Synthesis of novel hydrated ferric oxide biochar nanohybrids for efficient arsenic removal from wastewater

Hydrated ferric oxide(HFO)has high adsorption efficiency for As(Ⅲ).However,its high self-aggregation usually reduces the efficiency and limits the scaledup application.Herein,biochar(BC),with large surface area and amounts of surface functional groups was used to tune the loading and distribution of HFO to prepare an efficient adsorbent(HFO/BC)via in-situ synthesis method.The influence of the mass ratio of iron salt to BC on HFO/BC morphology was investigated,and the mechanism was discussed.The results showed that novel HFO was formed and distributed uniformly on the surface of BC when the mass ratio of iron salt to BC was 5:1.The adsorption kinetics and isotherms studies show that the novel HFO/BC(5:1)composite can fast treat As(Ⅲ)with a high adsorption capacity of 104.55 mg·g^(-1),indicating that it is a potential material for removing arsenic from polluted water.

Fabrication and catalytic performance of meso-ZSM-5 zeolite encapsulated ferric oxide nanoparticles for phenol hydroxylation

An encapsulation-structured Fe_(2)O_(3)@mesoZSM-5(Fe@MZ5)was fabricated by confining Fe_(2)O_(3) nanoparticles(ca.4 nm)within the ordered mesopores of hierarchical ZSM-5 zeolite(meso-ZSM-5),with ferric oleate and amphiphilic organosilane as the iron source and meso-porogen,respectively.For comparison,catalysts with Fe_(2)O_(3)(ca.12 nm)encapsulated in intra-crystal holes of meso-ZSM-5 and with MCM-41 or ZSM-5 phase as the shell were also prepared via sequential desilication and recrystallization at different pH values and temperatures.Catalytic phenol hydroxylation performance of the as-prepared catalysts using H_(2)O_(2) as oxidant was compared.Among the encapsulation-structured catalysts,Fe@MZ5 showed the highest phenol conversion and hydroquinone selectivity,which were enhanced by two times compared to the Fe-oxide impregnated ZSM-5(Fe/Z5).Moreover,the Fe-leaching amount of Fe@MZ5 was only 3% of that for Fe/Z5.The influence of reaction parameters,reusability,and ·OH scavenging ability of the catalysts were also investigated.Based on the above results,the structure-performance relationship of these new catalysts was preliminarily described.

Effect of Metal Oxide on Electrical Resistivity of Conductive Wood Charcoal

To analyze the effect of metal oxide on electrical resistivity of conductive wood charcoal,wood powder of Masson pine was mixed with ferric oxide (Fe_2O_3) and nickel oxide (NiO), respectively,and then the mixed powders were carbonized at high temperature in a laboratory-scale tube furnace in a nitrogen atmosphere. DCY-3 resistivity tester was used to measure electrical resistivity of conductive wood charcoal. When carbonization temperature was 1200 ℃, the electrical resistivity of controlsamples, Fe_2O_3 (4%) added samples, and NiO (4%) added samples was 0.104 Ω·lcm, 0.071 Ω·lcm, and 0.066 Ω·lcm, respectively. When carbonization temperature was 1 500 ℃, the electrical resistivity of control samples, Fe_2O_3 (4%) added samples, and NiO(4%) added samples was 0.091 Ω·lcm,0.052 Ω·lcm, and 0.052Ω·lcm, respectively. And electrical resistivity of conductive wood charcoaldecreased from 0.060Ω·lcm to 0.041Ω·lcm when the ferric oxide addition increased from 2% to 10%.The results showed that the electrical resistivity of conductive wood charcoal decreased with the increase of carbonization temperature. Ferric oxide and nickel oxide could be used as catalysts todecrease electrical resistivity of conductive wood charcoal. And electrical resistivity of conductivewood charcoal reduced with increasing the ferric oxide addition.

Synergistic co-removal of zinc(Ⅱ) and cefazolin by a Fe/amine-modified chitosan composite

A novel Fe/amine modified chitosan composite(Fe/N-CS) was facilely synthesized and showed higher affinity to both Zn(Ⅱ) and cefazolin(CEF) than its precursors.Synergistic co-adsorption of them by Fe/NCS was observed in varied conditions.The adsorption amount maximally increased by 100.1% for Zn and68.2% for CEF in bi-solute systems.The initial adsorption rate of Zn(Ⅱ) also improved with CEF.The increasing temperature facilitated coadsorption.The results of the preloading tests,FTIR/XPS characterizations and DFT calculations suggested that(1) both polyamines and Fe sites participated in the adsorption of Zn(Ⅱ) and CEF,(2) Zn(Ⅱ) could serve as a new efficient site for CEF,forming [amineZn-CEF]/[FeOH-Zn-CEF] ternary complexes,and(3) the co-presence of CEF shielded the electrostatic repulsion between protonated amines and Zn(Ⅱ),contributing to the enhancement of Zn(Ⅱ) adsorption.Further,the ion strength exerted positive and negative influences on the adsorption of Zn(Ⅱ) and CEF,respectively.Additionally,CEF and Zn(Ⅱ) were successively recovered by 0.1 mol/L NaOH followed by2 mmol/L HCl.Fe/N-CS could be stably reused five times.The findings imply that Fe/N-CS is promising for the highly efficient co-removal of concurrent heavy metals and antibiotics.