the article's clarity and reliability, raising doubts about the authors' understanding of the subject. As a result, the review's credibility is compromised, limiting its value as a reliable resource for researchers. This critique highlights these issues, stressing the importance of accuracy and rigor in scientific writing.
Wastewater management has become necessary in this industrialized era to meet the water needs of the world. Wastewater is one of the major crises in depletion of the environment. Photocatalysis is considered as the best way to remove pollutants. Therefore, in this study, pure and g-C3N4-SnWO4 nanocomposites were produced employing hydrothermal route. Prepared composites were studied by various techniques. SnWO4 band gap were altered by introduction of g-C3N4. The morphology was uniformly developed by the addition of g-C3N4 to the SnWO4. Evans Blue dye was employed as model pollutant. The photocatalytic action was improved by adding g-C3N4, which formed a heterojunction with SnWO4. The calculated rate constant was 0.000878, 0.0068, 0.01 and 0.0122 min-1 for EB, SnWO4-EB, 0.1g g-C3N4-SnWO4-EB and 0.2g g-C3N4-SnWO4-EB. The rate constant increased for 0.2 g g-C3N4-SnWO4 photocatalyst. A heterojunction appeared between g-C3N4 and SnWO4 facilitated SnWO4 for better e-/h+pair's separation and a lower recombination rate, which increased photocatalytic action of product. 0.2 g of g-C3N4-SnWO4 is a promising candidate for future wastewater degradation.
This study explores an innovative integrated system for removing the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) from aquatic environments, utilizing a combination by modified biochar derived from waste biomass of palm kernel shells (PKS-BM) and water hyacinth (Eichhornia crassipes). The characterization of the biochar revealed significant surface functional groups, a substantial surface area, and a mesoporous structure conducive to adsorption application. Biochar-assisted phytoremediation demonstrated markedly higher removal efficiencies of 2,4-D as compared to phytoremediation alone, achieving up to 98.7%, 96.9%, and 90.3% removal efficiency for 2,4-D concentrations of 50 mg/L, 100 mg/L, and 150 mg/L, respectively. Additionally, the presence of biochar significantly enhanced the morphological growth of Eichhornia crassipes, particularly under higher concentrations of 2,4-D, by mitigating toxic effects and supporting healthier plant development. These findings suggest that integrating biochar into phytoremediation system offers a promising, sustainable approach for effectively removing herbicides from contaminated water bodies while also promoting plant health and growth.
The quest for a good life, urbanization, and industrialization have led to the widespread distribution of endocrine-disrupting chemicals (EDCs) in water bodies through anthropogenic activities. This poses an imminent threat to both human and environmental health. In recent years, the utilization of advance materials for the removal of EDCs from wastewater has attracted a lot of attention. Metal-oxide nanocatalysts have emerged as promising candidates due to their high surface area, reactivity, and tunable properties, as well as enhanced surface properties such as mesoporous structures and hierarchical morphologies that allow for increased adsorption capacity, improved photocatalytic activity, and enhanced selectivity towards specific EDCs. As a result, they have shown extraordinary efficacy in removing a wide range of EDCs from aqueous solutions, including pharmaceuticals, agrochemicals, personal care items, and industrial chemicals. This study give insight into the unique physicochemical characteristics of metal-oxide nanocatalysts to effectively and efficiently remove harmful EDCs from wastewater. It also discussed the advances in the synthesis, and properties of metal-oxide nanocatalysts, and insight into understanding the fundamental mechanisms underlying the adsorption and degradation of EDCs on metal-oxide nanocatalysts using advanced characterization techniques such as spectroscopic analysis and electron microscopy. The findings of the study present metal-oxide nanocatalysts as a good candidate for the spontaneous sequestration of EDCs from wastewater is an intriguing approach to mitigating water pollution and safeguarding public health and the environment.
