Java plum and amaltash seed biomass based bio-adsorbents for synthetic wastewater treatment

Biochar and biosorbents derived from biomass for arsenic remediation

Global groundwater contamination by Arsenic (As) presents a grave danger to the health of living beings and wildlife, demanding comprehensive remediation strategies. This review delves into the complex landscape of arsenic remediation, encompassing its chemical forms, occurrences, sources, and associated health risks. Advanced techniques, notably biomass-derived adsorbents, emerge as promising and cost-effective solutions. The exploration spans preparing and modifying biomass-derived adsorbents, unraveling their adsorption capacity, influencing factors, isotherms, kinetics, and thermodynamics. Noteworthy attention is given to plant-agricultural waste, algal-fungal-bacterial, and iron-modified biomass-derived adsorbents. The comprehensive discussion of the adsorption mechanism highlights the efficacy of low-cost biomass, particularly from plant, animal, and agricultural residues, offering a sustainable remedy for arsenic removal. This insightful review contributes to the understanding of evolving technologies essential for addressing arsenic contamination in wastewater, emphasizing the potential of renewable biomaterials in advancing efficient remediation practices.

Adsorptive removal of heavy metals from aqueous solutions: Progress of adsorbents development and their effectiveness

Increased levels of heavy metals (HMs) in aquatic environments poses serious health and ecological concerns. Hence, several approaches have been proposed to eliminate/reduce the levels of HMs before the discharge/reuse of HMs-contaminated waters. Adsorption is one of the most attractive processes for water decontamination; however, the efficiency of this process greatly depends on the choice of adsorbent. Therefore, the key aim of this article is to review the progress in the development and application of different classes of conventional and emerging adsorbents for the abatement of HMs from contaminated waters. Adsorbents that are based on activated carbon, natural materials, microbial, clay minerals, layered double hydroxides (LDHs), nano-zerovalent iron (nZVI), graphene, carbon nanotubes (CNTs), metal organic frameworks (MOFs), and zeolitic imidazolate frameworks (ZIFs) are critically reviewed, with more emphasis on the last four adsorbents and their nanocomposites since they have the potential to significantly boost the HMs removal efficiency from contaminated waters. Furthermore, the optimal process conditions to achieve efficient performance are discussed. Additionally, adsorption isotherm, kinetics, thermodynamics, mechanisms, and effects of varying adsorption process parameters have been introduced. Moreover, heavy metal removal driven by other processes such as oxidation, reduction, and precipitation that might concurrently occur in parallel with adsorption have been reviewed. The application of adsorption for the treatment of real wastewater has been also reviewed. Finally, challenges, limitations and potential areas for improvements in the adsorptive removal of HMs from contaminated waters are identified and discussed. Thus, this article serves as a comprehensive reference for the recent developments in the field of adsorptive removal of heavy metals from wastewater. The proposed future research work at the end of this review could help in addressing some of the key limitations facing this technology, and create a platform for boosting the efficiency of the adsorptive removal of heavy metals.

Recent insights into mechanism of modified bio-adsorbents for the remediation of environmental pollutants

Rapid industrialization has exacerbated the hazard to health and the environment. Wide spectrums of contaminants pose numerous risks, necessitating their disposal and treatment. There is a need for further remediation methods since pollutant residues cannot be entirely eradicated by traditional treatment techniques. Bio-adsorbents are gaining popularity due to their eco-friendly approach, broad applicability, and improved functional and surface characteristics. Adsorbents that have been modified have improved qualities that aid in their adsorptive nature. Adsorption, ion exchange, chelation, surface precipitation, microbial uptake, physical entrapment, biodegradation, redox reactions, and electrostatic interactions are some of the processes that participate in the removal mechanism of biosorbents. These processes can vary depending on the particular biosorbent and the type of pollutants being targeted. The systematic review focuses on the many modification approaches used to remove environmental contaminants. Different modification or activation strategies can be used depending on the type of bio-adsorbent and pollutant to be remediated. Physical activation procedures such as ultrasonication and pyrolysis are more commonly used to modify bio-adsorbents. Ultrasonication process improves the adsorption efficiency by 15-25%. Acid and alkali modified procedures are the most effective chemical activation strategies for adsorbent modification for pollution removal. Chemical modification increases the removal to around 95-99%. The biological technique involving microbial culture is an emerging field that needs to be investigated further for pollutant removal. A short evaluation of modified adsorbents with multi-pollutant adsorption capability that have been better eliminated throughout the adsorption process has been provided.

