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•Alkali modification improves physicochemical properties of pristine SCG biochars.•Chemisorption is responsible for adsorptions of micropolluants by SCG biochars.•Adsorption isotherms ...of micropollutants are highly affected by alkali modification.•Log D values play a critical role in removal of micropollutants by SCG biochars.•Alkali-modified SCG biochars exhibit higher adsorption capacities of micropolluants.
This study investigated the single and competitive adsorption characteristics of micropollutants using the pristine and alkali-modified spent coffee grounds (SCG) biochars. The alkali modification substantially improved the physicochemical characteristics of the SCG biochars (specific surface area and pore volume), which may have led to differences in the adsorption behaviors of the micropollutants. The pseudo second order model (R2 ≥ 0.990) better described the single and competitive adsorption kinetics than the pseudo first order model (R2 ≥ 0.664). It is evident that chemisorption played a key role in the removal of the micropollutants by the pristine and alkali-modified SCG biochars. The single and competitive adsorptions of the micropollutants were highly dependent on the solution pH and ionic strength since the pore-filling effects, electrostatic and hydrophobic interactions governed their removal by the pristine and alkali-modified SCG biochars. The higher removal efficiencies of the micropollutants by the alkali-modified SCG biochars (≥ 44.5%) in the presence of dissolved organic matter compared to the pristine SCG biochars (≤ 18.5%) support the assumption that alkali modification could markedly reinforce the surface structural properties of the SCG biochars related to the adsorption capacities.
This study investigated the competitive adsorption mechanisms of pharmaceuticals (i.e., naproxen, diclofenac, and ibuprofen) toward the pristine and NaOH-activated biochars from spent coffee wastes ...(SCW) in lake water and wastewater effluent. The kinetic and isotherm studies revealed that the improved physicochemical characteristics and physically homogenized surfaces of the pristine SCW biochar through the chemical activation with NaOH were beneficial to the adsorption of pharmaceuticals (competitive equilibrium adsorption capacity (Qe, exp): NaOH-activated SCW biochar (61.25–192.07 μmol/g) > pristine SCW biochar (14.81–20.65 μmol/g)). The adsorptive removal of naproxen (Qe, exp = 14.81–18.81 μmol/g), diclofenac (Qe, exp = 15.73–20.00 μmol/g), and ibuprofen (Qe, exp = 16.20–20.65 μmol/g) for the pristine SCW biochar showed linear correlations with their hydrophobicity (log D at pH 7.0: ibuprofen (1.71) > diclofenac (1.37) > naproxen (0.25)). However, their Qe, exp values for the NaOH-activated SCW biochar (naproxen (176.39–192.07 μmol/g) > diclofenac (78.44–98.74 μmol/g) > ibuprofen (61.25–80.02 μmol/g)) were inversely correlated to the order of their log D values. These results suggest that the reinforced aromatic structure of the NaOH-activated SCW biochar facilitated the π-π interaction. The calculated thermodynamic parameters demonstrated that the competitive adsorption of pharmaceuticals on the NaOH-activated SCW biochar compared to pristine SCW biochar occurred more spontaneously over the entire pH (5.0–11.0) and ionic strength (NaCl: 0–0.125 M) ranges. These observations imply that the NaOH-activated SCW biochar might be potentially applicable for the removal of pharmaceuticals in lake water and wastewater effluent.
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•Competitive adsorption of pharmaceuticals investigated under real water matrices.•NaOH-activated SCW biochar has high specific surface area and total pore volume.•NaOH-activated SCW biochar eliminates NPX, DCF, and IBU more effectively.•Adsorption of pristine SCW biochar corresponds to Log D values of micropollutants.•Increased aromaticity of NaOH-activated SCW biochar stimulates π-π interaction.
Non-invasive delivery of artificial implants, stents or devices in patients is vital for rapid and successful recovery. Unfortunately, because the delivery passage is often narrower than the size of ...the delivered object, a compromise between the shape that is effective at the targeted location and a thin form that allows smooth unobstructed travel to the destination is needed. We address this problem through two key technologies: 3D printing and shape memory polymers (SMPs). 3D printing can produce patient-customizable objects, and SMPs can change their initially formed shape to the final desired shape through external stimulation. Using these two technologies, we examine the design and fabrication of bifurcated stents. This study presents a mock-up where blood vessels are fabricated using moulded silicon, which supports the effectiveness of the proposed method. The experimental results reveal that a bifurcated stent with a kirigami structure can smoothly travel inside a vessel without being obstructed by branched parts. We believe that this work can improve the success rate of stent insertion operations in medicine.