Climate change may put more industrial sites at risk of Natech incidents, particularly in coastal areas due to the compounding effects of climate hazards. This study investigates industrial facilities with potential for Natech due to emerging floods and delineates awareness of the exposed stakeholders, using the best available information, to strengthen local level climate change adaptation and disaster resilience in IKS Kuala Selangor, Malaysia. Two major methods were employed, conceptual site modelling using the source-pathway-receptor-consequence approach and semi-structured interviews to get insights from the local stakeholders. Findings reveal that in the worst-case scenario, manufacturing industries are exposed to floods, have limited flood protection and unknown containment and storage measures of hazardous materials within their facilities. While the high concentration of total metals in the surrounding topsoil has not been linked directly to the manufacturing industries, they have potential for Natech in future flood events. An area with environmentally available lead and arsenic accumulation linked to agricultural activities is also a potential point source for pollution during flood events in the worst-case scenario. Although most of the exposed local stakeholders are aware of climate hazards, they are not prepared for the risks of Natech. The local adaptation plan should include awareness building on Natech targeting the exposed local stakeholders as well as adequate flood protection and updated guidance on managing the safety of hazardous materials at manufacturing industry facilities.
Nitrogen dioxide (NO2) is a major cause of respiratory disorders in outdoor and indoor environments. Real-time NO2 monitoring using nonintrusive wearable devices can save lives and provide valuable health data. This study reports a room-temperature, wearable, and flexible smart NO2 gas sensor fabricated via cost-effective printing technology on a polyimide substrate. The sensor uses alkali lignin with edge-oxidised graphene oxide (EGO-AL) ink, demonstrating a sensitivity of 1.70% ppm⁻1 and a detection limit of 12.70 ppb, with excellent selectivity towards NO2. The high sensing properties are attributed to labile oxygen functional groups from GO and alkali lignin, offering abundant interacting sites for NO2 adsorption and electron transfer. The sensor fully recovers to the baseline after heat treatment at 150 °C, indicating its reusability. Integration into lab coats showcased its wearable application, utilising a flexible printed circuit board to wirelessly alert the wearer via cell phone to harmful NO2 levels (>3 ppm) in the environment. This smart sensing application underscores the potential for practical, real-time air quality monitoring, personal safety enhancement, and health management.
Nature iron is considered one of the promising catalysts in advanced oxidation processes (AOPs) that are utilized for soil remediation from polycyclic aromatic hydrocarbons (PAHs). However, the existence of anions, cations, and organic matter in soils considered impurities that restricted the utilization of iron that was harnessed naturally in the soil matrix and reduced the catalytic performance. In this regard, tropical soil naturally containing iron and relatively poor with impurities was artificially contaminated with 100 mg/50 g benzo[α]pyrene (B[α]P) and remediated using a slurry phase reactor supported with persulfate (PS). The results indicated that tropical soil containing iron and relatively poor with impurities capable of activating the oxidants and formation of radicals which successfully degraded B[α]P. The optimum removal result was 86% and obtained under the following conditions airflow = 260 mL/min, temperature 55 °C, pH 7, and [PS]0 = 1.0 g/L, at the same experimental conditions soil organic matter (SOM) mineralization was 48%. After the remediation process, there was a significant reduction in iron and aluminum contents, which considered the drawbacks of this system. Experiments to scavenge reactive species highlighted O2•- and SO4•- as the main radicals that oxidized B[α]P. Additionally, monitoring of by-products post-remediation aimed to assess toxicity and elucidate degradation pathways. Mutagenicity tests yielded positive results for two B[α]P by-products. The toxicity tests considered were the lethal concentration of 50% (LC50 96 h) for fat-head minnows revealed that all B[α]P by-products were less toxic than the parent pollutant itself. This research marks a significant advancement in soil remediation by advancing the use of the AOP method, removing the requirement for additional catalysts in the AOP system for the removal of B[α]P from soil.
