This work studies the reduction of biological and organic compounds in hospital wastewaters (HWW) by advanced oxidation process (AOP). The HWW samples were previously treated with an extended aeration process and, thereafter, a post-treatment with AOP based on UV/H₂O₂/O₃ system with a medium pressure mercury lamp was applied. After using the AOP system, the water samples were characterized using chemical oxygen demand (COD), turbidity, color test, coliforms and E. coli test, gas chromatography coupled to mass spectrometry (GC-MS), and UV-Visible absorption spectra. The results showed that 73% of organic compounds were removed in 20 min and the HWW sample was sterilized; nevertheless, 10 persistent organic compounds and 8 by-products formed after AOP UV/H₂O₂/O₃ were observed, some of them are toxic compounds. In this sense, current HWW treatment plants cannot eliminate all contaminants in HWW; therefore, it is necessary to improve current processes by techniques as AOP and create standards to control biological and organic compounds in HWW in Mexico

Summarized the heavy metal pollution caused by natural and human activities. The natural causes include the migration and redistribution of soil debris and the hydraulic migration of soil parent rock with high background value under the action of wind; human factors include mining, abandoned mining areas, fertilizer and pesticide application, and sewage irrigation. By examining the sources of heavy metals in soil, the temporal and spatial variation and source variation of heavy metal pollution can be summarized, and then find a reasonable way to intervene as early as possible from the origin to reduce the harm of this pollution to the soil. Finally, future research trends and key problems were indicated, which laid a theoretical foundation for further effective research. Graphical abstract

Lead is a metal capable of affecting physiology and metabolism in fish, including Nile tilapia (Oreochromis niloticus). However, few studies have evaluated the effects of lead on digestive enzyme activities in fry. At that stage, independent feeding begins, and there is increased demand and consumption of food, so chronic exposure to metal during this stage of development would cause null or minimal growth in organisms. In this study, fry from Nile tilapia was used to evaluate the effects of lead acetate by chronic exposure on the growth and the activities of the digestive enzymes after 30 and 60 days exposures. Four treatment groups 0.025, 0.050, 0.075 and 0.100 mg/L of lead acetate and a lead-free control were established. The activity of enzymes decreased, in the case of acidic proteases after 30 days and lipases after 60 days of exposure, from 0.025 and 0.050 mg/L of lead acetate, respectively. The amylase activity increased in metal-treated, while the chymotrypsin decreased partially at 60 days. Lipases decreasing activity might be causing an increase of triglycerides (lipids) and body mass observed during the first 30 days of exposure. Concentrations, equal to or above 0.075 mg Pb/L, cause significant effects on size and weight of fry, with nearly 54% lower than controls. At chronic exposure and early stage of development, the enzymatic activity is partially reduced along with body weight gain, which would affect subsequent growing and aquaculture production. The digestive enzyme response is discussed as a possible limited biomarker of exposure, to be used in biomonitoring.

This study contemplates the effectiveness of the cognitive CEO on corporate environmental performance for the 1058 listed Chinese firms on Shenzhen and Shanghai stock exchanges for the years 2015–2019. The contributive concept of the cognitive CEO has been demonstrated through CEO tenure, education, goodwill, and attainment of tacit knowledge while implementing the DAE statistical technique. Additionally, the corporate environmental performance has been formulated, signifying the eight environmental attributes. Convincingly, innovation is intertwined with corporate environmental responsibility, which has been analyzed as a mediator. Remarkably, our findings envisage the cognitive CEO as a promoter of corporate environmental responsibility. Meanwhile, under the patronage of the cognitive CEO, innovation output has been ascertained as a vigorous intensifier of corporate environmental performance as compared with innovation input. Moreover, firms exhibiting specific characteristics like firm age, presence of independent directors, and being a state-owned enterprise proclaim their orientation towards corporate environmental responsibility. Specifically, under the patronage of stakeholder theory, empirical results have been interpreted. Significantly, the integrity of empirical results has been authenticated via the execution of GMM instrumental regression. Lastly, the implication of the study recommends the mangers, academicians, and organizational theorists to perceive the significance of cognitive CEO who can manage the funds for both innovation and corporate environmental responsibility.

Diuron is one of the major hazardous pollutants which posses severe risk to the environment and human healthiness. On the other hand, salinity is the most severe environmental stressor that limits crop productivity. Therefore, it is required to address this co-existing abiotic stresses in agricultural soil. Plant growth–promoting rhizobacteria have gained an engaging role in the degradation of pesticides in agricultural soil. However, their role against the restoration of diuron-contaminated saline soil is still not known. Thus, in this study, diuron-degrading, salinity-tolerant Stenotrophomonas rhizophila strain CASB3 was isolated and characterized. Strain CASB3 showed important PGP traits under normal and diuron or salt stresses. Complete degradation of 10–50 mg L⁻¹ diuron in the aqueous medium under normal and salinity stress conditions was achieved within 48–120 h and 48–192 h, respectively. A unique pathway for diuron biodegradation was proposed based on GC-MS analysis. In a greenhouse study, CASB3 inoculated into diuron-contaminated saline soil efficiently degraded diuron (50 mg kg⁻¹) by 94% in 42 days and simultaneously resulted in an enhancement of root-shoot length (47.22–63.41%), fresh-dry biomass (136.36–156.66%), and photosynthetic pigments (36.93–92.28%) in Lactuca sativa plants. These results suggest the strain CASB3 could be used as a bioresource for the reclamation of diuron-contaminated saline soils.