This study examined differences in the adsorption kinetics, isotherms, and thermodynamics of the dyes (methyl orange and fast green FCF) by pristine (M–biochar) and chemical activated mandarin peel ...biochars (MN–biochar and MZ–biochar). The specific surface area (1085.0 m2/g) and pore volume (0.194 cm3/g) of MZ-biochar much higher than those of the M–biochar (specific surface area = 8.5 m2/g, pore volume = 0.016 cm3/g) and MN–biochar (specific surface area = 181.1 m2/g, pore volume = 0.031 cm3/g). The equilibrium adsorption capacities (mg/g) of MO and FG using M–biochar (MO = 0.95, FG = 0.78) MN–biochar (MO = 2.52, FG = 2.13), and MZ–biochar (MO = 16.27, FG = 12.44) have well-matched the pseudo-second-order model (R2 ≥ 0.952) compared with the pseudo-first-order model (R2 ≥ 0.008). Furthermore, the better explanation of the adsorption behavior of dyes by the Freundlich isotherm model (R2 ≥ 0.978) than the Langmuir isotherm model (R2 ≥ 0.881) supports the assumption that the multilayer adsorption governed the adsorption of dyes using mandarin peel biochars. The adsorptions of dyes were significantly dependent on the solution pH and temperature since the electrostatic and spontaneous endothermic reactions governed their removal using the pristine and chemical activated mandarin peel biochars.
Plants produce and accumulate stress-resistant substances when exposed to abiotic stress, which involves a protein conversion mechanism that breaks down stress-damaged proteins and supplies usable ...amino acids. Eukaryotic protein turnover is mostly driven by the ubiquitination pathway. Among the three enzymes required for protein degradation, E3 ubiquitin ligase plays a pivotal role in most cells, as it determines the specificity of ubiquitination and selects target proteins for degradation. In this study, to investigate the function of
(Plant U-box gene in
), we constructed a CRISPR/Cas9 vector, generated
gene-edited individuals, and evaluated resistance to abiotic stress using gene-edited lines. A stress-tolerant phenotype was observed as a result of drought and salinity stress treatment in the T
gene-edited null lines (PUB7-GE) lacking the T-DNA. In addition, although PUB7-GE did not show any significant change in mRNA expression analysis, it showed lower ion leakage and higher proline content than the wild type (WT). Protein-protein interaction analysis revealed that the expression of the genes (
,
,
, and
) known to be involved in stress increased in PUB7-GE and this, by forming a 1-node network with
and
, acted as a negative regulator of drought and salinity stress. This result provides evidence that
will be a useful target for both breeding and future research on drought tolerance/abiotic stress in rice.
Carbonate alkalinity is crucial in regulating the pH and buffering capacity of natural water systems. Thus, its accurate measurement is essential to understand various water environments that affect ...water quality and ecosystem health. However, conventional potentiometric titration has some limitations. It results in inaccurate measurements of carbonate alkalinity when the alkalinity levels are low or when high dissolved organic matter or inorganic ion levels exist. Herein, we propose a novel approach to accurately measure carbonate alkalinity using a total organic carbon (TOC) analyzer. An extensive study comparing the accuracy and reliability of the conventional potentiometric titration method with those of the newly developed TOC method was conducted to develop and verify highly accurate measurements of carbonate alkalinity. The TOC method has several advantages over the conventional potentiometric titration methods, such as its ability to accurately measure carbonate alkalinity in the presence of high dissolved organic matter or inorganic ion levels and its ability to provide rapid and automated measurements with high reproducibility. Because, the limit of detection, limit of quantification, and the variation coefficient of the measurements was 0.016 mM (0.2 mgC/L), 0.050 mM (0.6 mgC/L), and 3.68 % respectively. Thus, the development of a novel TOC method has significant environmental implications as it provides a reliable and accurate means to measure carbonate alkalinity in solutions containing various organic matter types.
This study examined differences in the adsorption isotherms, kinetic equations, and thermodynamics of Sr
2+
by biochar from spent coffee grounds (SCG) and powdered activated carbon (PAC). The ...specific surface area (957.6 m
2
/g) and pore volume (0.676 cm
3
/g) of PAC were much greater than those of SCG biochar (specific surface area = 11.0 m
2
/g, pore volume = 0.009 cm
3
/g). However, SCG biochar showed a higher maximum adsorption capacity of Sr
2+
(
Q
max
= 51.81 mg/g) compared with PAC (
Q
max
= 32.79 mg/g) due to its abundance of O-containing functional groups. The negligible removal efficiencies of Sr
2+
by SCG biochar and PAC under acidic conditions (pH = 1.0–3.0) are evidence that the electrostatic repulsion might hinder severely the adsorption of Sr
2+
by the carbonaceous adsorbents. The higher
R
2
values of the pseudo-second-order model (
R
2
≥ 0.999) compared with the pseudo-first-order model (
R
2
≥ 0.815) suggest that chemisorption governed the removal of Sr
2+
using SCG biochar and PAC. Furthermore, the better description of the adsorption behavior of Sr
2+
by the Langmuir isotherm model (
R
2
≥ 0.994) than the Freundlich isotherm model (
R
2
≥ 0.982) supports the assumption that the monolayer adsorption played critical roles in the removal of Sr
2+
using SCG biochar and PAC. The thermodynamic studies revealed that adsorption of Sr
2+
onto SCG biochar and PAC was endothermic and happened spontaneously. Despite the significant inhibitory effects of DOM, SCG biochar exhibited the higher removal efficiencies of Sr
2+
compared with PAC. Hence, SCG biochar could be considered as an alternative to PAC for the removal of Sr
2+
from aqueous solutions.