This study investigates the potential of spent coffee ground biochar (SCGB) as a sustainable and cost-effective adsorbent for the removal of methylene blue (MB), a hazardous dye commonly used in the textile and printing industries. A response surface methodology (RSM) approach with central composite design (CCD) was employed to systematically investigate the effects of key process parameters, including adsorbent dosage, solution pH, contact time and temperature, on MB removal efficiency. The analysis revealed that adsorbent dosage and temperature as critical factors influencing MB removal, with a linear model providing a strong correlation. Optimal conditions for MB removal were determined to be 0.99 g of SCGB, 30 min of contact time, 30 °C temperature, and a solution pH of 7. Under these conditions, MB removal reached 99.99%, with a desirability of 1.000. The experimental results closely matched the predicted values, differing by only 0.02%, thus validating the accuracy of the model. Kinetic studies indicated a rapid adsorption process, well-described by both pseudo-first and pseudo-second order models. Isotherm analysis confirmed the applicability of the Freundlich model, suggesting favorable adsorption with increasing MB concentration. The high adsorption capacity of SCGB is attributed to its carbonaceous and porous structure, highlighting its potential as an effective adsorbent for dye removal in wastewater treatment applications.
The demand for developing bioindicators to assess environmental pollution has increased significantly due to the awareness of potential threats of diseases. Herein, the eukaryotic ubiquitous microorganism Acanthamoeba sp. was used as a bioindicator to explore further the influence of functionalized organic molecules containing -C≡C- and -CH=N- moieties prior application in the potential electronic components. The acetylide and hybrid acetylide-imine derivatives (FYD3A, FYD4B, and FYD4C) were tested for their cytotoxicity potentials based on dose-response analysis, morphological observation, and mode of cell death assessment on Acanthamoeba sp. (environmental-isolate). The biological activities of optimized compounds were evaluated by HOMO-LUMO energy gap and MEP analysis. The determination of the IC50 value through the MTT assay showed functionalized organic molecules of FYD3A, FYD4B, and FYD4C, revealing the inhibition growth of Acanthamoeba sp. with IC50 values in the 3.515 - 3.845 μg/mL range. Morphological observation displayed encystment with cellular agglutination and overall cell shrinkage. AO/PI-stained moieties-treated Acanthamoeba sp. cells appeared with shades of red to orange in necrotic Acanthamoeba cells whilst green to yellow apoptotic Acanthamoeba cells when compared to entirely green fluorescence untreated cells. Moreover, the results of the mitochondrial membrane potential (MMP) assay demonstrate the integrity and functionality potential of the mitochondrial membrane in cells, where a decrease in the MMP assay is linked to apoptosis. This study confirmed that the functionalized organic molecule featuring acetylide and its designated acetylide-imine moieties exhibit cytotoxicity towards the Acanthamoeba sp. by apoptotic and necrotic mode of cell death. This indicates that seeping these derivatives as electronic components can lead to the leaching of hazardous chemicals and contribute to environmental pollution that negatively affects the ecosystem. This study proposes the selection of efficient systems and elements for functionalized organic molecules that are safe to be released into the environment.
Microbial fuel cells (MFC) are emerging energy-efficient systems for copper (Cu) electrowinning from waste streams by coupling it with anodic oxidation of organics in wastewater. However, there is a lack of research examining scalable electrocatalysts for Cu electrowinning at low cathodic overpotentials in highly saline catholytes often found in e-waste leachates. The challenge of developing resilient anodic biofilms that withstand the antagonistic effects of ions migrating from catholytes in saline MFC also needs to be addressed. In this study, polypyrrole (PPy) cathodic electrocatalysts were developed and coupled with a robust halophilic anodic biofilm in MFC to improve the kinetics of Cu electrowinning from acidic chloride-based catholytes. Electrochemical characterisation of these cathodes revealed shuttling of electrons by redox-active PPy via the formation of intermediate Cu+-complexes as an energy-efficient pathway for producing metallic Cu. High power densities ranging from 0.63 ± 0.17 to 0.73 ± 0.05 W m-2 were achieved with undoped-PPy and phytic acid doped-PPy cathodes with simultaneous recovery of ∼97% Cu. These electrocatalysts also exhibited low charge transfer resistance (3-8 mΩ m2) that met the requisites for scalable cathodes in MFC. However, a decrease in the efficiency of PPy cathodes was observed over 5 d due to competing reactions at their interfaces, including re-oxidation of deposited Cu and cathodic corrosion, with further studies suggested to enhance their corrosion resistance. Nonetheless, integrating PPy electrocatalysts for Cu electrowinning in saline MFC has advanced its outlooks as an energy-efficient downstream process for urban mining of Cu from e-waste.
