This study describes the role of zinc oxide nanoparticles (ZnO NPs) in alleviating arsenic (As) stress in rice (Oryza sativa) germination and early seedling growth. Seeds of rice were primed with different concentrations (10, 20, 50, 100, and 200 mg L⁻¹) of ZnO NPs and As (0, and 2 mg L⁻¹) for 12 days in petri dishes. Two milligrams per liter of As treatment represented a stress condition, which was evidenced by germination rate, seedling length, seedling dry weight, chlorophyll, superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) content of rice shoot. ZnO NPs amendment (10–100 mg L⁻¹) increased the germination rate (2.3–8.9%), shoot weight (18.2–42.4%), root weight (5.2–23.9%), and chlorophyll content (3.5–40.1%), while elevated the SOD (2.2–22.8%) and CAT (7.2–60.7%) activities and reduced the MDA content (17.5–30.8%). As concentrations were significantly decreased by 8.4–72.3% and 10.2–56.6%, respectively, in rice roots and shoots with ZnO NPs amendment (10–200 mg L⁻¹) by the As adsorption of ZnO NPs and promoted biomass of rice. All the amendments improved the Zn concentrations in rice shoots and roots. Overall, ZnO NPs provide effective resistance to arsenic toxicity by increasing germination, biomass, and nutrients of Zn and decreasing As uptake in rice.

Humic acids (HA) are natural substances which exhibit a remarkable spectrum of health benefits, such as their role in chelation. This study aims to supplement the current knowledge on the chelating effects of HA in chronic lead intoxication in rat femurs and in liver, heart and kidney mitochondria in an experiment lasting 10 weeks. Lead acetate trihydrate was administered to rats for 5 weeks at a daily dose of 155.5 mg/kg body weight. At the same time, rats were given three concentrations of HA, with their effect measured over the following 5 weeks. Increased Pb concentrations were detected in the femur after the first week, while HA-administered groups showed a tendency towards inhibiting the increase in Pb deposition. After 5 weeks, Pb concentrations dropped significantly in the HA groups. At the same time, however, other elements were redistributed, with a decrease in Se and Zn being particularly noteworthy. While an increase in Pb concentrations was found after 5 weeks of Pb administration, a concentration of 1% HA resulted in the least significant increase in Pb as well as an increase/decrease in Se/Cu, respectively. In mitochondria, an increase in Pb content was detected after the first and fifth weeks with concomitant redistribution of other elements. At the end of the experiment, again in the 1% HA group, Pb concentrations remained higher only in the liver with the other elements sufficiently normalized, indicating this concentration to be useful in the treatment of Pb intoxication.

The geo-ecosystems of the lakes play an important role in their wider geographical areas, such as energy and biological resources, as well as water sources for agriculture, industry, and drinking water. The main goal of the present paper is to develop a new approach to the effective monitoring of lakes water quality. Three new optical decision-making systems (ODMS) are being set up first as components of this new monitoring system. The first ODMS is based on an 8-channel universal spectrophotometer. The second involves a 35-channel spectrophotometer to diagnose water sampling and the third includes a 128-channel spectroellipsometer. All versions of ODMS include special software that incorporates algorithms and models to solve optical inverse tasks and decision making about the quality of lakes water. ODMS provides a spectral image of the water quality of the lakes in wavelengths ranging between 350 and 910 nm depending on the optical device. The recognition of spectral images generated by ODMS allows the detection of adverse changes in water quality and the decision-making on the choice of strategy to deal with this change. In particular, a case study of Lake Sevan in Armenia is being conducted for the ODMS demonstration, and the results of the lakes water diagnosis are being discussed. The ODMS estimate for water quality error does not exceed 18%, while the forecast for water quality for 1 month includes an error not exceeding 10% and 20% for 1 year.

Due to human activities, there is an increasing presence of agrochemicals residues in water bodies, which could be attributed to an increased use of these chemicals, incorrect disposal of packaging materials, and crop leaching. The effects of these residues on prey-predator relationship of aquatic animals are poorly known. Here, we show that fish acutely exposed to glyphosate, 2,4-D, and methylbenzoate-based agrichemicals have their anti-predatory responses impaired. We exposed zebrafish to sub-lethal concentrations of agrichemicals and evaluated their behavioral reaction against a simulated bird predatory strike. We observed that agrichemical-exposed fish spent more time in a risky area, suggesting that the pesticides interfered with their ability of risk perception. Our results highlight the impairment and environmental consequences of agrochemical residues, which can affect aquatic life and crucial elements for life (food web) such as the prey-predator relationship.

In this study, a new composite membrane has been prepared by means of blending with maifanite (MFS), activated alumina (AA), and poly(vinylidene fluoride) (PVDF) and tested as a sorbent material (MFS-AA-PVDF) to remove fluoride from water. The morphology and structure of the synthetic composite films have been identified with FT-IR and SEM. Dynamic adsorption data show that the sorption of fluoride on MFS-AA-PVDF is more in line with pseudo-second-order rate equations. Fluoride in water is being adsorbed on MFS-AA-PVDF in a monolayer way described by the Langmuir adsorption isotherm. The effects of pH, temperature, and initial fluoride concentration on fluoride removal efficiency of the membrane have been investigated. The Box-Behnken design and response surface methodology have been used to further study the optimum conditions of defluoridation by MFS-AA-PVDF. The main conclusions can be drawn as follows: pH is equal to 5.02, initial concentration of fluoride 12.37 mg L⁻¹, suitable temperature 36.75 °C, and membrane/solution ratio 0.55 g/50 mL. The maximum removal rate of fluoride has been found to constitute 84.04% that is well reproducible under the optimum conditions.

