Lin Fu

This study aims to develop a cost-effective and scalable modification strategy for valorizing lignin-rich biogas residue (BR) into high-performance adsorbents for anionic dye removal. To screen the optimal modification pathway, three distinct reagents, L-cysteine-based amino acid ionic liquids (AAILs, as green alternatives), conventional hydrochloric acid (HCl) and sodium hydroxide (NaOH, as traditional modification reagents), were compared in modifying non-carbonized BR for Congo Red (CR) adsorption. Comprehensive characterizations and adsorption tests revealed that each modifier exerted unique effects: NaOH only caused mild surface etching with limited performance improvement; AAILs achieved moderate adsorption capacity via a green, mild route; while HCl modification (BR-HCl) stood out with the most superior performance through a “selective dissolution-pore reconstruction” mechanism. Notably, despite a modest specific surface area increase to 12.05 m²/g, BR-HCl’s high CR adsorption capacity (120.21 mg/g at 45 °C) originated from the synergy of chemical bonding and enhanced electrostatic attraction—its isoelectric point (pH_PZC ≈ 9.02) was significantly higher than that of AAIL- and NaOH-modified samples, enabling strong affinity for anionic CR across a wide pH range. BR-HCl attained over 99% CR removal at a dosage of 0.4 g/L, fitted well with Langmuir isotherm and pseudo-second-order kinetic models (confirming monolayer chemisorption), and retained 82% of its initial capacity after five regeneration cycles. These results demonstrate that while AAILs show promise as green modifiers and NaOH serves as a baseline, the facile, low-cost HCl modification offers the most pragmatic pathway to unlock BR’s potential for sustainable wastewater treatment.

Against the challenge of extreme lead (Pb) contamination (>15,000 ppm) in industrial polluted soils, where conventional agents fail to disrupt stable Pb–soil complexes—this study extends our prior cadmium (Cd) remediation research to validate amino acid ionic liquids (AAILs) for highly recalcitrant metals. Fifteen AAILs were screened via batch washing, with [Met][NO₃] (methionine-based) demonstrating the highest Pb removal efficiency. Single-factor optimization revealed that under the conditions of 0.8 mol/L, 6:1 liquid–soil ratio, 60 min, 85.4% Pb was removed from severely contaminated soil by [Met][NO₃]. Kinetic analysis using four common models showed that the second-order kinetic equation provided the best fit, indicating that Pb removal was predominantly driven by chemical reactions such as complexation or ion exchange. After washing, the contents of various Pb species were significantly reduced, thereby mitigating environmental risks. Notably, no substantial changes in soil texture were observed. However, a marked increase in organic matter content was detected, accompanied by decreases in soil pH and mineral element concentrations. Analysis of soil mineral composition, functional groups, and chemical speciation revealed that [Met][NO₃] primarily facilitated Pb removal through ion-exchange and coordination reactions. This study establishes [Met][NO₃] as a green agent with dual efficacy: it achieves high-efficiency remediation of severely Pb-contaminated soil while ensuring environmental sustainability, thus highlighting its potential for practical application.

To investigate the feasibility of cellulose extraction from lignocellulosic waste biomass using ionic liquids—a sustainable and efficient approach—for preparing cellulose aerogel adsorbents, we employed a fully green amino acid-derived ionic liquid, cysteine nitrate ([Cys][NO₃]), for cellulose separation from diverse biomass sources. The extracted cellulose, with a purity range of 83.8–93.9%, was processed into cellulose aerogels (CAs) via a conventional aerogel preparation protocol. The resulting CA exhibited promising adsorption capacities, including 0.2–11.6 mg/g for Na⁺, 4.4–19.9 mg/g for Ca²⁺, 4.15–35.6 mg/g for Mg²⁺, and 1.85–13.3 mg/g for Cd²⁺, as well as 9.7–17.7 g/g for engine oil. These results demonstrate the presence of effective mass transfer channels in the CA, proving that the cellulose’s fibrillation capacity was preserved in the pre-treatment. This study illuminates the potential of this green, straightforward method for preparing aerogels from cellulose derived from waste biomass, with promising applications in wastewater treatment and material recovery.

