The role of Lysinibacillus fusiformis S01 in cadmium removal from water and immobilization in soil.

Cadmium pollution is widespread in water and soil worldwide. Microbial remediation is an effective method for removing heavy metals. This study explored the cadmium remediation mechanism and efficiency of Lysinibacillus fusiformis S01.

Impact of varying dissolved organic carbon load on sediment phosphorus release and its periodic mechanisms.

Phosphorus (P) release from sediment poses a severe challenge for eutrophication management in the aquatic environment. The dissolved organic carbon (DOC) concentrations in riverine ecosystems have shown an increasing trend due to intensified climate change and anthropogenic activities, while their impact on sediment P cycling remains unclear. To investigate the effects of different DOC loads on sediment P release and the underlying mechanisms, we conducted a two-month experiment in 15 plexiglass tanks, with five gradient-increasing target DOC concentrations set according to reality: control (S), 5 mg/L (S), 10 mg/L (S), 15 mg/L (S), and 20 mg/L (S).

Enhancing lead adsorption capacity prediction in biochar: a comparative study of machine learning models and parameter optimization.

Machine learning models for predicting lead adsorption in biochar, based on preparation features, are currently lacking in the environmental field. Existing conventional models suffer from accuracy limitations. This study addresses these challenges by developing back-propagation neural network (BPNN) and random forest (RF) models using selected features: preparation temperature (T), specific surface area (BET), relative carbon content (C), molar ratios of hydrogen to carbon (H/C), oxygen to carbon (O/C), nitrogen to carbon (N/C), and cation exchange capacity (CEC).

Metabolic and Physiological Changes in the Roots of Two Oat Cultivars in Response to Complex Saline-Alkali Stress.

Saline-alkali stress is a major abiotic stress factor in agricultural productivity. Oat ( L.) is a saline-alkali tolerant crop species.

Nickel-loaded shrimp shell biochar enhances batch anaerobic digestion of food waste.

This study evaluated the effectiveness of shrimp shell biochar (SBC) and nickel (Ni) loaded SBC in increasing methane yield during anaerobic digestion of food waste. The results indicated that the methane yields of control (without SBC), SBC, SBC loaded with the low concentration of Ni, and SBC loaded with the high concentration of Ni were 81.8, 116.

Mitigation of organic fouling of ultrafiltration membrane by high-temperature crayfish shell biochar: Performance and mechanisms.

The paper applied crayfish shell (CFS) biochar to the mitigation of ultrafiltration (UF) membrane fouling induced by humic acid (HA) and sodium alginate (SA). Results indicated that the high adsorption capacity of CFS800 to HA made it effective in alleviating the irreversible membrane fouling induced by HA, and the cross-linking reaction between the hydroxyl calcium components on CFS800 and SA reduced the reversible membrane fouling induced by SA rapidly. Further analysis showed that the "hydrogel flocs" generated by the cross-linking reaction would accumulate on the surface of the substrate membrane and form an amorphous hydrogel layer to intercept the subsequent foulant and purify the water quality further.

Biomineralization of lead in wastewater: Bacterial reutilization and metal recovery.

Biomineralization has not been widely applied due to the lack of bacterial reusability, which needs to be investigated urgently. In this study, we found Lysinibacillus could immobilize Pb at initial pH ≥ 2.0.

Continuous and efficient immobilization of heavy metals by phosphate-mineralized bacterial consortium.

Traditional sewage treatment technology cannot remove heavy metals, which needs to be improved urgently. Lysinibacillus with the function of bio-mineralization was screened and loaded on granular sludge to form a phosphate-mineralized bacterial consortium, which demonstrated the ability of self-regulating pH and automatic solid-liquid separation. Heavy metals could be fixed on the bacterial consortium to produce stable and harmless phosphate minerals.

Kinetics, isotherm and chemical speciation analysis of Hg(Ⅱ) adsorption over oxygen-containing MXene adsorbent.

A facile method was used to prepare two-dimensional MXene for the treatment of heavy metal ions in wastewater. The adsorbent has good selectivity for the adsorption of Hg (Ⅱ) in mixed divalent cationic metal solutions due to a large number of oxygen-containing functional groups on the surface of the material. The adsorption of mercury was tested using mercuric chloride and mercury nitrate solutions.

