Long-term evaluation of palm oil mill effluent (POME) steam reforming over lanthanum-based perovskite oxides.

To replace the obsolete ponding system, palm oil mill effluent (POME) steam reforming (SR) over net-acidic LaNiO3 and net-basic LaCoO3 were proposed as the POME primary treatments, with promising H2-rich syngas production. Herein, the long-term evaluation of POME SR was scrutinized with both catalysts under the optimal conditions (600 °C, 0.09 mL POME/min, 0.3 g catalyst, & 74-105 µm catalyst particle size) to examine the catalyst microstructure changes, transient process stability, and final effluent evaluation. Extensive characterization proved the (i) adsorption of POME vapour on catalysts before SR, (ii) deposition of carbon and minerals on spent SR catalysts, and (iii) dominance of coking deactivation over sintering deactivation at 600 °C. Despite its longer run, spent LaCoO3 (50.54 wt%) had similar carbon deposition with spent LaNiO3 (50.44 wt%), concurring with its excellent coke resistance. Spent LaCoO3 (6.12 wt%; large protruding crystals) suffered a harsher mineral deposition than spent LaNiO3 (3.71 wt%; thin film coating), confirming that lower reactivity increased residence time of reactants. Transient syngas evolution of both SR catalysts was relatively steady up to 4 h but perturbed by coking deactivation thereafter. La2O2CO3 acted as an intermediate species that hastened the coke removal via reverse Boudouard reaction upon its decarbonation. La2O2CO3 decarbonation occurred continuously in LaCoO3 system but intermittently in LaNiO3 system. LaNiO3 system only lasted for 13 h as its compact ash blocked the gas flow. LaCoO3 system lasted longer (17 h) with its porous ash, but it eventually failed because KCl crystallites blocked its active sites. Relatively, LaCoO3 system offered greater net H2 production (72.78%) and POME treatment volume (30.77%) than LaNiO3 system. SR could attain appreciable POME degradation (>97% COD, BOD5, TSS, & colour intensity). Withal, SR-treated POME should be polished to further reduce its incompliant COD and BOD5.

Enhancing Sustainable Production of Fatty Acid Methyl Ester from Palm Oil Using Bio-Based Heterogeneous Catalyst: Process Simulation and Techno-Economic Analysis.

A new sustainable solid carbon catalyst has been developed for biodiesel synthesis using pyrolytic coconut shell ash (CSA). The CSA support was loaded with various amounts of potassium carbonate (K2CO3), and response surface methodology with a central composite design was used to optimize the transesterification process. The best-performing catalyst was the 30 wt % K2CO3/CSA catalyst. The optimal conditions included a catalyst loading of 3.27 wt %, methanol:oil molar ratio of 9.98:1, reaction time of 74 min, and temperature of 65 °C, resulting in an obtained biodiesel yield of 97.14%. This catalyst was reusable for up to four cycles, but a reduction in the biodiesel yield was observed due to potassium ion leaching during the recovery process. A techno-economic analysis to assess the financial viability of the project revealed a net present value of 5.16 million USD for a project lifetime of 20 years, a payback period time of 2.49 years, and an internal rate of return of 44.2%. An environmental assessment to evaluate the impact of global warming potential from the production of biodiesel revealed a lower level of carbon dioxide emission (1401.86 ton/y) than in the conventional process (1784.6 ton/y).

Epitomizing biohydrogen production from microbes: Critical challenges vs opportunities.

