Environmental Technology & Innovation最新文献

This study investigated the Ceftriaxone (CFT) degradation by photocatalytic process using AgCuFe₂O₄@MWCNT/ZnO as novel nanophotocatalyst. Firstly, the catalyst was prepared by microwave-assisted chemical coprecipitation method as a simple, fast, and green procedure with high efficiency. FESEM, EDS, Mapping, Line scan, FTIR, XRD, BET, DRS, PL, TGA, and VSM analyzes was carried out to identify the characteristics of the AgCuFe₂O₄@MWCNT/ZnO. The effect of key operational parameters for CFT photodegradation including solution pH, catalyst dosage, CFT concentration, and irradiation time was elaborated. Under optimal photocatalytic conditions (pH 7, 5 mg/L of CFT concentration, catalyst dosage of 0.24 g/L, and 60 minutes of irradiation) removal efficiency reached 90.1 % in synthetic samples and 75 % in real wastewater samples. ^•OH and ^•O₂^– are the dominant generated reactive oxygen species in the process. The kinetic study of the process revealed that the CFT degradation process followed the pseudo-first-order kinetic and Langmuir-Hinshelwood models with k_c = 0.412 mg/L.min and k_L-H =0.053 L/mg. Photocatalytic process indicated a powerful ability for mineralization of CFT (85.31 % of COD degradation). After four catalyst recovery cycles, the CFT degradation efficiency was achieved by 58.14 %, demonstrating the catalyst's recovery capability and chemical stability. The results of toxicity assessment using lettuce and basil seeds germination indicated a significant detoxification of CFT-containing effluent compared to the untreated CFT-containing wastewater. This study offers AgCuFe₂O₄@MWCNT/ZnO as effective, stable, and competitive catalyst for hastening and enhancing the photocatalytic process to mitigate environmentally related pollutants of high concern.

Cadmium (Cd) pollution in paddy fields is becoming a great threat to the ecosystem. Phytoremediation with hyper-accumulating plants is an economic strategy to attenuate the hazards of Cd in the paddy fields. However, its Cd-removing efficiency remains to be improved. In this study, we prepared the moss-derived biochars by heating the dried moss bodies and investigated their effect on plant growth, Cd removal, and rhizosphere microbiome compositions. The biochars promoted the growth of the two remediation plants, i.e., Solanum nigrum and Echinochloa crus-galli, and improved Cd removal from paddy fields, leading to the increase in Cd-removing rate from 11 % to 15 % to 23–35 % after 60 days. Furthermore, the biochars increased the number of rhizosphere bacteria from 2.26 to 2.76×10⁶ cell/g soil to 3.89–4.78×10⁶ cell/g soil, together with soil organic matters from 18.3 mg/kg to 24.5 mg/kg for Solanum nigrum, and from 18.0 mg/kg to 21.1 mg/kg for Echinochloa crus-galli on day 30. Consistently, the activity of urease, acid phosphatase, and catalase increased to 1.18–1.29 times, 1.26–1.32 times and 1.13–1.18 times, respectively. Bacterial community analysis further showed the biochars increased both the abundance-based coverage estimator index and the Simpson index, implying the increased bacterial diversity induced by the biochars. Moreover, biochars strongly changes the bacterial compositions, leading to the increased abundance in Microbacteriaceae, Alcaligenaceae, Acidimicrobiales, Rhizobiales, etc., most of which are involved in stress tolerance and biofilm formation. This study provides new information on the positive effect of biochars on phytoremediation and implies the important role of rhizosphere microbiome remodeling in pollutant removal.