This study investigates the effects of lead (Pb) on earthworm Eisenia fetida and its potential to recover from Pb exposure. Adult earthworms E. fetida were exposed for 4 weeks to lead (40–2500 mg Pb kg⁻¹) in soil, and after the period of exposure, earthworms were transferred to clean unpolluted soil for 4 weeks to recover. Pb had no effect on the earthworm’s survival but inhibited earthworm growth; growth rate decreased with Pb concentration in the soil. During the recovery period, Pb pre-exposed earthworms did not manage to recover completely their growth. Lead had a highly significant effect on the malondialdehyde (MDA) concentration during both exposure and recovery periods. Pb showed concentration dependent toxicity relationships (weight, lipid peroxidation) for total earthworm Pb concentration. However, earthworm Pb bioconcentrations after recovery period could not explain the higher MDA concentration and lower earthworm fresh weight. Earthworms pre-exposed to low Pb levels have the potential to recover their growth and decrease Pb bioconcentrations, though more prolonged recovery period is needed to full recovery.

This study uses ecological modernization and environmental transition theories to estimate the interaction among energy intensity, carbon emission and urbanization for the period of 1980–2017. We have systematically examined the empirical connections among emission, urbanization, income per capita, imports, exports, energy use, trade openness and energy intensity. The Johnson co-integration and Vector Error Correction Model (VECM) causality methods are employed for the sake of analysis. Overall findings confirm the dynamic and U-shaped relationship between emission and urbanization, and carbon emission and income per capita. The empirical results of urbanization, inflation and financial development illustrate positive association with the energy intensity, whereas trade openness, labour force participation and carbon emission show a negative association with the dependent variable. Moreover, outcomes of causality analysis provide evidence of varied causality link among the variables across the models. The study provides the implications for the decision makers in Pakistan to choose new urbanization patterns that are less reliant on energy consumption.

Heterotrophic system for carbon sequestration is gaining importance in the recent decades. Carbonic anhydrase (CA) is a major enzyme involved in carbon sequestration and biomineralization process. In this paper, we evaluate the effect of pesticide on CA activity using inhibitory assay. 2,4-D, being one of the most extensively used pesticide, being deleterious to soil health, its usage should be minimized to regain the soil health. Maximum inhibitory constant (Kᵢ) was observed for 5% 2,4-D (49.53 mM) followed by 5% glyphosate (43.92 mM). The maximum Km increase with increase in pesticide concentration by 3.05-fold was in case of glyphosate which was higher than that of 2,4-D (2.08-fold) and dichlorvos (2.38-fold). Moreover, we evaluated the carbon sequestration using CA enzyme in the soil microcosm. In the present study, we identified the negative impact of 2,4-D on carbonic anhydrase produced by Bacillus halodurans PO15. The inhibition was a mixed type and had significantly lowered the carbon reduction to about 2.38 ± 0.17% in a soil microcosm study. Based on the molecular docking, the inhibition was contributed due to weak H-bonding interaction with amino acid residues (Gly65, Gly95, Val147, Ser150 and Gly65, Ser146, and Ser150).

Feeding a growing population requires striking a balance between increasing production and decreasing environmental impacts in agricultural settings. We established 12 experimental mesocosms with silt loam atop a base of sand and examined the ability of three emergent aquatic plants common to the USA to remediate pesticides and nutrients in agricultural runoff. Mesocosms were planted in monocultures of Myriophyllum aquaticum, Polygonum amphibium, and Typha latifolia, or left unvegetated to serve as controls. All mesocosms were amended with target concentrations of 10 mg L⁻¹ (each) nitrate, ammonium, and orthophosphate; 20 μg L⁻¹ (each) of the pesticides propanil and clomazone; and 10 μg L⁻¹ of the pesticide cyfluthrin. After a 6-h-simulated agricultural runoff with amended water, mesocosms sat idle for 48 h before flushing with unamended water for another 6 h. Outflow water samples were collected and analyzed for contaminant concentrations. Most significant differences between vegetated mesocosms and controls occurred when comparing mean contaminant transfer/transformation rates post-amendment. Differences among plant species occurred regarding retention of dissolved nutrients orthophosphate, ammonium, and nitrate. Similarly, all three plant species retained more propanil than controls during post-amendment (8–48 h), but individual plant differences occurred with regard to clomazone and cyfluthrin retention. While variation in mitigation of specific dissolved components of nutrients suggests different mechanisms involved in nutrient cycling within our mesocosms, consistent overall total nutrient and pesticide reduction during the post-amendment period indicate that holding runoff in vegetated ditches may reduce transport of agricultural contaminants to downstream aquatic ecosystems.

In this presented work, poly(2-hydroxyethyl methacrylate-glycidyl methacrylate) [p(HEMA-GMA)] cryogels were prepared by using the radicalic cryopolymerization technique, and then modified with lectin protein ConA. These ConA functionalized cryogels were used for the immobilization of laccase, and enzyme loading was found to be as 7.1 mg/g cryogel. Finally, these laccase immobilized cryogels were successfully used for the decolorization of six different types of dye molecules.