Hydrogen is a clean and green biofuel choice for the future because it is carbon-free, non-toxic, and has high energy conversion efficiency. In exploiting hydrogen as the main energy, guidelines for implementing the hydrogen economy and roadmaps for the developments of hydrogen technology have been released by several countries. Besides, this review also unveils various hydrogen storage methods and applications of hydrogen in transportation industry. Biohydrogen productions from microbes, namely, fermentative bacteria, photosynthetic bacteria, cyanobacteria, and green microalgae, via biological metabolisms have received significant interests off late due to its sustainability and environmentally friendly potentials. Accordingly, the review is as well outlining the biohydrogen production processes by various microbes. Furthermore, several factors such as light intensity, pH, temperature and addition of supplementary nutrients to enhance the microbial biohydrogen production are highlighted at their respective optimum conditions. Despite the advantages, the amounts of biohydrogen being produced by microbes are still insufficient to be a competitive energy source in the market. In addition, several major obstacles have also directly hampered the commercialization effors of biohydrogen. Thus, this review uncovers the constraints of biohydrogen production from microbes such as microalgae and offers solutions associated with recent strategies to overcome the setbacks via genetic engineering, pretreatments of biomass, and introduction of nanoparticles as well as oxygen scavengers. The opportunities of exploiting microalgae as a suastainable source of biohydrogen production and the plausibility to produce biohydrogen from biowastes are accentuated. Lastly, this review addresses the future perspectives of biological methods to ensure the sustainability and economy viability of biohydrogen production.

Rice husk waste into various template-engineered mesoporous silica materials for different applications: A comprehensive review on recent developments.

Following the discovery of Stöber silica, the realm of morphology-controlled mesoporous silica nanomaterials like MCM-41, SBA-15, and KCC-1 has been expanded. Due to their high BET surface area, tunable pores, easiness of functionalization, and excellent thermal and chemical stability, these materials take part a vital role in the advancement of techniques and technologies for tackling the world's largest challenges in the area of water and the environment, energy storage, and biotechnology. Synthesizing these materials with excellent physicochemical properties from cost-efficient biomass wastes is a foremost model of sustainability. Particularly, SiO2 with a purity >98% can be obtained from rice husk (RH), one of the most abundant biomass wastes, and can be template engineered into various forms of mesoporous silica materials in an economic and eco-friendly way. Hence, this review initially gives insight into why to valorize RH into value-added silica materials. Then the thermal, chemical, hydrothermal, and biological methods of high-quality silica extraction from RH and the principles of synthesis of mesoporous and fibrous mesoporous silica materials like SBA-15, MCM-41, MSNs, and KCC-1 are comprehensively discussed. The potential applications of rice husk-derived mesoporous silica materials in catalysis, drug delivery, energy, adsorption, and environmental remediation are explored. Finally, the conclusion and the future outlook are briefly highlighted.

Nanotechnology- A ray of hope for heavy metals removal.

Environmental effects of heavy metal pollution are considered as a widespread problem throughout the world, as it jeopardizes human health and also reduces the sustainability of a cleaner environment. Removal of such noxious pollutants from wastewater is pivotal because it provides a propitious solution for a cleaner environment and water scarcity. Adsorption treatment plays a significant role in water remediation due to its potent treatment and low cost of adsorbents. In the last two decades, researchers have been highly focused on the modification of adsorption treatment by functionalized and surface-modified nanomaterials which has spurred intense research. The characteristics of nano adsorbents attract global scientists as it is also economically viable. This review shines its light on the functionalized nanomaterials application for heavy metals removal from wastewater and also highlights the importance of regeneration of nanomaterials in the view of visualizing the economic aspects along with a cleaner environment. The review also focused on the proper disposal of nanomaterials with crucial issues that persist in the adsorption process and also emphasize future research modification at a large-scale application in industries.

Hydrothermal synthesis temperature induces sponge-like loose silica structure: A potential support for Fe2O3-based adsorbent in treating As(V)-contaminated water.

