Many of South Africa’s freshwater impoundments are compromised by pesticide pollution, and the Roodeplaat Dam, near Pretoria, is no exception. This paper is, to the best of our knowledge, the first report of the herbicides Dacthal, metribuzin, simazine, tebuthiuron, terbuthylazine, and the fungicides azoxystrobin, carbendazim, epoxiconazole, metalaxyl (Ridomil), propiconazole, pyrimethanil and thiabendazole in a South African freshwater impoundment. This short note reports on the screening results of water and muscle tissue samples against a comprehensive library of pesticides, herbicides and fungicides in the polluted Roodeplaat Dam. Muscle samples of Oreochromis mossambicus screened positive for p,p'-DDE and p,p'-DDD and for DCPA (chlorthal-methyl). The muscle tissue of Clarias gariepinus screened positive for p,p'-DDE and p,p'-DDD, chlorpyrifos, trans-chlordane, DCPA and terbuthylazine. The presence of these pesticides, herbicides and fungicides in this impoundment is of great concern as there is substantial evidence of adverse health effects in fish exposed to these chemicals.

Water hyacinth (WH) has high tolerance in extreme environmental conditions. Here, we examined the potentials of WH (Eichhornia crassipes (Mart) solms) to remove excess nutrients from sewage wastewater. We used four prototypes of water systems: prototypes A (WH + underlay water) and C (WH + sewage water), whereas prototypes B and D were experimental control for A and C, respectively. For prototype A, the percentage removal efficiencies (%Rₑ) for nitrate and phosphate achieved were 75.12 ± 4.22% and 78.90 ± 8.72%, respectively, with a pH increase from 6.29 to 7.69; whereas for prototype C, the values were 54.7 ± 8.11% and 86.10 ± 7.34%, respectively, with a pH decrease from 8.13 to 7.15. For the 3-week retention time, the biomass weight increased in both prototype A (33.26%; [Formula: see text] rate = 15.46 g/week) and prototype C (26.43%; [Formula: see text] rate = 12.54 g/week). Further, the respective mechanical strength and nutritional values of the WH’s fiber and the organic extracts were examined. The air-dried WH stem showed an average tensile stress of 0.04 MPa on a load at maximum stress of 137.1 N. By comparison, a strand of WH has a tensile strength of 14 MPa, inferior to 15, 61, and 400 MPa shown by timber, wood, and steel, respectively. However, by knitting, four strands of WH yielded a much-improved tensile strength of 315 MPa. Finally, a gas chromatography-mass spectrometer analysis of the plant’s extract showed that it contains 35.51% oleic acid, a nutritional extract of high value. Thence, we established a profound economic significance of WH, a macrophyte with latent immense benefits.

Based on expectancy valence theory, people’s behavior is affected by their self-perception and the external environment. In rural China, policy instruments as robust external environment factors have a strong effect on waste separation behavior (WSB). The purpose of the paper is to explore the influencing mechanism of policy instruments (infrastructure and information) on perceived value (perceived benefit and perceived cost) and waste separation behaviors. The data were collected from 689 rural households of Shaanxi province in China, and analyzed by using structural equation model (SEM). According to the results, the mediation effect proves that policy instruments not only can affect WSB directly but also can affect it indirectly through the perceived value. Specifically, information and infrastructure influence the perceived benefit positively and the perceived cost negatively, and information and infrastructure have an indirect effect on WSB through the mediation effect of the perceived cost. Second, policy instruments have a stronger effect on rural people’s waste separation behavior than perceived value. Specifically, infrastructure has the most important impact on waste separation behavior, followed by information and then perceived cost. Third, the perceived cost is significantly negatively related to WSB, and perceived benefit has a positive effect but is statistically insignificant. It has a practical implication for the government. Providing sufficient infrastructure and launching effective information activities could improve the perceived benefit including biospheric, egoistic, social-altruistic, and reputation; and reduce the perceived cost of time, physical, learning, and money, which could then induce rural households to engage in WSB.

