Surface modification can effectively improve the ability of hydrochar to capture pollutants from wastewater. In this work, polyaminophosphonated-functionalized hydrochar (PAP-HC) was successfully synthesized by a chemical grafting approach and applied efficiently to adsorb aqueous Pb(II). Properties of PAP-HC were characterized by ICP, FTIR, XPS, SEM–EDS, elemental analysis, zeta potential, and BET. The Pb(II) adsorbing behavior of PAP-HC was tested by batch adsorbing assays, including the pH impact, uptake kinetics, sorption isotherms, sorption thermodynamics, and PAP-HC recycling. Sorption isotherms were better illustrated by a Langmuir equation, while the kinetic profile was modeled by a pseudo-second-order equation. Adsorption of Pb(II) onto PAP-HC mainly relied on chelating Pb(II) with aminophosphonate groups of PAP-HC by XPS and FTIR analyses. The actual adsorbed amount of PAP-HC maximized to 179.92 mg·g⁻¹ at 298 K, which showed high adsorption ability. Nitric acid and hydroxide solutions were suitable for desorption of adsorbed Pb(II) and activated PAP-HC, respectively. PAP-HC can be reused for at least five cycles without obvious change in adsorption performance. The results suggest PAP-HC is a prospective adsorbent to capture Pb(II) from wastewater.

The strategy of the Silk Road Economic Belt in China has promoted the urban development of the backward regions in the west, but it might also cause serious eco-environmental concerns. Studying the coupling relationship between urbanization and the eco-environment (UEE) is essential to promote the sustainable development in backward regions. This study developed a combined method of coupling coordination degree (CCD) model, linear regression, and gray relational analysis (GRA) model to investigate the spatio-temporal coupling relationship and the influencing factors between UEE in Ningxia Hui Autonomous Region (NHAR), a typical backward region along the Silk Road Economic Belt. Results show that (1) the economic urbanization and eco-environmental pressure made the largest contribution to the system of urbanization and eco-environment, respectively. (2) The overall CCD in NHAR showed a linear upward trend from 2001 to 2018, while the CCD of each district presented significant spatial difference. The CCDs in the more developed northern regions were generally higher than those in southern mountainous regions. (3) Furthermore, population factors were the main mechanism imposing stress on the eco-environment, and the factors of eco-environmental status had higher restrictive effect on urban development in NHAR. This study could provide theoretical basis for investigating the interaction between UEE in backward regions, which might enable policymakers to formulate targeted sustainable development plans.

Predicting the flocculant dosage in the drinking water treatment process is essential for public health. However, due to the complexity of water quality and flocculation, many difficulties remain. The present study aimed to report on using artificial intelligence, namely, the Elman neural network (ENN), to predict the flocculant dosage and explore the applications of the proposed model in waterworks. The flocculation process of drinking water was introduced in this study, and four typical models were developed based on multiple linear regression (MLR), the radial basis function neural network (RBFNN), the least squares support vector machine (LSSVM), and the ENN. To improve the prediction accuracy, a mixed term including long-term data and short-term data was proposed to capture the periodic and time-varying characteristics of water quality data. The weights of each part are updated adaptively according to the comparison of effluent turbidity and set values. The results demonstrate that the proposed ENN model performed better than the other three models in terms of the prediction performance. With the ENN model of flocculant dosage, the root mean square error (RMSE), mean absolute percentage error (MAPE), and coefficient of determination (R²) of the test data were 1.8917, 5.0067, and 0.8999, which were improved by 36.9%, 41.5%, and 14.0% in comparison with the best one (RBFNN) of the other three models, respectively. The effluent turbidity of sedimentation tank was more stable under the control of proposed ENN model of flocculant dosage than the other three models. Considering its performance, the ENN model can be taken as a preferred data intelligence tool for predicting the drinking water flocculant dosage.