Low cost Fe2O3-based sorbents with an exceptional selectivity toward the targeted As(V) pollutant have gained extensive attention in water treatment. However, their structural features often influence removal performance. In this respect, we present herein a rational design of silica-supported Fe2O3 sorbents with an enhanced morphological structure based on a simple temperature-induced process. Low-hydrothermal temperature synthesis (60 and 100 °C) provided a large silica-cluster size with a close packed structure (S-60 and S-100), contributing to an increase in mass transport resistance. Fe2O3/S-60 with 6.2-nm pore width silica achieved a maximum As(V) uptake capacity (qm) of only 3.5 mg g-1. Supporting Fe2O3 on S-100 with an approximately two-fold increase in the pore size (13 nm) did not lead to any evident enhancement in qe (3.7 mg g-1). However, expanding the pore window up to 22.6 nm (S-140) and 39.5 nm (S-180), along with changing from close-packed to sponge-like loose structures induced by high-temperature synthesis (140 °C and 180 °C), resulted in substantial increases in qm. Fe2O3/S-140 had 1.7 and 1.6 times higher qm (5.9 mg g-1) than Fe2O3/S-100 and Fe2O3/S-60, respectively. The highest qm (7.4 mg g-1) was achieved for Fe2O3/S-180, which was attributed to its relatively small-sized silica cluster and the largest cavities that facilitated easier access by As(V) to adsorbing sites.

Fe2O3-decorated hollow porous silica spheres assisted by waste gelatin template for efficient purification of synthetic wastewater containing As(V).

Purification of As(V)-contaminated water through adsorption by Fe2O3-based materials is a promising technology due to its low-cost and high efficiency. Dispersing the Fe2O3 phase on silica supports can improve both the adsorption rate and capacity due to the reduction in Fe2O3 particle sizes and the prevention of clumping of the Fe2O3 particles. However, the clusters in conventional silica materials largely impede the diffusion of As(V) to reach the Fe2O3 sites dispersed inside the clusters. Here, by applying a gelatin template strategy, the structure of silica materials was tailored by changing the gelatin-to-silica ratio (0, 0.6, 1.2 and 1.8) and hydrothermal temperature (60 °C, 100 °C and 140 °C). The silica cluster size could be reduced using either a low gelatin-to-silica ratio (0.6) or a low hydrothermal temperature (60 °C). Increasing the gelatin-to-silica ratio to 1.2 created porous silica spheres with a hollow structure. The Fe2O3-loaded hollow porous silica spheres with a shell thickness of 280 nm had twice the maximum As(V) adsorption capacity (7.66 mg g-1) compared to the Fe2O3-loaded silica product prepared in the absence of gelatin (3.82 mg g-1). The maximum As(V) adsorption capacity could be further enhanced to 9.94 mg g-1 by reducing the shell thickness to 80 nm through increasing the gelatin-to-silica ratio to 1.8 and the hydrothermal temperature to 140 °C. In addition, the best Fe2O3-loaded hollow porous silica spheres had rapid As(V) adsorption and showed excellent durability as the As(V) removal efficiency slightly decreased to 98.9% subsequent to five adsorption-regeneration cycles.

Fabrication and characterization of a novel Ba2+-loaded sawdust biochar doped with iron oxide for the super-adsorption of SO42- from wastewater.

Biochar is a low-cost adsorbent used in the treatment of contaminated wastewater. We investigated the potential of an Fe-impregnated, Ba2+-loaded biochar (Fe-(Ba-BC)) for the removal of SO42- from aqueous solutions. The Ba2+-loaded biochar was synthesized from sawdust impregnated with iron oxide via pyrolysis at 600 °C. The porous structure of the Fe-(Ba-BC) was identified by scanning electron microscopy before sulfate was adsorbed onto the adsorbent. Functional groups were determined by energy-dispersive spectrophotometry and Raman spectrometry.. The Fe-(Ba-BC) Raman peaks before the experiment were higher than after, suggesting the precipitation of BaSO4. The presence of BaCl2 on the surface of the biochar was confirmed by X-ray diffraction. Batch sorption results showed that Fe-(Ba-BC) strongly adsorbed aqueous SO42- with a removal efficacy of 96.7% under the optimum conditions of 0.25 M BaCl2, a contact time of 480 min, a pH of 9 and an adsorbent dose of 2 g. The optimum condition for removal and reaction rate kinetics analysis indicated that adsorption curve fitted well with PSO, k2 0.00015 confirmed the removal of SO42- via chemisorption. Thus, Fe-(Ba-BC) was found to be a favorable adsorbent for removing SO42-.

