Clean-soil Air Water最新文献

Algae have adsorption properties and reducing agents due to their rich content. In this study, palladium nanoparticles (Pd NP), platinum nanoparticles (Pt NP), and iron oxide nanoparticles (Fe₃O₄ NP) were prepared from Codium macroalgae using green synthesis. The structure of the synthesized nanoparticles was elucidated by X-ray diffractometry, Fourier transforms infrared spectroscopy, Brunauer–Emmett–Teller analysis, transmission electron microscopy, ultraviolet-visible spectroscopy and scanning electron microscopy-energy dispersive X-ray spectrometry and their use as nanoadsorbents for the removal of pollutants from aqueous media was investigated in detail. Naproxen (NPX), an anti-inflammatory drug, and the dyes methylene blue (MB) and cresol red (CR) were selected as pollutants for this study. Batch adsorption experiments were conducted using both real wastewater obtained from the Organised Industrial Zone of Isparta Province and synthetic water samples prepared with tap water from Burdur Province and pure water. Under optimum adsorption conditions, Pd NP showed significant efficiency in the real wastewater sample, with an adsorption capacity of 37.19 and 50.03 mg g^–1 for CR and NPX, respectively, within 150 min. In comparison, Pt NP showed an adsorption capacity of 40.01 mg g^–1 for MB within the same timeframe. These findings indicate that while Pd NP showed the highest adsorption capacity for both CR and NPX, Pt NP showed the highest adsorption capacity for MB. The Langmuir model and the pseudo-second-order equation were more suitable to describe the adsorption behavior of CR, MB, and NPX. In addition, studies on the desorption and reusability of the nanoadsorbents were carried out under the same optimum experimental conditions.

The main goal of the present study was to highlight how crucial odor evaluation methods may be for raising the general standard of living in a region. For this, the dispersion of odor concentrations detected by an olfactometric method in an area of Kocaeli, Turkey, where odor problems are frequently experienced, was investigated using the AERMOD atmospheric dispersion modeling system. According to the findings of the olfactometric measurement, the mean odor concentrations in the industrial area was high at 1342 OU m^–3, while in the residential areas the values were lower, at 578 OU m^–3 within the selected study area. As a result of the modeling study, the maximum odor concentration was 2081 OU m^–3 at the 1 h. The model also showed that the coordinate points where the maximum odor concentration was observed changed with time, and that the concentrations recorded at the 1 h may decrease by as much as 88%–91% at the 24 h. In the study, a survey was also conducted to identify possible effects of odor pollution on people. The survey findings showed a statistically significant difference (p < 0.05) between the two areas (industrial and residential) for seven variables of a total 28. We suggest that measuring odor concentrations, modeling their distribution, and conducting surveys are effective methods when managing the urban planning process.

Petroleum-contaminated soil (PCS) is urgently to be remediated due to its risk to ecological environment and human health. In this study, a Fenton oxidation–pyrolysis strategy was employed to accomplish effective petroleum removal and PCS remediation. The highest total petroleum hydrocarbon removal efficiency could achieve 99.6% after 2 h Fenton oxidation, with H₂O₂/Fe²⁺, 6:1, and pH 3, followed by pyrolysis at 370°C. The organic compositions of the soil after Fenton oxidation, the kinetics and process of the pyrolysis, morphologies and structures of the treated soil, as well as energy consumption and cost savings were comprehensively researched and analyzed. Through the Fenton oxidation–pyrolysis treatment, the macromolecules were effectively degraded and the contents of asphaltenes and resins were significantly reduced in the soil. Graphitized carbon was dominatingly existed after the pyrolysis. A 1.5 order reaction model was proposed to reasonably describe the pyrolysis remediation process of PCS. The Fenton oxidation–pyrolysis treatment can reduce energy consumption and cost compared with pyrolysis alone. This work not only offered an alternative approach of PCS remediation, but also provided theoretical guidance for practical soil remediation.

