Adsorption Mechanisms of Dodecylbenzene Sulfonic Acid by Corn Straw and Poplar Leaf Biochars

Abstract

Biochar is an eco-friendly, renewable, and cost-effective material that can be used as an adsorbent for the remediation of contaminated environments. In this paper, two types of biochar were prepared through corn straw and poplar leaf pyrolysis at 300 °C and 700 °C (C300, C700, P300, P700). Brunaer–Emmett–Teller N2 surface area, scanning electron microscope, elemental analysis, and infrared spectra were used to characterize their structures. These biochars were then used as adsorbents for the adsorption of dodecylbenzene sulfonic acid (DBSA). The microscopic adsorption mechanisms were studied by using infrared spectra, 13C-nuclear magnetic resonance spectra, and electron spin resonance spectra. The surface area and pore volume of C700 (375.89 m2/g and 0.2302 cm3/g) were the highest among all samples. Elemental analysis results showed that corn straw biochars had a higher aromaticity and carbon to nitrogen (C/N) ratio than the poplar leaf biochars. High temperature caused the increase of carbon content and the decrease of oxygen content, which also gave the biochars a higher adsorption rate. Pseudo-second order kinetic provided a better fit with the experimental data. Adsorption isotherm experiments showed that the adsorption isotherm of C300 fit the linear model. For other biochars, the adsorption isotherms fitted Langmuir model. Biochars with high temperatures exhibited enhanced adsorption capacity compared with ones at low temperatures. The qmax values of biochars to DBSA followed the order of P700 > C700 > P300. The adsorption mechanisms were complex, including partition, anion exchange, the formation of H bonds, covalent bonds, and charge transfer. The adsorption by covalent bonding might be the key mechanism determining the adsorption capacity of P700.

Utilization of Jujube Biomass to Prepare Biochar by Pyrolysis and Activation: Characterization, Adsorption Characteristics, and Mechanisms for Nitrogen

“…Therefore, the physical adsorption mainly comprises surface adsorption (contact adsorption, similar to gravitational interaction between the mass objects), intraparticle diffusion, and electrostatic interaction for NO 3 − and NH 4 + adsorption on JB. This can be clearly observed in the SEM data collected after adsorption ( Figure 11 ), and is widely accepted by the scholars [ 14 , 41 , 42 ]. As shown in Figure 11 , the pores of the JB surface are filled with adsorbed NO 3 − and NH 4 + , and a white residue is also present inside the pores.…”

The Eco-Friendly Biochar and Valuable Bio-Oil from Caragana korshinskii: Pyrolysis Preparation, Characterization, and Adsorption Applications

“…The high temperature pyrolysis is generally the most common and important carbonization method [ 9 ]. Under limited oxygen supply or anoxic conditions and at a certain temperature (<700 °C), biomass resources can be carbonized into biochar, a carbon-rich, stable, and highly aromatic solid product [ 10 , 11 , 12 , 13 ]. At present, because of its large specific surface area, high stability, strong adsorption capacity, porous structure, as well as its wide range of raw materials, and low cost, biochar was widely used in agricultural and environmental protection fields such as pollution remediation, modified materials, soil improvement, etc., [ 14 , 15 ].…”

Synthetic Routes for Designing Furanic and Non Furanic Biobased Surfactants from 5‐Hydroxymethylfurfural

“…The overall yield and selectivity of the two combined steps for the production of biodegradable and renewable anionic surfactants with the different fatty alcohols (C 8 -C 18 ) were very high (Table 2), which demonstrated the high efficiency and sustainability of the developed catalytic process. Measurements of the surface tension in water solutions of these surfactants showed that 5-(octadecyloxymethyl)-2-furoic acid sodium salt (SODF) had a similar surface tension (35 m Nm À 1 ) as the commercial dodecylbenzene sulfonic acid sodium salt (SDBS) (33 m Nm À 1 ) for 1 wt% concentration in water, although the CMC for SODF was 0.9 g g À 1 while reported CMC [49] for SDBS was 0.413 g L À 1 . [48]…”