Remediation of heavy metal polluted waters using activated carbon from lignocellulosic biomass: An update of recent trends.

The use of a cheap and effective adsorption approach based on biomass-activated carbon (AC) to remediate heavy metal contamination is clearly desirable for developing countries that are economically disadvantaged yet have abundant biomass. Therefore, this review provides an update of recent works utilizing biomass waste-AC to adsorb commonly-encountered adsorbates like Cr, Pb, Cu, Cd, Hg, and As. Various biomass wastes were employed in synthesizing AC via two-steps processing; oxygen-free carbonization followed by activation. In recent works related to the activation step, the microwave technique is growing in popularity compared to the more conventional physical/chemical activation method because the microwave technique can ensure a more uniform energy distribution in the solid adsorbent, resulting in enhanced surface area. Nonetheless, chemical activation is still generally preferred for its ease of operation, lower cost, and shorter preparation time. Several mechanisms related to heavy metal adsorption on biomass wastes-AC were also discussed in detail, such as (i) - physical adsorption/deposition of metals, (ii) - ion-exchange between protonated oxygen-containing functional groups (-OH, -COOH) and divalent metal cations (M2+), (iii) - electrostatic interaction between oppositely-charged ions, (iv) - surface complexation between functional groups (-OH, O2-, -CO-NH-, and -COOH) and heavy metal ions/complexes, and (v) - precipitation/co-precipitation technique. Additionally, key parameters affecting the adsorption performance were scrutinized. In general, this review offers a comprehensive insight into the production of AC from lignocellulosic biomass and its application in treating heavy metals-polluted water, showing that biomass-originated AC could bring great benefits to the environment, economy, and sustainability.

Fungal Fermented Palm Kernel Expeller as Feed for Black Soldier Fly Larvae in Producing Protein and Biodiesel.

Being the second-largest country in the production of palm oil, Malaysia has a massive amount of palm kernel expeller (PKE) leftover. For that purpose, black soldier fly larvae (BSFL) are thus employed in this study to valorize the PKE waste. More specifically, this work elucidated the effects of the pre-fermentation of PKE via different amounts of Rhizopus oligosporus to enhance PKE palatability for the feeding of BSFL. The results showed that fermentation successfully enriched the raw PKE and thus contributed to the better growth of BSFL. BSFL grew to be 34% heavier at the optimum inoculum volume of 0.5 mL/10 g dry weight of PKE as compared to the control. Meanwhile, excessive fungal inoculum induced competition between BSFL and R. oligosporus, resulting in a reduction in BSFL weight. Under optimum feeding conditions, BSFL also registered the highest lipid yield (24.7%) and protein yield (44.5%). The biodiesel derived from BSFL lipid had also shown good compliance with the European biodiesel standard EN 14214. The high saturated fatty acid methyl esters (FAMEs) content (C12:0, C14:0, C16:0) in derived biodiesel made it highly oxidatively stable. Lastly, the superior degradation rate of PKE executed by BSFL further underpinned the sustainable conversion process in attaining valuable larval bioproducts.

Rapid effectual entrapment of arsenic pollutant by Fe2O3 supported on bimodal meso-macroporous silica for cleaning up aquatic system.