Cadmium removal by MgCl modified biochar derived from crayfish shell waste: Batch adsorption, response surface analysis and fixed bed filtration.

Cadmium (Cd) pollution is regarded as a disturbing environmental problem due to its serious risks to the water body and human health. The removal of cadmium from wastewater is thus crucial to avoid its harmful effects on the ecosystem. This study comprehensively investigated Cd(II) adsorption onto MgCl modified biochar (MgC600) and results showed that the adsorption capacity of MgC600 was more than twice of that of pristine biochar due to its enhanced ion exchange ability.

Biodegradable chitosan-ethylene glycol hydrogel effectively adsorbs nitrate in water.

Nitrate, existing as inorganic anions in water, possesses high water-solubility and has caused lots of contaminations around the world. It is thus extremely urgent to develop an effective method to effectively remove nitrate from water in a sustainable way. In this study, chitosan-ethylene glycol hydrogel (CEGH) was synthesized using the repeated freezing-thawing procedure.

Persulfate activation by two-dimensional MoS confining single Fe atoms: Performance, mechanism and DFT calculations.

Developing efficient catalysts for persulfate (PS) activation is important for the potential application of sulfate-radical-based advanced oxidation process. Herein, we demonstrate single iron atoms confined in MoS nanosheets with dual catalytic sites and synergistic catalysis as highly reactive and stable catalysts for efficient catalytic oxidation of recalcitrant organic pollutants via activation of PS. The dual reaction sites and the interaction between Fe and Mo greatly enhance the catalytic performance for PS activation.

[Effects of slow-release urea combined with common urea application layered in different soil depths on soil nitrogen, enzyme activity, and maize yield].

We examined the effects of a combination of slow-release urea (PCU) and common urea (PU) applied at different soil depths (0-30 cm soil layer) on inorganic nitrogen content, enzyme activity, and crop yield during two years (2017-2018) in a field experiment. There were eight treatments: CK (without N fertilizer); PU(common urea applied at 5-10 cm deep soil layer); PU(common urea applied at 5-10 cm deep soil layer, 60% seed fertilizer + 40% topdressing); PU(20% common urea at 5-10 cm soil depth, 30% common urea at 15-20 cm soil depth, 50% common urea at 25-30 cm soil depth); PCU(20% total nitrogen application rate at 5-10 cm soil depth, 30% total nitrogen application rate at 15-20 cm soil depth, 50% total nitrogen application rate at 25-30 cm soil depth), the N fertilizer at 5-10 cm was common urea, but, at 15-20 and 25-30 cm, it was a combination of PCU and PU at ratios of 3:7 and 3:7; PCU was as PCU but the ratio of PCU and PU was 5:5 at 15-20 cm and 5:5 at 25-30 cm; in PCU, the ratio of PCU and PU was 3:7 at 15-20 cm and 5:5 at 25-30 cm; in PCU, the ratio of PCU and PU was 5:5 at 15-20 cm and 3:7 at 25-30 cm. The results showed that PU could meet nitrogen demand at the 0-10 cm layer in the early growth stage compared with CK.

Crayfish shell biochar modified with magnesium chloride and its effect on lead removal in aqueous solution.

In this study, crayfish shell was pyrolyzed at 600 °C to obtain an unmodified biochar (CS600). MgCl was used as a modifier to pretreat crayfish shell to produce a modified biochar (CS600-MgCl) under the same pyrolysis conditions. The two biochars were characterized for physicochemical properties and evaluated for lead (Pb) sorption ability to determine the modification mechanism.

Removal of lead from acidic wastewater by bio-mineralized bacteria with pH self-regulation.

Microorganisms with the function of bio-mineralization were isolated from a soil. They were identified as urease-producing bacteria and phosphate-solubilizing bacteria. These two kinds of bacteria belong to the eosinophilic bacteria, which regulated the pH of solution and removed Pb the best at the initial solution pH of 4.

Enhanced alginate-based microsphere with the pore-forming agent for efficient removal of Cu(Ⅱ).

