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In this study, new, efficient, eco-friendly and magnetically separable nanoadsorbents, MNPs-G1-Mu and MNPs-G2-Mu, were successfully prepared by covalently grafting murexide-terminated polyamidoamine dendrimers on 3-aminopropyl functionalized silica-coated magnetite nanoparticles, and used for rapid removal of lead (II) from aqueous medium. After each adsorption process, the supernatant was successfully acquired from reaction mixture by the magnetic separation, and then analyzed by employing ICP-OES. Chemical and physical characterizations of new nanomaterials were confirmed by XRD, FT-IR, SEM, TEM, and VSM. Maximum adsorption capacities (q m ) of both prepared new nanostructured adsorbents were compared with each other and also with some other adsorbents. The kinetic data were appraised by using pseudo-first-order and pseudo-second-order kinetic models. Adsorption isotherms were found to be suitable with both Langmuir and Freundlich isotherm linear equations. The maximum adsorption capacities for MNPs-G1-Mu and MNPs-G2-Mu were calculated as 208.33 mg g −1 and 232.56 mg g −1 , respectively. Antimicrobial activities of nanoparticles were also examined against various microorganisms by using microdilution method. It was determined that MNPs-G1-Mu, MNPs-G2-Mu and lead (II) adsorbed MNPs-G2-Mu showed good antimicrobial activity against S. aureus ATTC 29213 and C. Parapsilosis ATTC 22019. MNPs-G1-Mu also showed antimicrobial activity against C. albicans ATTC 10231.

The objective of this study is to employ an adsorption technology to remove methylene blue from the aqueous solution. Methylene blue is one of the dyestuffs that are discharged to wastewater after being used extensively in the industry and creating pollution. A residue of an agricultural product called corn silk was employed in the adsorption process, along with corn silk that had been sulphuric acid‐treated. Using methods like FT‐IR, SEM, EDX, and TGA, the structures of crude corn silk (CCS) and modified corn silk (MCS) were clarified. The ideal adsorption conditions for both adsorbents were found to be equilibrium contact period, pH, the dose of adsorbent, and beginning methylene blue concentration. At 293, 313, and 333 K, adsorption kinetic and isotherm experiments were conducted. It was determined that both adsorptions were compatible with the pseudo‐second‐order kinetic model kinetically and the Freundlich isotherm model isothermally with higher R2 values. At 333 K, the maximum adsorption capacities (qm) of CCS and MCS were calculated to be respectively 59.5 mg g−1 and 400 mg g−1. The findings demonstrated that although crude corn silk adsorbs methylene blue, sulphuric acid treatment greatly increases its adsorption ability.

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Bu çalışmada daha önceden sentezlenmiş bir nano adsorban olan MNPs-G1-Mu tarafından Cr (III) metal iyonlarının adsorpsiyon işlemi ile sudan uzaklaştırılması amaçlanmıştır. MNPs-G1-Mu adsorbanı; Pamam dendrimeri ile modifiye edilmiş demir oksit nanopartiküllerden sentezlenmiştir. Cr (III) iyonlarının MNPs-G1-Mu üzerindeki adsorpsiyonunu etkileyen faktörler (denge temas süresi, pH, adsorban miktarı, Cr (III) iyonları çözeltisinin başlangıç konsantrasyonu) incelenmiştir. Daha sonra adsorpsiyon kinetiğinin anlaşılması için kinetik çalışma yapılmıştır. Kinetik deney sonuçlarından elde edilen veriler yalancı birinci ve ikinci derece kinetik denklemlerinde değerlendirilmiş ve adsorpsiyonun her iki kinetik denkleme de uyduğu belirlenmiştir. Yalancı ikinci derece kinetik denkleminden üç sıcaklık için (298, 308 ve 318 K) elde edilen hız sabitleri Arrhenius denklemine uyarlanmış olup adsorpsiyonun aktivasyon enerjisi 2.58 kJ mol -1 olarak hesaplanmıştır. Son olarak adsorpsiyona ait izoterm çalışması yapılmıştır. Adsorpsiyonun, Freundlich adsorpsiyon izotermine uyduğu görülmüştür. Freundlich izoterm sabitleri olan "k" ve "n" sabitleri sırasıyla 26.964 ve 0.8899 olarak hesaplanmıştır. Sonuç olarak, MNPs-G1-Mu adsorbanının Cr (III) iyonlarını etkili bir şekilde sudan uzaklaştırdığı belirlenmiştir.