The safe disposal of industrial effluents always remained a challenging process because of their high level of nutrients, toxic elements, and salts. A pot experiment was conducted to investigate the effects of various concentrations (5%, 10%, 15%, and 20%) of sugar industry effluent spentwash (SW) fertigated with tab water (TW), on soil properties, crop growth, physiological parameters, yield components, and accumulation of potentially toxic elements (PTEs) in rice (Oryza sativa L.) grains and straw. The results showed that soil physico-chemical properties were modified with rise in SW concentration. Application of 5% SW significantly enhanced the plant growth, and yield components. Photosynthesis rate, transpiration rate, and stomatal conductance were significantly higher under 5% SW concentration in comparison with control. However, SW concentrations of > 5% showed inhibitory effects for all growth, physiological, and yield components. Accumulation of PTEs showed increasing trend with rise in SW concentration. However, under 5% SW concentration, all the PTEs in rice grain and straw were within the permissible limits (PLs) recommended by FAO/WHO and no health hazards were detected by health risk assessment. Based on the study results, 5% SW fertigation with TW can be applied as fertilizer for enhancing the growth and productivity of rice. Graphical abstract

Catalytic reduction of Cr(VI) to less toxic Cr(III) form using metal nanoparticles is one of the novel approaches adopted to deal with Cr toxicity. In this work, we report the fabrication of a facile, reusable, and robust Pd nanoparticles-immobilized catalytic reactor (Pd-NICaR) system using green, environment-friendly gamma radiolytic, and plasma polymerization processes. A room temperature, RF-powered plasma polymerization process was employed to functionalize a polyethylene–polypropylene (PE–PP) non-woven matrix with epoxy group containing monomer 2,3-epoxypropyl methacrylate (EPMA). EPMA-functionalized PE–PP (EPMA-f-PE–PP) substrate was subsequently used as a template for in situ generation and immobilization of Pd NPs via gamma radiolytic route. The samples were characterized using FTIR, SEM, XPS, and XRF techniques. The catalytic efficacy of Pd-NICaR towards Cr(VI) reduction, in the presence of formic acid (FA) as a reductant, was investigated spectrophotometrically, and reaction parameters were optimized at reaction temperature of 50 °C and [FA]/[Cr(VI)] = 680 to achieve catalytic reduction efficiency of 99.7% within 10 min in batch process. The system showed excellent reusability (~ 20 cycles) and storage stability (> 30 days) without substantial loss (~ 11%) of activity. Practical applicability of the robust catalytic system towards Cr(VI) toxicity mitigation was established in continuous flow mode using a fixed-bed column reactor.

Loss of suitable seminatural habitats and homogenization of crop types have led to the population decline of pollinating insects in farmland. As these insects support crop production, many practical efforts aim to sustain pollinator diversity which is especially challenging in intensively managed and homogeneous farmland. However, there are ongoing changes of the farmland toward its multifunctionality that includes, for example, wind farm development. Windmills are often built within crops; thus, we examined if the noncropped area around windmills can be valuable habitats for wild plants and pollinating insects: bees, butterflies, and flies. Species richness, abundances, and species diversity index of plants and pollinators around windmills were similar to those found in grassland patches (a typical habitat for these insects) and higher than in the adjacent crops. Pollinator diversity index and species richness at windmills increased with the distance to the nearest grassland patch and windmill. The population sizes of pollinating insects were also positively associated with plant diversity. Particular groups of pollinators showed specific habitat associations: bees occurred mostly at windmills, butterflies were highly associated with grasslands, while flies occurred in a similar number at windmill and on grasslands. Since windmills are frequently built within extensive homogeneous fields, thus, they introduce pollination services into the interior of cropped areas, contrary to field margins, road verges, or seminatural grasslands. Thus, although the development of wind farms has various negative environmental consequences, they can be alleviated by the increase of the local population size and diversity of wild plants and pollinating insects at windmills.

