Wastewater is contaminated water that must be treated before it may be transferred into other rivers and lakes in order to prevent further groundwater pollution. Over the last decade, research has ...been conducted on a wide variety of contaminants, but the emerging contaminants are those caused primarily by micropollutants, endocrine disruptors (EDs), pesticides, pharmaceuticals, hormones, and toxins, as well as industrially-related synthetic dyes and dye-containing hazardous pollutants. Most emerging pollutants did not have established guidelines, but even at low concentrations they could have harmful effects on humans and aquatic organisms. In order to combat the above ecological threats, huge efforts have been done with a view to boosting the effectiveness of remediation procedures or developing new techniques for the detection, quantification and efficiency of the samples. The increase of interest in biotechnology and environmental engineering gives an opportunity for the development of more innovative ways to water treatment remediation. The purpose of this article is to provide an overview of emerging sources of contaminants, detection technologies, and treatment strategies. The goal of this review is to evaluate adsorption as a method for treating emerging pollutants, as well as sophisticated and cost-effective approaches for treating emerging contaminants.
•This review focuses on high-risk emerging contaminants (ECs) in the environment.•ECs are explored in terms of their occurrence, sources and important mechanisms.•The negative environmental and health effects of ECs are addressed.•Numerous emerging pollutants and improvements in their remediation are reviewed.•Recent progress and possible advances in emerging pollutant adsorption are reviewed.
In this study, Moringa seed powder (M
SP
) was pyrolyzed at 450 °C to synthesize Moringa seed powder biochar (M
SP
B) and treated with phosphoric acid (H
3
PO
4
) to synthesize phosphate-modified ...Moringa seed powder biochar (M
SP
B-HPO) as an adsorbent for the removal of diclofenac (Dfc) from aqueous solution. Fourier transform infrared (FTIR) analysis, energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and pH point of zero charge (pH
pzc
) were conducted to give more insight into the adsorbent’s properties. The SEM analysis showed the transformations in the surface morphology from the parent material to the synthesized materials after the thermal and acid treatment. EDS analysis revealed the variation in the elemental composition of the materials prior to and after adsorption of Dfc ions. The FTIR analysis showed changes and peak intensities of functional groups involved in Dfc removal. The pH
pzc
showed the charge carried by M
SP
B-HPO in different pH conditions. Isotherm data best matched the Sips model, and the pseudo-second-order model best described the adsorption kinetics. The maximum adsorption capacity of M
SP
B-HPO by Sips model was found to be 100.876 mg g
−1
.
Display omitted
•The sustainability of biofuel technologies is discussed in depth.•Biofuels' present and future challenges and requirements are studied.•Productivity and sustainability are improved ...by bioengineering.•The production of biofuels from organic waste ensures sustainability.
Specifically, human activities, such as those in industry and transportation, have resulted in an increase in the demand for fossil fuels, resulting in severe environmental problems.Throughout this article, we discuss the potential and challenges associated with the production of biofuels from a variety of feedstocks and advances in processing technologies utilizing a range of feedstocks. Based on the conclusion of the study, we conclude that bioenergy is a green alternative to be used for diverse energy needs, once the appropriate conversion processes are applied. The production of biofuels and their use in industries and transportation have significantly reduced the use of fossil fuels. The literature review concluded that producing biofuels from energy crops and microalgae was the most efficient and attractive method. The purpose of this review is to explain all aspects of biofuels and their sustainability criteria. With a particular focus on the role of nanotechnology in biofuel production, this article discusses the most recent advances in biofuel production. A number of emerging techniques have been investigated for improving process quality, including integrated techniques, less energy-intensive distillation strategies, and the use of microorganisms in engineering. A challenging aspect of biofuel production on a large scale remains; therefore, a novel technology must be developed in order to enhance biofuel production in order to meet the challenges and meet future energy needs.
•Ligand based functional composite material was fabricated for Pb(II) capturing.•The Pb(II) ion detected in optical visualization from the sufficient color formation.•The Pb(II) detection limit was ...low and the maximum adsorption capacity was high.
