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Water Research Feb 2022Drinking water treatment plants use granular activated carbon (GAC) to adsorb and remove trace organics, but the GAC has a limited lifetime in terms of adsorptive... (Review)
Review
Drinking water treatment plants use granular activated carbon (GAC) to adsorb and remove trace organics, but the GAC has a limited lifetime in terms of adsorptive capacity and needs to be replaced before it is exhausted. Biological degradation of target contaminants can also occur in GAC filters, which might allow the GAC to remain in service longer than expected. However, GAC biofiltration remains poorly understood and unpredictable. To increase the understanding of adsorption and biodegradation in GAC, previous studies have conducted parallel column tests that use one column of GAC (potentially biologically active) to assess overall removal via both adsorption and biodegradation, and one column with either sterilized GAC or biological non-adsorbing media to assess adsorption or biodegradation alone. Mathematical models have also been established to give insight into the adsorption and biodegradation processes in GAC. In this review, the experimental and modeling approaches and results used to distinguish between the role of adsorption and biodegradation were summarized and critically discussed. We identified several limitations: (1) using biological non-adsorbing media in column tests might lead to non-representative extents of biodegradation; (2) sterilization methods may not effectively inhibit biological activity and may affect adsorption; (3) using virgin GAC coated with biofilm could overestimate adsorption; (4) potential biofilm detachment during column experiments could lead to biased results; (5) the parallel column test approach itself is not universally applicable; (6) competitive adsorption was neglected by previous models; (7) model formulations were based on virgin GAC only. To overcome these limitations, we proposed four new approaches: the use of gamma irradiation for sterilization, a novel minicolumn test, compound-specific isotope analysis to decipher the role of adsorption and biodegradation in situ, and a new model to simulate trace organic adsorption and biodegradation in a GAC filter .
Topics: Adsorption; Biodegradation, Environmental; Charcoal; Drinking Water; Water Purification
PubMed: 34996013
DOI: 10.1016/j.watres.2021.118026 -
The Science of the Total Environment Apr 2022In recent years, defect engineering sprung up in the artificial nanomaterials (NMs) has attracted significant attention, since the physical and chemical properties of... (Review)
Review
In recent years, defect engineering sprung up in the artificial nanomaterials (NMs) has attracted significant attention, since the physical and chemical properties of NMs could be largely optimized based on the rational control of different defect types and densities. Defective NMs equipped with the improved electric and catalytic ability, would be widely utilized as the photoelectric device and catalysts to alleviate the growing demands of industrial production and environmental treatments. In particular, considering that the features of targeting, adsorptive, loading and optical could be adjusted by the introduction of defects, numerous defective NMs are encouraged to be applied in the biological fields including bacterial inactivation, cancer therapy and so on. And this review is devoted to summarize the recent biological applications of NMs with abundant defects. Moreover, the opportunity of these defective NMs released into the surrounding environment continue to increase, the direct and indirect contact with biological molecules and organisms would be inevitable. Due to its high reactivity and adsorption triggered by defects, NMs tend to exhibit overestimate biological behaviors and effects on organisms. Thus, the sections regarding toxicological effects of NMs with abundant defects are also carried out to supplement the safety assessments of NMs and guide further applications in the industrial production and living.
Topics: Adsorption; Catalysis; Nanostructures
PubMed: 34785228
DOI: 10.1016/j.scitotenv.2021.151647 -
Environmental Technology Feb 2022Biochar is known to be a highly adsorptive material, especially when the biochar is altered by activation to further increase its sorption ability. Little information,...