Rice is the main source of cadmium (Cd) and arsenic (As) in Chinese diet. The formulation of targeted agronomic interventions for mitigating Cd and As bioaccumulation in rice grains constitutes a critical pathway toward ensuring food safety and public health security. Foliar spraying technology with ionic liquids, effectively reduces Cd/As content in rice. In this study, an ionic liquid of amino acids ([Glu][H₂PO₄]) as a foliar conditioner was applied to two varieties of rice (X24 and Z35) to explore the mechanism of reducing the accumulation of Cd/As in rice. The results showed that [Glu][H₂PO₄] reduced Cd/As levels by up to 58.57% and 44.09%, respectively. [Glu][H₂PO₄] reduced the transfer factor from the root system to flag leaves, nodes, and other organs, thus reducing the Cd/As content in them. [Glu][H₂PO₄] promoted amino acid synthesis in seeds, increased Ca²⁺ level, increased OsGLR3.1–3.5 expression, and decreased OsLsi1–3 expression in flag leaves, thereby Cd/As was inhibited from being absorbed and transported by rice. The results demonstrated that the foliar application of [Glu][H₂PO₄] significantly mitigated the accumulation of Cd/As in rice. This study introduces a novel and effective strategy for reducing Cd/As accumulation in rice, hoping to enhance the safety and quality of rice crops.

A field experiment with double cropping rice was carried out to study the foliar application effects of dicarboxylicdimethylammonium chloride (DDAC) on cadmium (Cd) and arsenic (As) accumulation in rice grains. The results showed that the spraying of DDAC could significantly reduce the accumulation of Cd and As in rice grains. The highest reductions in Cd and As content were observed when 1.5 mmol L⁻¹ DDAC was sprayed, with 49.1% and 27.4% reductions in Cd and As content in early rice grains and 56.5% and 28.1% reductions in Cd and As content in late rice grains, respectively. In addition, the content of calcium (Ca) in rice grains increased significantly after DDAC foliar application, which was also conducive to the synthesis of amino acids such as glutamate (Glu), glycine (Gly) and cysteine (Cys) in rice grains. The results indicated that the foliar spraying of DDAC can inhibit the absorption, transport, accumulation and toxicity of Cd and As in rice grains by increasing amino acid synthesis and regulating the absorption and transport of essential elements.

Perovskites with nano-flexible texture structures and excellent catalytic properties have attracted considerable attention for persulfate activation in addressing the organic pollutants in water. In this study, highly crystalline nano-sized LaFeO₃ was synthesized by a non-aqueous benzyl alcohol (BA) route. Under optimal conditions, an 83.9% tetracycline (TC) degradation and 54.3% mineralization were achieved at 120 min by using a coupled persulfate/photocatalytic process. Especially compared to LaFeO₃-CA (synthesized by a citric acid complexation route), the pseudo-first-order reaction rate constant increased by 1.8 times. We attribute this good degradation performance to the highly specific surface area and small crystallite size of the obtained materials. In this study, we also investigated the effects of some key reaction parameters. Then, the catalyst stability and toxicity tests were also discussed. The surface sulfate radicals were identified as the major reactive species during the oxidation process. This study provided a new insight into nano-constructing a novel perovskite catalyst for the removal of tetracycline in water.

To explore the effect of exogenous application of chlorinated amino acetic acid on cadmium (Cd) transport characteristics in rice seedlings, X24 and Z35 rice were taken as the research objects to carry out hydroponics experiments, and the changes of Cd content in rice seedlings, rice mineral elements and amino acid content in rice were analyzed. The results showed that exogenous application of 1.2 mmol·L⁻¹ chlorinated amino acetic acid inhibited cadmium in shoots and roots of rice seedlings; Cd content in shoots and roots were reduced by up to 62.19% and 45.61%, respectively. The majority of cadmium was in the cell wall of shoots and roots; this decreased with the increase of the concentration of chlorinated acetic acid. In addition, the Mn content in shoots and Ca content in roots of rice seedlings increased significantly after the application of chlorinated amino acetic acid. The results of amino acid analysis showed that the contents of aspartic acid, glutamic acid and cystine in rice seedlings were increased. These results indicate that exogenous application of chlorinated amino acetic acid is beneficial to the synthesis of aspartic acid, glutamic acid and cysteine in rice seedlings, increases the content of Mn in shoots and Ca in roots of rice seedlings, and significantly alleviates cadmium stress in seedlings. This provides a theoretical basis for the development of an environmentally friendly Cd-lowering foliar fertilizer for rice.