The current improvement in science and engineering, actively dealing with surfaces and interfaces, turns into a functioning control with a thriving advancement propensity. Superlyophobic/superlyophilic phenomena in surface sciences have pulled in broad considerations of researchers and specialists. Inspired by the natural and living organism, researchers have designed different biomimetic materials with exceptional surface wettability, such as the smart wetting of asymmetric spider silk surfaces. These smart materials with superlyophobic/superlyophilic wettability are generally utilized for water assortment, self-cleaning, fluid transportation and separation, and many researchers’ domains. Among them, emulsion separation, including division of oil-water blend, mixtures of immiscible liquids and oil-water emulsions, is highlighted by an increasing number of researchers. Numerous materials with one- and two-dimensional morphology, smart surfaces, and super wettability have been effectively designed and utilized in various scientific research applications. We expect that these bioinspired materials with super wettability can have promising applications in practical for emulsion destabilization and liquid transportation.

In this study, 30 pesticide residues in 45 fresh-eating cucumber, tomato, and okra fruit samples collected from the Khuzestan province as the main agricultural products in Iran using the QuEChERS extraction method were analyzed. In addition, noncarcinogen and carcinogen health risk assessments were evaluated. Results indicated that 93% of cucumber samples had at least one pesticide, of course, less than the maximum residue limit (MRL). All tomato and okra fruit samples were contaminated by diazinon. All pesticides detected in tomato samples were below national MRL except for thiamethoxam in four samples. In okra fruit samples, all detected diazinon and malathion, but only tebuconazole fungicide exceeded MRL. In addition, the hazard index (HI) was 0.23 and 1.06 in cucumber samples, 0.33 and 1.51 in tomato samples, and 5.5E-03 and 0.025 in okra fruit samples in adults and children, respectively. The use of cucumber and tomato may have notable risks in the short term in children group age. Ranking based on total CR was 1.2E-05 in tomato, 7.7E-06 for cucumber, and in okra 9.1E-11 because of the difenoconazole residue. However, significant carcinogenic risk threatens cucumber and tomato consumers.

The baseline data of radioactivity levels in food is one of the main factors for the assessment of resident’s health risk. Gross beta and alpha activity was identified for selected commercial freshwater fish species, including 29 types of fish species by a gas-flow proportional detector. The samples were collected from wholesale markets in Hanoi city, Vietnam. The highest gross alpha activity was recorded in blotched snakehead, a pelagic and carnivorous species, and the lowest one was recorded in common carp, a demersal and omnivorous species. Meanwhile, the gross beta activity was much higher than the gross alpha activity with the highest value of gross beta, observed in Wels catfish, a demersal and carnivorous species, and the lowest one found in Mudskipper a demersal, herbivores species. Regarding feeding types, the gross alpha activity was observed in the order of Alcₐᵣₙᵢᵥₒᵣₑₛ > Alₒₘₙᵢᵥₒᵣₑₛ > Alₕₑᵣbᵢᵥₒᵣₑₛ whereas the gross beta was non-distinction. In terms of living behavior, the gross alpha activity in pelagic species was much higher than that in demersal species (Alₚₑₗₐgᵢc > > Aldₑₘₑᵣₛₐₗ) and indifferent for gross beta. There was an insignificant relationship between the trophic level with gross beta and alpha activities in freshwater fish species. The calculated annual effective dose ​​ranged from 0.19 to 1.88 and 0.78 mSv.y⁻¹ on average, being within the limited dose for the public as reported by UNSCEAR in which gross beta activity has a strong correlation with the total annual effective dose.

Carbon footprint analysis method was employed to evaluate the ecological benefits of the straw collection, transportation, and storage system based on the case of Laifa Straw Recycling Company, and the emergy-based carbon emission indicator system was also set up to assess the relationship between input resource and carbon emission. In the condition of collecting 2 × 10⁸ kg of straw production, the carbon emission of the artificial model (7.26 × 10³ t CO₂ₑq) and mechanical model (6.11 × 10³ t CO₂ₑq) was greatly lower than that of the straw burned in the field (2.78 × 10⁵ t CO₂ₑq). According to the emergy-based carbon emission indicator system, the carbon emission of straw recycling system was mainly triggered from labor input, which could be reduced by adjusting the resource structure. The ratio of carbon emission to environmental loading rate (ELRCO₂) and ratio of carbon emission to emergy sustainability index (ESICO₂) of the artificial model were 90.75E+6 kgCO₂ₑq and 1.52E+6 kgCO₂ₑq, respectively, which were higher than that of the mechanical model, 55.55E+6 kgCO₂ₑq and 1.22E+6 kgCO₂ₑq. It was obviously that the mechanical model had weaker influence on environmental loading than that of the artificial model and presented promising sustainable development ability in the case of mitigating carbon emissions.