We have measured ²³⁶U/²³⁸U and ²³⁵U/²³⁸U values in JMS-1 (geochemical reference material of Tokyo Bay sediments) and coastal seawater using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) equipped with both the retarding potential quadrupole lens and desolvating nebuliser system. For the accurate measurement of ²³⁶U/²³⁸U values (e.g., in the range of 10⁻⁹), mass spectrometric interferences on ²³⁶U isotope from both the peak tailing of ²³⁸U and polyatomic ion of ²³⁵UH were carefully corrected. With the sequential extraction experiments for JMS-1, whose U isotopic signatures were characteristic of isotopically-depleted U with industrial uses, authigenic U was extracted into a soluble fraction, and lithogenic U and anthropogenic U were gathered in an insoluble fraction. The anthropogenic U is likely to have been provided in insoluble forms and have deposited on the bay floor. Absence in differences of ²³⁶U/²³⁸U and ²³⁵U/²³⁸U values for seawater observed between inside and outside Tokyo Bay implies the negligibly small contribution of the anthropogenic U to U in the seawater. The data obtained here demonstrate the effective reduction of the interferences on ²³⁶U and the versatility of the isotopic signatures of U as an effective tracer for environmental circulation of U in nature.

Soil microbial biomass stoichiometry homeostasis is essential for microorganism survival and ecosystem stability. Despite its importance, research on soil microbial homeostasis in Natural World Heritage Sites (NWHS) is lacking. This study analyzed ecological stoichiometry and microbial homeostasis in surface (0–20 cm) and subsurface (20–40 cm) soils across various vegetation types in Fanjing Mountain, an NWHS in China. The objective was to explore microbial homeostasis in relation to soil ecological stoichiometry and identify key influencing factors. Results indicated that microbial biomass stoichiometry in surface soil is higher than in subsurface soil for 5 vegetation types, mirroring nutrient stoichiometry but contrasting enzyme stoichiometry. Vector length (VL) suggests higher C limitation in subsurface soil for all vegetation types, while vector angle (VA) shows P limitation in surface soil of certain types and N limitation in subsurface soil across all types. Random forest analysis revealed that the microbial carbon-nitrogen ratio (MB C/N) was mainly contributed by C/N (14.11 %), SOC (12.31 %), pH (10.52 %), NH₄⁺-N, SWC, NO₃^--N in the surface soil, and NO₃^--N (15.74 %), altitude, SWC, SOC, C/N in the subsurface soil, whereas for the microbial carbon-phosphorus ratio (MB C/P), altitude (12.16 %), SWC (9.86 %), and AP were the main contributing factors in the surface soil, and in the subsurface soil, altitude (10.49 %), C/P, SWC, SOC, and TP. This study provides insights into ecological stoichiometry, homeostasis, and nutrient limitations in Fanjing Mountain, aiding vegetation nutrient balance management in NWHS.

Utilization of effective and economical nanoparticles/nanocomposite materials in civil engineering is still remaining a significant challenge in current research arena. In this study, microbial-induced precipitation was formulated for integration of white cement mortar to enhance efficiency and evaluate its potential applications in antibacterial and photocatalytic degradation of methylene blue. Hexagonal wurtzite structure of synthesized ZnO exhibited high crystallinity with significant contribution of hydration product after 28days analysis. Morphology of produced material showed less homogeneity with high densification and morphology altered from needles-like structure to tube with the integration of adsorbent ratio from ZnO-0 to 2.5, presented all the required chemical components in EDXS analysis. The water absorption rate in sample slurry of ZnO-2.5 exhibited significant reduction of 52.75 % compared to baseline water absorption rate of 12.71 % in commercial ZnO and contact angle was noted higher as 89.54°, which indicates hydrophilic character of material. The highest compressive strength of sample ZnO-2.5 was noted 508.89 kgf/cm² in 28days of wet curing method, indicated the effective gel formation of calcium silicate in samples. Maximum methylene blue dye degradation recorded 79.95 % in case of using ZnO-2.5, which showed another influential character with excellent efficiency. In addition, prepared sample has shown almost complete bactericidal efficiency under simulated sunlight. Compared to commercial white cement mortar, biological white cement mortar can save NT$149,531 per cubic meter at industrial scale. Therefore, results indicate that microbial-induced zinc precipitation incorporated using hydrothermal preparation of biological white cement mortar improves the surface properties for applications and reduces its cost of study.