In the hilly areas of southern China, uplands and paddies are located adjacent to each other. Using rice straw as mulch for upland soil may improve crop production and partially replace chemical fertilizers, which may mitigate N₂O emissions. A field experiment was conducted to investigate the potential of rice straw mulching for mitigating N₂O emissions and increasing crop production. The treatments included no mulching (CK), 5000 kg ha⁻¹ of straw mulching (SM5), and 10,000 kg ha⁻¹ of straw mulching (SM10). Moreover, all the treatments received equivalent amounts of nitrogen, phosphorus, and potassium from chemical fertilizers plus rice straw. Relative to CK, cumulative N₂O emissions decreased by 23.1 and 33.5% with SM5 and SM10, respectively. Significant positive correlations were observed between N₂O fluxes and soil water-filled pore space (WPFS) (r ² = 0.495, P < 0.05) and between seasonal cumulative N₂O fluxes and the chemical N fertilization rate (r ² = 0.814, P < 0.05). These findings indicate that soil WPFS was the key environmental factor in N₂O emissions and that the substitution of chemical nitrogen fertilizer with rice straw was the main driver of N₂O mitigation. Relative to CK, the maize yield increased by 16.5 and 29.6% with SM5 and SM10, respectively, which can be attributed primarily to the increases in soil moisture. The chemical fertilizer input could be decreased and N₂O emissions could be mitigated through straw mulching, while achieving improved crop yield. This management strategy has great potential, and this study provides an important reference for low-carbon agriculture.

Removal of emerging pollutants, such as pharmaceuticals, from wastewater is a challenge. Adsorption is a simple and efficient process that can be applied. Clays, which are natural and low-cost materials, have been investigated as adsorbent. In this work, raw vermiculite and its three modified forms (expanded, base, and acid/base treated) were tested for removal of a widely used antidepressant, venlafaxine. Adsorption kinetics followed Elovich’s model for raw vermiculite while the pseudo-2nd order model was a better fit in the case of other materials. Equilibrium followed Langmuir’s model for the raw and the acid/base-treated vermiculite, while Redlich-Peterson’s model fitted better the expanded and the base-treated materials. The adsorption capacity of vermiculite was significantly influenced by the changes in the physical and chemical properties of the materials caused by the treatments. The base-treated, raw, and expanded vermiculites showed lower maximum adsorption capacities (i.e., 6.3 ± 0.5, 5.8 ± 0.7, 3.9 ± 0.2 mg g⁻¹, respectively) than the acid/base-treated material (33 ± 4 mg g⁻¹). The acid/base-treated vermiculite exhibited good properties as a potential adsorbent for tertiary treatment of wastewater in treatment plants, in particular for cationic species as venlafaxine due to facilitation of diffusion of the species to the interlayer gallery upon such treatment. Graphical abstract ᅟ

The concentration of pollution directly determines the occupational health risk, and the exposure time is an important influencing factor. We evaluated the inhalation risks of working in a printing room. Eight units with centralized printing rooms were randomly selected. Formaldehyde, ozone, benzene, toluene, xylene, and fine particulate matter were detected by spectrophotometry, gas chromatography, and direct reading instruments, respectively. The U.S. EPA inhalation risk assessment model was used to assess cancer and non-cancer risks. The formaldehyde inhalation cancer risk value was 1.35–3.45 × 10⁻⁶, which is greater than the limit of 1 × 10⁻⁶, suggesting a risk of squamous cell carcinoma. The benzene inhalation cancer risk in five of the rooms was 1.09–4.65 × 10⁻⁶, which is greater than the limit of 1 × 10⁻⁶, suggesting a risk of leukemia. In terms of non-cancer risk, in five of the rooms, the hazard quotient (HQ) was > 1 (range 1.99–4.69) due to benzene pollution, suggesting a risk of reduced lymphocyte count. In one room, due to benzene and xylene pollution, the HQ was > 1, suggesting a risk of lymphocyte count drop and motor coordination impairment. Collectively, the study concludes that staff members of printing rooms are exposed to both cancer and non-cancer occupational health risks.

The combined effect of Vitashield 40EC (chlorpyrifos ethyl-CPF) and Bassa 50EC (fenobucarb-F) was compared with the effects from exposure to the two pesticides separately, by measuring the brain acetylcholinesterase (AChE) activity in climbing perch fingerlings (Anabas testudineus). The experiment was conducted under controlled laboratory conditions and included three treatments containing 0.173 mg/L of CPF, 1.137 mg/L of F, 0.173 mg/L of CPF + 1.137 mg/L of F (M), and a control. The inhibition of the brain AChE activity in fish exposed to F was weaker and shorter than in fish exposed to CPF. The inhibition by the mixture of CPF and F was significantly lower and less prolonged than the inhibition by only CPF but significantly higher than the inhibition by only F.

