Removal of low-concentration formaldehyde in air by adsorption on activated carbon modified by hexamethylene diamine

Formaldehyde is one of the most common difficult-to-eliminate indoor air pollutants. Among the available methods of eliminating formaldehyde, adsorption is still the most commonly used due to its simplicity, efficiency, and economic viability. This study investigated the potential of diatomaceous earth (DE) adsorbent for formaldehyde (low concentration in air). DE was considered because of its high silica content and high porosity. It also examined the effect of adding ethylene-diamine (EDA) on the adsorption performance of DE. Amine groups have been proven to improve the adsorption of formaldehyde through their reaction that produces imine. The amount of added EDA was varied from 0.25 to 0.75 g per gram of DE. For pure DE adsorbent, the adsorption performance was 298 mg/g. Adding 0.75 g of EDA resulted in maximum DE adsorption performance (565 mg/g). EDA-modified DE was shown to be a potential adsorbent for removing formaldehyde in air.

Section: Adsorption Experimentssupporting

confidence: 56%

Adsorption of Low Concentration Formaldehyde in Air Using Ethylene-Diamine-Modified Diatomaceous Earth

Bernabe

Herrera

Doma

et al. 2015

“…3(b)). The experimental results showed that the adsorption ability of formaldehyde was as high as ~22.8 mg/g for G-GND (5.5 mg/g, calculated with the mass of sponge), with more excellent adsorption capacity than previously reported work (Carter et al, 2011;Ma et al, 2011;Wen et al, 2011;Zhang et al, 2011;Chen et al, 2014).…”

Section: Fig 2 Ft-ir Spectra (A) Xps Survey Scans (B) Of Go and G-mentioning

confidence: 57%

“…Wen et al (2011) used activated carbon derived from sewage sludge to remove formaldehyde, but the adsorption capacity just was 7.62 mg/g at a low concentration of formaldehyde (about 0.41 mg/m 3 ). Ma et al (2011) studied the removal of low-concentration formaldehyde using activated carbon modified by hexamethylene diamine and found that modification significantly improved the adsorption performance of AC (form 0.08 to 3.8 mg/g). The nitrogencontaining functional groups played an important role in increasing formaldehyde adsorption ability, as also described elsewhere.…”

Section: Introductionmentioning

confidence: 99%

Facile Synthesis of 3D Amino-Functional Graphene-Sponge Composites Decorated by Graphene Nanodots with Enhanced Removal of Indoor Formaldehyde

Zhang

Meng

et al. 2015

Amino-functional graphene-sponge composites decorated by graphene nanodots (G-GND/S) were synthesized. The preparation technology prevents the loss of nano-materials and reduces the amount of graphene addition. G-GND/S was used as adsorbents to remove formaldehyde, and then their performances for formaldehyde adsorption were evaluated by dynamic adsorption experiment. The adsorption properties of three different materials: sponge, graphene-sponge, and G-GND/S, the breakthrough time and adsorption capacity had been compared, the results showed G-GND/S had better formaldehyde adsorption properties with longer breakthrough time (~2137 min/g) and adsorption ability of formaldehyde (22.8 mg/g). Large amounts of amine groups were the most important factor for the strength enhancement of the adsorption efficiency.

“…High specific surface materials, such as activated carbon and molecular sieve are common used in adsorption technology to remove formaldehyde (Kosuge et al, 2007;Ma et al, 2011;Chen et al, 2014), but the difficulty of regeneration on absorbent have restricted the applicant in high concentration of HCHO. At room temperature, HCHO can be decomposed through the activity of hydroxyl radicals and superoxide radicals by using TiO 2 nanoparticles as photocatalyst.…”

Section: Introductionmentioning

confidence: 99%

Effect of MnO2 Crystalline Structure on the Catalytic Oxidation of Formaldehyde

Lin

Chen

et al. 2017

Manganese oxides prove to be a promising catalyst for formaldehyde (HCHO) elimination in catalytic oxidation. In this study, MnO 2 with different crystalline structure (α-MnO 2 , β-MnO 2 , γ-MnO 2 , and δ-MnO 2 ) were synthesized by hydrothermal method to investigate their catalytic performances towards the abatement of formaldehyde. The prepared catalysts were characterized and analyzed by the X-ray diffraction (XRD), hydrogen-temperature programmed reduction (H 2 -TPR), BET specific surface area, X-ray photoelectron spectroscopy (XPS), and ammonia-temperature programmed desorption (NH 3 -TPD). In addition, the apparent activation energy was also calculated by using Arrhenius plots. Among the above four prepared catalysts, the γ-MnO 2 has the best destruction and removal efficiency (DRE), which was approaching to 100% for HCHO at 155°C. The catalytic activity of γ-MnO 2 is associated with abundant mesopores, higher reducibility of surface oxygen species, and more oxygen vacancies as compared to other types of crystalline MnO 2 .