Detection and removal of toxic metal ions from aqueous solutions is considered among the most important environmental issues in recent years as these metals are hazardous, carcinogenic, and classified as toxic pollutants. In this study, organic ligand embedded large-pore facile composite material was prepared by the direct anchoring method and then, was characterized in systematic ways for understanding the lead (Pb(II)) detection and removal in naked-eye ability in an aqueous solution was evaluated. The material was exhibited the specific functionality for Pb(II) detection and removal from aqueous media with the addition of trace level of Pb(II) ion. The Pb(II) ion detection limit of the presented method was 0.44 µg/L at optimum conditions. The impact of effective Pb(II) ion removal parameters including solution pH, the initial concentration, contact time and desorption ability was studied. The results demonstrated that the addition composite material have synergistic effect on Pb(II) adsorption capacity. The data of adsorption processes clarified that with increased pH up to 5.50, the Pb(II) adsorption was suitable at pH 5.50. Moreover, the composite material exhibited the large surface area-to-volume ratios and uniformly mesostructures shaped pores that were actively working to selective capturing of Pb(II) ion. The adsorption data were well fitted to the Langmuir model and the maximum adsorption capacity was 176.66 mg/g. The material was capable to uptake the Pb(II) ion even in the presence of a high amount of coexisting metal ions. The adsorbed Pb(II) ion was completely eluted with 0.20 M HCl and simultaneously regenerated into the initial form for the next operation after washing with water without loss in its initial performances. Then the modified composite material enhanced the affinity between Pb(II) and functional surface for improving the selectivity to uses a very promising in purification of wastewater.
Display omitted
Magnetic chitosan (Chi@Fe3O4) nanocomposite was synthesized and modified with graphene oxide (Chi@Fe3O4GO) and the potential of both materials as adsorbents was assessed for the removal of chromium ...(Cr(VI)) from water. The physico-chemical characteristics of magnetic nanocomposites were studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), x-ray diffraction (XRD), Raman spectroscopy and Brunauer–Emmett–Teller (BET). The synthesized adsorbents exhibited varied Cr(VI) removal efficiency at solution pH 2. The reaction kinetics correlated well with the pseudo-second-order model. The maximum adsorption capacity was found to be 142.32 and 100.51 mg g−1 for Chi@Fe3O4 and Chi@Fe3O4GO, respectively. Analysis of thermodynamic parameters suggested that the reaction occurred spontaneously and was endothermic in nature. Reusability studies showed that the adsorbents can be reused for up to four cycles of regeneration. Fixed bed column experiments revealed that the adsorption performance of Chi@Fe3O4 was affected by the flow rate, adsorbent loading and influent metal ion concentration. The results suggest that the prepared adsorbents have the potential to be used in removing Cr(VI) ions from contaminated water.
•Adsorption of Cr(VI) by Chi@Fe3O4 and Chi@Fe3O4GO was investigated.•Adsorption data was described by Freundlich and Langmuir isotherm models.•Adsorption process fitted better with pseudo-second-order kinetic model.•Regeneration studies showed that the composite can be reused multiple times.
The use of Advance Oxidation Process (AOPs) has been extensively examined in order to eradicate organic pollutants. This review assesses the efficacy of photolysis, O3 based (O3/UV, O3/H2O2, ...O3/H2O2/UV, H2O2/UV, Fenton, Fenton-like, hetero-system) and sonochemical and electro-oxidative AOPs in this regard. The main purpose of this review and some suggestions for the advancement of AOPs is to facilitate the elimination of toxic organic pollutants. Initially proposed for the purification of drinking water in 1980, AOPs have since been employed for various wastewater treatments. AOPs technologies are essentially a process intensification through the use of hybrid methods for wastewater treatment, which generate large amounts of hydroxyl (•OH) and sulfate (SO4·−) radicals, the ultimate oxidants for the remediation of organic pollutants. This review covers the use of AOPs and ozone or UV treatment in combination to create a powerful method of wastewater treatment. This novel approach has been demonstrated to be highly effective, with the acceleration of the oxidation process through Fenton reaction and photocatalytic oxidation technologies. It is clear that Advance Oxidation Process are a helpful for the degradation of organic toxic compounds. Additionally, other processes such as •OH and SO4·− radical-based oxidation may also arise during AOPs treatment and contribute to the reduction of target organic pollutants. This review summarizes the current development of AOPs treatment of wastewater organic pollutants.
•Advance oxidation process- Fenton and Fenton Type reaction.•Electrochemical advance oxidation process.•Removal of organic pollutants through advance oxidation.•Photo-Fenton types of reaction through Chloride ion.•Pesticides degradation by nano-zero valent materials.
Activated carbon is a carbonaceous material with highly porous structure. Different functionalities can be introduced to its surface by various physical and chemical treatments. Various precursors ...can be used for the synthesis of activated carbon such as fossil fuels, agricultural wastes, and lignocellulosic wastes, etc. Number of papers have been reported in literature devoted to the synthesis, characterization, and various applications of activated carbon. Herein, in this review, special attention has been paid to the basic properties of activated carbon and its surface chemistry originated due to physical and chemical treatment. In addition, a general introduction to adsorption process, various adsorption isotherms, and adsorption kinetics is also included. A brief description of mechanism of adsorption onto activated carbon is also presented. At last, most probable applications of activated carbon such as adsorption of pollutants (e.g., dyes, heavy metal ions, pesticides, pharmaceutical waste products, and volatile organic organic), as catalyst support, anduse in food and pharmaceutical industries is also presented.
