Conventional leather processing poses serious threat to the environment due to its numerous chemical treatments which include hazardous chemicals such as sodium sulphide and lime. To minimise the pollutants and harmful substances during leather processing, an enzymatic rehydration–dehairing–fibre-opening process has been achieved in shortest possible time compared to conventional process. The physicochemical characteristics of experimental leathers were found to be comparable with those of conventionally processed leathers. The releases of sugar and proteoglycans were found to be in congruence with the scanning electron micrographs and histology. TGA and DSC results ascertained the stability of enzymatically processed leathers. Pollution load in terms of TOC, BOD, COD, and TDS was reduced up to 80% compared to that of the conventional process. The present work provides immense potential for a new approach in leather making with environmental safeguards. Graphical abstract

Five field tracer experiments and relevant detailed investigations of physical characterizations were conducted to investigate the effects of channel geomorphic settings on nitrate uptake efficiency on a 310-m long geomorphically distinct stream reach in a headwater agricultural stream in Hefei District, Lake Chaohu Basin. The model-fitted parameters from the one-dimensional transport with inflow and storage model were used to estimate the transient storage metric ([Formula: see text]) and determine the total nitrate uptake coefficient (k) for the study reach. And then, a nutrient spiraling approach was applied to reach-scale nitrate uptake estimates (Sw, Vf, and U). The results showed that the main channel was the major contributor to nitrate uptake retention, and the higher geomorphic complexity might result in better nitrate uptake efficiency. The partial least squares regression (PLSR) analysis showed strong correlations between the independent variables as geomorphic settings, Reynolds number and transient storage, and the dependent variables as nitrate uptake metrics, which further underscored the importance of stream physical characteristics on measurement of stream nitrate uptake.

Cadmium is an important widely distributed heavy metal in the environment due to its several industrial uses, while milk thistle is an important herb and is a source of several antioxidant particularly silymarin which is a pharmacological active substance present in seeds of milk thistle plant (Silybum marianum). The current study investigated pathological effects of cadmium (Cd) and their amelioration with silymarin (SL) and milk thistle (MT) quails. A total of 144 quails were equally divided into 9 groups and given different combinations of cadmium chloride (150 and 300 mg/kg feed), SL (250 mg/kg), and MT (10 g/kg) feed. Parameters studied were clinical signs, mortality, organ weights, testes weight and volume, and gross and microscopic pathology. Results of this study indicated an increased mortality and reduced body weight in cadmium-treated quails. Quails were dull, depressed compared with control. Swollen hemorrhagic liver along with atrophied testes were also observed in these groups. No active spermatozoa were observed in lumen of seminiferous tubules of Cd-treated birds presenting arrest of spermatogenesis. Supplementing MT and SL ameliorated mortality, organ weights, spermatogenesis, and histopathological lesions. It may be concluded that MT and SL proved beneficial in cadmium-induced toxicities in Japanese quails.

The increasing load of nanoplastic pollution in the environment has become a major concern toward human and environmental safety. The current investigation mainly focused on assessing the toxic behavior of nanoplastics (polystyrene nano-spheres (PNS)) toward blood cells and marine crustacean. The study also investigated the temporal stability of PNS under different water matrices and its size-dependent sedimentation behavior in the sea water dispersion. The nano-dispersion showed mean particle size of 561.4 ± 0.80 and 613.7 ± 0.11 nm for PNS 1 and 781.4 ± 0.80 and 913.7 ± 0.11 nm for PNS 2 in lake and seawater, respectively after 48-h incubation, which is ~ 8-fold increase from its original size. The LC50 value against Artemia salina and lymphocytes were found to be 4.82 and 8.79 μg/mL, and 75 μg/mL, respectively for PNS 1 and PNS 2. The genotoxic study reveals that around 50% of lymphocytes were affected by both PNS at 50 μg/mL concentration, whereas the cytotoxic studies on RBC and lymphocytes showed 50% toxicity only at 100 μg/mL concentration. The genotoxic study displayed numerous tri- and multi-nucleated cells. The biochemical profile of A. salina exposed to lethal concentration demonstrated a significant decrease in the total protein, reduced glutathione, and catalase activity and increase in lipid peroxidation activity as a result of PNS permeation to tissues. In conclusion, the present study demonstrated that the polystyrene nano-spheres are emerging pollutant in the environment and are hazardous to humans.