Mass cultivation of high-value aromatic herbs such as Vietnamese coriander and Persicaria odorata required specific soil, nutrients, and irrigation, mostly found in the limited natural wetland. This study aimed to evaluate the capacity of P. odorata at different densities in nutrient removal and the growth performance of African catfish, Clarias gariepinus in aquaponic systems. P. odorata was cultivated for 40 d with less than 10% water exchange. The effects of increasing crop densities, from zero plants for the control, 0.035 ± 0.003 kg/m2 in Treatment 1, 0.029 ± 0.002 kg/m2 in Treatment 2, and 0.021 ± 0.003 kg/m2 in Treatment 3, were tested on the growth performance of C. gariepinus with an initial density of 3.00 ± 0.50 kg/m3. The specific growth rate (SGR), daily growth rate of fish (DGRf), and survival rate (SR) of the C. gariepinus were monitored. Nutrient removal, daily growth rate of plant (DGRp), relative growth rate (RGR), and the sum of leaf number (Ʃn) of the P. odorata plant were also recorded. It was found that nutrient removal percentage significantly increased with the presence of P. odorata at different densities. The growth performance of C. gariepinus was also affected by P. odorata density in each treatment. However, no significant difference was observed in the DGRp and RGR of the P. odorata (p>0.05), except for Ʃn values. Treatment 1 had the highest Ʃn number compared to Treatment 2 and Treatment 3, showing a significant difference (p<0.05). This study demonstrates that the presence of P. odorata significantly contributes to lower nutrient concentrations, supporting the fundamental idea that plants improve water quality in aquaponic systems.
Globally, soil contamination with heavy metals (HMs) pose serious threats to soil health, crop productivity, and human health. The present investigation involved synthesis and analysis of biochar with bimetallic combination of iron and magnesium (Fe-Mg-BC). Our study evaluated how Fe-Mg-BC affects the absorption of cadmium (Cd), lead (Pb), and copper (Cu) in spinach (Spinacia oleracea L.) and remediation of soil contaminated with multiple HMs. Results demonstrated the successful loading of iron (Fe) and magnesium (Mg) onto pristine biochar (BC) derived from peanut shells. The addition of Fe-Mg-BC (3%) notably increased spinach biomass, enhancing photosynthesis, transpiration, stomatal conductance, and intercellular CO2 levels by 22%, 21%, 103%, and 15.3%, respectively. Compared to control, Fe-Mg-BC (3%) suppressed metal-induced oxidative stress by boosting levels of superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) in roots by 40.9%, 57%, 54.8 %, and in shoots by 55.5%, 65.5%, and 37.4% in shoots, respectively. The Fe-Mg-BC effectively reduced the uptake of Cd, Pb, and Cu in spinach tissues by transforming their bioavailable fractions to non-bioavailable forms. The Fe-Mg-BC (3%) significantly reduced the mobility of Cd, Pb and Cu in soil and limited the concentration of Cd, Pb, and Cu in plant roots by 34.1%, 79.2%, 47%, and shoots by 56.3%, 43.3%, and 54.1%, respectively, compared to control. These findings underscore the potential of Fe-Mg-BC as a promising amendment for reclaiming soils contaminated with variety of HMs, thereby making a significant contribution to the promotion of safer food production.
