Removal Of Contaminants In Water Research Articles

Textile waste valorization as potential activated carbon precursor for the removal of water contaminants: Commentary

Textile waste has become a global concern as its generation is increasing at an alarming rate. Various ways to manage and reduce textile waste are currently being sought, including reutilization and conversion into value-added products, to diversify its usage in an effort to minimize its environmental impact. Recent trends have shown the potential of textile waste as low-cost adsorbent for wastewater treatment applications. This paper aims to highlight the activation methods to convert textile waste into activated carbon and discuss its textural characteristics and performance in water contaminants removal. Data from literature showed promising high adsorption capacities of heavy metals, dyes, and pharmaceuticals by textile waste-derived activated carbons. Overall, the valorization of textile waste into activated carbon is generally feasible. Also, the superior surface chemistry and textural properties are imperative towards the exceptional performance of textile waste activated carbon in wastewater treatment applications.

Thermoresponsive Scaffolds Fabricated Using Covalent Organic Frameworks for the Selective Removal of Water Contaminants

In contrast to coordination channels, the feasibility of covalent organic frameworks (COFs) for the fabrication of 2D and 3D polymeric architectures has not been studied. Well-defined channels, inert and hydrolyzable...

Eco-synthesis, characterization and application of waste plastics pyrolysis char in arsenic removal from contaminated water: An integrated circular framework with parametric response surface methodology optimization-cum-artificial neural network model

Eco-synthesis of a novel, cost-effective activated adsorbent from waste low-density polyethylene plastic pyrolysis char at 550 °C and its arsenic adsorption potential in simulated aqueous media has been investigated. Characterization reveals good surface chemistry and evolved morphology of activated char adsorbent with carbon structures at high pyrolysis temperature, thereby facilitating high arsenic adsorption uptake. A unique integrated framework of kinetic equilibrium investigation, parametric optimization applying response surface methodology (RSM) with responsive arsenic adsorption efficiency and artificial neural network (ANN) model for response validation has been presented. There is reasonably good fitting of experimental equilibrium figures into the Langmuir isotherm model (R2 = 0.9920). The effects of adsorbent pyrochar dose, arsenic concentration, contact time and pH on the arsenic removal capacity have been depicted via conjugate RSM graphs. The ANN regression curves showed R2 value of 0.99436, validating the model with ANN architecture as 4–8-1. Iron oxide complexation with arsenic on adsorbent surface is reported to play a dominant role in the proposed adsorption mechanism. The proposed hybridized model can be applied to examine the adsorptive removal of various contaminants in water. Techno-economic analysis of scaled-up community arsenic filter showed high removal efficiency (> 90%) of arsenic by activated plastic pyro-char adsorbent from contaminated water at an affordable cost of 0.67 $/m3 of treated water. The activated plastic waste pyro-char with an adsorption capacity of 7.21 mg/g is, therefore, environmentally sustainable in plastic waste management in the post-pandemic era for a ‘waste to wealth’ circular economy with perspective arsenic removal from contaminated water.

Fabrication of novel Ag3PO4/LiFe5O8 nanocomposites for dual applications in sustainable photocatalytic removal of harmful antibiotics and ratiometric electrochemical detection of hazardous carbendazim insecticide

Herein, for the first time bi-functional magnetic nanocomposites based on Ag3PO4 (SP) and LiFe5O8 (LF) were prepared with different ratio of LF (xLFSP, x = 2.5, 5, 10, 15 and 20 wt% of LF) and synergy between the individual components of the nanocomposite were studied for dual applications. Different analytical techniques were employed to examine the physicochemical features of the synthesized materials. In the presence of H2O2 and visible light, 10LFSP nanocomposite possess superior photocatalytic activity towards levofloxacin (LFX, 98% removal) and tetracycline (TC, 95% removal) drugs. Further, 10LFSP was employed to modify a glassy carbon electrode (GCE) and fabricate a ratiometric electrochemical sensor for the detection of the pernicious insecticide carbendazim (CBM). Under optimized conditions, ratiometric signal is linear to the CBM concentration in the range of 0.05 to 10 μM with a detection limit of 20 nM. Moreover, the proposed sensor 10LFSP/GCE was successfully validated in the detection of CBM in real water samples. Thus, the present work provides a venue for the design of multifunctional nanomaterial that could solve the dual purpose of detection and removal of water contaminants.