In order to increase the adsorption properties of sodium alginate gel beads, a series of SA@PF-beads (sodium alginate-based beads with different amount of pore-forming agent) were prepared with calcium carbonate as the pore forming agent. The experimental results showed that the adsorption capacity of Cu(Ⅱ) increased by at least two times (from 13.69 mg/g to 33.

Desorption of calcium-rich crayfish shell biochar for the removal of lead from aqueous solutions.

In this study, crayfish shell was pyrolyzed at 600 °C to obtain a calcium-rich biochar (CS600). The biochar was saturated with Pb in batch adsorption experiment. Six desorption reagents including HCl, HNO, HSO, NaOH, EDTA and EDTA-2NaCa were then used to desorb Pb from the post-adsorption CS600 to determine the desorption mechanism.

Novel chitosan-ethylene glycol hydrogel for the removal of aqueous perfluorooctanoic acid.

It is urgent to explore an effective removal method for perfluorooctanoic acid (PFOA) due to its recalcitrant nature. In this study, a novel chitosan-based hydrogel (CEGH) was prepared with a simple method using chitosan and ethylene glycol through a repeated freezing-thawing procedure. The adsorption of PFOA anions to CEGH agreed well to the Freundlich-Langmuir model with a maximum adsorption capacity as high as 1275.

Lead removal by phosphate solubilizing bacteria isolated from soil through biomineralization.

Microorganisms with the function of biological mineralization were isolated from a soil. The bacteria were identified by 16S rRNA as Bacillus sp and possessed a significant lead removal ability. Lead removal experiment indicated that the mathematical model of η=η-ηe fit the variation of removal rate with time well.

Study on the influence of surface potential on the nitrate adsorption capacity of metal modified biochar.

Carbon materials, as effective adsorbents to numerous aqueous cationic contaminants, have been hardly applied to remove anions in wastewater. In this work, different modifying agents were used to modify corncob biochars (CC) and the surface potentials of these modified biochars were determined. Based on the findings, modification principle was determined to reveal the relationship between surface potentials of the biochars and their nitrate adsorption capacities.

Adsorptive removal of As(V) by crawfish shell biochar: batch and column tests.

As a toxic and metalloid substance, excess arsenic (As) can cause serious harm to the environment and public health. In this work, crayfish shell biochar (CFS450) and modified biochar (MCFS450) were prepared to remove As(V) from aqueous solutions under various conditions. Compared to CFS450, MCFS450 had a higher specific surface area, better pore structure, and higher As(V) adsorption capacity.

Characteristics and batch experiments of acid- and alkali-modified corncob biomass for nitrate removal from aqueous solution.

In this study, modified biochar was adopted as an adsorbent for the nitrate removal in aqueous solutions. Raw material was impregnated in sulfuric acid (HSO, 1 mol/L) and sodium hydroxide (NaOH, 2 mol/L) separately and then prepared at 600 °C. After treated with acid, the BET specific surface area was much higher than that of unmodified and alkali-modified biochars.

Adsorption of nitrate onto biochar derived from agricultural residuals.

To develop low-cost adsorbents for aqueous nitrate, biochars were prepared from three types of agricultural residuals at different pyrolysis temperatures (300 °C, 450 °C, and 600 °C). The corncob biochar produced at 600 °C (CC600) was the best nitrate adsorbent of all the tested biochars. Characterization results showed that CC600 had good thermal stability, porous structure, and abundant surface functional groups.

Preparation and characterization of NaS-modified biochar for nickel removal.

Biochar has good adsorption ability to various contaminants. In this work, peanut shell, corncob, cotton stalks, and crayfish shell were pyrolyzed under three temperatures (300, 450, 600 °C) to obtain biochars for the removal of Ni. The biochars were further modified with 2 mol/L NaS solution.

Constructed wetland using corncob charcoal substrate: pollutants removal and intensification.

To investigate the feasibility of using corncob charcoal substrate in constructed wetlands, four laboratory-scale vertical flow constructed wetlands (VFCWs) were built. Effluent pollutant (chemical oxygen demand (COD), NH-N, total phosphorus (TP)) concentrations during the experiment were determined to reveal pollutant removal mechanisms and efficiencies at different stages. In the stable stage, a VFCW using clay ceramisite substrate under aeration attained higher COD (95.