Yearly reports of detrimental effects resulting from harmful algal blooms (HAB) are still received in Malaysia and other countries, particularly concerning fish mortality and seafood contamination, both of which bear consequences for the fisheries industry. The underlying reason is the absence of a dependable early warning system. Hence, this research aims to develop a single DNA biosensor that can detect a group of HAB species known for producing saxitoxin (SXT), which is commonly found in Malaysian waters. The screen-printed carbon electrode (SPCE)-based DNA biosensor was fabricated by covalent grafting of the 3' aminated DNA probe of the sxtA4 conserved domain in SXT-producing dinoflagellates on the reverse-phase polymerized polyaniline/graphene (PGN) nanocomposite electrode via carbodiimide linkage. The introduction of a carboxyphenyl layer to the PGN nanotransducing element was essential to augment the carboxylic groups on the graphene (RGO), facilitating attachment with the aminated DNA. The synergistic effect of the asynthesized nanocomposite of PANI and RGO, tremendously enhanced the electron transfer rate of the ferri/ferrocyanide redox probe at the SPCE transducer surface, allowing for the label-free bioanalytical assay of complementary DNA targets. The developed DNA biosensor featuring the capacity to detect a broad range of Alexandrium minutum (A. minutum) cell concentrations, ranging from 10 to 10,000,000 cells L-1. The quantification of A. minutum cells from pure algal culture by the electrochemical DNA biosensor has been well-validated with traditional microscopic techniques. Furthermore, Alexandrium tamiyavanichii, another toxigenic HAB species, exhibited a similar electrochemical characteristic signal to those observed with A. minutum, whilst the biosensor yielded appreciably distinctive results when subjected to a non-toxigenic microalgae species as a negative control, i.e. Isochrysis galbana. A compendium DNA biosensor design and electrochemical detection strategy at laboratory scale serves as a precursor to the potential development of portable device for on-site detection, thus expanding the utility and scope of biosensor technology.
Chiral drugs play an important role in modern medicine, but obtaining pure enantiomers from racemic mixtures can pose challenges. When a drug is chiral, only one enantiomer (eutomer) typically exhibits the desired pharmacological activity, while the other (distomer) may be biologically inactive or even toxic. Racemic drug formulations introduce additional health risks, as the body must still process the inactive or detrimental enantiomer. Some distomers have also been linked to teratogenic effects and unwanted side effects. Therefore, developing efficient and scalable methods for separating chiral drugs into their pure enantiomers is critically important for improving patient safety and outcomes. Metal-organic frameworks (MOFs) show promise as novel materials for chiral separation due to their highly tunable structures and interactions. This review summarizes recent advancements in using MOFs for chromatographic and spectroscopic resolution of drug enantiomers. Both the opportunities and limitations of MOF-based separation techniques are discussed. A thorough understanding of these methods could aid the continued development of pure enantiomer formulations and help reduce health risks posed by racemic drug mixtures.
The application of artificial neural networks (ANNs) in the treatment of wastewater has achieved increasing attention, as it enhances the efficiency and sustainability of wastewater treatment plants (WWTPs). This paper explores the application of ANN-based models in WWTPs, focusing on the latest published research work, by presenting the effectiveness of ANNs in predicting, estimating, and treatment of diverse types of wastewater. Furthermore, this review comprehensively examines the applicability of the ANNs in various processes and methods used for wastewater treatment, including membrane and membrane bioreactors, coagulation/flocculation, UV-disinfection processes, and biological treatment systems. Additionally, it provides a detailed analysis of pollutants viz organic and inorganic substances, nutrients, pharmaceuticals, drugs, pesticides, dyes, etc., from wastewater, utilizing both ANN and ANN-based models. Moreover, it assesses the techno-economic value of ANNs, provides cost estimation and energy analysis, and outlines promising future research directions of ANNs in wastewater treatment. AI-based techniques are used to predict parameters such as chemical oxygen demand (COD) and biological oxygen demand (BOD) in WWTP influent. ANNs have been formed for the estimation of the removal efficiency of pollutants such as total nitrogen (TN), total phosphorus (TP), BOD, and total suspended solids (TSS) in the effluent of WWTPs. The literature also discloses the use of AI techniques in WWT is an economical and energy-effective method. AI enhances the efficiency of the pumping system, leading to energy conservation with an impressive average savings of approximately 10%. The system can achieve a maximum energy savings state of 25%, accompanied by a notable reduction in costs of up to 30%.