Karst processes play an important role in the global carbon cycle. Aquatic phototrophs can transform bicarbonate, which is mainly derived from the weathering of carbonates, into organic carbon. Carbonate mineral weathering coupled with aquatic photosynthesis can be considered a stable and durable carbon sink process. In this study, we addressed seasonal variations in water chemistry in the Lijiang River Basin, which is a typical karst basin, through a comprehensive geochemical study of the river water in four seasons. The parameters were measured in situ, including major ions and isotopes of inorganic and organic carbon. The results showed that (1) DIC was mainly derived from the weathering of carbonates; (2) the transformation from bicarbonate to organic carbon by aquatic phototrophs was evident, and the water chemistry changed, especially in spring and autumn and in the mainstream from Guilin to Yangshuo, which benefited the growth of aquatic phototrophs; and (3) the organic carbon derived from bicarbonates by aquatic phototrophs was nearly half the total organic carbon and 8% of the dissolved inorganic carbon. These results imply that aquatic phototrophs in karst basins can significantly stabilize carbon originating from carbonate rock weathering processes in karst areas.

The pollutants’ emissions from on-road transport are critical pressure on the climate change scenario, and most developing countries rely on mostly diesel transportation. The current study aimed to estimate the environmental impact of the distance from the agricultural production area of fresh food (papaya, potato, and tomato) to a fresh food distribution center located in Campinas, Sao Paulo, Brazil. The way the products were carried was assessed for calculating the total transported volume. The total amount carried was measured, considering the number of trips multiplied by the total distance traveled within a year of supply. An online calculator was used to evaluate the amount of CO₂ emission, and to allow the estimative of the amount of CO₂-eq, that is the Global Warming Impact (GWP) in 100 years. The highest CO₂ emission was identified in the potato transported from Paraná State to the distribution center, with a CO₂-eq emission of 3237 t/year (64% of contribution), followed by the papaya from Bahia State (2723 t/year, 42% of contribution), and the tomato from Sao Paulo State (625 t/year, 71% of contribution). However, when computing the GWP, the highest value was found in the transport of potato from the Minas Gerais State (8 × 10⁻² in 100 years) followed by the papaya from Rio Grande do Norte State (5 × 10⁻² in 100 years) and the papaya from Bahia (3 × 10⁻² in 100 years). The higher the amount of product transported by a trip, the smaller the environmental impact in the long run. A proper strategy to reduce the environmental impact would be to have large freight volume when transporting food from vast distances within continental countries.

To investigate how the organic fouling layers on nanofiltration (NF) membrane surface and the strong matrix effect (particularly by Ca²⁺) influence the rejection of trace organic compounds (TOrCs), filtration experiments with two TOrCs, bisphenol A (BPA) and sulfamethazine (SMT), were carried out with virgin and organic-fouled NF membrane. Organic fouling layer on the membrane was induced by sodium alginate (SA) at different concentrations of Ca²⁺. The results indicated that NF membrane maintained consistently rejection of TOrCs with little influence by membrane fouling at lower Ca²⁺ concentration. In contrast, organic fouling caused at higher concentration of Ca²⁺ observably restrained the rejections of both BPA and SMT. Furthermore, based on the cake-enhanced concentration polarization (CECP) model, the rejection of TOrCs was divided to the real rejection and the mass transfer coefficient. Moreover, it was found that the decrease in rejection resulted by organic fouling was due to the real rejection that was restrained by fouling layer with irregular impact on the mass transfer coefficient. Although the mechanism of trace compounds rejection was complex, the controlling factors varied among foulants. Nevertheless, the steric effect of the cake layer played an important role in determining solute rejection by organic-fouled NF membrane.

