Plants establish symbiosis with arbuscular mycorrhizal fungi (AMFs) for nutrient exchange and also for tolerance to contaminants. During February 2019, soil and rhizosphere samples of Laguncularia racemosa (Lr) and Avicennia germinans (Ag) were collected on 4.15 hectares of a mangrove forest established in Histosol affected since 1967 by chronic oil spill in southeastern Mexico. The site was divided into four zones based on the amounts of total hydrocarbons of weathered petroleum (THWPs) accumulated in the soil for half a century. The abundance of intraradical propagules and the colonization structure of the AMFs in the roots of the two mangrove species were compared. The density of phosphate-solubilizing bacteria (PSBs) in soil and rhizosphere samples was also evaluated. The degraded oil stimulated the amount of PSBs in Lr but not in Ag. AMF biodiversity was lower in the Ag root; however, spore abundance was higher. We found abundant spores of Glomus claroideum and Diversispora aurantium in tertiary and quaternary roots of the Ag in soils contaminated with 48462 mg of THWPs. This study provides evidence of the presence and abundance of intraradical propagules in different types of roots, which may be an alternative that contributes to the understanding of oil dissipation and in future applications for the restoration of degraded ecosystems.

Health effects resulting from the smoke of carbonyl compounds (aldehydes and ketones) and metal-containing incense particles at temples during incense burning periods were evaluated at temple A (without incense reduction activities) and B (with incense reduction activities), Nantou County, in 2018. The predominant size fractions of particles were PM₁, PM₁–₂.₅, and PM₂.₅–₁₀ at both temples. The total particle mass at temple A was approximately 1.1 times that of temple B due to incense reduction at temple B. The most abundant metal elements in all particle size fractions at both temples were Fe, Al, and Zn. Metal species of incense smoke are divided into three groups by hierarchical cluster analysis and heatmaps, showing higher metal contents in groups PM₁, PM₁₈–₁₀, and PM₁₈–₂.₅ at temple A. In contrast, higher metal contents were observed in PM₁₈–₁₀ and PM₂.₅–₁ at temple B. Most of the carbonyl species were formaldehyde and acetaldehyde, released during incense burning periods, with concentrations ranging from 6.20 to 13.05 μg/m³ at both temples. The total deposited fluxes of particle-bound metals at temples A and B were determined to be 83.00% and 84.82% using the International Commission on Radiological Protection (ICRP) model. Health-risk assessments revealed that the risk values of metals and carbonyls were above recommended guidelines (10⁻⁶) at temple A. Since worshippers and staff are exposed to incense burning environments with poor ventilation over a long period, these toxic organic compounds and metals increase health risks in the respiratory tract. Therefore, incense reduction is important to achieve healthy temple environments.

In this study, titania/silica nanocomposite and mesoporous TiO₂ (m-TiO₂) photocatalysts are developed by KIT-6 template via a sol-gel approach. The synthesized photocatalysts are characterized by XRD, EDX, SEM, Raman, PL, and UV–vis DRS analysis techniques. The as-synthesized series revealed a high surface area, smaller size, a greater number of accessible active sites, and enhanced light-harvesting capability. The m-TiO₂ photocatalysts’ charge recombination capability was curiously inferior to the rest of as-synthesized TiO₂/KIT-6 nanocomposite materials. The band-gap of as-synthesized materials were suitable for their activity in UV light irradiations. It was pragmatic that the photocatalytic degradation efficiency of m-TiO₂ photocatalysts was superior as compared to that of commercial TiO₂ photocatalyst under UV light irradiations, owing to the synergistic outcome of the anatase phase and a greater number of accessible active-sites availability as a result of high surface area. Moreover, the m-TiO₂ was critically evaluated by investigating various parameters affecting the photocatalytic degradation reaction of MB including the effect of irradiation time, pH, catalyst dosage, and dye concentration. The m-TiO₂, 45wt% composite material and commercial-TiO₂ exhibited 99.27, 91.20, and 84.67% degradation of methyl blue in 50 min, respectively. Finally, the m-TiO₂ exhibited excellent recyclability with negligible loss of activity performance.