Thermal and Viscoelastic Responses of Selected Lignocellulosic Wastes: Similarities and Differences

Woody lignocellulosic biomasses comprise the non-edible parts of fruit trees. In recent years, the exploitation of this biomass has been widening in order to mitigate environmental issues. At the same time, this waste could be transformed into a value-added product (active carbon by pyrolysis, isolation of nanocellulose, oils or proteins). For either valorization path, a complete thermo-mechanical characterization is required. A detailed thermo-mechanical study (TGA, DSC, DMA) was performed on two types of lignocellulosic wastes, with and without kernels: on one side, the walnut shells (WS) and the pistachio shells (PsS) and, in the second category, the apricot seeds (AS), the date seeds (DS), and the plum seeds (PS). The results of the sample-controlled thermal analyses (HiRes TGA) evidenced a better resolution of the degradation steps of WS. Kinetic studies conducted also by conventional TGA (Flynn-Wall-Ozawa) and modulated TGA (MTGA) allowed us to make comparative reasonings concerning the degradation of the investigated biomasses. The DMA results revealed the effect of water traces and oil kernels on relaxation and supported the atypical DSC endotherm emphasized in the freezing temperature domain.

Feasible synthesis of bifunctional polysilsesquioxane microspheres for robust adsorption of Hg(II) and Ag(I): Behavior and mechanism

The pollution of Hg(II) and Ag(I) to water system exerts hazardous effect to aquatic ecosystem and public security. Simple strategy for constructing adsorbents to efficient remove them is greatly desired. Thus, a series of thiol and amino groups containing bifunctional polysilsesquioxanes (ASPSS) microspheres with adjustable porous structure and functional group content were synthesized by one-step feasible sol-gel process. The adsorption behavior and mechanism of ASPSS microspheres toward Hg(II) and Ag(I) was thoroughly determined. The maximum adsorption capacity of ASPSS for Hg(II) and Ag(I) are 4.32 and 3.86 mmol·g^-1 under 25 ℃. The as-prepared ASPSS microspheres can 100% selectively capture Hg(II) with the coexisting of Mn(II), Co(II), Pb(II), Cd(II), Cu(II), Fe(III). And they can 100% adsorb Ag(I) with the presence of Cd(II), Pb(II), Co(II), Ni(II), and Zn(II). Moreover, the ASPSS microspheres exhibit good removal efficiency for Hg(II) and Ag(I) from simulated industrial wastewater with the coexistence of multiple pollutants. Adsorption mechanism suggests the adsorption for Hg(II) and Ag(I) is the synergistic coordination effect of amino and thiol groups. The excellent adsorption selectivity for Hg(II) and Ag(I) is attributed to the super binding ability of these functional group. ASPSS microspheres also exhibit good regeneration ability and could be reused for removing Hg (II) and Ag(I) from aqueous solution with practical value.

Chemical Modification of Neem (Azadirachta indica) Biomass as Bioadsorbent for Removal of Pb2+ Ion from Aqueous Waste Water

In this study, neem biomass (a mixture of neem leaf and bark), obtained from the matured neem tree, which is an eco-friendly and low-cost material was selected as a bioadsorbent to remove lead metal ion (Pb2+) from aqueous solutions. Neem biomass-based bioadsorbent having a carboxylic group was prepared by activation using chemical modification by NaOH and citric acid with a very simple method. The optimal activation conditions were determined as 37 min, 120°C, in 0.73 M citric acid, with a sample/acid ratio of 1/100 (mass/volume). To determine the basic properties such as chemical structure, porosity, and surface properties of the neem biomass (NB) and chemically modified neem biomass (CMNB), they were characterized by BET, FTIR, SEM, XRD, and pHpzc methods. It was observed that activation has improved the adsorption capacity of the NB and also caused a more amorphous structure. The effects of adsorption parameters such as pH (2–7), contact time (10–110 min), initial Pb2+ ion concentration (100–300 g/L), and bioadsorbent dosage (01–1.1 g/L) on percentage removal of Pb2+ ion were studied. Maximum removal of Pb2+ ion (97.29%) was recorded at 0.9 g/L bioadsorbent dosage, 50 min contact time, pH of 6, and initial metal ion concentration of 100 mg/L. Kinetics and isotherm studies showed that the adsorption mechanism of Pb2+ ion using CMNB follows pseudosecond-order while isotherm studies fit with both models but, relatively, Freundlich model better fit having a little higher $R^2=0.9804$ . The outcome specifies that the modified bioadsorbent can be utilized as a good and low-cost alternative for the treatment of effluent containing lead (II) ions in water.