Investigation of Calcination Duration on the Surface Morphology and Specific Surface Area of Zeolite-Chitosan Composite with Oil Palm Ash for Potential Water Contaminant Remediation

This research investigates how varying calcination durations affect the surface characteristics of a Zeolite-Chitosan composite with oil palm ash, aiming to determine its water contaminant removal potential. Three different calcination durations (1, 2, and 3 hours) are studied. The synthesis involves mixing oil palm ash with Zeolite-Chitosan, followed by varying-duration calcination. Scanning electron microscopy (SEM) and surface area analysis (SAA) are used to assess surface characteristics. Initial findings indicate that changing calcination duration significantly impacts the composite’s surface features and specific surface area. Longer calcination leads to increased surface roughness and higher specific surface area. The 3-hour calcination results in the highest surface roughness and specific surface area among the durations tested. These findings suggest that calcination duration is crucial in altering the composite’s structural properties, which could affect its efficacy in adsorbing water contaminants. Ongoing research aims to better understand the relationship between calcination duration and the composite’s adsorption performance, ultimately optimizing the synthesis of the Zeolite-Chitosan composite with oil palm ash for efficient water contaminant remediation.

Study on the biodegradation of phenol by Alcaligenes faecalis JH1 immobilized in rice husk biochar

Immobilized microbial technology is a sustainable solution to reduce water pollution. Understanding the microorganisms in immobilized biochar is critical for the removal of contaminants in water. Biochar as a carrier of microorganisms, there are some problems need to be focused on, microporous structure blockage limiting the contact between microorganisms and pollutants for further degradation, unstable microbial loading, and low cycle times. To solve these problems, Alcaligenes faecalis was immobilized with rice hull biochar to study its adsorption and degradation characteristics of phenol. It was found that A. faecalis JH1 could effectively remove 300 mg/L of phenol within 24 h. The adsorption capacity of rice husk biochar for phenol increased with the increasing pyrolysis temperature (700 > 500>300°C). The immobilized biomass of JH1 from 700°C rice husk biochar reached 249.45 nmol P/g at 24 h of fixation reaction. It was found that the phenol removal rate of JH1 immobilized at all temperature biochar reached 300 mg/L within 12 h after the sixth cycle. As the number of cycles increased, bacteria grew and adhered to the biochar, forming a thick viscous biofilm and accelerating the removal of phenol. The results showed that A. faecalis could firmly adhere to rice hull biochar and degrade phenol effectively, with good durability and cyclicity.

Photothermal porphyrin-based covalent organic framework for efficient removal of perfluoroalkyl substances

Temperature is vital to the removal ability of adsorbent materials. The application of convenient and energy-efficient light-induced heating to promote the removal of emerging contaminants is rarely reported. Here, we report synthesis of a photothermal porphyrin-based covalent organic framework (COF) called Por-MA for efficient removal of perfluoroalkyl substances (PFASs) in environment water. The crystalline Por-MA with rich nitrogen and ordered structure can provide electrostatic and hydrogen bonding interactions for adsorption of PFASs, further give a large adsorption capacity (686.6 mg g−1) and rapid adsorption kinetics (equilibrium time < 10 min) for perfluorooctanoic acid (PFOA) at 25 °C, outperforming several other COF-based sorbents. Moreover, endothermic adsorption of PFOA on Por-MA made promoting adsorption of PFASs on photothermal Por-MA with facile illumination possible. Removal efficiencies of PFASs on Por-MA in environmental water samples also significantly improved with LED irradiation, indicating the high potential of photothermal COFs for removal of contaminants in practical water.

