Adsorption Behaviour of Pymetrozine by Four Kinds of Biochar from Aqueous Solution

Abstract

A laboratory experiment was performed to investigate the potential of biochar (BC) as an adsorbent for removing pymetrozine from aqueous solution. The adsorption data were well described by Langmuir isotherm, with maximum pymetrozine adsorption capacities of 13.8, 20.6, 11.0 and 18.8 mg g −1 for bush-, wheat straw-, peanut-and corn-derived BC in a single solution at 25 °C, respectively. The functional groups of BCs were -NH (1628.25 cm . The rate of pymetrozine adsorption was fast, with 50-80% of the adsorption occurring in the first 120 minutes, followed by a much slower approach to equilibrium. The ∆G°values decreased (increasingly negative) from −165.3% to 235.9% at 298 K compared with 318 K for the adsorption of pymetrozine onto different BCs in a single solution. The study results indicate that plant residue-or agricultural waste-derived BC can act as an effective surface sorbent, but their ability to treat mixed waste streams needs to be carefully evaluated on an individual basis.

Removal of the Pesticide Pymetrozine from Aqueous Solution by Biochar Produced from Brewer's Spent Grain at Different Pyrolytic Temperatures

“…With pyrolysis temperature greater than or equal to 700 °C, about 90% of organic carbon in feedstocks was produced as inorganic carbon in BC, so pyrolysis temperature played a significant role in improving BC characteristics (Lian et al 2011). Compared with the results of Cui et al (2013), the conclusion was that the adsorption of pymetrozine by different BCs was affected by the raw BC materials produced process. In the present work, similar effects on BC removal of the pollution were obtained under the same adsorption conditions.…”

“…During the adsorption process, the BSG BC adsorption capacity increased from pH 2 to pH 4, then decreased with increasing pH, probably due to the electrostatic interactions between positive pymetrozine functional groups and negative functional groups of adsorbents (Cui et al 2013). The BC can also decrease the uptake of Cd by plants, which bonded with Cd in interior of BC particles (Bian et al 2014).…”

“…There is a new approach to using wet BSG as a feedstock for carbonization, whereby biomass is converted into carbonaceous materials, namely biochar (BC) (Baccile et al 2009). Cui et al (2013) also found that four kinds of BCs (bush-, wheat straw-, peanut-, and corn-derived BCs) were highly efficient in adsorbing the Pymetrozine. Poerschmann et al (2014) showed that the BC had a significant sorption rate for functionalized, hydrophilic organic compounds, as well as inorganic species.…”

Renewable Material-derived Biochars for the Efficient Removal of 2,4-Dichlorophen from Aqueous Solution: Adsorption/Desorption Mechanisms

“…where Qe is the 2,4-DCP adsorption capacity (mg g -1 ), Ce is the 2,4-DCP concentration after the equilibrium (mg L -1 ), Xmax is the maximum adsorption capacity (mg g -1 ), and K is the adsorption equilibrium coefficient (Cui et al 2013;Peng et al 2016).…”

“…This negative correlation between 2,4-DCP adsorption and solution pH could be due to the reason that at very low pH, H3O + ions surround the biochar surface, which promotes the interactions between the ionizable chlorophenols and the biochar surface (Wang et al 2007). At elevated pH (> 7), it is possible that the negative charge of 2,4-DCP increases due to loses of H + and therefore reducing the adsorption due to repulsion phenomena of the anionic dichlorophenate (Müller et al 1998;Cui et al 2013). Moreover, the functional groups and adsorption sites of the BCs might have changed with increased solution pH and thus could have resulted in the decrease adsorption of BCs (Lou et al 2011).…”