SIMULTANEOUS ADSORPTION OF TETRACYCLINE AND AMOXICILLIN BY CLADOPHORA AND SPIRULINA ALGAE BIOMASS

Adsorption studies were performed at different initial Tetracycline (TC) and Amoxicillin (AMO) concentration, different biomass dosage and type, contact time, agitation speed, and initial pH. In the batch mode were investigated. The optimum pH of solutions is 6.5 for TC and 5 for AMO, agitation speed 200 rpm and concentration 50 ppm. The results in FTIR showed that there were -OH and amides (N-H) and other functional groups on the surface of Cladophora and Spirulina algae. The equilibrium isotherm data were modeled with Freundlich, Temkin, and Langmuir isotherm models. The data best fitted with the Langmuir model. The maximal adsorption capacity from the Langmuir model was (9.86, 20. 5 mg/g) for TC and (7.89, 17.4 mg/g) for AMO on Cladophora and Spirulina algae, respectively. Finally, the pseudo-second-order kinetic model was best fitted the experimental kinetic data of TC and AMO onto Cladophora and Spirulina algae biomass with a high coefficient of determination between 0.97 and 0.99. Cladophora and Spirulina algae, low-cost and eco-friendly adsorbents, can be used to adsorb the TC and AMO from the solution.

Biosorption of Cu and Zn in a Batch System via Dried Macroalgae Halimeda opuntia and Turbinaria turbinata

Biosorption is the most favourable technique for the treatment of heavy metals as it is fast, powerful, and low cost, it takes place in a wide range of temperatures as well as it can be used for almost all types of heavy metals. In this study, the biosorption technique adsorbs Cu2+ and Zn2+ on the dried macroalgae (Halimeda opuntia and Turbinaria turbinata) in a batch system. Experimental parameters affecting the biosorption process are initial metal ion concentrations (5, 10, 15 and 25 mg/L), pH between (4.5 and 5.2), biomass dosage (1 gm) and agitation speed 150 rpm applied at contact time (30, 60 and 120 min). The significant-high average removals of Cu2+ by H.opuntia (> 96%) were recorded in concentrations of 10, 15 and 25 ppm at 120 min and the highest average removals by T.turbinata (81.07%, 78.32% and 74.7%) were recorded in concentrations of 5, 10 and 15 ppm at 120 min. The lowest average removal of Cu2+ 89.22% was recorded by H.opuntia and 49.9% was recorded by T.turbinata in a concentration of 25 ppm at 30 min. In the same way, significant-high average removals (>94%) were recorded in a concentration of 10 ppm at 120 min for H.opuntia and in a concentration of 5 ppm by at 60 min for T.turbinata. In conclusion, the dead biomass of marine algae can provide a promising and low-cost technique for removing heavy metal pollutants in medical industries.

Application of Alginate Extraction Residue for Al(Iii) Ions Biosorption: A Complete Batch System Evaluation

The residue derived from the alginate extraction from S. filipendula was applied for the biosorption of aluminum from aqueous medium. The adsorptive capacity of the residue (RES) was completely evaluated in batch mode. The effect of pH, contact time, initial concentration and temperature was assessed through kinetic, equilibrium and thermodynamic studies. The biosorbent was characterized prior and post-Al biosorption by N2 physisorption, Hg porosimetry, He picnometry and thermogravimetry analyses. Equilibrium was achieved in 60 minutes. Kinetics obeys pseudo-second order model at aluminum higher concentrations. Isotherms followed Freundlich model at low temperature (293.15 K) and D-R or Langmuir model at higher temperatures (303 and 313 K). Data modeling indicated the occurrence of both chemical and physical interactions in the aluminum adsorption mechanism using RES. The maximum adsorption capacity obtained was of 1.431 mmol/g at 293 K. The biosorption showed a spontaneous, favorable and exotherm character. A simplified batch design was performed, indicating that the residue is a viable biosorbent, achieving high percentages of removal using low biomass dosage.

The Synthesis of PbS NPs and Biosorption of Pb(II) by Shinella Zoogloeoides PQ7 in Aqueous Conditions

Increasing heavy metal pollution in water continues to endanger human health. The genus Shinella has potential for heavy metal bioremediation but has rarely been studied. In this study, we report that Shinella zoogloeoides PQ7 turns black in the presence of lead ions. Transmission electron microscopy (TEM), Scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) indicated that PbS nanoparticles (NPs) were synthesized by PQ7. Moreover, PQ7 was used as a biosorbent to remove Pb(II) from aqueous solutions. Biosorption performance was evaluated in terms of contact time, pH, biomass dosage and initial Pb(II) concentration. The equilibrium and kinetic data were consistent with the Freundlich isotherm model (R2 = 0.986) and pseudo-second-order model (R2 = 0.977), respectively. The maximum (qmax) Pb(II) adsorption reached 222.22 mg/g, which was higher than that of other bacteria reported in previous literature. SEM–EDS, XRD and Fourier transform infrared (FTIR) analyses also confirmed the adsorption of Pb(II) by the PQ7 cells. In conclusion, PQ7 is a promising strain in removing and recovering Pb(II) from wastewater.