The vulnerability of aquatic ecosystems due to the entry of cadmium (Cd) is a concern of public and environmental health. This work explores the ability of tissues and symbiotic corpuscles of Pomacea canaliculata to concentrate and depurate Cd. From hatching to adulthood (4 months), snails were cultured in reconstituted water, which was a saline solution in ASTM Type I water. Then, adult snails were exposed for 8 weeks (exposure phase) to Cd (5 μg/L) and then returned to reconstituted water for other 8 weeks (depuration phase). Cadmium concentration in the digestive gland, kidney, head/foot and viscera (remaining of the snail body), symbiotic corpuscles, and particulate excreta was determined by electrothermal atomic absorption spectrometry. After exposure, the digestive gland showed the highest concentration of Cd (BCF = 5335). Symbiotic corpuscles bioaccumulated Cd at a concentration higher than that present in the water (BCF = 231 for C symbiotic corpuscles, BCF = 8 for K symbiotic corpuscles). No tissues or symbiotic corpuscles showed a significant change in the Cd levels at different time points of the depuration phase (weeks 8, 9, 10, 12, and 16). The symbiotic depuration through particulate excreta was faster between weeks 8 and 10, and then slower after on. Our findings show that epithelial cells of the digestive gland of P. canaliculata and their symbiotic C corpuscles are sensitive places for the bioindication of Cd in freshwater bodies.

Millipedes are organisms of the edaphic fauna and have been used as bioindicators for the evaluation of pollutants in the environment, as they are in constant contact with the soil. This study used the millipede Rhinocricus padbergi as surrogate to evaluate the toxicity of two metallic-insecticides that has been developed for leaf-cutting ants management. Millipedes were exposed in terrariums containing different concentrations of the metallic-insecticides and, after periods of 21 and 90 days, three individuals from each terrarium were dissected in order to remove the midgut, the organ where absorption of nutrients and, consequently, toxic substances occurs. The toxic action of the metallic-insecticides was analyzed through qualitative and semi-quantitative analysis of morphophysiological alterations and by quantitative analysis of the HSP70 stress protein. The results showed that the metallic-insecticides may increase HSP70 labeling, although not at all concentrations and periods of exposure. Histopathological alterations were not significant at any concentration, indicating that the cytoprotective action of HSP70 is able to prevent severe damage to the midgut. It is therefore suggested that the metallic-insecticides are not toxic to the species studied here as no toxicity was observed under the conditions tested. In addition, stress protein localization in midgut helps understand how morphophysiological processes can potentially be affected by pesticide exposure.

TiO₂-grafted β-cyclodextrin nanocomposite was synthesized by treating the triazole modified β-cyclodextrin with the amino functionalized titanium dioxide nanoparticles, and applied for removal of fluoride ion from aqueous media by batch technique. The structural changes of nanocomposite before and after fluoride sorption were characterized using BET, BJH, AFM, and elemental mapping based on EDX analyses. The adsorption parameters including pH, adsorbent dosage, contact time, temperature, initial fluoride ion concentration, and coexisting anions have been investigated to determine the optimal adsorption conditions. The experimental data were evaluated by the Langmuir, Freundlich, and Temkin isotherms, and the pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models. Evaluation of experimental data with adsorption isotherms, Langmuire (R² = 0.9988 and Qₘₐₓ = 48.78 mg g⁻¹), Temkin (R² = 0.9939), and Freundlich (nF = 2.73) reveals the high adsorption efficiency of nanocomposite and suggests a monolayer chemical adsorption for fluoride ions. The adsorption experimental data fitted well with the pseudo-second order kinetic model, suggesting that a chemical sorption is involved in the rate-determining step. Thermodynamic parameters (ΔG° < 0, ΔH° > 0 and ΔS° > 0) confirmed the spontaneity, feasibility, and endothermic nature of fluoride sorption. The nanoadsorbent was regenerated in NaOH solution and reused for three adsorption-desorption cycles. The adsorption results represented the nanocomposite as a potential adsorbent for the fluoride ions removal from aqueous solutions.