There is an urgent need for fast and cost-effective in-situ remediation of sites contaminated with odor pollutants. The focus of this study was to develop an effective and environmentally sustainable pollutant control system based on a persulfate (PS)−coupled electrokinetic (EK) strategy. The system was evaluated by comparing the removal efficiencies of odor pollutant mixtures, degree of soil disturbance, and economic costs. A novel EK device was established based on the characteristic volatility of odor pollutants and the need for the in-situ collection of soil solutions. Several common activators, i.e., sodium hydroxide (0.25 mol L⁻¹), citric acid chelated iron (II) (CA-Fe (II), PS/ citric acid/ Fe²⁺ molar ratio of 4:1:1), and bamboo derived biochar (BC) (2 %, w/w) pyrolyzed at 700°C, were used to enhance the PS−EK strategy when remediating freshly prepared composite soil contaminated with an odor pollutant mixture. After the six-day experiment, the removal efficiencies of typical odor substances (dimethyl disulfide (DMDS)/trichloroethylene (TCE)/benzene) using the three activators referred to above were 57.4−89.0 %, 52.0−81.7 %, and 44.7−69.9 %, respectively. Chemical probe technology and quenching experiments indicated that singlet oxygen played the dominant role in the degradation of DMDS, while hydroxyl radicals were the main participants in the degradation of TCE and benzene. From the perspective of green remediation, the activation system including BC had positive effects on soil stability and reusability.

Centrifuge effluent, or centrate, is a liquid stream generated in the sludge line of wastewater treatment plants in the sludge dewatering process. Nutrients are solubilized in the anaerobic digestion of the sludge, mainly in the form of ammonium-nitrogen and phosphates. Thus, when the dewatering of the digested sludge is performed (usually by centrifugation), a sludge liquor stream enriched in nutrients is generated. However, it also contains microparticles, including microplastics, since most of the microparticles from the wastewater are transferred to the sludge treatment line in wastewater treatment plants. In this work, microplastics in centrate have been analyzed (counted and identified), and membrane technologies (ultrafiltration and forward osmosis) have been applied to concentrate nutrients and to obtain a microplastic-free stream for further nutrient recovery. Two alternative configurations have been compared, changing the application order of these processes. The results showed that obtaining a stream with a concentration higher than 6000 mg/L of ammonium has been possible by using ammonium sulfate (150 g/L) as a draw solution in the forward osmosis process. On the other hand, as a consequence of the ultrafiltration application, microparticles were concentrated in the reject stream up to 800 microparticles/L. At the same time, the permeate presents a lower concentration of microplastics without reducing the concentration of the nutrients. In this way, this pioneering study enables the production of a nutrient-enriched stream with reduced microplastic concentrations, that could be applied to the agricultural soil as biofertilizer.

The Chinese Chernozems face extreme challenges of soil degradation and crop productivity decline. Biochar-based organic fertilizer (BOF) is effectively applied to improve crop yield and soil quality. Nonetheless, the mechanisms involved in yield enhancement in interaction with root traits, soil quality, and microorganisms after BOF application remain unclear. Herein, a two-year field experiment with three BOF rates [3.0 Mg ha⁻¹ (BOF3), 6.0 Mg ha⁻¹ (BOF6), 9.0 Mg ha⁻¹ (BOF9)] was conducted to evaluate the impact of BOF on root traits, soil quality, and soil microorganisms, with no BOF applied as control treatment (CK). Compared to CK, BOF increased maize yield by 9.1 ∼ 32.0 % in the second year of application, and the highest yield (16.1 Mg ha⁻¹) was obtained with BOF6. BOF increased the plant growth index by 29.7 ∼ 98.9 %, mainly attributed to the increase in root volume (2.4 ∼ 57.4 %), aboveground biomass (31.4 ∼ 44.0 %), and nitrogen (N) uptake (123.2 ∼ 216.0 %). The soil quality index was increased not only in the topsoil (27.7 ∼ 31.1 %) but also in the subsoil (22.7 ∼ 25.1 %) with BOF, particularly with the two highest rates (BOF6 and BOF9). This was mainly ascribed to the notable increase in microbial biomass carbon, total N, NH₄⁺-N, and N-acquiring enzyme activity (normalized by leucine aminopeptidase and alkaline phosphatase). Moreover, BOF increased the abundance of Actinobacteria, Mortierellomycota at 0–40 cm, Chloroflexi at 0–20 cm, Acidobacteriota, and Ascomycota at 20–40 cm, which confirmed their key roles in activating soil nutrient and subsequent enhancing soil quality and stimulating plant growth. Overall, biochar-based organic fertilizer with a rate of 6.0 Mg ha⁻¹ is a promising fertilizer regime to enhance soil quality by regulating soil keystone taxa, thereby boosting maize growth and yield on the Chernozem soil.

