Sustainable green nanoadsorbents for remediation of pharmaceuticals from water and wastewater: A critical review

In the last three decades, pharmaceutical research has increased tremendously to offer safe and healthy life. However, the high consumption of these harmful drugs has risen devastating impact on ecosystems. Therefore, it is worldwide paramount concern to effectively clean pharmaceuticals contaminated water streams to ensure safer environment and healthier life. Nanotechnology enables to produce new, high-technical material, such as membranes, adsorbent, nano-catalysts, functional surfaces, coverages and reagents for more effective water and wastewater cleanup processes. Nevertheless, nano-sorbent materials are regarded the most appropriate treatment technology for water and wastewater because of their facile application and a large number of adsorbents. Several conventional techniques have been operational for domestic wastewater treatment but are inefficient for pharmaceuticals removal. Alternatively, adsorption techniques have played a pivotal role in water and wastewater treatment for a long, but their rise in attraction is proportional with the continuous emergence of new micropollutants in the aquatic environment and new discoveries of sustainable and low-cost adsorbents. Recently, advancements in adsorption technique for wastewater treatment through nanoadsorbents has greatly increased due to its low production cost, sustainability, better physicochemical properties and high removal performance for pharmaceuticals. Herein, this review critically evaluates the performance of sustainable green nanoadsorbent for the remediation of pharmaceutical pollutants from water. The influential sorption parameters and interaction mechanism are also discussed. Moreover, the future prospects of nanoadsorbents for the remediation of pharmaceuticals are also presented

Microwave Foaming of Materials: An Emerging Field

In the last two decades, the application of microwave heating to the processing of materials has to become increasingly widespread. Microwave-assisted foaming processes show promise for industrial commercialization due to the potential advantages that microwaves have shown compared to conventional methods. These include reducing process time, improved energy efficiency, solvent-free foaming, reduced processing steps, and improved product quality. However, the interaction of microwave energy with foaming materials, the effects of critical processing factors on microwave foaming behavior, and the foamed product’s final properties are still not well-explored. This article reviews the mechanism and principles of microwave foaming of different materials. The article critically evaluates the impact of influential foaming parameters such as blowing agent, viscosity, precursor properties, microwave conditions, additives, and filler on the interaction of microwave, foaming material, physical (expansion, cellular structure, and density), mechanical, and thermal properties of the resultant foamed product. Finally, the key challenges and opportunities for developing industrial microwave foaming processes are identified, and areas for potential future research works are highlighted

Evaluation of mechanical and thermal properties of microwave irradiated poly (styrene-co-methyl methacrylate)/ graphene nanocomposites

<div>Poly (styrene-co-methyl methacrylate) (P(S-co-MMA)) was blended with pristine graphene (G) by melt mixing technique and treated under microwave irradiation. The anocomposites were irradiated for 5 and 10 min at frequency 1245 MHz.</div><div>Structure changes in the irradiated nanocomposites were observed by Fourier transform infrared spectroscopy and Raman spectroscopy. The irradiated composites showed a significant increase in the storage modulus i.e. 21% for 0.1% and 31% for 1% graphene polymer composites after 5 min irradiation. However at higher irradiation (10 min), degradation of nanocomposites was observed. The concept of improvement of interfacial interaction between graphene and P(S-co-MMA) chains at 5-min microwave exposure and degradation of nanocomposites at higher irradiation duration was assessed and supported by X-ray diffraction and  canning electron microscopy.</div

Process Optimization and Modeling of Phenol Adsorption onto Sludge-Based Activated Carbon Intercalated MgAlFe Ternary Layered Double Hydroxide Composite

A sewage sludge-based activated carbon (SBAC) intercalated MgAlFe ternary layered double hydroxide (SBAC-MgAlFe-LDH) composite was synthesized via the coprecipitation method. The adsorptive performance of the composite for phenol uptake from the aqueous phase was evaluated via the response surface methodology (RSM) modeling technique. The SBAC-MgAlFe-LDH phenol uptake capacity data were well-fitted to reduced RSM cubic model (R2 = 0.995, R2-adjusted = 0.993, R2-predicted = 0.959 and p-values &lt; 0.05). The optimum phenol adsorption onto the SBAC-MgAlFe-LDH was achieved at 35 °C, 125 mg/L phenol, and pH 6. Under the optimal phenol uptake conditions, pseudo-first-order and Avrami fractional-order models provided a better representation of the phenol uptake kinetic data, while the equilibrium data models’ fitting follows the order; Liu &gt; Langmuir &gt; Redlich–Peterson &gt; Freundlich &gt; Temkin. The phenol uptake mechanism was endothermic in nature and predominantly via a physisorption process (ΔG° = −5.33 to −5.77 kJ/mol) with the involvement of π–π interactions between the phenol molecules and the functionalities on the SBAC-LDH surface. The maximum uptake capacity (216.76 mg/g) of SBAC-MgAlFe-LDH was much higher than many other SBAC-based adsorbents. The improved uptake capacity of SBAC-LDH was attributed to the effective synergetic influence of SBAC-MgAlFe-LDH, which yielded abundant functionalized surface groups that favored higher aqueous phase uptake of phenol molecules. This study showcases the potential of SBAC-MgAlFe-LDH as an effective adsorbent material for remediation of phenolic wastewate