Excessive copper (Cu) exposure ultimately results in toxicosis in all organisms. The protective potential of resveratrol compound against the CuCl₂ toxicity was evaluated in Allium cepa L. root tip cells. For this aim, A. cepa bulbs were divided into six groups and the groups were treated with tap water, 400 mg/L resveratrol, 800 mg/L resveratrol, 20 μM CuCl₂, 400 mg/L resveratrol + 20 μM CuCl₂, and 800 mg/L resveratrol + 20 μM CuCl₂ solutions, respectively for 72 h. The first group irrigated with tap water was accepted as control. All groups were screened for the germination percentage, root elongation, total bulb weight gain, micronucleus (MN) frequency, mitotic index (MI), chromosomal aberrations, and anatomical changes. Furthermore, superoxide dismutase (SOD) and catalase (CAT) activities as well as malondialdehyde (MDA) level as an indicator of lipid peroxidation were investigated. It was found that CuCl₂ exposure alone triggered a definite negative effects on all parameters examined. On the other hand, the groups treated with resveratrol did not have statistically different values compared to the control group. Resveratrol doses induced a remarkable recovery in growth parameters including germination percentage, root elongation, and total bulb weight gain when applied with CuCl₂. In these groups, MN frequency, chromosomal aberrations, and anatomical abnormalities were alleviated, whereas the MI levels increased significantly. Moreover, lipid peroxidation level and antioxidant enzyme activities showed a marked amelioration when resveratrol and CuCl₂ were applied together. Copper compounds have become common pollutants due to their direct uses as pesticides in agricultural areas as well as their spreading to natural areas from industrial fields. The study clearly demonstrated the therapeutic potential of resveratrol against the harmful effects of CuCl₂ exposure in Allium roots. So, resveratrol could be considered as a plant-derived restorative agent for the reduction of the risks from the other copper compounds.

The use of cork granules for cleaning up crude oil or oil derivative spills and further oil recovery appears as a promising option due to their unique properties, which allow a high oil sorption capacity, low water pickup and excellent reuse. The present work reports the effect of oil viscosity on cork sorption capacity by using five types of oils (lubricating oil, 5.7 gₒᵢₗ gcₒᵣₖ⁻¹; heavy oil, 4.2 gₒᵢₗ gcₒᵣₖ⁻¹; light oil, 3.0 gₒᵢₗ gcₒᵣₖ⁻¹; biodiesel, 2.6 gₒᵢₗ gcₒᵣₖ⁻¹; and diesel, 2.0 gₒᵢₗ gcₒᵣₖ⁻¹). The cork sorption capacity for light petroleum was also evaluated as a function of temperature and sorbent particle size. Additionally, improvements on oil recovery from cork sorbents by a mechanical compression process have been achieved as a result of a design of experiments (DOE) using the response surface methodology. Such statistical technique provided remarkable results in terms of cork sorbent reusability, as the oil sorption capacity was preserved after 30 cycles of sorption-squeezing steps. The sorbed oils could be removed from the sorbent surface, collected simply by squeezing the cork granules and further reused. The best operational region yielded near 80% oil recovery, using a cork mass of 8.85 g (particle size of 2.0–4.0 mm) loaded with 43.5 mL of lubricating oil, at 5.4 bar, utilising two compressions with a duration of 2 min each. Graphical abstract

Improper treating, sorting, storing, transporting, or disposing of wastes poses a potential risk to the health of humans and the environment. The workers of waste management plants are at risk of exposure to heavy metals and their toxic and hazardous effects through respiratory or cutaneous routes. Accordingly, concentrations of two heavy metals in the biological samples of workers of a municipal waste management (MSW) plant in Iraqi Kurdistan were measured in 139 persons who worked for at least 6 months. Blood and plasma samples were collected to measure lead and zinc concentrations, respectively. Their working units, occupational history, smoking habits, and the distance living from the landfill site were recorded in a predesigned questionnaire. A blood lead level (BLL) of less than 40 μg/dL was considered a safe cutoff. The lower limit of normal fasting plasma zinc was set at 70–120 μg/dL. The study showed that the mean age of the workers was 33.43, ranging from 16 to 67 years old, and they worked for the last 4.93 years. Further, 22.3% of the staff had previous experience in a job with suspected exposure to heavy metals. The mean BLL concentrations and the plasma zinc level were 31 μg/dl and 5.77 μg/dl, respectively. The study did not find a substantial difference in lead and zinc among workers with different characteristics. We did not find any predictor for lead and zinc concentrations in our sample. The study showed that the mean levels of lead and zinc were lower than the permitted ranges.

The GIS-based water quantity and water quality model is widely used to provide decision-making supports for water resource and water quality management. However, the existing integration patterns of GIS and model system mainly depend on data communication between themselves which may lead to low operating efficiency and time-consuming model setup. In this paper, a generalized data structure (dual object structure (DOS)) which can store the data of GIS objects and model objects together is proposed and realized for the first time, avoiding frequent data communication during the period of numerical simulation and result expression, realizing the fusion of GIS objects and model objects at the data structure level, improving the operating efficiency of the system. Finally, the water quantity and water quality modeling software (digital basin simulation system (DBSS)) based on DOS was developed by using C++ language. The software has been applied successfully in large-scale river basins of China, and one of the cases was demonstrated to show the application process and the outstanding results.