Biochar is known to be a highly adsorptive material, especially when the biochar is altered by activation to further increase its sorption ability. Little information, however, is available on the potential reversibility of both ammonium () and nitrate () sorption on the inherent biochar pH. The objective of our study was to characterise biochars made using different pyrolysis conditions from five various plant materials and rubber tyre, and to use them to investigate the biochar properties responsible for and adsorption and desorption. The rubber tyre, maize stover and sugarcane pith were the weakest adsorbing biochars (5.7-7.8 mg g) and best described by the Freundlich adsorption isotherm. The grape pip, grape skin and pine wood biochars had adsorption capacities in the range 8.3-9.4 mg g and best described by a linear adsorption isotherm at 100 mg L. The adsorption results were associated with physisorption which implies that they can act as slow release fertilisers if is bioavailable. The six biochars had adsorption capacities in the range 15.2-15.9 mg g and were well fitted to the linear adsorption isotherm at 100 mg L. All six biochars had a stronger removal affinity (82-89%) compared to (33-39%). Adsorbed nitrate was not desorbable (0.01-0.23%) compared to adsorbed which was 53-60% desorbable. The desorption result was possibly due to competing redox reactions or being too strongly adsorbed for extraction. Desorption of was associated with biochar net negative pH values and volatilisation of ammonia.
Topics: Adsorption; Ammonium Compounds; Charcoal; Nitrates
PubMed: 32741271
DOI: 10.1080/09593330.2020.1804466 -
Journal of Hazardous Materials Mar 2022This review gives a proper dedicated understanding of the contamination level, sources, and biological dangers related with different classes of antibiotics in... (Review)
Review
This review gives a proper dedicated understanding of the contamination level, sources, and biological dangers related with different classes of antibiotics in consumable water. The literature on the adsorption of antibiotics is relatively uncommon and developments are still under progression, especially for adsorbents other than activated carbon. Also, adsorption technique has already been applied vastly for water treatment. Notwithstanding significant progressions, designed natural wastewater treatment frameworks are just bearably effective (48-77%) in the expulsion of antibiotics. Hence, the compilation of available literature especially for antibiotic adsorption was much needed. Moreover, the conventional adsorbents have some limitations of their own. In this study, the main focus was laid on unconventional adsorbents such as Biochar, Biopolymers, Carbon Nanotubes, Clays, Metal-Organic Frameworks, Microalgae and some miscellaneous adsorbents. The mechanism of adsorption by the unconventional adsorbents includes electrostatic interactions, π-π bonding, weak Van der Waal forces, H-bonding and surface complexation, which was similar to that of conventional adsorbents and hence these unconventional adsorbents can easily replace the costlier conventional adsorbents with even better adsorption efficiency. This paper also briefly discussed the thermodynamics, adsorption equilibrium; isotherm and kinetics of adsorption. This review paper seizes the critical advances of adsorption phenomenon at various interfaces and lays the foundation for current scenario associated with further progress. Besides, this study would help in understanding the antibiotic adsorption, cost estimation and future goals that will attract the young the researchers of this field.
Topics: Adsorption; Anti-Bacterial Agents; Kinetics; Nanotubes, Carbon; Water Pollutants, Chemical; Water Purification
PubMed: 34891019
DOI: 10.1016/j.jhazmat.2021.127946 -
Journal of Environmental Management May 2017This work describes the adsorptive removal of three widely consumed psychiatric pharmaceuticals (carbamazepine, paroxetine and oxazepam) from ultrapure water. Two...
This work describes the adsorptive removal of three widely consumed psychiatric pharmaceuticals (carbamazepine, paroxetine and oxazepam) from ultrapure water. Two different adsorbents were used: a commercial activated carbon and a non-activated waste-based carbon (PS800-150-HCl), produced by pyrolysis of primary paper mill sludge. These adsorbents were used in single, binary and ternary batch experiments in order to determine the adsorption kinetics and equilibrium isotherms of the considered pharmaceuticals. For the three drugs and both carbons, the equilibrium was quickly attained (with maximum equilibrium times of 15 and 120 min for the waste-based and the commercial carbons, respectively) even in binary and ternary systems. Single component equilibrium data were adequately described by the Langmuir model, with the commercial carbon registering higher maximum adsorption capacities (between 272 ± 10 and 493 ± 12 μmol g) than PS800-150-HCl (between 64 ± 2 and 74 ± 1 μmol g). Multi-component equilibrium data were also best fitted by the single component Langmuir isotherm, followed by the Langmuir competitive model. Overall, competitive effects did not largely affect the performance of both adsorbents. Binary and ternary systems maintained fast kinetics, the individual maximum adsorption capacities were not lower than half of the single component systems and both carbons presented improved total adsorption capacities for multi-component solutions.
