Background: In recent years, various toxic chemicals/compounds have been widely detected at dangerous levels in drinking water in many parts of the world posing a variety of serious health risks to human beings. One of these toxic chemicals is LEAD, so this paper aimed to evaluate of efficiency coconut husk as cheap adsorbent for removal LEAD under different conditIONS.Methods: In the spring of 2015, batch studies were performed in laboratory (Branch of Hamadan, Islamic Azad University,) to evaluate the influences of various experimental parameters like pH, initial concentration, adsorbent dosage, contact time and the effect of temperature on the adsorption capacity of coconut husk for removal LEAD from aqueous solution.Results: Optimum conditIONS for Pb ((II)) removal were pH 6, adsorbent dosage 1g/100ml of solution and equilibrium time 120 min. The adsorption isotherm was also affected by temperature since the adsorption capacity was increased by raising the temperature from 25 to 45 oC. The equilibrium adsorption isotherm was better described by Freuindlich adsorption isotherm model.Conclusion: It is evident from the literature survey that coconut-based biosorbents have shown good potential for the removal of various aquatic pollutants. Coconut husk-based activated carbon can be a promising adsorbent for removal of Pb from aqueous solutIONS.

The biosorption of heavy metals can be an effective process for the removal of such metal IONS from aqueous solutIONS. In this study, the adsorption properties of nonliving biomass of phanerochaete chrysosporium for Pb ((II)) and Zn ((II)) were investigated by the use of batch adsorption techniques. The effects of initial metal ion concentration, initial pH, biosorbent concentration, stirring speed, temperature and contact time on the biosorption efficiency were studied. The experimental results indicated that the uptake capacity and adsorption yield of one the metal ion were reduced by the presence of the other one. The optimum pH was obtained as 6.0. The experimental adsorption data were fitted to both Langmuir and Frundlich adsorption models for Pb ((II)) and to the Langmuir model for Zn ((II)) ion. The highest metals uptake values of 57 and 87 mg/g were calculated for Zn ((II)) and Pb ((II)) respectively. Desorption of heavy metal IONS was performed by 50 mM HNO3 solution. The results indicated that the biomass of phanerochaete chrysosporium is a suitable biosorbent for the removal of heavy metal IONS from the aqueous solutIONS.

The removal of the most prevalent heavy metal IONS [cadmium((II)), LEAD((II)), copper((II)), and zinc((II))] by adsorption on Scots pine (Pinus sylvestris L.) biochar and Silver birch (Betula pendula) biochar has been investigated, following the determination of physical and chemical adsorption properties of biochar. The efficiency of adsorption of heavy metal IONS [cadmium((II)), LEAD((II)), copper((II)), and zinc((II))] on biochar was studied at different concentratIONS of heavy metals [onefold maximum contaminant level, twofold maximum contaminant level, fivefold maximum contaminant level (in accordance with the requirements set out in the Water Framework Directive 2000/60/EC), dosages of biochar (1.6-140 g), and biochar types (Scots pine (P. sylvestris L.) biochar and Silver birch (B. pendula) biochar produced at slow and fast pyrolysis) at constant pH of leaching solution, temperature, and contact time. Adsorption capacity of Scots pine (P. sylvestris L.) biochar and Silver birch (B. pendula) biochar was assessed by the application of extended Freundlich isotherm. In this study, biochar was evaluated as a potential adsorbent to efficiently reduce concentration of heavy metal IONS in metal-contaminated water. The maximum adsorption capacity were reached of copper((II)) on Silver birch (B. pendula) biochar (128.7 mg g-1) and of zinc((II)) on Scots pine (P. sylvestris L.) biochar (107.0 mg g-1). Adsorption capacity of LEAD ((II)) on Silver birch (B. pendula) and Scots pine (P. sylvestris L.) biochar varied from 1.29 to 3.77 and from 2.37 to 4.49 mg g-1, respectively.

The potential removal and preconcentration of LEAD ((II)), cadmium ((II)), and chromium ((II)I) IONS from wastewaters were investigated and explored. Magnetite nanoparticles were chemically modified with p -nitro aniline. The aniline-coated magnetite nanoparticles (ANMNPs) were fully characterized by FT-IR, XRD, SEM, and TEM measurements. Batch studies were performed to address various experimental parameters for the removal and determination of these IONS. ANMNPs showed high tendency to investigated metal IONS, in this order: Cr ((II)I)>Cd ((II))>Pb ((II)), owing to the strong contribution of surface loaded aniline. The potential applicatIONS of ANMNPs adsorbent for removal and preconcentration of Pb ((II)), Cr ((II)I), and Cd ((II)) from wastewaters as well as drinking tap water samples were successfully accomplished giving recovery values of (98–101 %), without any noticeable interference of the wastewater or drinking tap water matrices.

In the present study, the poly (vinyl alcohol)//graphene oxide Nano sheets (PVA/GO) were successfully synthesized via electrospinning process and its application for the removal of LEAD ((II)) and copper ((II)) IONS was investigated in a batch system. The graphiteNano sheets were also modified by HCl and H2SO4. The synthesized Nano fibrousadsorbents were characterized usingscanning electron microscopy (SEM), X-ray powder diffraction (XRD), and Brunauer– Emmett– Teller (BET) analysis. The effect of sorption parameters including pH, contact time and initial concentration on the removal of LEAD ((II)) and copper ((II)) IONS by the Nano fibrous samples were investigated. The known pseudo-first-order and pseudo-second-order kinetic models were applied to describe the kinetic data of metal IONS. The Freundlich and Langmuir isotherm models were used to describe the equilibrium data of metal IONS sorption. The both copper and LEAD experimental data were well described using pseudo-second-order kinetic and Langmuir isotherm models. The obtained results indicated that PVA/GO nanofibers can be considered as an efficient adsorbent for the removal heavy metal IONS.

Zeolite N. P. (Nano-Particles)/GO and zeolite N. P. /HPC/GO composites were synthesized and investigated as a heavy metal nanosorbent in the aquatic media. The Fourier-transform infrared spectroscopy (FT-IR) spectrum confirmed the expected pattern and the field-emission scanning electron microscopy (SEM) images revealed the formation of zeolite nanoparticles and graphene oxide layer structure. The presence of the expected elements was confirmed by the energy dispersive X-ray (EDS) analysis and the X-ray diffraction (XRD) pattern confirmed the formation of zeolite and graphene oxide by the crystalline structure. The nanosorbents used to remove LEAD ((II)) and cadmium IONS in the aquatic media and the effective parameters were investigated and optimized for the removal process. Optimal values of zeolite N. P. /GO composite for Pb2+ and Cd2+ IONS are: pH = 7 and 4 corresponding to contact times = 10 and 15 minutes, respectively, also the optimal amount of sorbent for both IONS is 0. 01g in the optimum temperature 25 ° C. The optimum contact time, temperature and sorbent dosage of zeolite N. P. /HPC/GO for both IONS were obtained 30 minutes, 25 ° C and 0. 005g, respectively. The optimum pH values of both IONS were as used for the previous nanosorbent. The interference IONS did not significantly affect the removal efficiency of both IONS by the synthesized nanosorbents. The nanosorbents showed effective removal efficiency in three samples of agricultural waters in south Tehran. The results showed that the data follow both Langmuir and Freundlich isotherms.