It has become a great habit for driving to work in people’s daily life in China. In order to understand the concentration of volatile organic compounds (VOCs) in vehicles and the health risks related to inhalation exposure to VOCs, this study investigated the pollution characteristics and health risks posed by VOCs emitted from interior materials in vehicles. A total of 47 of 62 VOCs were studied, using 23 randomly selected vehicles of different brands in Nanjing city, China. The potential cancer and non-cancer health risks associated with VOC inhalation were assessed based on conventional approaches proposed by the United States Environmental Protection Agency (USEPA). The mean concentration of total VOCs was 1126.85 μg/m³, with a range of 321.29 to 2321.94 μg/m³. Of these, halohydrocarbons and aromatic hydrocarbons were the dominant components of the detected VOCs. The concentrations of several individual VOC exceeded more than 100 μg/m³. The individual mean cancer risks for the 17 health-related VOCs ranged from 4.64 × 10⁻¹⁰ to 1.09 × 10⁻⁴, with a cumulative risk of 1.61 × 10⁻⁴. The mean cancer risks associated with naphthalene, chloroform, 1,4-dichlorobenzene, and 1,2-dibromoethylene were 1.09 × 10⁻⁴, 1.61 × 10⁻⁵, 1.11 × 10⁻⁵, and 1.07 × 10⁻⁵, respectively. These risks are higher than the acceptable risk levels defined by the USEPA and the World Health Organization (WHO). Of these, naphthalene was regarded as having a “definite risk”; chloroform, 1,4-dichlorobenzene, and 1,2-dibromoethylene were regarded as having a “probable risk”; and 1,2-dichloroethane and carbon tetrachloride were regarded as having “possible risk.” The individual mean non-cancer risks associated with 28 health-related VOCs and total VOCs were within acceptable ranges; naphthalene was the dominant pollutant.

More than 1 million tons of fresh organic wastes is produced in the Souss-Massa region in Morocco. Tomato organic residues represent more than 25% of the total organic wastes and are deposited in uncontrolled landfills. Thus, composting can represent a valuable and pertinent solution to this environmental problem. The objectives of this experiment are to identify the potential functional groups responsible for compost phytotoxicity and to determine the optimum initial carbon to nitrogen ratio (C/N) for maximum recovery of tomato residues. The experiment consisted of the variation of the initial C/N ratios (25, 30, 35, and 40) using mixtures of different raw materials (tomato residues, melon residues, olive mill pomace, and sheep manure). Physicochemical parameters (pH, electrical conductivity, C/N ratio, and humic acid/fulvic acid ratio) were determined and spectroscopic analyses (UV-vis and NMR-¹³C) were performed during the composting process along with quality parameters (germination and phytotoxicity tests) at the end. The results showed that the compost with the initial C/N ratio of 35 is the most humified with the least phytotoxic effect. The germination and phytotoxicity tests were negatively correlated with the methoxyl/N-alkyl-C ratio and O-alkyl-C. These two functional groups are probably the origin of phytotoxicity expression in compost quality tests. Thus, a simple and precise quality test could be performed to evaluate directly the phytotoxicity and maturity of compost.

Iron plaque (IP) is valuable in nutrient management and contaminant tolerance for rice (Oryza sativa) because it can adsorb various nutrients and toxic ions. Crystalline ratio (CR) can be defined as the proportion of crystalline iron (CI) to total IP to describe IP crystallinity. Although the knowledge on IP has abounded, the information on the relationship among its formation condition, surface properties, and CR remains insufficient. In this study, quartz sand–soil cultivation with rice was conducted to explore the effect of drying–submergence alternation (DSA) on CI, amorphous iron (AI), CR, root oxidizing capacity (ROC), and surface properties of IP with different treatment durations and at different stages. Fourteen-day DSA treatment increased CI to 2.20 times of that after continuous submergence (CS) but decreased AI to 72.3% of that after CS. Correspondingly, CR was raised to 6.89% from 4.08%. Remarkably, CR of IP after DSA ending in submergence and ending in drying was 6.89% and 4.23%, respectively. In addition, ROC after 14-day DSA was enhanced to twice of that after CS. Results from scanning electronic microscope suggested that 14-day DSA induced thinner sheets with finer particles in IP compared to that after CS. Results from X-ray diffraction revealed that IP contained higher proportions of goethite, lepidocrocite, magnetite, and hematite after DSA than those after CS. Variable charge and surface area of IP after DSA were only 26.5% and 32.0% of those after CS, respectively. Together, our results indicated that proper strength DSA promoted ROC and transformation from AI to CI, and consequently increased CR of IP, while it changed its surface properties.