In this study, the potential of the oriental arborvitae leaves for the adsorption of Pb(II) from aqueous solutions was evaluated. Brunauer–Emmett–Teller analysis showed that the surface area of arborvitae leaves was 29.52 m2/g with pore diameter ranging from 2 to 50 nm. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy showed C—;C or C—;H, C—;O, and O—;C=O were the main groups on the arborvitae leaves, which were the main sites for surface complexation. Finally, effects of adsorbent dose, initial pH, contact time, and coexisting natural organic matters (humic acid (HA)) on the adsorption of Pb(II) were investigated. The results indicated that the pHZPC (adsorbents with zero point charge at this pH) was 5.3 and the adsorption reached equilibrium in 120 min. Isotherm simulations revealed that the natural arborvitae leaves exhibit effective adsorption for Pb(II) in aqueous solution, giving adsorptive affinity and capacity in an order of ‘no HA’ > 5 mg/L HA > 10 mg/L HA, and according to the Langmuir models, the maximum adsorptions of Pb(II) were 43.67 mg/g, 38.61 mg/g and 35.97 mg/g, respectively. The results demonstrated that the oriental arborvitae leaves showed high potentials for the adsorption of Pb(II) from aqueous solutions.
- IWA Publishing
- Adsorption characteristics of Pb(II) from aqueous solutions onto ...
Overview of Rotating Disc Electrode (RDE) Optical Emission Spectroscopy for In-Service Oil Analysis
IntroductionThe basis of modern oil analysis is the use of optical emission spectroscopy (OES) to measure the ppm (parts per million) levels of wear metals, contaminants and additives in oil samples. Whatever else an oil lab may measure, a multi-elemental analysis is the core of in-service oil analysis. This paper gives an overview of Rotating Disc Electrode Elemental Spectroscopy and its use for in-service oil analysis applications. Sometime after World War II, the Denver and Rio Grande Railroad, now defunct,...
Guide To Coolant In Oil Test Methods
Liquid cooled engines and rotating equipment use glycol based coolants because of their excellent heat transfer abilities. However, glycol based coolants are not desirable at all in lubrication oil itself – Coolant ingression to the lubricant is a particularly nasty contaminant for the variety of damage it can cause. Glycol coolants break down in the high temperature engine environment, leading to formation of glycolic acids. These acids attack nonferrous bearing surfaces and form metal salts. The acids...
Effect of W doping level on TiO2 on the photocatalytic degradation of Diuron
In the present study, three compositions of W-doped titania nano-photocatalyst are synthesized via the sol–gel method. The powders obtained were characterized by X-ray diffraction, Raman spectroscopy and UV–visible diffuse reflectance spectroscopy. The photocatalytic performances of the different photocatalysts are tested with respect to the degradation of Diuron in water solutions under simulated solar light and visible light irradiation. The W0.03Ti0.97O2 catalyst exhibits better photoactivity than the pure...
3DEEM spectroscopy analysis to assess the EPS composition in different carriers in HMBR systems
A hybrid membrane bioreactor (HMBR) with biological band carriers (Reactor A) and an HMBR with suspended honeycomb carriers (Reactor B) were conducted in parallel to investigate the effects of different carriers on extracellular polymeric substances (EPS). Composition and concentration of EPS were examined by three-dimensional excitation-emission matrix (3DEEM) fluorescence spectra and parallel factor analysis (PARAFAC). 3DEEM spectra demonstrated that the main organic substances of the EPS in two reactors were...
Optimising next-generation lithium ion batteries with infrared spectroscopy
Lithium batteries have become the mainstay of modern portable electronics, providing a reliable power source to run mobile phones, laptop computers and electric vehicles. Lithium technology is now even being developed on a large scale to provide electricity storage to supplement the National Grid during peak demand . The issue with lithium batteries remains the same – energy density – and prompts the question how can more power be packed into a smaller and lighter space? In pursuit of a radically...