Arsenic (As) contamination in aqueous media is a major concern due to its adverse impacts on humans and the ecosystem more broadly because of its non-biodegradability. Consequently, an effective and selective sorbent is needed urgently to scavenge As pollutant. Herein, the adsorption behaviors of As(V) by Fe2O3 and Fe2O3 supported on different silica materials, consisting of unimodal mesoporous silica (Fe2O3/U-SiO2) and dual meso-macroporous silica (Fe2O3/B-SiO2), were compared to examine their structure-efficiency relationships in the elimination of As(V). Fe2O3/B-SiO2 was much faster at As(V) removal and had an impressively higher uptake capability, reaching nearly 50% and 2.5 mg g-1 within 5 min compared to bare Fe2O3 (6% and 0.3 mg g-1) and Fe2O3/U-SiO2 (11.9% and 0.59 mg g-1). These better results were because of the highly dispersed Fe2O3 nanoparticles on the B-SiO2 support that provided abundant reactive sites as well as a macropore structure facilitating As(V) diffusion into adsorptive sites. The maximum adsorptive capacity of Fe2O3/B-SiO2 (4.7 mg As per 1 g adsorbent) was 1.3- and 1.7-fold greater than for Fe2O3/U-SiO2 and Fe2O3, respectively. The outstanding performance and reusability of Fe2O3/B-SiO2 with its ease of production, economical and environmentally friendly features made it even more attractive for As(V) remediation. The explored relationship between the structure of SiO2-supported Fe2O3 sorbents and their performance in removing As(V) could be informative for the future design of highly efficient adsorbents for the decontamination of water.

Investigation into Lewis and Brønsted acid interactions between metal chloride and aqueous choline chloride-oxalic acid for enhanced furfural production from lignocellulosic biomass.

Furfural has been identified as a valuable biobased platform chemical that can be further converted into bioenergy and biochemicals. Furfural is derived from lignocellulosic biomass and can also be regarded as a sustainable alternative to petrochemical products. Herein, the performance of trivalent metal chlorides (FeCl3, AlCl3) and tetravalent metal chlorides (SnCl4, TeCl4) as Lewis acidic cocatalysts was investigated in an aqueous choline chloride-oxalic acid (16.4 wt% H2O) deep eutectic solvent (DES) system for producing furfural from oil palm fronds (OPFs). The metal chlorides with greater electrical field gradients were stronger Lewis acids that enhanced both furfural production and degradation reactions. The main degradation product in this reaction system was humin, and this result was confirmed by FTIR analysis. By subjecting OPFs to an aqueous DES reaction (120 °C, 45 min) with SnCl4 (2.50 wt%), a furfural yield of 59.4% was obtained; without incorporated metal chlorides, the furfural yield was 46.1%. Characterization studies showed synergistic Lewis and Brønsted acid interactions between metal chlorides and DES components. Overall, the residual OPFs showed high glucan content, which led to the production of glucose (71.4%) as a byproduct via enzymatic hydrolysis. Additionally, the aqueous DES system was recycled and reused for several additional runs. The proposed aqueous DES system presents a promising biorefinery approach for the conversion of OPFs to biochemicals.

The application of green solvent in a biorefinery using lignocellulosic biomass as a feedstock.

The high dependence on crude oil for energy utilization leads to a necessity of finding alternative sustainable resources. Solvents are often employed in valorizing the biomass into bioproducts and other value-added chemicals during treatment stages. Unfortunately, despite the effectiveness of conventional solvents, hindrances such as expensive solvents, unfavourable environmental ramifications, and complicated downstream separation systems often occur. Therefore, the scientific community has been actively investigating more cost-effective, environmentally friendly alternatives and possess the excellent dissolving capability for biomass processing. Generally, 'green' solvents are attractive due to their low toxicity, economic value, and biodegradability. Nonetheless, green solvents are not without disadvantages due to their complicated product recovery, recyclability, and high operational cost. This review summarizes and evaluates the recent contributions, including potential advantages, challenges, and drawbacks of green solvents, namely ionic liquids, deep eutectic solvents, water, biomass-derived solvents and carbon dioxide in transforming the lignocellulosic biomass into high-value products. Moreover, research opportunities for future developments and potential upscale implementation of green solvents are also critically discussed.

Heavy metal removal by biomass-derived carbon nanotubes as a greener environmental remediation: A comprehensive review.