In the present study, biosynthesized ZnO nanoparticles in food wastewater extract (FWEZnO NPs) was used in the photocatalytic degradation of real samples of printing ink wastewater. FWEZnO NPs were prepared using green synthesis methods using a composite food waste sample (2 kg) consisted of rice 30%, bread 20 %, fruits 10 %, chicken 10 %, lamb 10%, and vegetable 20%. The photocatalysis process was optimized using response surface methodology (RSM) as a function of time (15-180 min), pH 2-10 and FWEZnO NP (20-120 mg/100 mL), while the print ink effluent after each treatment process was evaluated using UV-Vis-spectrophotometer. The behaviour of printing ink wastewater samples for photocatalytic degradation and responses for independent factors were simulated using feed-forward neural network (FFNN). FWEZnO NPs having 62.48 % of the purity with size between 18 and 25 nm semicrystalline nature. The main functional groups were -CH, CH2, and -OH, while lipid, carbon-hydrogen stretching, and amino acids were the main component in FWEZnO NP, which contributed to the adsorption of ink in the initial stage of photocatalysis. The optimal conditions for printing ink wastewater were recorded after 17 min, at pH 9 and with 20 mg/100 mL of FWEZnO NPs, at which the decolorization was 85.62 vs. 82.13% of the predicted and actual results, respectively, with R2 of 0.7777. The most significant factor in the photocatalytic degradation was time and FWEZnO NPs. The FFNN models revealed that FWEZnO NPs exhibit consistency in the next generation of data (large-scale application) with an low errors (R2 0.8693 with accuracy of 82.89%). The findings showing a small amount of catalyst is needed for effective breakdown of dyes in real samples of printing ink wastewater.
Biosynthesized nanocomposites, particularly those incorporating carbon-based materials, exhibit exceptional tunability and multifunctionality, surpassing the capabilities of conventional materials in these aspects. Developing practical solutions is critical to address environmental toxins from pharmaceuticals, heavy metals, pesticides, and dyes. Biomass waste is a readily available carbon source, which emerges as a promising material for producing biochar due to its inherent advantages: abundance, low cost, and environmentally friendly nature. This distribution mainly uses carbon-based materials (CBMs) and biomass waste in wastewater treatment. This review paper investigates several CBM types, including carbon aerogels, nanotubes, graphene, and activated carbon. The development of bio-derived carbon-based nanomaterials are discussed, along with the properties and composition of carbon materials derived from biomass waste and various cycles, such as photodegradation, adsorption, and high-level oxidation processes for natural remediation. In conclusion, this review examines the challenges associated with biochar utilization, including cost, recovery, and practical implementation.
Water purification using adsorption is a crucial process for maintaining human life and preserving the environment. Batch and dynamic adsorption modes are two types of water purification processes that are commonly used in various countries due to their simplicity and feasibility on an industrial scale. However, it is important to understand the advantages and limitations of these two adsorption modes in industrial applications. Also, the possibility of using batch mode in industrial scale was scrutinized, along with the necessity of using dynamic mode in such applications. In addition, the reasons for the necessity of performing batch adsorption studies before starting the treatment on an industrial scale were mentioned and discussed. In fact, this review article attempts to throw light on these subjects by comparing the biosorption efficiency of some metals on utilized biosorbents, using both batch and fixed-bed (column) adsorption modes. The comparison is based on the effectiveness of the two processes and the mechanisms involved in the treatment. Parameters such as biosorption capacity, percentage removal, and isotherm models for both batch and column (fixed bed) studies are compared. The article also explains thermodynamic and kinetic models for batch adsorption and discusses breakthrough evaluations in adsorptive column systems. The review highlights the benefits of using convenient batch-wise biosorption in lab-scale studies and the key advantages of column biosorption in industrial applications.
PAHs is the group of emerging micro-pollutants present in most environmental matrices that has the tendency to bioaccumulate and cause carcinogenic effects to human health. The present research involved the quantification and treatment of leachate produced from secured landfill, to eliminate the PAHS. Electro-Fenton process, a class of advanced oxidation process, is adopted to degrade the PAHs using titanium electrodes as both anode and cathode. Artificial intelligence based statistical tool "Central Composite Design" a module of JMP -19 software was used to design the experiments and optimize the critical parameters involved in the research. It was observed that the value of P is significant (P