The passive flux sampling is an economic and easy way to estimate gas emissions from agriculture sources. In the last decade, specific passive flux samplers (PFSs) have been developed to estimate nitrous oxide (N₂O) emissions from agriculture sources. Packed with silica gel and zeolite 5A, the PFSs were placed facing the emission source direction close to the ventilation shafts. For validation, air samples were taken at different sampling time during 3 days on two commercial sites. The adsorbed mass of N₂O in PFSs was recovered by thermal desorption in the laboratory. Results indicated that the mass of N₂O adsorbed in PFSs was from 1.5 to 5.5 μg. A specific adsorption pattern was observed for each sampling. In farm 1, the mass of N₂O adsorbed in the PFSs presented a linear behavior as a function of sampling time, and the most determined coefficient values were higher than 0.80. In farm 2, in addition to the sampling time, the N₂O concentration and the air flow rate presented an effect on the mass adsorbed in the PFSs. On the other hand, comparison of PFSs versus other techniques indicated that PFSs offer different advantages. However, the selectivity and capacity of the adsorbent bed used need to be improved to enhance the use of PFSs proposed as a tool to estimate N₂O emissions. Graphical Abstract PFSs enabled N₂O sampling that followed a linear behavior as a function of sampling time. Sampling time, [N₂O], and air flow rate determined the mass of N₂O collected in PFSs

This study considered the temporal variations in rainfall and water level patterns as governing factors, which influence the geochemical process of coastal aquifer around Pondicherry, South India. Rainfall and water level data were collected from 2006 to 2016, which showed that the amount of rainfall from 2006 to 2011 was higher than that of 2011 to 2016. To understand the geochemical process governing groundwater, samples were collected during 2006 (n = 54), followed by 2011 (n = 93), and during 2016 (n = 63) as part of continuous observation. The major ions and stable isotopes (δ¹⁸O and δD) were analyzed in the samples to determine the geochemical variations. The predominant types were noted as Na-HCO₃ and Na-Cl; Ca-HCO₃ and Ca-Mg-Cl; and Na-Cl and Ca-Mg-Cl in 2006, 2011, and 2016, respectively. Saturation states of sulfate and carbonate minerals were compared for the study periods and it indicates that the saturation index (SI) values were increased from 2006 to 2011, but decreased from 2011 to 2016. PHREEQC inverse modeling revealed the predominance for the dissolution and leaching of carbonate minerals during increased rainy periods, and the increase of halite saturation during lesser rainfall period. AQUACHEM mixing studies suggested that geochemical signatures of 2006 and 2011 were preserved in samples of 2016 in different proportions. Considering the major factors, the main processes prevailing in the study area were inferred to be dissolution and leaching during 2006~2011 years and seawater intrusion along with ion exchange during 2011~2016 years. In all these periods of study, anthropogenic impact was also identified in the groundwater samples. Hence, this study revealed that the rainfall and water level gave a significant variation in the geochemical process of groundwater in the coastal aquifer system.

Soil pollution with heavy metals is a major problem in industrial areas. Here, we explored whether zeolite addition to soil and indigenous arbuscular mycorrhizal fungi (AMF) can reduce cadmium (Cd) uptake from soil by bread wheat. We conducted a pot experiment, in which the effects of indigenous soil AMF, zeolite addition, and Cd spiking to soil [0, 5, 10, and 15 mg (kg soil)⁻¹] were tested. Zeolite addition to soil spiked with 15 mg Cd kg⁻¹ decreased the Cd uptake to grains from 11.8 to 8.3 mg kg⁻¹ and 8.9 to 3.3 mg kg⁻¹ in the absence and presence of indigenous AMF, respectively. Positive growth, nitrogen (N), and phosphorous (P) uptake responses to mycorrhization in Cd-spiked soils were consistently magnified by zeolite addition. Zeolite addition to soil stimulated AMF root colonization. The abundance of AMF taxa changed in response to zeolite addition to soil and soil Cd spiking as measured by quantitative polymerase chain reaction. With increasing Cd spiking, the abundance of Funneliformis increased. However, when less Cd was spiked to soil and/or when zeolite was added, the abundance of Claroideoglomus and Rhizophagus increased. This study showed that soil-indigenous AMF and addition of zeolite to soil can lower Cd uptake to the grains of bread wheat and thereby reduce Cd contamination of the globally most important staple food.

