Clean-soil Air Water最新文献

There are very few reports about water purification and its influence on indigenous microorganisms by effective microorganisms (EM) in the fields. This study investigated the effect of EM on water purification and microbial community via in vitro and field experiments. In in vitro water purification experiments, we examined values for chemical oxygen demand (COD), total phosphorus, and total nitrogen (TN). In systems in which the active EM solutions were at a concentration of less than 1:2000 of the total water sample, the values after 28 days were equal to or lower than those of the control. In systems using 1:200 and 1:100 active EM solutions, COD and TN values were significantly lower in artificial wastewater compared to control. Conversely, they were significantly higher than the control in the pond water. When the active EM solutions were added to the pond water, total microbial plate counts were higher than the control after 28 days for all concentrations of the EM active solutions. Excessive use of EM caused deterioration of water quality and increase of microbial counts. The results of field experiments for 4 years suggested that EM treatment did not purify the pond water, establish introduced EM, or affect indigenous microorganisms.

The present study was conducted to address four key questions: (i) What are the levels of submicron particulate matter at the study area?, (ii) which are the major contributing sources of these particles?, and (iii) is there any seasonal changes in the levels of pollutants at the study site? Thus, the study was conducted at an urban residential site of Jaipur City, India, to determine the elemental and ionic composition of toxic elements associated with PM₁ using inductively coupled plasma optical emission spectroscopy and ion chromatography to reveal specific sources. Monitoring was done for a period of 8 months between October 2020 and May 2021 considering three seasons: winter (December–February), pre-monsoon (March–May), and post-monsoon (October–November). PM₁ samples were found to be highly enriched with Ag, Cd, B, Ni, and Zn. PM₁ mass concentrations were observed to be greater in winter (104.13 ± 30.16 µg m⁻³) and lower in the pre-monsoon season (83.62 ± 19.40 µg m⁻³). Ion concentrations (Cl⁻, NO₃²⁻, and SO₄²⁻) followed a similar pattern to PM₁ concentrations. Source apportionment by positive matrix factorization at the study site revealed six major sources of pollutants (soil dust, agro-based industry, automobile industry, salt aerosols, industrial activities, and biomass burning).

To fulfill a huge demand that is arising globally due to the skyrocketing population, the textile industry is shifting toward cheaper, sturdier, enduring fabrics. Apparently, innovations are turning out to be banes instead of boons, as they are generating a lot of waste, leading to the destruction of the environment. Microfibers are one such example of an emerging environmental contaminant with several irreversible, health, and ecosystem repercussions. This study deals with the effects of temperature on the generation of microfibrils from washing machines. Three different temperatures ranging from lower to higher were considered. The net weight of microfibers released from higher temperatures was found to be 1132.5 ± 41.3 mg/20 L using gravimetric analysis. The fibers released from the higher temperature, that is, 60°C, were 2.7 and 1.6 times higher than those released from colder temperatures, 30 and 40°C, respectively. The length and diameter of these microfibers were in the microplastic size range. The polyester fiber was found to be released in higher amounts after identification with Fourier transform infrared and Raman spectroscopy. The results of this study can help consumers implement sustainable behavior and regulations to lessen the release of microfibers from washing household textiles.

The analysis of UV filters (UVFs) in water has become increasingly important due to their adverse effects on aquatic organisms and humans. This study describes a method for the determination of benzophenone derivatives UVF in wastewater samples. The selected UVFs are 2-hydroxy-4-methoxybenzophenone (BP-3), 2,4-dihydroxybenzophenone (BP-1), 4-hydroxybenzophenone (4HB), 2,2′-dihydroxy-4-methoxybenzophenone (DHMB) and lastly, 4,4′-dihydroxybenzophenone (4DHB). The method includes solid-phase extraction (SPE) of analytes from wastewater followed by on-line derivatization with bis(trimethylsilyl)trifluoroacetamide (BSTFA) and analysis with GC-MS/MS. Method validation studies resulted in good recoveries (86–112%), relative standard deviation RSD = 0.8 and 7.3%, the limits of detection LODs = 1.00–10.8 ng/L, and the limits of quantification LOQs = 3.00–32.3 ng/L. The method was successfully applied to domestic wastewater samples collected from influent and effluent of touristic hotels’ biological wastewater treatment plants. BP-3 (24–1765 ng/L), BP-1 (8–703 ng/L), 4HB (26–96 ng/L), and 4DHB (20–22 ng/L) were the common benzophenone derivatives in the influent wastewater while effluent contained mainly BP-1 (8–32 ng/L), 4HB (12–57 ng/L) and 4DHB (20–102 ng/L). These results indicate that BP-3 and BP-1 are biodegraded in the treatment processes. However, 4HB and 4DHB are resistant to degradation and they are the main benzophenone metabolites discharged to receiving media.