This study systematically investigated the feasibility of the microbubble ozonation process to degrade the 17α-ethinylestradiol, ibuprofen, and atenolol through the comparison with the millibubble ...ozonation process for elucidating the degradation behavior and mechanisms during the microbubble ozonation processes. The proportions of small microbubbles (diameter 1–25 μm) were increased with increasing the cavity pump frequency (40 Hz: 51.4%; 50 Hz: 57.5%; 60 Hz: 59.9%). The increased concentrations of O3 and OH radicals due to the higher specific area of O3 microbubbles compared to O3 millibubbles could facilitate their mass transfer at the gas–water interface. Furthermore, the elevated reactivity of O3 by increasing the temperature might improve the degradation of the pharmaceutical compounds, which was more pronounced for the microbubble ozonated waters than the millibubble ozonated waters. Although the degradation efficiency of the pharmaceutical compounds during the microbubble ozonation processes was significantly influenced by the existence of humic acids compared to the millibubble ozonation process, the increased solubilization rate of O3 and OH radicals by collapsing O3 microbubbles enhanced the degradation of the pharmaceutical compounds. Overall, these results clearly showed that the microbubble ozonation process could be an alternative option to conventional ozonation processes for the abatement of the pharmaceutical compounds.
The cleaning efficiencies of fouled multibore ultrafiltration membrane (UFMB) operated from a pilot-scale UF process for surface water treatment were systemically investigated according to the ...sequences of two different cleaning solutions. The experimental results decisively confirmed that HPI DOM and HPO DOM/multivalent ions complexation significantly resulted in the fouling formations on UFMB due to their neutral charge characteristic. The basic cleaning agent effectively extracted the organic foulants attached on UFMB, indicating that the type of cleaning agent was a critical factor influencing on the cleaning efficiency of fouled UFMB. However, the cleaning sequence 1 (CS-1: 0.1 M NaOH >0.1 M HCl; the total DOC = 725.77 mgC∙m−2; the total TN = 146.35 mgN∙m−2, total inorganic contents = 132.62 mg m−2) much more effectively extracted the foulants on the UFMB surfaces than the cleaning sequence 2 (CS-2: 0.1 M HCl >0.1 M NaOH; the total DOC = 604.49 mgC∙m−2; the total of TN = 121.79 mgN∙m−2, total inorganic contents = 73.43 mg m−2). The morphological results also clearly showed that the cleaned UFMB surface using CS-1 were effectively recovered, as compared with those using CP-2. Overall, this study implied that the hydroxide ions from the basic cleaning agent promoted the infiltration of the acidic cleaning agent into the densely formed fouling layers on the UFMB surfaces and demonstrated that the cleaning sequences strategy could significantly govern the restoration of UFMB performance during the pilot-scale surface water treatment system operation.
•Cleaning efficiency of fouled UF membranes was investigated by extracted organics.•HPI DOM is mainly responsible for initial fouling formation of UFMB membranes.•HPO DOM and multivalent ions complexation contributed to organic fouling.•Basic cleaning agents effectively extracted organic foulants on UFMB membranes.•Using basic cleaning agent first shows effective cleaning result of UFMB membranes.
•The algal alert system is used worldwide for proactive management.•Alert levels of algal bloom were classified using two machine learning models.•Imbalanced class data induced biased training of the ...machine learning models.•Synthetic data by ADASYN increased the performance of the machine learning models.
Many countries have attempted to monitor and predict harmful algal blooms to mitigate related problems and establish management practices. The current alert system-based sampling of cell density is used to intimate the bloom status and to inform rapid and adequate response from water-associated organizations. The objective of this study was to develop an early warning system for cyanobacterial blooms to allow for efficient decision making prior to the occurrence of algal blooms and to guide preemptive actions regarding management practices. In this study, two machine learning models: artificial neural network (ANN) and support vector machine (SVM), were constructed for the timely prediction of alert levels of algal bloom using eight years’ worth of meteorological, hydrodynamic, and water quality data in a reservoir where harmful cyanobacterial blooms frequently occur during summer. However, the proportion imbalance on all alert level data as the output variable leads to biased training of the data-driven model and degradation of model prediction performance. Therefore, the synthetic data generated by an adaptive synthetic (ADASYN) sampling method were used to resolve the imbalance of minority class data in the original data and to improve the prediction performance of the models. The results showed that the overall prediction performance yielded by the caution level (L1) and warning level (L2) in the models constructed using a combination of original and synthetic data was higher than the models constructed using original data only. In particular, the optimal ANN and SVM constructed using a combination of original and synthetic data during both training (including validation) and test generated distinctively improved recall and precision values of L1, which is a very critical alert level as it indicates a transition status from normalcy to bloom formation. In addition, both optimal models constructed using synthetic-added data exhibited improvement in recall and precision by more than 33.7% while predicting L-1 and L-2 during the test. Therefore, the application of synthetic data can improve detection performance of machine learning models by solving the imbalance of observed data. Reliable prediction by the improved models can be used to aid the design of management practices to mitigate algal blooms within a reservoir.
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