This study determines the dynamic linkages between road transport intensity, road transport passenger and road transport freight, and road carbon emissions in G20 countries in the presence of economic growth, urbanization, crude oil price, and trade openness for the period of 1990 to 2016, under the multivariate framework. This study employs the residual-based Kao and Westerlund cointegration technique to find long-run cointegration, and continuously updated bias-corrected (CUP-BC) and continuously updated fully modified (CUP-FM) methods to check the long-run elasticities between the variables. The long-run estimators’ findings suggest a positive and significant impact of road transport intensity, road passenger transport, road freight transport on road transport CO₂ emissions. Economic growth and urbanization are significant contributing factors in road transport CO₂ emissions, while trade openness and crude oil price significantly reduce road transport CO₂ emissions. The Dumitrescu and Hurlin causality test results disclose unidirectional causality from road transport intensity and road transport freight to the road transport CO₂ emissions. However, the causality between road passenger transport and road transport CO₂ emissions is bidirectional. Finally, comprehensive policy options like subsidizing environmental-friendly technologies, developing green transport infrastructure, and enacting decarbonizing regulations are suggested to address the G20 countries’ environmental challenges.

High volumes of wastewater with high pollutant concentration form in the transesterification stage of the process applied for biodiesel production from waste vegetable oils. In this study, application of the advanced electrocoagulation process following acidification was investigated in the biodiesel wastewater treatment. Through the acidification step of the sequential process, respectively, 25.4%, 68.7%, and 50.0% removal efficiencies for COD, oil-grease, and volatile fatty acids (VFAs) were obtained. Electro-activated persulfate (EAP) oxidation was modeled and optimized by using the response surface methodology and Box–Behnken design. The effect of independent variables (current, persulfate/COD ratio, time) on COD, oil-grease, VFAs removal, and total cost and the interaction of the variables of the process were determined. The maximum oil-grease removal efficiency predicted by using the model was 98.3% under the optimum conditions (current: 4 A, persulfate/COD: 4.4, and time: 15 min), whereas oil-grease removal efficiency obtained by the verification experiments performed at optimum conditions was found to be 97.2%. Sequential acidification–EAP process is an appropriate treatment method for biodiesel wastewater with high oil-grease concentration, and response surface methodology is a powerful tool for optimizing the operational conditions of EAP oxidation for COD, oil-grease, VFAs removal, and total cost.

Harran Plain is the largest plain within the area administered under the Southeastern Anatolia Project (known as the GAP project in Turkey), covering an area of 1500 km². This article presents results of groundwater quality assessment based on some pollution indicators such as electrical conductivity (EC) and nitrate (NO₃⁻) values in Harran Plain between 2005 and 2015. In order to show the change of EC and NO₃⁻ contamination in 20 observation wells located on the plain, seasonal average concentration distribution maps based on 2005 and 2015 were created. The results were then evaluated based on national and international standards and classifications. As a result; EC and NO₃⁻ values decreased throughout the plain from 2005 (max 8235 μS/cm, 720 mg/L) to 2015 (max 2510 μS/cm, 327 μS/cm). The observation wells where EC and NO₃⁻ values registered as high in 2005 were W8-Kisas, W11-Ugurlu, W14-Kizildoruc, W15-Yardımli, W16-Ozlu, and W20-Ugrakli, while in 2015, it was W11-Ugurlu and W14-Kizildoruc. The positive effects of the measures taken and improvements in the plain such as irrigation systems, correct fertilizer applications, closed drainage systems, and product pattern change have realized positive results with the reduced NO₃⁻ and EC levels. However, a different situation was observed for NO₃⁻ at the points where nitrate was low in 2005, with a comparatively slight increase recorded in 2015. The reason for this minimal increase was considered to be continued fertilizer application, applied fertilization method, and increased urbanization in addition to uncontrolled and over-irrigation.

Scarcity of freshwater resources for agricultural purposes is a crucial problem in arid and semi-arid regions. The aim of this study was to evaluate the effects of Moringa seed powder on wastewater quality parameters and examine the responses of Leucaena leucocephala seedlings irrigated with Moringa-treated wastewater. Moringa seed powder was used for different wastewater types (gray, primary-, and tertiary-treated wastewater). Wastewaters were treated with Moringa seed powder using the following concentrations: 0.2, 0.4, and 0.8 g/L. The analyses of wastewaters before and after treatment with Moringa seed powder were conducted, and its impact on seed germination and seedling growth of Leucaena leucocephala was investigated using Moringa-treated wastewater. Our results revealed that Moringa seed powder decreased pH and increased electrical conductivity, phosphate, nitrate, and ionic abundance of calcium, magnesium, sodium, and potassium in the treated wastewater as Moringa seed powder concentration increases. Both germination rate index and percentages were not significantly different for treated wastewater as compared to control. However, the treatment showed the highest percentage at 0.8 g (95%) using M. oleifera compared to 0.2 g (86.3%) with M. peregrina. On the other hand, seedling characteristics of Leucaena leucocephala improved for both treatments. Shoot heights and root lengths were the highest at concentrations 0.2 g (10.48 and 7.28 cm, respectively) and 0.8 g (10.51 and 7.22 cm, respectively) for both M. peregrina and M. oleifera. Finally, Moringa seed powder improved the plant productivity using M. oleifera, while slight decline in plant height with M. peregrine was shown compared to control.