The concentrations of heavy metal ions found in waterways near industrial zones are often exceed the prescribed limits, posing a continued danger to the environment and public health. Therefore, greater attention has been devoted into finding the efficient solutions for adsorbing heavy metal ions. This review paper focuses on the synthesis of carbon nanotubes (CNTs) from biomass and their application in the removal of heavy metals from aqueous solutions. Techniques to produce CNTs, benefits of modification with various functional groups to enhance sorption uptake, effects of operating parameters, and adsorption mechanisms are reviewed. Adsorption occurs via physical adsorption, electrostatic interaction, surface complexation, and interaction between functional groups and heavy metal ions. Moreover, factors such as pH level, CNTs dosage, duration, temperature, ionic strength, and surface property of adsorbents have been identified as the common factors influencing the adsorption of heavy metals. The oxygenated functional groups initially present on the surface of the modified CNTs are responsible towards the adsorption enhancement of commonly-encountered heavy metals such as Pb2+, Cu2+, Cd2+, Co2+, Zn2+, Ni2+, Hg2+, and Cr6+. Despite the recent advances in the application of CNTs in environmental clean-up and pollution treatment have been demonstrated, major obstacles of CNTs such as high synthesis cost, the agglomeration in the post-treated solutions and the secondary pollution from chemicals in the surface modification, should be critically addressed in the future studies for successful large-scale applications of CNTs.

Elucidating the effect of process parameters on the production of hydrogen-rich syngas by biomass and coal Co-gasification techniques: A multi-criteria modeling approach.

The thermochemical processes such as gasification and co-gasification of biomass and coal are promising route for producing hydrogen-rich syngas. However, the process is characterized with complex reactions that pose a tremendous challenge in terms of controlling the process variables. This challenge can be overcome using appropriate machine learning algorithm to model the nonlinear complex relationship between the predictors and the targeted response. Hence, this study aimed to employ various machine learning algorithms such as regression models, support vector machine regression (SVM), gaussian processing regression (GPR), and artificial neural networks (ANN) for modeling hydrogen-rich syngas production by gasification and co-gasification of biomass and coal. A total of 12 machine learning algorithms which comprises the regression models, SVM, GPR, and ANN were configured, trained using 124 datasets. The performances of the algorithms were evaluated using the coefficient of determination (R2), root mean square error (RMSE), mean square error (MSE), and mean absolute error (MAE). In all cases, the ANN algorithms offer superior performances and displayed robust predictions of the hydrogen-rich syngas from the co-gasification processes. The R2 of both the Levenberg-Marquardt- and Bayesian Regularization-trained ANN obtained from the prediction of the hydrogen-rich syngas was found to be within 0.857-0.998 with low prediction errors. The sensitivity analysis to determine the effect of the process parameters on the model output revealed that all the parameters showed a varying level of influence. In most of the processes, the gasification temperature was found to have the most significant influence on the model output.

Biomass-derived carbon-based and silica-based materials for catalytic and adsorptive applications- An update since 2010.

Biomass, which defined as plant- or animal-based materials, is intriguing tremendous scientific attentions due to its renewable attribute in serving energy security. Amongst, the plant-based biomasses, particularly those that co-generated in the agriculture activities, are commonly regarded as fuel for burning, which overlooked their hidden potentials for high-end applications. Organically, the plant-based biomass constitutes of lignocellulose components, which can be served as promising precursors for functionalized carbon materials. Meanwhile, its inorganic counterpart made up of various minerals, with Si being the most concerned one. With the advancement of biomass technologies and material synthesis in recent years, numerous attempts were endeavoured to obtain valorised products from biomass. Particularly, syntheses of catalytic and adsorptive materials are actively researched in the field of biomass reutilization. Herein, our work systematically summarized the advancements of biomass-materials for these applications in recent 10 years (2010-2020), with a special focus on the carbon-based and Si-based catalytic/adsorptive materials. Significantly, the deriving steps, inclusive of both pre-treatment and post-treatment of such materials, are incorporated in the discussion, alongside with their significances revealed too. The performance of the as-obtained materials in the respective application is systematically correlated to their physicochemical properties, hence providing valuable insights to the readers. Challenges and promising directions to be explored are raised too at the end of the review, aiming to advocate better-usage of biomass while offering great opportunities to sustain catalysis and adsorption in the industrial scale.