Long-term disposal of tannery waste and effluent without rigorous treatment may result in severe chromium (Cr) contamination in soils. In order to reduce the toxicity of Cr in soil, rice straw was co-pyrolyzed with Cr-contaminated soil under 0.5 MPa pressure. The influences of co-pyrolysis temperature (100–300 °C) and rice straw/soil mixing ratio (0–20 wt%) on Cr immobilization were investigated. The synthetic precipitation leaching procedure (SPLP), total Cr(VI) measurement, and simple bioaccessibility extraction test (SBET) were conducted, and results showed that the leachable Cr, total Cr(VI), and bioavailable Cr in co-pyrolyzed soils were significantly decreased (up to 95%, 86%, 70%, respectively) compared with untreated soil. BCR sequential extraction also indicated that mobile fractions (F1, F2) of Cr were transformed to more stable fractions after pressurized co-pyrolysis treatment. Time-varying desorption tests showed that the pseudo-second order kinetic model fitted better (R² > 0.9) in all samples and co-pyrolysis could effectively reduce Cr desorption when extracted by citric acid, nitric acid, and CaCl₂ solution. X-ray diffraction (XRD) revealed that unstable forms of Cr transformed to stable Cr species and Cr(III) was the dominant species in the soil. In conclusion, pressurized co-pyrolysis of Cr-contaminated soil with 20% of rice straw at 300 °C effectively immobilized Cr and reduced Cr(VI), making it a promising method to minimize the potential bioavailable risk of Cr in soil.

The mining sector has great importance to the economic activity in Brazil. However, it is also responsible for several environmental impacts such as the rupture of the Fundão dam (Mariana, Brazil) that resulted in the spillage of 50 million m³ of mining tailings in the Doce River Basin. This study evaluated the acute and chronic effects of Fundão tailings on growth, development, respiration rates, swimming performance, and avoidance behavior of Lithobates catesbeianus tadpoles. Results showed that 96-h exposure to different dilutions (10, 25, 50, 75, and 100%) of a stock solution containing mining tailings (50 g/L) caused no mortality of tadpoles; however, the most concentrated solution decreased the swimming speed of the animals. After 16 days, tadpoles exposed to 25, 50, and 100% treatments had both swimming speed and distance traveled reduced. Oxygen consumption was also decreased in tadpoles exposed to the 100% solution after 20 days. Avoidance test indicated that tadpoles avoided lower tailing concentrations, but a reduced avoidance response was attested to the higher concentrations, probably due to the toxic effects of the residues that prevented animals’ displacement. Chemical analysis confirmed the occurrence of cadmium (Cd), lead (Pb), iron (Fe), manganese (Mn), zinc (Zn), and aluminum (Al) in Fundão tailings and its presence in the mouth and inside the intestine of treated tadpoles indicated the ingestion of metals by these organisms. This study showed that even presenting low lethal toxicity, long-term exposure to mining tailings from Fundão dam caused morphophysiological and behavioral damage in tadpoles.

The current study deals with the adsorption of hexavalent chromium using acid (H₃PO₄)-activated water caltrop (Trapa natans) shell (PWCS) using an up-flow packed bed column. Characteristics of breakthrough curve was obtained by investigating the effect of several operating parameters viz. inlet flow rate (2–6 mL/min), initial metal ion concentration (50–150 mg/L), and adsorbent’s column bed height (1–3 cm). Elevated time of breakthrough curve was reported with elevated adsorbent bed height and vice versa with enhanced initial metal concentration and inlet flow rate of sorbate solution. Process design and breakthrough curves under varying conditions were predicted by applying column models like Thomas model, Adams–Bohart model, Yoon Nelson model, and bed depth service Time (BDST). Column behavior was better described by the BDST and Thomas model and simultaneously gave a good fit with the experimental data of breakthrough curves. The percentage removal for Cr(VI) from aqueous solution having pH 2 and temperature 303.15 K was observed to be 52.46%. The maximum adsorption capacity was found to be 87.31 mg/g according to the Thomas model. Conclusively, phosphoric acid–modified T. natans shell (PWCS) showed better sorption potential for of Cr(VI) species from simulated wastewater.

Respiratory diseases’ mortality and morbidity have been a major public health burden primarily attributed to widespread exposure to indoor and outdoor pollutants in the environment. The study conducted among 510 Bangladeshi women residing in the northeastern zone of the Sylhet division from semi-urban and rural settings to compare the biomass fuel users (N = 255) with the non-biomass users (N = 255). It has been observed that all the symptoms had a higher prevalence among the women who were exposed to biomass fuel compared with those exposed to clean gas fuel. Women exposed to biomass group reported frequent cough and phlegm production episodes during a 3-month timeline before the survey period which was found statistically higher (p < 0.001) compared with that of the clean gas fuel group. Moreover, the use of biomass fuel has been associated with a significant decrease in forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and peak expiratory flow rate (PEFR). Appropriate strategies from stakeholders and government authorities in disseminating health hazards from biomass fuel along with supporting the community by providing alternative energy sources for cooking can largely impact people’s lives.