A New Two-Parameter Isotherm for Modeling Adsorptive Removal of Water Contaminants

A New Two-Parameter Isotherm for Modeling Adsorptive Removal of Water Contaminants

Modulatory effect of magnesium hydroxide-nanoparticles on lead-induced toxicity in river Clarias gariepinus near mining site

Effluents emerging from unprotected local mining activities pollute the nearby rivers containing aquatic lives. Advent of nanotechnology however, supposedly helps in removal of water contaminants and as well make waste water remediation possible. To this effect, Clarias gariepinus from rivers near mining site at Ijero-Ekiti, Ekiti-State, Nigeria were collected and exposed to 62.5, 125 and 250mg/L suspension of 10nm magnesium hydroxide nanoparticles (MgOHNPs) for 14-days under semi-static conditions. The suspected lead concentration in the river water was estimated using atomic absorption spectrophotometer while the quality of the river water was also examined. Clarias gariepinus collected were sacrificed and alterations in their biochemical and hematological indices were evaluated. The results showed that water sample from river I exhibit highest (0.033ppm) lead concentration while water sample from river III has the lowest (0.006ppm) lead concentration relative to their proximity to the mining site. Besides, the collected fishes demonstrated significant (P&lt;0.05) concentration dependent increase in some biochemical indices and no observable significant alteration in hematologic state of the fishes at tested doses. Hence, results from this study suggest that toxic lead effluent from local mining activities may have elevated lead concentration levels in nearby rivers while exposure to MgOHNPs could evoke alterations in physiological system of the inhabiting aquatic lives.

Adsorptive Recovery of Heavy Metal Ions from Aquatic Systems Using Metal‐Organic Frameworks: A Perspective in the Sustainable Development of Nanomaterials

AbstractRapid industrialization in the developing countries has facilitated the unwanted mixing of wastes into the already depleting sources of potable, domestic and industrial water. In particular, the mixing of toxic heavy metal wastes into the aquatic resources have not only increased the scarcity of water at the different levels of usage but also hygiene of the ecosystem is further threatened by the presence of abysmal quality of aquatic environment around the living world. Thus, it has become quite imperative to mitigate such problems through the removal of such water contaminants at the sources before supplied for a specific purpose. In this direction, among the other available mass transfer techniques, specific and efficient adsorption of heavy metal species on the nanomaterials such as metal‐organic frameworks (MOFs) are found to be a promising method of heavy metal ions recovery. This reports targets to provide a new perspective into heavy metal ions removal from wastewater as a rationale for sustainable nanomaterial engineering through the recycling of toxic metal species as precious precursors in the synthesis of nanomaterials. Decades of exploring materials sciences led to the generation of groundbreaking materials of nanoscale regime, which has advanced myriad avenues of science and technology, viz. electronic, energy, biomedical, environmental, agriculture applications, and more. In this regard, nanotechnology has had a global impact by several folds, which can be observed in all day‐to‐day facilities. This perspective aims to conceptualize a strategy of wastewater decontamination through the adsorptive retrieval of heavy metal species to be subsequently recycled in the design of smart nanomaterials.

Removal of Phosphorus and Cadmium from Wastewaters by Periphytic Biofilm

Phosphorus (Pi) and cadmium (Cd) contamination in water sources pose significant health risks and environmental concerns. Periphytic biofilms have been recognized for their ability to effectively remove these contaminants from aquatic environments. This study aimed to investigate the impact of photon and electron treatments on Pi and Cd removal by periphytic biofilms. The experiments spanned a monthly timeframe, focusing on how photon and electron treatments affected the contaminant removal efficiency of periphytic biofilms. The results revealed that while the introduction of electrons had a minimal impact on contaminant accumulation, the enhancement of photon exposure significantly improved the absorption capacity of periphytic biofilms. This, in turn, led to enhanced removal of Pi and Cd from the water. One possible explanation for this phenomenon is that photons played a crucial role in inducing nitrate and ammonium conversion, thereby facilitating the accumulation of 4.70 mg kg−1 Pi and 2.40 mg kg−1 Cd in periphytic biofilms. In contrast, electron treatment had limited effects on nitrate conversion. These findings provide valuable insights into the mechanisms underlying the removal of water contaminants by periphytic biofilms under the influence of electron and photon treatments. Furthermore, they have practical implications for improving pollutant removal capabilities in aquatic ecosystems using periphytic biofilms.