Phytostabilization emerges as an efficient and enduring remediation technique for heavy metal-contaminated mine soils using plants acclimatized to such circumstances. In this research, the synergistic effects of Marrubium cuneatum, Verbascum speciosum, and Stipa arabica species, alongside municipal solid waste compost (MSWC) amendment at 0, 1, 3, and 5 % rates, were assessed for a six-month pot experiment aimed at remediating naturally polluted soil containing lead (Pb) and cadmium (Cd) and mitigating the health risks associated with these metal exposures for grazing ruminants. Applying compost improved the aboveground biomass of M. cuneatum and V. speciosum and S. arabica by 13, 19, and 18 %, respectively. Also, soil dehydrogenase and urease enzyme activities were enhanced up to 131 and 34 %. Upon MSWC application, all three species uptake Cd and Pb at a significantly lower rate, except in the V. speciosum shoot at 3 and 5 % doses, and bioaccumulation factors were markedly diminished. Compost notably augmented the antioxidant system, leading to a reduction in malondialdehyde content of V. speciosum, M. cuneatum, and S. arabica by 35, 29, and 23 %, respectively, and an elevation in chlorophyll level. Superoxide dismutase, catalase, glutathione peroxidase, and ascorbate peroxidase activities either increased or displayed no significant differences. Risk assessment revealed that MSWC substantially decreased the daily intake of Pb and Cd and their accumulation in animal organs, thereby eliminating limits on meat consumption. Findings affirm the combined efficacy of MSWC and the study species in stabilizing contaminated Pb and Cd soils, diminishing risks to animal feed security and human health.

Researchers have recently become interested in utilizing biochar amendment as an organic approach to enhance soil quality and minimize the mobility of toxic metals (TMs), which can help grow TM-tolerant plant species in polluted areas. A pot experiment was conducted to examine the efficacy of bamboo biochar (BB) in reducing the phytotoxicity of four unique mine-contaminated soil types. According to a completely randomized design (CRD), in four replications on Brassica juncea, a five-level bamboo biochar treatment (0 % Control, 2.5 % BB, 5 % BB, 7.5 % BB, and 10 % BB) was administered in naturally contaminated areas of Sarcheshmeh, Gol-Gohar, Chadormalu, and Anguran mines. The data show that Bamboo Biochar (BB) increased soil enzymatic activities (58 %), reformed soil structure, including pH (7 %) and electrical conductivity (EC) (51 %), and decreased the availability of TMs (Zn (37 %), Pb(34 %), Cd(51 %), Cu(34 %)), preventing accumulation in roots (42 %) and translocation to shoots (38 %). The phytochelatin (79 %), ascorbic acid (56 %), glutathione contents (57 %), and antioxidant (51 %) and glyoxalase activities (71 %) in B. juncea ultimately enhanced root-shoot dry biomass (44 %) and overall tolerance to TMs in mine-polluted soil (43 %). BB at 10 % might be used as a reliable soil amendment and natural metal immobilization adsorbent in the soil, as well as a suitable option for reducing oxidative stress caused by TMs in B. juncea plants, which are strong phytoremediation candidates in polluted soils. Future research endeavors might aim to discover cost-effective, efficient, and natural substances that can enhance and diminish environmental toxicity, eliminate soil contamination caused by heavy metals, and ultimately enhance human well-being. Keywords: Biochar Application; Soil amendment; Plant stress tolerance; Toxic metal; Phytoremediation