Microplastics (MPs) have been reported in fish species from several freshwater environments. However, the mechanisms underlying MPs ingestion by fish are still unclear, although they are important to determine the pathway of MPs along freshwater environments food webs. Here, we investigates a fundamental question of why wild freshwater fish ingest plastic. To address this, we conducted a laboratory experiment to assess MP fragments intake according to color (red, green, yellow, white, black, and blue) by a small omnivorous fish species Psalidodon eigenmanniorum (Characidae). Results showed that yellow and blue were the most consumed fragments, whereas fish avoided white fragments. Although it is not yet clear how plastic coloration relates to the selectivity and feeding of freshwater fish, the visual skills at a species-specific level could plausibly explain why certain colors are attractive or deterrent to a particular fish species. This data set can be used as a screening tool that could help to understand the mechanisms underlying the patterns of plastic ingestion by fish, with special emphasis on the color of plastic particles. Future research on mechanisms MPs intake by fish, also providing a multi-species approach is highly recommended.

Pregnancy and feto-gestational toxicities on exposure to fluoride and its possible amelioration on co-administration with aloe vera were studied in pregnant Swiss albino mice. Once the confirmed pregnancy was tested, animals were equally divided into four groups as follows: group I was given no treatment and served as control, and groups II and III were administered with 100 and 300 ppm sodium fluoride, respectively, while group IV was co- administered aloe vera (300 mg/kg bw) along with sodium fluoride (300 ppm) daily for 14 days prior to gestation and continued till the 18th day of gestation. Animals were sacrificed on the 19th day of gestation for prenatal observations. Maternal body weight, the gravid uterine weight, number of corpora lutea in both the ovaries, number of implantations and resorptions, number of live (mature and immature) fetuses, and number of dead fetuses were examined in each dam. The treatment continued in another set of animals till the completion of the weaning period to observe postnatal changes due to test substances on the mother and pups. Sodium fluoride–treated animals showed morphometric and skeletal changes which were more pronounced in the high-dose group showing significantly decreased body weight gain in pregnant mothers and dead/immature fetuses. Morphometric changes included open eyelids, limb defects, wrinkles on the whole body, anophthalmia, pulmonary edema, enlarged esophagus, and decreased body weight of fetuses and pups. Alizarin-prepared skeletal structures of fetuses of such female mice showed delayed ossification or bending in the number of bones of skull, thoracic, and limb regions. However, concomitant exposure to sodium fluoride and aloe vera in treated animals led to a marked improvement in all the prenatal and postnatal variables. The study suggests that sodium fluoride at high concentrations may be teratogenic while co-administration of aloe vera during fluoride exposure might be beneficial in reducing these toxic effects. The use of aloe vera as a preventive agent or as a complimentary agent is thus recommended following fluoride exposure through the oral route.

A series of metal- and metal oxide-modified biochars were prepared to remove ammonia (NH₃). Maize straw was used as the precursor to fabricate biochar, four kinds of biochar with different metal modification were prepared by impregnation method, and the part of metal on the surface of biochar was converted to metal oxide after secondary pyrolysis. It was found that adsorption capacity of BC-Ni–O on NH₃ was the highest (118.6 mg/g), which was due to the strong coordination and complexation between metal nickel and ammonia molecules. BC-Ni–O also shows good cycling performance. The mechanism analysis shows that the formation of metal oxides can increase the specific surface area of the adsorbent which plays an important role in the adsorption. The formation of NiO and Ni²⁺ in secondary pyrolysis plays a major role in the adsorption process, and their contribution is about 86%. To assess the reliability of adsorbent in practical application, the air purification experiment was conducted in a 30-m³ air chamber. High removal rate of ammonia is recorded 85.9% in single-component gas, and it still maintained at 72.6% in a mixed-component gas (the concentration of toluene, formaldehyde, and ammonia is 1 mg/m³, 1 mg/m³, and 1.5 mg/m³, respectively).