In this study, we have investigated UV-B-induced alterations including chloroplast ultrastructure, chlorophyll fluorescence parameters, physiological metabolism, and chloroplast proteome profile. Comparison of seedling phenotypic characterization and physiological status revealed that the low level of 1.08 KJ m⁻² of UV-B irradiation had no obvious effects on seedling phenotype and growth and maintained better chloroplast ultrastructure and higher photosynthetic efficiency. Nevertheless, the high dose of 12.6 KJ m⁻² of UV-B stress caused significant inhibitory effects on the growth and development of wheat seedlings. Proteomic analysis of chloroplasts with or without 1.08 KJ m⁻² of UV-B irradiation identified 50 differentially expressed protein spots, of which 35 were further analyzed by MALDI-TOF/TOF mass spectrometry. These proteins were found to be involved in multiple cellular metabolic processes including ATP synthesis, light reaction, Calvin cycle, detoxifying and antioxidant reactions, protein metabolism, malate and tetrapyrrole biosynthesis, and signal transduction pathway. We also identified 3 novel UV-B-responsive proteins, spots 8801, 8802, and 9201, and predicted three new proteins might be UV-B protective proteins. Our results imply chloroplasts play a central protective role in UV-B resistance of wheat seedlings and also provide novel evidences that UV-B stress directly affects on the structure and function of chloroplasts and explore molecular mechanisms associated with plant UV-B tolerance from chloroplast perspective.

Production of Scenedesmus sp. biomass in chicken slaughterhouse wastewater (CSWW) is a promising alternative technique for commercial culture medium due to the high nutritional content of the generated biomass to be used as fish feeds. The current work deals with optimising of biomass production in CSWW using response surface methodology (RSM) as a function of two independent variables, namely temperature (10–30 °C) and photoperiod (6–24 h). The potential application of biomass yield as fish feeds was evaluated based on carbohydrate, protein and lipid contents. The results revealed that the best operating parameters for Scenedesmus sp. biomass production with high contents of carbohydrates, proteins and lipids were determined at 30 °C and after 24 h. The actual and predicted values were 2.47 vs. 3.09 g, 1.44 vs. 1.27 μg/mL, 29.9 vs. 31.60% and 25.75 vs. 28.44%, respectively. Moreover, the produced biomass has a high concentration of fatty acid methyl ester (FAME) as follows: 35.91% of C15:1; 17.58% of C24:1 and 14.11% of C18:1N9T. The biomass yields have 7.98% of eicosapentaenoic acid (EPA, C20:5N3) which is more appropriate as fish feeds. The Fourier transform infrared (FTIR) analysis of biomass revealed that the main functional groups included hydroxyl (OH), aldehyde (=C–H), alkanes and acyl chain groups. Scanning electron micrograph (SEM) and energy-dispersive X-ray spectroscopic analysis (EDS) indicated that the surface morphology and element distribution in biomass produced in BBM and CSWW were varied. The findings have indicated that the biomass produced in CSWW has high potential as fish feeds.

The removal of three over-the-counter pharmaceuticals from aqueous solution using four different adsorbents was analyzed. To study the effect of infused pharmaceutical and adsorbent on the adsorption system, both the concentration of drug and adsorbent dosage were varied, with constant temperature and pressure at different contact time. Adsorption kinetics, isotherm models, and ANOVA allegorized a generic trend for pharmaceutical removal efficiency of the adsorbents that varied as follows: activated carbon > fly ash > bentonite > sugar cane bagasse ash. The Tempkin model appears to fit the isotherm data better than Freundlich and Langmuir. Correspondingly, the kinetic studies implied a pseudo-second-order fit, to understand the mechanism by which the solute accumulates on the surface of a solid and gets adsorbed to the surface via intra-particle diffusion. Furthermore, some special cases of removal tendencies were noted based on sorbate-sorbent interaction. Effectively, it was observed that at an adsorbent loading of 2 g and initial concentration of 0.2 mmol L⁻¹, bentonite, fly ash, and activated carbon were able to strip more than 80% of all pharmaceuticals from urine. A framework for the highest significance of the experiments was obtained using response surface methodology by the combination of ciprofloxacin-bentonite followed by paracetamol-activated carbon and ibuprofen-activated carbon. Quasi-Newton and Bayesian regression methods were implemented on Langmuir isotherm by designing the neural network for the batch adsorption experiments. Based on the numerical calculations and graphical representations, the proposed model leads to the result that error is minimized and the values are optimized for different pharmaceuticals such as paracetamol, ibuprofen, ciprofloxacin that can be removed from wastewater streams by locally available adsorbents. Graphical abstract