Fipronil (FIP) is an organic pesticide with many practical uses. Although some results indicated toxic effects in some terrestrial and aquatic animal species, little is known on its influence on behavioral and physiological endpoints of cladocerans. The aim of our study was to determine the short-term effects of FIP at concentrations of 0.1 μg/L, 1 μg/L, 10 μg/L, and 100 μg/L on Daphnia magna sublethal indices: behavioral (swimming speed, distance traveled) and physiological endpoints (heart rate, post-abdominal claw activity and thoracic limb movements). The results showed that FIP induced reduction of swimming speed and distance traveled in a concentration- and time-dependent manner at all the concentrations used. The lowest concentration of the insecticide temporarily stimulated post-abdominal claw activity after 24 h and thoracic limb activity after 48 h; however, the highest concentrations reduced all the studied physiological endpoints. IC50 values showed that thoracic limb activity, swimming speed, and distance traveled were most sensitive to FIP after 24-h exposure. The most sensitive parameter after 48 h and 72 h was swimming speed and post-abdominal claw activity, respectively. The study indicated that (i) behavioral and physiological endpoints of Daphnia magna are reliable and valuable sublethal indicators of toxic alterations induced by FIP; however, they respond with different sensitivity at various times of exposure, (ii) FIP may alter cladoceran behavior and physiological processes at concentrations detected in the aquatic environment; therefore, it should be considered as an ecotoxicological hazard to freshwater cladocerans.

Phosphate-solubilizing (PS) microbes are important to improve phosphorus availability and transformation of insoluble phosphate, e.g., rock phosphate (RP). The use of phosphate solubilizing bacteria (PSB) as inoculants have been proposed as an alternative to increase phosphate availability in RP and composting fertilizers. In this study, the effect of compound PSB coinoculation and single-strain inoculation on the transformation of insoluble phosphate were compared in a liquid medium incubation and RP-enriched composting. The goal of this study was to understand the possible mechanisms of insoluble phosphate transformation driven by the interactions of compound PS microbes during composting. The correlations between organic acids production, P-solubilization capacity and bacterial community with PSB inoculation were investigated in the RP-enriched composting by redundancy analysis (RDA) and structural equation models (SEM). Results showed that both single-strain and compound PSB inoculants had a high P-solubilization capacity in medium, but the proportion of Olsen P to total P in composts with inoculating compound PS microbes was 7% higher than that with single strain. PS inoculants could secrete different organic acids and lactic was the most abundant. However, RDA and SEM suggested that oxalic might play an important role on PS activity, inducing RP solubilization by changing pH during composting. Interaction between compound microbes could intensify the acidolysis process for insoluble P transformation compared to the single strain. Our findings help to understand the roles of complex microbial inoculants and regulate P availability of insoluble phosphate for the agricultural purposes.

Substantial particulates and phosphorus (P) loads are carried into the reservoir by flood runoff and the P exchange between water and settling particulates under variable water conditions in the reservoir after flooding is critical to the removal of active P from water. To investigate the impact of particulate sedimentation on P changes in reservoir water, runoff samples were collected at four locations in the upstream channels of two reservoirs after a rainstorm. Two batches of particulate sedimentation simulations were conducted separately in four plexiglass columns to analyze the changes of water P and environmental factors during particulate sedimentation. The results showed that the contents of total P (TP), total particulates P (TPP), and phosphate (PO₄³⁻) decreased with the settlement of particulates. The correlation between the environmental factors and the amount of PO₄³⁻ in water changed from uncorrelated to correlated with particulate settlement, implying that the rapid settling of particulates might weaken the effect of environmental factors on P exchange between water and particulates. Particulates firstly release PO₄³⁻ rapidly in river or reservoir and then adsorb PO₄³⁻ slowly during settlement in reservoirs. Coarse particulates release more and adsorb less PO₄³⁻ during settlement, and fine particulates play an important role in the removal of water PO₄³⁻ due to the slow sedimentation rates. Therefore, to mitigate the reactive P content of reservoir water, the loss of coarse particulates from the watershed should be controlled, and the discharge of water with particulates downstream should also be avoided during the flood season.