A comprehensive review on the techniques for coconut oil extraction and its application.

Virgin coconut oil is a useful substance in our daily life. It contains a high percentage of lauric acid which has many health benefits. The current industry has developed several methods to extract the oil out from the coconut fruit. This review paper aims to highlight several common extraction processes used in modern industries that includes cold extraction, hot extraction, low-pressure extraction, chilling, freezing and thawing method, fermentation, centrifugation, enzymatic extraction and supercritical fluid carbon dioxide. Different extraction methods will produce coconut oil with different yields and purities of lauric acid, thus having different uses and applications. Challenges that are faced by the industries in extracting the coconut oil using different methods of extraction are important to be explored so that advancement in the oil extraction technology can be done for efficient downstream processing. This study is vital as it provides insights that could enhance the production of coconut oil.

Application of statistical modeling for the production of highly pure rhamnolipids using magnetic biocatalysts: Evaluating its efficiency as a bioremediation agent.

In the present study, highly pure rhamnolipids (RLs) was produced using biocatalysts immobilized on amino-functionalized chitosan coated magnetic nanoparticles. Upon immobilizing naringinase and Candida antarctica lipase B (CaLB) under the optimized conditions, an enhanced operational stability with biocatalytic loads of 935 ± 2.4 U/g (naringinase) and 825 ± 4.1 U/g (CaLB) were achieved. Subsequently, the immobilized biocatalysts were utilized sequentially in a two-step RLs synthesis process. The key parameters involved in RLs production were optimized using artificial neural network (ANN) coupled genetic algorithm (GA) and were compared with composite central design (CCD). On validating the efficiency of both models, mean square errors of 1.58% (CCD) and 1.04% (ANN) were obtained. Optimization of parameters by ANN-GA resulted in 1.2-fold increase in experimental RLs yield (80.53%), which was 1.05-fold higher when compared to CCD model. Further, to establish the efficiency of RLs as a bioremediation agent, it was utilized as washing agent. It was observed that at a soil to RLs volume of 1:05, RLs concentration of 0.4 mg/mL, a 95.35 ± 1.33% removal of Total Petroleum Hydrocarbons (TPHs) was obtained at 35 â„ƒ and 160 rpm in 75 min. Thus, this strategy provides an efficient biocatalytic toolbox for RLs synthesis, which can be effectively used as a bioremediation agent.

Potential application of Allium Cepa seeds as a novel biosorbent for efficient biosorption of heavy metals ions from aqueous solution.

Abatement of pollutants i.e. heavy metals by using green biomaterials is an emerging area of interest due to its cost-effective and renewability. In the present study, the potential of Alium Cepa seed biomass (ACSB) as a novel biosorbent for the adsorption of Cr(VI), Cd(II), Zn(II), Cu(II) and Pb(II) was investigated. The FTIR spectrum of ACSB confirmed a presence of surface OH bond, an essential functional group for metal uptake. Biosorption factors such as pH (2-10), time (15-190 min), dosage (1-5 g/L) and initial metal concentration (50-200 mg/L) were optimized at the ambient conditions. The equilibrium adsorption time was obtained at 90 min for Cd(II), Cu(II) and Pb(II), as well as 120 min for Cr(VI) and Zn(II), respectively, for the mentioned metal ions removal. The maximum removal efficiency was obtained at 4 g/L of ASCB for 50 mg/L adsorbate and a neutral pH. Under this condition, the maximum uptake was 0.67, 1.50, 1.68, 1.03 and 1.75 mg/L for Cr(VI), Cd(II), Zn(II), Cu(II) and Pb(II), respectively. Monolayer biosorption was determined for the studied heavy metals. The removal of the metal ions by ACSB followed a pseudo 2nd order sorption kinetics. The results suggested that ACSB is more suitable to remove (99%) Pb(II), Cu(II), Cd(II) as compared to Zn(II) and Cr(VI).