The advent of biotechnology provided the synthesis of nanoproducts with diverse applications in the field of medicine, agriculture, food, among others. However, the toxicity of many nanoparticles (NP) currently used, which can penetrate natural systems and impact organisms, is not known. Thus, in this study, we evaluated whether the short exposure (5 days) to low concentrations of chitosan-coated zein nanoparticles (ZNP-CS) (0.2 ng/kg, 40 ng/kg, and 400.00 ng/kg) was capable of causing behavioral alterations compatible with cognitive deficit, as well as anxiety and depression-like behavior in Swiss mice. However, we observed an anxiogenic effect in the animals exposed to the highest ZNP-CS concentration (400.00 ng/kg), without locomotor alterations suggestive of sedation or hyperactivity in the elevated plus maze (EPM) test. We also observed that the ZNP-CS caused depressive-like behavior, indicated by the longer immobile time in the tail suspension test and the animals exposed to ZNP-CS presented deficit in recognition of the new object, not related to locomotor alteration in this test. To the best of our knowledge, this is the first report of the neurotoxicity of ZNP in a mammal animal model, contributing to the biological safety assessment of these nanocomposites.

We compared the concentrations of 17 heavy metals and essential elements in post-hatching eggshells of two waterbirds, the obligate piscivorous great cormorant Phalacrocorax carbo (GCM) and the more omnivorous grey heron Ardea cinerea (GHR), breeding sympatrically in eight mixed colonies in Poland. We found significant inter-species and inter-colony differences in the levels of most of the elements. GHR had significantly higher concentrations of Al, which can be explained by its very low stomach pH: an acidic environment favours the release of Al compounds. Differences in Mn, Ni, Cu, Se and Hg concentrations can be attributed to the various contributions of fish and other aquatic organisms to the diet, and to the exploration of different habitats (GCM exclusively aquatic, GHR a wider range) and microhabitats (GCM, in contrast to wading GHR, dive for food, exploring the whole depth range of water bodies), differently exposed to contamination by those elements from sediments. Inter-colony differences were related to the level of industrialisation. We recorded higher levels of some elements in the eggshells (Fe, Mn in both species and Cr, Ni and Zn in GCM) collected in industrialised areas, which may be associated with the negative environmental impact of industrial areas.

Aluminum (Al) had well-identified adverse influences on the nervous system mainly through the creation of reactive oxygen species (ROS). Melatonin works as an antioxidant through the inhibition of ROS and attenuating peroxidation of lipids. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a pivotal transcription factor which controls the transcription of antioxidant enzymes. This study was conducted to determine the potential neuroprophylactic impacts of melatonin in aluminum chloride (AlCl₃)-initiated neurotoxicity including potential mechanism(s) of action and relevant signaling in rats. Thirty-six male rats were distributed into 4 groups: Control; AlCl₃ (50 mg/kg bwt, i.p, 3 times weekly for 3 months); melatonin (5 mg/kg bwt, i.p daily for 2 weeks before AlCl₃ and sustained for the next 3 months); and melatonin with AlCl₃. Neuronal alterations were histopathologically and biochemically evaluated. The neuronal antioxidant-related genes and relevant Nrf2 protein expression were determined by real-time PCR and Western blotting, respectively. The current data showed a substantial increase in brain damage biomarkers, acetylecholinesterase (AchE) activity, and malondialdehyde (MDA) content while the enzymatic antioxidant expression as glutathione-s-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) were substantially attenuated in the aluminum-treated group, with cleared histopathological changes as inflammatory cell infiltration with neuronal degeneration. Supplementation of melatonin resulted in an obvious amelioration in all previous abnormal alteration observed in AlCl₃-treated rats rather than increased Al burden and/or altered Fe and Cu homeostasis with upregulating both total and phosphorylated Nrf2 expression. Therefore, the study concluded that melatonin has a potential ability to be neuroprophylactic against Al-induced neurotoxic effect and oxidative damage in the rat brain through upregulating and instigating Nrf2 signaling apart from metal chelation.

Freshwater lakes provide critical ecological services to the local ecosystem. However, many of them are facing serious challenges, such as ecosystem degradation and water contamination, due to irrational water utilization and a lack of effective management. Under such a circumstance, it is crucial to examine the ecosystem services of freshwater lakes and uncover the driving forces so that appropriate protection policies can be raised. This study aims to fill such a research gap by employing an emergy accounting method. A case study of Erhai Lake (the second largest freshwater lake in Yunnan province, southwest China) was conducted for the period of 2001–2015. Driving forces that affect ecosystem services were analyzed by using Logarithmic Mean Divisia Index (LMDI). Results show that the total ecosystem services of Erhai Lake were reduced from 334.03E + 18 sej in 2001 to 274.37E + 18 sej in 2015. This was caused by the obvious decline of regulating services and supporting services, far exceeding the increase of provisioning services and cultural services. In 2015, two types of increased services that benefit human life in the market became the primary services of Erhai Lake. And their proportions were far beyond the two reduced ones that were overlooked due to their public and free attributes. The key driving forces include economic scale factor (∆EES), the fast and intensive economic activities. This development was at the cost of environmental degradation based upon the analysis of emergy benefit factor (∆EEB). Finally, several suggestions are presented. This study provides valuable insights to understand ecosystem services of freshwater lakes so that a sustainable development pathway can be found to protect such freshwater lakes.