Mechanism insights into photo–assisted peroxymonosulfate activation on oxygen vacancy–enriched nolanites via an electron transfer regime

The utilization of photo–assisted persulfate activation for the removal of organic contaminants in water has garnered significant research interest in recent times. However, there remains a lack of clarity regarding specific contributions of light irradiation and catalyst structure in this process. Herein, a photo–assisted peroxymonosulfate (PMS) activation system is designed for the highly efficient degradation of organic contaminants on oxygen vacancy–enriched nolanites (Vo–FVO). Results suggest that the degradation of bisphenol A (BPA) in this system is a nonradical–dominated process via an electron transfer regime, in which VO improves the local electron density and thus facilitates the electron shuttling between BPA and PMS. During BPA degradation, PMS adsorbed at the surface of FVO–180 withdraws electrons near VO and forms FVO–PMS* complexes. Upon light irradiation, photoelectrons effectively restore the electron density around VO, thereby enabling a sustainable electron transfer for the highly efficient degradation of BPA. Overall, this work provides new insights into the mechanism of persulfate activation based on defects engineering in nolanite minerals.

Boron and nitrogen co-doped carbon-based nanomaterials/nickel oxide/hydroxide hybrids for sunlight induced photocatalytic water cleaning

B doped as well as B and N co-doped highly reduced graphene oxide and multiwall carbon nanotubes/Ni oxide and Ni hydroxide nanohybrid layers were synthesized using a one-step laser technique. NiO nanoparticles, graphene oxide platelets, and multiwall carbon nanotubes were used as starting materials for the preparation of the composite layers. H3BO3 was used as B precursor and urea as well as NH3 as N precursors for B and N co-doping of the composite layers. The influence of the nature and concentration of the B and N precursors on the physico-chemical properties of the nanohybrid layers, chemical composition and chemical bonding states, crystalline structure, as well as charge transfer properties was systematically investigated. The relation between the physico-chemical properties and functional characteristics of the nanohybrid layers, photocatalytic removal of water contaminants under simulated sun irradiation conditions was studied, identifying the optimum concentrations of the dopant precursor materials. The mechanism of the photodegradation process was explored, based of the band structure of the composites. The main intermediates, reactive oxygen species implied in the photocatalytic degradation processes of organic molecules, was investigated through the addition of scavengers to the organic dye test solutions. The highest photocatalytic activities were achieved for B and N co-doped samples synthesised using H3BO3 as B and urea as N precursors.

Effective photocatalytic degradation of methylene blue (MB) and reactive red 120 (RR120) using Al substituted ZnO nanoparticles

The discharge of dyes into the environment from industries can have an adverse impact on human and aquatic health, even at low concentrations. Therefore, this work aims to eliminate the toxic dyes using aluminium (Al) substituted ZnO nanoparticles (NPs) before they mix into the water bodies. The substitution of Al modifies its crystal structure and extends its optical absorption, that improves the photocatalytic activity of ZnO NPs. The X-ray diffraction of the prepared NPs exhibited a well-defined wurtzite phase of ZnO. The crystallite size of ZnO nanoparticles decreases with an increase in Al concentration. The scanning electron microscopic images of Al substituted ZnO NPs revealed vertically aligned rod-like particles. The size of synthesized particles decreased by rising the concentration of Al, and this impact was due to the inhibition of particle growth. The band gap of the Al substituted ZnO decreased compared to pure ZnO. The 20 mg of Al (5%) substituted ZnO catalysts degrade 99.7% of methylene blue (MB) and 99.6% of reactive red 120 (RR120) with rate constants of 0.01701 min−1 and 0.0680 min−1. The 5% Al substituted ZnO NPs were found to be an efficient catalyst for the removal of toxic contaminants in water.