Topics: Adsorption; Carbon; Charcoal; Kinetics; Sewage; Water Pollutants, Chemical; Water Purification
PubMed: 28130988
DOI: 10.1016/j.jenvman.2017.01.029 -
International Journal of Environmental... Dec 2022In our work, the transition-metal-oxide precursor (TMO@BC, M = Fe, Co, Ni) has been loaded on the pollen carbon by the hydrothermal method and annealed at different...
In our work, the transition-metal-oxide precursor (TMO@BC, M = Fe, Co, Ni) has been loaded on the pollen carbon by the hydrothermal method and annealed at different temperatures to generate a composite material of metal oxide and pollen carbon in this study, which can effectively prevent agglomeration caused by a small size and magnetism. The XRD patterns of the samples showed that the as-synthesized metal oxides were γ-FeO, CoO, and NiO. In the 20 mg/L methyl orange adsorption experiment, the adsorption amount of CoO@C at 500 ℃ reached 19.32 mg/g and the removal rate was 96.61%. Therefore, CoO@C was selected for the adsorption correlation-model-fitting analysis, which was in line with the secondary reaction. The pseudo-second-order kinetic model (: 0.9683-0.9964), the intraparticle diffusion model, and the Freundlich adsorption isotherm model indicated that the adsorption process was the result of both physical and chemical adsorptions, and the judgment was based on the electrostatic action. The adsorption and removal efficiency of ciprofloxacin (CIP) by changing the pH of the reaction was about 80%, so the electrostatic attraction worked, but not the main factor. Recovered by an external magnetic field, the three-time recycling efficiency was still maintained at more than 80%. This novel biomass-derived magnetic porous carbon material embedded with transition-metal-oxide nanoparticles is highly promising for many applications, especially in the field of environmental remediation.
Topics: Oxides; Carbon; Porosity; Metals; Adsorption; Metal Nanoparticles; Magnetic Phenomena; Water Pollutants, Chemical; Kinetics; Charcoal
PubMed: 36554621
DOI: 10.3390/ijerph192416740 -
Revista de Investigacion Clinica;... Dec 2023Membranes and sorbents play a crucial role in extracorporeal blood purification therapies, which aim to remove harmful molecules and toxins from the blood. Over the... (Review)
Review
Membranes and sorbents play a crucial role in extracorporeal blood purification therapies, which aim to remove harmful molecules and toxins from the blood. Over the years, advancements in hemodialysis (HD) membranes and sorbents have significantly enhanced their safety and effectiveness. This review article will summarize the latest breakthroughs in the development and clinical application of HD membranes and sorbents. We will commence with a concise examination of the mechanisms involved in solute transport across membranes and sorbents. Subsequently, we will explore the evolutionary path of HD membranes, from early cellophane membranes to high-flux membranes, including the development of high-cutoff membranes and the emergence of medium- cutoff membranes. We will discuss each type of HD membrane's advantages and limitations, highlighting the most promising advancements in novel biomaterials and biocompatibility, technologies, research in membrane performance, and their clinical applications. Furthermore, we will delve into the evolution and progress of sorbent technology, tracing its historical development, outlining its key characteristics, examining the mechanism involved in the adsorption process, and exploring its clinical application. This review aims to underscore the growth and future landscape of HD membranes and sorbents in extracorporeal blood purification techniques.