Mortality Associated with Neck Compression Deaths –An Autopsy Based Study

Objective: To determine the frequency of deaths due to compression of neck autopsied in three major mortuaries of Karachiand to evaluate the association of cause of neck compression deaths with the age and gender.Materials and Methods: This autopsy- based descriptive cross-sectional study was conducted from 1st March 2008 to 28thFebruary 2009 in the mortuaries at Civil Hospital, Jinnah Postgraduate Medical Center and Abbasi Shaheed Hospital Karachi.The study included 90 cases of deaths due to hanging and strangulation, brought to mortuaries of public sector hospitals ofKarachi. Details of findings from autopsy reports and police papers were entered in a performa under the heading of cause,causative agent, manner, age and gender.Results: 90 out of 2090 unnatural deaths were due to hanging and strangulation. Hanging was the most frequent cause amongthe deaths due to neck compression. Male to female ratio was 1.7:1. Male dominated in hanging and ligature strangulation whilefemale dominated in manual strangulation. Age group ranging from 15 to 35years was chiefly involved. 100 % suicidal andhomicidal manner of death was seen in hanging and strangulation respectively. Cause of neck compression death was significantlyassociated with gender (P value &lt;0.036) but not with the age (P value &lt;0.732).Conclusion: Hanging is the most frequent neck compression death involving males of young age group. Hanging and strangulationare still used to commit suicide and homicide respectively. Such deaths indicate frustrated and stressful condition of youngpopulation necessitating comprehensive program of counseling for healthy environment

Removal of Phenolic Compounds from Water Using Sewage Sludge-Based Activated Carbon Adsorption: A Review

Due to their industrial relevance, phenolic compounds (PC) are amongst the most common organic pollutants found in many industrial wastewater effluents. The potential detrimental health and environmental impacts of PC necessitate their removal from wastewater to meet regulatory discharge standards to ensure meeting sustainable development goals. In recent decades, one of the promising, cost-effective and environmentally benign techniques for removal of PC from water streams has been adsorption onto sewage sludge (SS)-based activated carbon (SBAC). This is attributed to the excellent adsorptive characteristics of SBAC and also because the approach serves as a strategy for sustainable management of huge quantities of different types of SS that are in continual production globally. This paper reviews conversion of SS into activated carbons and their utilization for the removal of PC from water streams. Wide ranges of topics which include SBAC production processes, physicochemical characteristics of SBAC, factors affecting PC adsorption onto SBAC and their uptake mechanisms as well as the regeneration potential of spent SBAC are covered. Although chemical activation techniques produce better SBAC, yet more research work is needed to harness advances in material science to improve the functional groups and textural properties of SBAC as well as the low performance of physical activation methods. Studies focusing on PC adsorptive performance on SBAC using continuous mode (that are more relevant for industrial applications) in both single and multi-pollutant aqueous systems to cover wide range of PC are needed. Also, the potentials of different techniques for regeneration of spent SBAC used for adsorption of PC need to be assessed in relation to overall economic evaluation within realm of environmental sustainability using life cycle assessment

Biochar Produced from Saudi Agriculture Waste as a Cement Additive for Improved Mechanical and Durability Properties&mdash;SWOT Analysis and Techno-Economic Assessment

The Kingdom of Saudi Arabia generates an enormous amount of date palm waste, causing severe environmental concerns. Green and strong concrete is increasingly demanded due to low carbon footprints and better performance. In this research work, biochar derived from locally available agriculture waste (date palm fronds) was used as an additive to produce high-strength and durable concrete. Mechanical properties such as compressive and flexural strength were evaluated at 7, 14, and 28 days for control and all other mixes containing biochar. In addition, the durability properties of the concrete samples for the mixes were investigated by performing electric resistivity and ultra-sonic pulse velocity testing. Finally, a SWOT (strengths, weaknesses, opportunities, and threats) analysis was carried out to make strategic decisions about biochar&rsquo;s use in concrete. The results demonstrated that the compressive strength of concrete increased to 28&ndash;29% with the addition of 0.75&ndash;1.5 wt% of biochar. Biochar-concrete containing 0.75 wt% of biochar showed 16% higher flexural strength than the control specimen. The high ultrasonic pulse velocity (UPV) values (&gt;7.79 km/s) and low electrical resistivity (&lt;22.4 k&Omega;-cm) of biochar-based concrete confirm that the addition of biochar resulted in high-quality concrete free from internal flaws, cracks, and better structural integrity. SWOT analysis indicated that biochar-based concrete possessed improved performance than ordinary concrete, is suitable for extreme environments, and has opportunities for circular economy and applications in various construction designs. However, cost and technical shortcomings in biochar production and biochar-concrete mix design are still challenging

