Adsorption behavior and performance of ammonium onto sorghum straw biochar from water

Abstract

Sorghum has been widely used for liquor production and brewing, but how to make efficiently utilize sorghum straw (SS) has become an urgent problem. Meanwhile, the wastewater produced by winemaking is typical organic wastewater with a high ammonium concentration. To solve the problem of resource utilization of SS and remove ammonium from water, SS was used to prepare biochar as an adsorbent for ammonium adsorption. Batch adsorption experiments were carried out to study the influencing factors and adsorption mechanisms of ammonium onto sorghum straw biochar (SSB). The results showed that the adsorption capacity of SSB was much higher than that of SS. The SSB pyrolyzed at 300 °C had the highest adsorption capacity. The favorable pH was 6–10, and the optimal dosage was 2.5 g/L. The adsorption process and behavior conformed to the pseudo-second-order kinetic and Langmuir isotherm adsorption models. The maximum ammonium adsorption capacity of SSB at 45 °C was 7.09 mg/g, which was equivalent to 7.60 times of SS. The ammonium adsorption of SS and SSB was mainly chemical adsorption. The regeneration test indicated that SSB had good regeneration performance after three adsorption-regeneration cycles. This work suggests that SSB could be potentially applied to sewage treatment containing ammonium to achieve the purpose of resource recycling.

Phosphoric acid surface modified Moringa oleifera leaves biochar for the sequestration of methyl orange from aqueous solution: Characterizations, isotherm, and kinetics analysis

“…The SEM images of activated biochars revealed the presence of tunnel‐shaped cracks and cylindrical pores, which acted as diffusion paths for MO molecules (Jjagwe et al, 2021), resulting in the higher sorption of MO compared to raw biochar. The irregular distribution of pores and cracks of activated biochar may favor the sorption of MO by physical trapping and diffusion mechanisms (Wang et al, 2005) reported a similar phenomenon with activated carbon for the sorption of dyes, and oil palm fiber‐derived activated carbon also exhibited such a complex network of pores (Xu et al, 2022) and cracks (Foo & Hameed, 2012). The availability of pores, cracks, and fissures may facilitate the enhanced surface areas of the activated biochar, according to the results obtained from BET surface area results (Table 1).…”

In situ ATR‐FTIR spectroscopy for evidencing the adsorption mechanism of ammonium on a pinewood‐derived biochar

“…In our observed results, for pH 8.5, a higher wavenumber shifts (1,458 → 1,484 cm −1 ) in the biochar adsorbed NH 4 + suggested a surface interaction similar to H‐bonding. In fact, ‐COOH & ‐OH functional groups are ubiquitous in the biochar and are known to engage in surface interactions with NH 4 + (Xu et al., 2022; Yu et al., 2018). Thus, the shift of IR band from 1,458 to 1,484 cm −1 can be rationalized (Figure 1A).…”

Ammonium removal by alkaline‐activated coconut coir from synthetic and ground waters

“…Although ammonium adsorption capacity of NaACC was still low when compared with those of other materials such as biochar (7.09 mg/g), 23 mineral clays (40.84–50.06 mg/g), 25 or activated carbon (2.48 mg/g), 18 the biomaterial is derived from an agricultural by‐product, which is abundant and cheap in Viet Nam. Moreover, the production procedure of material is simple and easy to be carried out by non‐expertise people such as citizens in suburban and rural communities.…”

“…The effectiveness of NaACC in removal of ammonium as well as its stable-adsorptive capability demonstrated that NaACC derived from agricultural wastes was a potential biomaterial for cleaning ammonium from contaminated groundwater. Although ammonium adsorption capacity of NaACC was still low when compared with those of other materials such as biochar (7.09 mg/g), 23 mineral clays (40.84-50.06 mg/g), 25 or activated carbon (2.48 mg/g), 18 the biomaterial is derived from an agricultural by-product, which is abundant and cheap in Viet Nam. Moreover, the production procedure of material is simple and easy to be carried out by non-expertise people such as citizens in suburban and rural communities.…”

“…Adsorption has been received considerable attention by worldwide researchers because of high effectiveness and economic for treatment of ammonium. 17,18 Therefore, numerous adsorbents have been developed to study their adsorptive performance on ammonium such as activated zeolite and chitosan, 19 greensand, 20 biochar, 17,[21][22][23][24] activated carbon, 18 clay minerals, 25 fiber, 26 magnetically modified excess sludge, 27 NaA zeolites, 28 and banana peels (BPs). 29 It was reported that the characteristics of surface chemistry is more important than surface area and pore structure of adsorbents in adsorption of inorganic compounds from aqueous solution.…”