Biomass-derived foams with three-dimensional hierarchical structure for efficient p-arsanilic acid removal

As an emerging micro-pollutant, p-arsanilic acid (p-ASA) exist widely in the environment, and it can form highly toxic arsenate and arsenite during the migration and transformation process, which greatly increases the risk of arsenic pollution in the ecosystem. Additionally, three-dimensional (3D) porous block materials have the advantage of stronger adsorption performance, faster adsorption rate and easy recovery, showing broad application prospects in water pollution control. Hence, the aminozed collagen fibers foam (ACFF) with 3D porous block structure was synthesized. The maximum adsorption capacity of ACFF for p-ASA was 476.19 mg·g−1 due to the rich honeycomb porous structure and the synergistic effect of electrostatic attraction, hydrogen bonding effect and amphiphilicity. Moreover, ACFF is not only easy to recycle, but also has good elastic recovery and regeneration performance. The pore size of ACFF was concentrated in the range of 25–5000 nm, and the porosity was 71.66%. ACFF may be an adsorbent with great potential for the removal of organoarsenic contaminants in water.

Adsorption and Removal of Composite Contaminants in Water Using Thermoplastic Polyurethane Nanofiber Membranes with Polydopamine–Polyethyleneimine Coatings

Dye wastewater containing bisphenol A (BPA) and dyes as pollutants has not been adequately studied. Our previous study revealed that thermoplastic polyurethane (TPU) nanofiber membranes (NFMs) modified by the addition of polyethyleneimine (PEI) and polydopamine (PDA) satisfactorily adsorb dyes. Herein, we first optimized the synthesis conditions for such membranes, noting a PEI/PDA monomer ratio of 2:2 and a deposition time of 48 h to be optimal. Experiments using these membranes revealed that binary systems containing BPA and the dyes (Congo red (CR), Eosin yellow (EY), or sunset yellow (SY)) exhibit three adsorption behaviors. CR and BPA compete with each other for adsorption sites, decreasing the maximum adsorption capacity (Qmax) for CR 208.3 mg/g (in a monomeric system) to 182.4 mg/g. The adsorption rates for CR and BPA decreased from 0.002 min−1 and 0.331 min−1 in the monomeric systems to 8.37 × 10−4 min−1 and 0.072 min−1, respectively, in the binary CR–BPA system, exhibiting antagonistic effects. When EY and BPA coexisted, Qmax for EY increased from 60.0 (monomeric) to 71.9 mg/g, whereas that for BPA increased from 35.6 to 43.2 mg/g, showing a synergistic effect due to the possible bridging effect. The adsorption sites for SY and BPA are independent of each other. The novelty of this study is the finding that PDA/PEI-TPU NFMS exhibited high adsorption capacity for dyes and BPA in binary composite systems and PDA/PEI-TPU NFMs showed different adsorption patterns for three dye–BPA binary composite systems. The preparation of PDA/PEI-TPU NFMs and the investigation of the adsorption mechanism for dye–BPA binary composite systems are not only of theoretical importance but also provide experimental and data support for practical applications.

Multifunctional sodium alginate/chitosan-modified graphene oxide reinforced membrane for simultaneous removal of nanoplastics, emulsified oil, and dyes in water