The objectives of this study were to determine the biofilm microbial activity and bacterial community structure and successions in greywater treatment filters and to relate the treatment efficiency to the bacterial community parameters. This 10-month study was performed in a newly established experimental system for domestic greywater treatment that consisted of three parallel vertical flow filters (VFs) followed by a horizontal flow filter (HF). A rapid increase in the bacterial community abundance occurred during the first 85 days of filter operations, followed by a short-term decrease and the stabilization of the 16S rRNA gene copy numbers at average levels of 1.2 × 10⁹ and 3.2 × 10⁸ copies/g dw in VFs and HF, respectively, until the end of the experiment. The dominant bacterial phyla and genera differed between the VFs and HF. The temporal variation in the bacterial community structure was primarily related to the species replacement, and it was significantly affected by the influent organic carbon and nitrogen compounds in the VFs and the ammonia and organic carbon in the HF filters. Despite the differences in the community structure and assembly mechanisms, the temporal dynamics of the bacterial community showed high congruence between the filter types. The treatment efficiency was related to the biofilm bacterial community diversity and abundance and the abundance of certain bacterial genera in the VF filters. The results suggest that the dominant pathway of nitrogen removal by greywater treatment VFs occurs via coupled heterotrophic nitrification and denitrification, while the contribution of aerobic denitrification is temporally variable in these filters.

Hydroponic experiments were conducted to investigate the role of different root plaque formation on oxytetracycline (OTC) uptake/translocation by rice seedlings (Oryza sativa L.) and solution–OTC elimination at two initial OTC concentrations (10 and 30 mg L⁻¹). The results indicated OTC accumulation in rice was always in the order root surface > shoot > inside root whether plaques were formed or not. It demonstrated that Fe–Mn–Mt (montmorillonite) treatment was easier to promote significantly (p < 0.05) OTC accumulation in the underground part (root surface and inside root) and decrease significantly (p < 0.05) OTC translocation from the root to the shoot in rice compared to no plaque treatments (CK), especially for OTC 30 mg L⁻¹ level with the lowest shoot–OTC accumulation in Fe–Mn–Mt treatment. Plaque treatments increased half-life of solution–OTC elimination in the order Fe–Mn–Mt > Fe–Mn > Fe > CK, which was caused mainly by OTC degradation from Fe²⁺-binding influence in solution, not by the enhancement of OTC accumulation on the root surface and inside root. And solution–OTC elimination increased with decreasing initial OTC concentrations, the drop of Fe²⁺ and the increment of Fe³⁺ and pH during the experiment. These findings are useful for reducing OTC accumulation and translocation in rice aboveground parts and eliminating OTC contamination in agricultural environment simultaneously through complicated plaque formation under higher OTC concentration exposure (30 mg L⁻¹) in the future design.

The present study describes the experimental and numerical analysis of the combustion and emission characteristics of CI engine operated with diesel-butanol blends. Experiments were carried with neat diesel fuel (i.e., Bu00) and its blends of n-butanol, 10%, 20% and 30% by volume (Bu10, Bu20 and Bu30) at a constant speed and rated load. From the experimental results, it is observed that CO, NOₓ and smoke emissions decreased, whereas the unburned hydrocarbon (UBHC) emission increased with increasing butanol content, as compared to Bu00. From the experimental analysis, it is also observed that Bu20 blend gives higher brake thermal efficiency (BTE) and lower brake specific energy consumption (BSEC) as compared to Bu00, Bu10 and Bu30, but produces higher UBHC. In order to decrease the UBHC emission, different piston bowl geometries were analysed using simulation studies. The combustion and emission characteristics of the CI engine operating with Bu20 blend for three different piston bowl geometries viz., hemispherical combustion chamber (HCC), shallow combustion chamber (SCC) and toroidal combustion chamber (TCC), were studied using CONVERGE CFD code. The simulation model was validated with experimental results of the baseline engine configuration (HCC) for diesel fuel as well as Bu20 blend. The results showed that there is a significant reduction in UBHC and improvement of performance for SCC and TCC piston geometry compared to HCC piston geometry. However, a slight increment of NOₓ emissions was observed.