Recent progress in layered double hydroxides (LDH)-containing hybrids as adsorbents for water remediation

<div>With rapidly growing industrial development worldwide, the need for a new class of nanoparticles and techniques for treating wastewater remains a major concern to protect the environment. Layered double hydroxides and particularly LDH-containing hybrids are emerging as potential nano-sized adsorbents for water treatment. Recent studies have demonstrated LDH-containing hybrids as promising multifunctional materials for potential utilization in various applications such as, photo-catalysis, energy storage, nanocomposites and water purification. This article reviews the recent applications of LDH-containing hybrids as adsorbents for water</div><div>remediation. The maximum adsorption capacities of various toxic heavy metals and dyes on different LDH hybrids were reported as 483 mg/g for Pb2+, 95 mg/g for Cd2+, 181 mg/g for Cu2+, 649 mg/g for Cr6+, 180 mg/g As5+, 813 mg/g for Hg2+, 450 for Ag+, 277 mg/g for U6+, 1062 mg/g for methyl orange, 185 mg/g for methylene blue, and 1250 mg/g for Congo red, which is comparatively higher than other commercial adsorbents. This review discusses the adsorption performance of manifold LDH-containing hybrids for treating various pollutants such as heavy metals and dyes. The mechanisms of interaction of LDH-containing hybrids with pollutants and the influence of key adsorption parameters such as pH, contact time, adsorbent dose and</div><div>temperature have been comprehensively discussed. Moreover, the regeneration potential and reuse of spent</div><div>LDH-containing hybrids and its toxicity effects have also been reviewed. </div

Comparative Adsorptive Removal of Phosphate and Nitrate from Wastewater Using Biochar-MgAl LDH Nanocomposites: Coexisting Anions Effect and Mechanistic Studies

In this study, date-palm biochar MgAl-augmented double-layered hydroxide (biochar&ndash;MgAl&ndash;LDH) nanocomposite was synthesized, characterized, and used for enhancing the removal of phosphate and nitrate pollutants from wastewater. The biochar&ndash;MgAl&ndash;LDH had higher selectivity and adsorption affinity towards phosphate compared to nitrate. The adsorption kinetics of both anions were better explained by the pseudo-first-order model with a faster removal rate to attain equilibrium in a shorter time, especially at lower initial phosphate-nitrate concentration. The maximum monolayer adsorption capacities of phosphate and nitrate by the non-linear Langmuir model were 177.97 mg/g and 28.06 mg/g, respectively. The coexistence of anions (Cl&minus;, SO42&minus;, NO3&minus;, CO32&minus; and HCO3&minus;) negligibly affected the removal of phosphate due to its stronger bond on the nano-composites, while the presence of Cl&minus; and PO43&minus; reduced the nitrate removal attributed to the ions&rsquo; participation in the active adsorption sites on the surface of biochar&ndash;MgAl&ndash;LDH. The excellent adsorptive performance is the main synergetic influence of the MgAl&ndash;LDH incorporation into the biochar. The regeneration tests confirmed that the biochar&ndash;MgAl composite can be restored effortlessly and has the prospective to be reused after several subsequent adsorption-desorption cycles. The biochar-LDH further demonstrated capabilities for higher removal of phosphate and nitrate from real wastewater

Revolutionizing corrosion protection in seawater using innovative layered double hydroxide/polyvinylidene fluoride LDH@PVDF composite coatings

This study pioneers a novel approach to achieving sustainable corrosion protection in seawater environments by incorporating layered double hydroxide (LDH) fillers into polymeric polyvinylidene fluoride (PVDF) coatings to create a corrosion-resistant coating for mild steel. LDH composites were successfully synthesized using co-precipitation and hydrothermal methods, with characterization through x-ray diffraction analysis (XRD), fourier-transform infrared spectroscopy FTIR, morphological analysis, and elemental mapping. LDH@PVDF coatings with the thickness of 40 ± 2 µm exhibited improved surface properties, superior adhesion, hydrophobicity, and antifouling characteristics. Corrosion resistance was comprehensively assessed using open circuit potential (OCP), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). ZLDH@PVDF coating outperformed others, demonstrating exceptional long-term corrosion protection (up to 60 days) without diffusion-controlled processes. The mechanism of corrosion protection of ZLDH@PVDF coating has been discussed