Membrane technology is widely recognized as an efficient and advanced approach for wastewater treatment. However, the development of environmentally friendly and versatile membranes capable of effectively removing multiple contaminants remains a significant challenge. Inspired by natural magnets, we developed a heterostructured membrane using biomass materials to achieve the efficient removal of multiple contaminants from wastewater. Specifically, a bionic three-layer SA/GO/CS composite membrane was prepared by using sodium alginate (SA) and chitosan (CS) to modify graphene oxide (GO), respectively, and then assembled to both sides of the glass fiber (GF) membrane. The composite membranes achieved 99.87 % and 97.10 % removal of NPs with particle sizes of 500 nm and 50 nm. Moreover, the membrane demonstrated superior separation performance for mixed wastewater, enabling effective treatment of a broad spectrum of contaminants. Additionally, the membrane exhibited excellent stability when exposed to strong acid and alkali environments and demonstrated good recyclability throughout the multiple contaminants removal process. The bionic membrane, prepared using a straightforward method proposed in this study, provides an effective approach for enhanced removal of multiple contaminants in water. These findings contribute to the advancement of eco-friendly and versatile wastewater treatment membranes, opening new possibilities for sustainable water purification technologies.

A review on the versatility of Carica papaya seed: an agrogenic waste for the removal of organic, inorganic and microbial contaminants in water

AbstractThe advent of civilization, coupled with growing industrialization in many countries, is placing more demand on the available water sources. At the same time, the daily surge in wastes generated by man's anthropogenic activities has led to microbial, organic and inorganic contamination of water sources. Based on available evidence, significant research efforts are being made into the use of low‐cost agricultural materials such as Carica papaya seed (CPS) in the removal of these contaminants from water sources in a bid to provide clean water. In the present review, the organic, inorganic and microbial contaminants in waters were elucidated. Furthermore, the chemical composition of the CPS was illustrated. The adsorption capacity and efficiency of CPS and their composites in the remediation of the selected contaminants were discussed while identifying the various factors affecting the adsorption efficiency. Finally, the reusability of this agricultural material was discussed. Solution pH was identified as a major factor influencing the sorption process. The high removal efficiency reported in the studies that adopted CPS showed its vast potential in the elimination of contaminants from water sources. Also, the regenerative potential of the adsorbent over several cycles indicated its long‐term use. The economic feasibility and environmental sustainability afforded by using CPS chart a path for further investigation into the use of other low‐cost agricultural materials in the elimination of environmental contaminants. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley &amp; Sons Ltd on behalf of Society of Chemical Industry (SCI).

Photocatalytic activity of solvothermally synthesized rutile TiO2 nanorods for the removal of water contaminants

The TiO2 nanorods are synthesized via a solvothermal route by varying reaction temperatures. The XRD analysis reveals that the synthesized TiO2 nanorods grown with rutile phase with a 14 to 26 nm average crystallite size. The FESEM and HRTEM analysis confirmed the rod-like shape of the synthesized TiO2 nanoparticles, which grew in the same direction. In addition, the EDS analysis revealed the titanium-oxygen elemental ratio is equal to 1:2, confirming the stoichiometry of the grown sample. The UV–vis analysis of TiO2 nanorods shows a red shift in the band gap with a rising temperature. The TiO2 nanorods synthesized at 180 °C (T2) achieves methyl orange and rhodamine B degradation up to 90 and 97% within 50 and 60 min, respectively, under 125 W mercury light irradiation. Since the T2 sample has a high surface area, small crystallite size and a narrow band gap, it significantly affects the photodegradation of methyl orange and rhodamine B dye.

A Review on Cassava Residues as Adsorbents for Removal of Organic and Inorganic Contaminants in Water and Wastewater

An increase in water demand for drinking, agriculture, and industries necessitates the treatment of water and wastewater. Among various conventional treatment techniques available, adsorption is found to be one of the most economical and feasible methods. Adsorbents from plant biomass are effective for the removal of organic and inorganic pollutants. Cassava has gained attention among researchers during the past decades due to its plentiful availability and resilient characteristics. Even though cassava contains cyanogenic glucosides as toxins, it is used in industries for development of various products. Cassava stem, rhizome, peel, and bagasse are industrial residues that are generated in abundance. The present review focusses on factors affecting adsorption using cassava residues, adsorbent preparation and activation methods, equilibrium, mass transfer, kinetics, and thermodynamic studies of adsorption.