Topics: Humans; Renal Dialysis; Adsorption
PubMed: 37913784
DOI: 10.24875/RIC.23000223 -
Chemosphere May 2023Over the last decade, the removal of pharmaceuticals from aquatic bodies has garnered substantial attention from the scientific community. Ibuprofen (IBP), a... (Review)
Review
Over the last decade, the removal of pharmaceuticals from aquatic bodies has garnered substantial attention from the scientific community. Ibuprofen (IBP), a non-steroidal anti-inflammatory drug, is released into the environment in pharmaceutical waste as well as medical, hospital, and household effluents. Adsorption technology is a highly efficient approach to reduce the IBP in the aquatic environment, particularly at low IBP concentrations. Due to the exceptional surface properties of carbonaceous materials, they are considered ideal adsorbents for the IBP removal of, with high binding capacity. Given the importance of the topic, the adsorptive removal of IBP from effluent using various carbonaceous adsorbents, including activated carbon, biochar, graphene-based materials, and carbon nanostructures, has been compiled and critically reviewed. Furthermore, the adsorption behavior, binding mechanisms, the most effective parameters, thermodynamics, and regeneration methods as well as the cost analysis were comprehensively reviewed for modified and unmodified carbonaceous adsorbents. The compiled studies on the IBP adsorption shows that the IBP uptake of some carbon-based adsorbents is significantly than that of commercial activated carbons. In the future, much attention is needed for practical utilization and upscaling of the research findings to aid the management and sustainability of water resource.
Topics: Ibuprofen; Adsorption; Porosity; Anti-Inflammatory Agents, Non-Steroidal; Thermodynamics; Water Pollutants, Chemical
PubMed: 36841446
DOI: 10.1016/j.chemosphere.2023.138241 -
Journal of Environmental Sciences... Jun 2019Environmental pollution is one of the most serious problems facing mankind today, and has attracted widespread attention worldwide. The burgeoning class of crystalline... (Review)
Review
Environmental pollution is one of the most serious problems facing mankind today, and has attracted widespread attention worldwide. The burgeoning class of crystalline porous organic framework materials, metal-organic frameworks and covalent organic frameworks present promising application potential in areas related to pollution control due to their interesting surface properties. In this review, the literature of the past five years on the adsorptive removal of various hazardous materials, mainly including heavy metal ions, harmful gases, organic dyes, pharmaceutical and personal care products, and radionuclides from the environment by using COFs and MOFs, is summarized. The adsorption mechanisms are also discussed to help understand their adsorption performance and selectivity. Additionally, some insightful suggestions are given to enhance the performance of MOFs and COFs in the adsorptive removal of various hazardous materials.
Topics: Adsorption; Coloring Agents; Environmental Pollutants; Environmental Pollution; Gases; Hazardous Substances; Ions; Metal-Organic Frameworks; Metals, Heavy; Models, Chemical; Porosity; Surface Properties
PubMed: 30952335
DOI: 10.1016/j.jes.2018.12.010 -
Water Research Mar 2019This study utilized physical adsorption and filtration of carbon nanotubes (CNTs) and laccases to fabricate biomimetic dynamic membrane (BDM) for the advanced treatment...
This study utilized physical adsorption and filtration of carbon nanotubes (CNTs) and laccases to fabricate biomimetic dynamic membrane (BDM) for the advanced treatment of dye wastewater. In BDM, the adsorption, enzymatic degradation and membrane separation demonstrated a synergism effect on pollutant removal. At first, the fabrication methods of BDM were investigated, and the mixed filtration for laccases and CNTs showed a better performance than the stepwise filtration. Furthermore, the operation parameters of BDM, including CNTs and laccase loading amounts, dye concentration, agitation speed and transmembrane pressure (TMP), were studied. Suitable CNTs and laccase amounts could reduce filtration resistance and increase catalysis efficiency, while moderate TMP and agitation speed were in favor of boosting the BDM structure for catalysis and permeability. Optimized operation parameters (CNT loading amount = 20 g m, laccase loading amount = 74.6 g m, agitation speed = 100 rpm, and TMP = 1.0 bar) sustained a high removal rate, and the flux was over 120 L m h, even for 7 operation cycle' tests. BDM exhibited an excellent dye removal rate, stable flux and great antifouling capacity, on the ground that adsorption saturation and foulant may be alleviated "online and in-situ" by the enzymatic degradation. Afterwards, the bionic layer on BDM, after absorption saturation and catalyst deactivation, could be eliminated rapidly by carrying out a simple backwash cleaning operation, then a new one could be fabricated immediately. Therefore, BDM is a good candidate for functional membrane materials in future water treatment.
Topics: Adsorption; Biomimetics; Filtration; Nanotubes, Carbon; Water Purification
PubMed: 30599283
DOI: 10.1016/j.watres.2018.11.078