Emerging contaminants (ECs) are a category of relatively newly identified chemicals lacking regulatory status and generally of synthetic origin. ECs encompass a range of substances, including pharmaceuticals, antibiotics, antidiabetics, pesticides, personal care products (PCPs), and endocrine-disrupting chemicals. ECs are frequently found in surface water, groundwater, and wastewater. Wastewater treatment plants (WWTPs) are often identified as sources of these chemicals. ECs enter wastewater through improper disposal or usage of consumer goods, agricultural runoff, toxic spillage, and prescription drug excretion in urine and feces, as the human body metabolizes a fraction of administered drugs. The presence of ECs in aquatic environments poses a significant threat, as they can potentially harm both the ecosystem and humans, even at low concentrations. For a comprehensive understanding of the impacts of ECs, it is essential for researchers to investigate the occurrence, sources, fate, and transport of these substances in wastewater. This review investigates the origins and ultimate fate of these ECs, examining their interactions with the surrounding aquatic environments. It aims to provide a comprehensive understanding of the characteristics and behaviors of ECs through an in-depth analysis. This review discusses treatment techniques and processes and examines potential pathways for future advancement.

Worldwide climate change, rising population, and industrialization have raised the global demand for freshwater. Desalinating brackish water has become a sustainable technology for drinking and agriculture to overcome global water scarcity. Thriving biodesalination technology has become more attractive and eco-friendly than the present physicochemical desalination methods, which are expensive and energy-intensive. Researchers are exploring the bioutilization of nature's potential for desalination using halophiles like haloarchaea, halobacteria, halophytic algae, and plants. Biomimetic desalination membranes have been developed, inspired by the desalination mechanism in animals. This comprehensive review explores recent advancements and potential applications of halophiles in biodesalination to exploit them effectively. It provides an overview of the opportunities and challenges associated with harnessing halophiles for the removal of salts from brackish and seawater sources. This review also focuses on insights into biomolecules produced by the halophilic microorganisms and halophytes in the desalination process. Understanding the mechanism of action of these biomolecules will edify the effective unexplored research areas in biomimicry and bioutilization to overcome the existing limitations in water treatment.

In this work, a composite (CuBTC/superparamagnetic iron oxide nanoparticles [SPION]) based on copper, benzene-1,3,5-tricarboxylic acid (CuBTC) and SPION was synthesized by electrochemical method for the magnetic separation of methylene blue (MB) from aqueous solutions. The synthesis of the proposed composite was carried out under various experimental conditions from 1.4 to 5.4 V for 1–5 h and subsequently studied using different techniques. Scanning electron microscopy showed a granular structure, whereas Brunauer–Emmett–Teller results revealed a well-developed surface area of around 182 m² g⁻¹. Fourier transform infrared confirmed the presence of functional groups characteristic to CuBTC and Fe₃O₄, whereas X-ray diffraction revealed the phase structure of CuBTC 1D, CuBTC 3D, and Fe₃O₄ in the obtained composite. Based on the experimental results, the sample synthesized under a potential of 1.4 V for 5 h was selected for MB adsorption studies in the function of adsorbent mass, contact time, solution pH, ionic strength, initial concentration, and temperature. The maximum adsorption capacity was 681 mg g⁻¹, and the adsorption undergoes the Redlich–Peterson and Sips isotherm model. The results obtained for CuBTC/SPION indicate that the nanocomposite is a promising adsorbent for removing MB in synthetic dye water and wastewater.

In the last few years, urban trees have emerged as an effective nature-based solution to mitigate increasing air pollutant levels due to urbanization and industrialization. This study aims to assess the synergistic effect of urban trees on improving air quality by combining real-time PM_2.5 monitoring with the i-Tree Eco model. The monitoring was conducted during rush hours with high traffic volume and during non-rush hours, in both the tree alley and a non-tree road section within the industrial areas of the north-west region of the National Capital Territory of Delhi, India. The i-Tree Eco model was run using the diameter at breast height values of tree species present in the study area, and the PM_2.5 reduction ability of the trees was quantified. The results from both approaches indicated that urban trees can significantly reduce the traffic-fed PM_2.5 concentrations. Therefore, it is suggested that tree plantations be integrated into air pollution management strategies in urbanized regions with high traffic volumes. Although this study explores the initial link between trees and air quality in Delhi, further research incorporating local wind speed and direction measurements would provide a more comprehensive understanding of how trees influence air quality in any highly polluted urban setting.