Biosorption of Pb(II) and Cd(II) Ions from Aqueous Solution by Chemically Modified Syzygium cumini Leaves and its Equilibrium, Kinetic and Thermodynamic Studies

The removal of Pb (II) and Cd (II) ions from aqueous solution by a novel low-cost biosorbent; chemically modified Syzygium cumini leaves (CMSCL) was studied. The effects of biomass dosage, pH, concentration, temperature and contact time were investigated. Characterization of CMSCL was carried out by FT-IR spectroscopy, pore size, and surface area analyzer. The maximum biosorption capability of CMSCL for Pb (II) and Cd (II) ions was 104 and 50 mg/g at optimum conditions of pH 6 and 7, biomass dosage of 5 g/L, contact time of 120 and 90 min and temperature of 50 and 40 0C, respectively. The experimental data was analyzed using pseudo-first order and pseudo-second order kinetics models. The biosorption of Pb (II) and Cd (II) followed pseudo-second order model. Langmuir, Freundlich and Temkin adsorption isotherm models were applied to explain the removal of heavy metal ions by CMSCL biosorbent. Langmuir isotherm model fitted better than other isotherm models. Thermodynamics parameters such as �H0, �G0 and �S0 showed that the biosorption of Pb (II) and Cd (II) ions onto CMSCL was spontaneous, exothermic and feasible under examined conditions. The occurrence of various functional groups and change in the absorption frequency after metal uptake indicates that complexation was the main mechanism involved in the process of biosorption. Based on the present investigation, it was proved that CMSCL is an effective, alternative and economical biosorbent for the removal of Pb (II) and Cd (II) ions. Keywords:

The remediation of chlorpyrifos-contaminated soil by immobilized white-rot fungi

This research focused on the degradation of chlorpyrifos via immobilized white rot fungi in soil, with the aim to select excellent degrading strains and an optimal carrier of white rot fungi. Immobilization of white rot fungi was assessed on corn stover, wheat straw, peanut shells, wood chip, and corn cobs. Phlebia sp., Lenzites betulinus and Irpex lacteus were grown in defined nutrient media for the remediation of pesticide-contaminated soils. The carrier of the biomass was determined by observing the growth of white rot fungi. The results showed that corn stover and wheat straw are suitable carriers of the immobilized white rot fungi and that Phlebia sp. and Lenzites betulinus have a positive effect on the degradation of chlorpyrifos. At 30?C and neutral pH, the degradation rate of chlorpyrifos was 74.35 %, Phlebia sp. being immobilized by corn stover in 7 days, which was the best result compared to other combinations of strains and carriers. The orthogonal experiment showed that the pH value and temperature affected the pollutant degradability more than the initial concentration and the biomass dosage.

Equilibrium and Kinetic Studies of Biosorptive Removal of 2,4,6-Trichlorophenol from Aqueous Solutions Using Untreated Agro-Waste Pine Cone Biomass

The present work discusses the adsorptive removal of a phenolic pollutant, i.e., 2,4,6-trichlorophenol (TCP), using low cost untreated agricultural waste pine cone powder (PCP). The present biosorbent was thoroughly characterized with the help of FTIR, SEM, XRD, and CHN analysis. The presence of amine (-NH2), hydroxyl (-OH) and carbonyl (C=O) functional groups was detected by the FTIR analysis. The important biosorption factors like agitation time, biomass dosage, initial adsorbate concentration, and the initial pH were examined by batch studies. The biosorption kinetic process was fast, reaching equilibrium in 75 min. The experimental kinetic data revealed an excellent agreement with the pseudo second order (PSO) model. On the other hand, the Langmuir isotherm model best described the equilibrium data with the maximum biosorption capacity (qmax) of 243.90 mg/g. These values are better than the adsorption capacities of most agro-based untreated adsorbents previously reported in the literature. Owing to fast removal rates and high biosorption capacity, PCP can be used for cost-effective treatment of TCP from aqueous streams.

Biomass-Assisted Reductive Leaching in H2SO4 Medium for the Recovery of Valuable Metals from Spent Mixed-Type Lithium-Ion Batteries

A hydrometallurgical method involving natural biomass waste as reductant was proposed for the treatment of spent mixed-type lithium-ion batteries. Results showed that almost complete dissolution of Li, Ni, Mn and nearly 90% dissolution of Co were achieved under the optimal conditions of H2SO4 concentration of 2 M, waste tea biomass dosage of 0.3 g/g, solid/ratio of 50 g L−1, temperature of 90°C and time of 120 min. The leaching kinetics was further investigated, and the activation energies were determined to be 1.7 kJ mol−1, 10.3 kJ mol−1, 10.1 kJ mol−1 and 10.9 kJ mol−1 for Li, Ni, Mn and Co, respectively. The cathode materials before leaching and the leaching residue were characterized with different analytical methods. The characterization results confirmed that the addition of the waste tea acted as reductant and resulted in better dissolution of the metals, supporting the principles of sustainable processes by decreasing the chemical consumption and integrating waste into a secondary use.

Validation of Flory-Huggins model for phenol adsorption by Parthenium hysterophorus in a batch system

Parthenium hysterophorus weed powder was studied as adsorbent for phenol adsorption from its aqueous standardized solution. The adsorption of pollutant was found improving with an increase of biomass dosage and contact time. The intraparticle diffusion of phenol onto adsorbent surface was identified to be the rate limiting step. Linear form of Flory-Huggins model revealed preeminence to Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich due to highest value of R2. The remediation process was figured out as a physisorption rather than a chemical one based on value of E (0.21KJ/mol). Active sites of sorbent surface identified by FT-IR were oxygen containing functional groups. Recent study proposes cost effective utilization of toxic allergent for treatment of toxic waste.