Pig production contributes significantly to the high environmental footprint of the livestock sector. Therefore, in this framework, a transition toward more sustainable production is essential. Local natural livestock resources, such as Mexican Creole Hairless Pigs, provide a good opportunity to achieve sustainable pig production. In the present study, a first approximation to compare the carbon emissions of Mexican Creole Hairless Pig manure from Commercial Pig manure is presented. Under the same feeding and housing conditions, the specific methane emissions of both Mexican Creole Hairless Pigs and Commercial Pigs manure were determined experimentally at room temperature. In addition, specific methane production kinetics was modeled using the Gompertz equation to estimate the specific methane production rate. The methane emission factors for Mexican Creole Hairless Pig manure (0.33 ± 0.02 kg[CO₂-eq]/LU per day) were half those of Commercial Pig manure (0.7 ± 0.04 kg[CO₂-eq]/LU per day), and biochemical manure analysis suggested that Mexican Creole Hairless Pigs had better digestibility of the diet. In general, due to physiological factors such as food intake rate and gut microbiota development, which could influence the fat and fiber digestibility of Creole genotypes, pig genotype should be included as an additional factor to estimate greenhouse gas emissions from pig manure. The production of Mexican Creole Hairless Pigs in an extensive local system is therefore an attractive option for developing new sustainable markets.

Antibiotic residues in water represent an urgent environmental challenge. To efficiently remove these residues, a low-carbon integrated biochar synthesis method was proposed, and an optimized typha biochar (TBI_K) was prepared. Compared with the biochar prepared by a conventional two-step carbonization and activation method (TBT_K), the TBI_K preparation process reduced energy consumption by 43849.58 J and cut carbon dioxide emissions by 32.80%. TBI_K exhibited a large surface area of 1252.40 m²/g and rapidly achieved an equilibrium removal efficiency of 99.95% within 20 min for simulated antibiotics wastewater. Furthermore, TBI_K possessed more number of functional groups than TBT_K, especially O-H and C-S groups. The adsorption stability and tolerance of TBI_K in solutions with different ionic strengths and coexisting anions were examined. Characterization techniques such as scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS) as well as Brunauer, Emmett and Teller (BET) analyses were employed to elucidate the morphology and adsorption mechanism of the adsorbent. The microporous structure and abundance of functional groups are key to the excellent adsorption capabilities of TBI_K. Thus, this integrated method for biochar production, optimized for treating antibiotic wastewater, holds significant potential for future applications.

Tannery effluent waste comprises various potentially toxic metals, including chromium (Cr) with varying acute or chronic toxicity. Cr(VI) is known to be a category-A carcinogen. Reduction of toxic Cr(VI) to Cr(III), which has lesser bioavailability, is one of the mechanisms used by many microbes to withstand Cr(VI) toxicity in the contaminated effluents. Oxidoreductase (OXRs) reduces toxic Cr(VI) to Cr(III); hence a thorough understanding of the OXRs is important for developing a suitable strategy to minimize Cr(VI) toxicity. Therefore, the OXR-encoding genes were sequenced using metagenomic DNA shotgun sequencing from the tannery effluent-contaminated soil. Six OXR-encoding genes were expressed in Escherichia coli, and OXR activity was confirmed by in situ quantitative assays. The six proteins were subjected to phylogenetic and evolutionary analysis. Further, detailed structural analysis of the two OXRs, namely, OXR3 and OXR8 with lowest and highest activity respectively, were investigated in silico for structural characteristics. The results revealed that both the proteins were soluble FMN-linked oxidoreductases. Eight conserved active site residues (Pro24, Thr26, Ala59, Tyr139, His178, Tyr180, His219, Tyr221, Arg269, and Lys360) in the enzyme OXR3 were predicted. Similarly, nine conserved active site residues (Pro20, Thr22, Ala55, Glu97, His191, Tyr193, Arg241, Cys334, and Arg335) were predicted in OXR8. The tertiary structure of OXR8 was an aldolase TIM barrel structure, like Thermus scotoductus chromate reductase. Docking with FMN revealed the involvement of all the nine predicted active site residues in FMN binding with Pro20, Thr22, and Cys334 as the most important ones.