Elucidation the influence of design variables on coagulation-flocculation mechanisms in the lab-scale bio-coagulation on toxic industrial effluent treatment

Bio-coagulants are environmentally friendly substances that have shown potential in removing organic and inorganic contaminants from wastewater from the Imitation Paint Industry. Under the optimized conditions, the use of the three bio-coagulants (of plant origin), Strychnos potatorum, Cactus opuntia and Portunus sanguinolentus (crab) shell (of animal origin) were evaluated, and their removal mechanism was based on kinetic models and adsorption isotherms. The error analysis method was used to find the best isotherm fit. In addition, the kinetic model parameters showed the absence of chemisorption and confirmed the existence of pore diffusion. The interaction between coagulant and pollutant, the type, homogeneity and intensity of the coagulation process, the pollutant absorption capacity of the coagulant were evaluated with the aid of the adsorption isotherm models. From the Pseudo first-order kinetic model an equilibrium pollutant uptake (mg/g) was marked as 598, 554 and 597 for Strychnos potatorum, Cactus opuntia and Portunus sanguinolentus respectively. The better affinity between the pollutants and the bio coagulants were observed through the lower values of Langmuir isotherm constant k_L. The adsorption intensity from Freundlich model (n_F) were ranged between 1 and 10 for all the listed coagulants, which revealed the physisorption behavior and heterogeneous mechanism of removal. With these results, it would be possible to conduct scale-up studies to adopt the process for practical systems.

Waste biomass based potential bioadsorbent for lead removal from simulated wastewater

Present study deals with the lead removal from simulated wastewater using cost effective bio-adsorbent of mango seeds cover with kernel (M), and jamun seeds cover with kernel (JP). Lead removal optimization of adsorption parameters has been analyzed by using Response surface methodology (RSM). The optimum adsorption was attained at speed of 500 rpm, 60 mg, pH 6.5 and contact time of 120 min. The adsorption capacities are around 39.15 mg/g of M and 20.28 mg/g of JP bio-adsorbent, and also the maximum Pb removal were observed ̴ 94.85% and 92.78%, respectively. The regression coefficient was best fitted for both bio-adsorbents are Freundlich model and pseudo-first order reaction kinetic.

Arsenate removal on the iron oxide ion exchanger modified with Neodymium(III) ions

In this study the iron oxide ion exchanger with the quaternary ammonium groups, Ferrix A33E was modified with neodymium (III) ions in order to obtain the new material Ferrix A33E-Nd(III) characterized by greater sorption efficiency of arsenate(V) ions. A33E-Nd(III) was described by various techniques including scanning electron microscopy SEM, nitrogen adsorption/desorption isotherms, Fourier transform infrared spectroscopy FTIR and X-ray photoelectron spectroscopy XPS. The point of zero charge, pH_PZC was also determined. The kinetic and thermodynamic parameters of the arsenate(V) sorption were calculated. The experimental data was fitted to the four isotherm models - Langmuir, Freundlich, Dubinin-Radushkevich and Halsey. Kinetic and equilibrium studies allowed to get to know the behaviour of arsenate(V) ions during the sorption on A33E-Nd(III). The obtained material A33E-Nd(III)- was found to possess a larger maximum sorption capacity than A33E, great stability and the possibility of regeneration at least 3 times without a significant decrease in efficiency. This allows for the complete removal of As(V) ions from a solution with a concentration of 50 mg/dm³ in just 30 min. The Nd(III)-modification improved the sorption properties of the tested ion exchanger.

Almalki A, F Alkhanani M, Pal DB. Waste seeds of Mangifera indica, Artocarpus heterophyllus, and Schizizium commune as biochar for heavy metal removal from simulated wastewater

The threat of arsenic contamination in water is a challenging issue worldwide. Millions of people utilize untreated groundwater having high levels of arsenic in developing countries. Design Expert 6.0.8 has been used to design experiments and carried out statistical analysis for optimization of different parameters. It is of prime importance to develop cheap environment friendly bio-sorbent for protecting health of the poor from ill effects of arsenic. In the present investigation, we prepared bio-sorbent from the solid waste seed biomass of Mangifera indica (M), Artocarpus heterophyllus (JF), and Schizizium commune (JP). The characterization of bio-sorbents has been done by using different techniques namely FTIR and XRD. Arsenic concentration was estimated using ICP and adsorption parameters optimized for pH, adsorbent dose, and initial arsenic concentration. At pH 8.4, kinetics study of arsenic removal was M (94%), JF (93%), and JP (92%) for initial concentration of 2.5 ppm. The adsorption kinetics was well explained by Freundlich model and pseudo-second reaction order.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13399-021-02078-5.