Water pollution due to increase in population and high rates of wastewater generation have become serious concerns since the last few decades. Heavy metals are amongst the main wastewater pollutants ...due to their ability to persist in the environment. Materials and techniques are being investigated for the treatment of heavy metals in wastewater. Cellulose is one of the materials gaining attention due to its excellent physical, chemical, and mechanical properties. Cellulose‐based materials are being widely studied for the adsorption of heavy metals. This overview highlights research efforts to enhance the role of cellulose in wastewater treatment through cellulose‐based materials. It also discusses the effects of cellulose modifications such as cellulose gels, cellulose composites, cellulose derivatives, functionalized cellulose, and nanocrystalline cellulose on the capacity of heavy metals adsorption.
The naturally occurring biopolymer cellulose has the potential to be used for wastewater treatment when some modifications are introduced. The effect of cellulose modifications in the form of cellulose gels, cellulose composites, cellulose derivatives, functionalized cellulose as well as nanocrystalline cellulose for the removal of heavy metals from wastewater has been discussed.
In this work, bismuth-doped titania (Bi
x
TiO
2
) with improved oxygen vacancies was synthesized by sol-gel protocol as a novel peroxymonosulfate (PMS, HSO
5
−
) activator. HSO
5
−
and adsorbed ...oxygen molecules could efficiently be transformed into their respective radicals through defect ionization to attain charge balance after their trapping on oxygen vacancies of the catalyst. XRD study of Bi
x
TiO
2
with 5 wt% Bi (5BiT) revealed anatase, crystalline nature, and successful doping of Bi into TiO
2
crystal lattice. The particle size obtained from BET data and SEM observations was in good agreement. PL spectra showed the formation rates of
•
OH by 3BiT, 7BiT, 5BiTC, and 5BiT as 0.720, 1.200, 1.489, and 2.153 μmol/h, respectively. 5BiT catalyst with high surface area (216.87 m
2
g
−1
) and high porosity (29.81%) was observed the excellent HSO
5
−
activator. The catalytic performance of 0BiT, 3BiT, 5BiT, and 7BiT when coupled with 2 mM HSO
5
−
for recalcitrant flumequine (FLU) removal under dark was 10, 27, 55, and 37%, respectively. Only 5.4% decrease in catalytic efficiency was observed at the end of seventh cyclic run. Radical scavenging studies indicate that SO
4
•−
is the dominant species that caused 62.0% degradation. Moreover, strong interaction between Bi and TiO
2
through Bi-O-Ti bonds prevents Bi leaching (0.081 mg L
−1
) as shown by AAS. The kinetics, degradation pathways, ecotoxicity, and catalytic mechanism for recalcitrant FLU were also elucidated. Cost-efficient, environment-friendly, and high mineralization recommends this design strategy; Bi
x
TiO
2
/HSO
5
−
system is a promising advanced oxidation process for the aquatic environment remediation.
The alkali-soluble cell wall polysaccharides (CWPs), extracted from
Nelumbo nucifera
rhizome flour (NNRF), were treated with microwave radiation to modify their physical characteristics, functional ...properties, and antioxidant potential. The NNRF was treated at different levels of microwave treatment time (1, 2, 3, 4 and 5 min) using the low-medium intensity (200 W). The cell wall was isolated and CWPs were extracted in 10% KOH solution followed by their physical, functional, and antioxidant characterization. Microwave treatment resulted in the morphological, structural and compositional modifications in CWPs that were directly correlated with their functional properties and antioxidant potential. A significant (p < 0.05) time-dependent exponential decrease in extract yield, exponential increase in water holding, oil holding, and swelling capacities, a polynomial increase in iron-binding capacity, and a linear increase in antioxidant properties including Trolox equivalent total antioxidant activity, ferrous reducing power, and free radical scavenging capacity of microwave-treated CWPs was observed. The increase in the studied functional and antioxidant potential of the treated samples may be due microwave-induced exposure of hydroxyl groups and uronic acid residues in CWPs. The data would be a valuable contribution to the literature regarding microwave-induced modification in physical, functional and antioxidant properties of CWPs of
N. nucifera
rhizome.
PDF