Lead removal from synthetic wastewater by biosorbents prepared from seeds of Artocarpus Heterophyllus and Syzygium Cumini

The present investigation deals with removal of lead (Pb⁺²) ions from waste water using biosorbent prepared from seeds of Artocarpus heterophyllus (SBAh) and Syzygium cumini (SBSc). Biosorbents surface has been characterized through FT-IR spectroscopy to probe the presence of functional groups. Response surface methodology enabled optimized conditions (Pb⁺² concentration 2 μg/mL, pH 5.8 and bioadsorbent dose 60 mg) resulted in Pb⁺² removal ~96% for SBAh and ~93% for SBSc at agitation speed 300 rpm. The adsorption capacity has been found to be 4.93 mg/g for SBAh and 3.95 mg/g for SBSc after 70 min. At optimal experimental conditions, kinetics of biosorption was explained well by inter-particle diffusion model for SBAh (R² = 0.99) whereas Elovich model best fitted for SBSc (R² = 0.98). Further, both the biosorbents followed Temkin adsorption isotherm model.

Sustainable removal of arsenic from simulated wastewater using solid waste seed pods biosorbents of Cassia fistula L

The present investigation is focused to develop a new type of solid waste based biosorbent, derived from the Cassia fistula pod biomass. The prepared biosorbent has been characterized through different techniques including field emission scanning electron microscopy, fourier transform infrared spectroscope and X-ray diffraction to investigate the physiochemical properties which are potential for the bioadsorbent application. The experiments have been performed considering four parameters namely; pH, biosorbent dose, initial concentration of As⁺³ and duration in the batch reactor. The experimental results have been analyzed using the design-expert software for the optimization of different parameters. The maximum removal of arsenic could be achieved ∼91% whereas monolayer adsorption capacity is found to be 1.13 mg g^-1 in 80 min at pH 6.0 and 30 °C by using 60 mg dose of bioadsorbent. The arsenic adsorption behavior of the bio-adsorbent has been well interpreted in terms of pseudo-first order and Freundlich model.

Low-cost biochar adsorbents prepared from date and delonix regia seeds for heavy metal sorption

In this study, low-cost biochar as bio-adsorbents derived from locally accessible delonix regia seed and date seeds were explored for heavy metal environmental cleaning. These prepared biochars were characterized by proximate and elemental analyses, CHNS/O analysis, Fourier-transformed infrared spectroscopy and thermo-gravitational methods. Bio-sorbent's ability to adsorb arsenic ions in synthetic wastewater was studied and optimized at varying solution pH, adsorbent dose, and starting metal concentrations. Experimentation and optimization studies were also carried out with the help of Design-software 6.0.8. The trials were designed by using response-surface methods, which includes three components and stages of Box-Behnken design. Date seeds derived-biochars eliminated 95% of arsenic from synthetic wastewater, whereas Delonix regia seeds removed 93.8%. The kinetics, isotherms and mechanism of As adsorption were also postulated. This study proposes that these seed's biochars might be employed as an effective, low-cost, and environmentally friendly adsorbent to remove heavy metals from the environment.

Sustainable Chromium Recovery From Wastewater Using Mango and Jackfruit Seed Kernel Bio-Adsorbents

Wastewater is a rich source of valuable chemicals of industrial importance. However, their economic recovery is crucial for sustainability. The objective of the present work is to recover hexavalent chromium (Cr VI) as a value-added transition metal from wastewater cost-effectively; the biosorbent derived from seed kernels of mango (M) and jackfruit (JF) were applied for removing the metal from simulated wastewater. The functional groups of the biomass were analysed with the help of Fourier transform infrared (FTIR) spectroscopy, micrographs were generated using a scanning electron microscope, and crystallinity was determined by an x-ray diffractometer (XRD). The concentration of Cr VI in wastewater was analysed by an inductively coupled plasma optical emission spectrometer (ICP-OES). Process parameters (pH, dose, contact time, temperature, and initial concentration) were optimized for efficient Cr VI adsorption using a response surface methodology-based Box-Behnken design (BBD) employing Design-software 6.0.8. The batch experiment at room temperature at pH 4.8 and Cr VI removal ∼94% (M) and ∼92% (JF) was achieved by using a 60-mg dose and an initial Cr (VI) concentration of 2 ppm in 120 min. The equilibrium Cr binding on the biosorbent was well explained using Freundlich isotherm (R ² = 0.97), which indicated the indirect interactions between Cr (VI) and the biosorbent. Biosorption of Cr (VI) followed the pseudo-order and intra-particle diffusion models. The maximum adsorption capacity of the M and JF bio-adsorbent is 517.24 and 207.6 g/mg, respectively. These efficient, cost-effective, and eco-friendly biosorbents could be potentially applied for removing toxic Cr (VI) from polluted water.