Environments, Volume 7, Issue 12 (December 2020) – 10 articles

A soil and an organic biomix (soil/vine branch/garden compost 20/40/40) were used in this lab experiment to evaluate adsorption and degradation parameters for three pesticides (chlorpyrifos, metalaxyl and cymoxanil) used in a vineyard. Adsorption in the biomix material was higher than in the soil for the three pesticides and chlorpyrifos was the most adsorbed pesticide. The role of the organic carbon is essential for enhancing the adsortion of the three pesticides, especially for the most apolar chlorpyrifos. Degradation was generally faster in the biomix material than in the soil although the process was slower in the case of chlorpyrifos if compared with the other two chemicals, due to a more toxic effect of this pesticide on soil microflora and a larger adsorption of this pesticide on the organic biomix that reduces its availability for dissipation. Amendment with cheap and available organic wastes or a grass-covered management of soil in the vineyard could reduce the impact of pesticides in the vineyard ecosystem and contribute to the sustainable management of chemicals in the environment. Full article

Biofilms can be used as a biomonitoring tool to determine metal bioavailability in streams affected by mining and other anthropogenic activities. Surface water and biofilm were sampled over two years from rivers located in the vicinity of a mine located in a Nordic ecosystem (Nunavik, Quebec). Biofilm metal content (Cd, Cu, and Ni) as well as a variety of physicochemical properties were determined to examine relationships between metal accumulation and water quality. Among the three metals of interest, copper and nickel had the highest levels of accumulation and cadmium had the lowest. When considering the exposure levels, nickel was the most abundant metal in our sampling sites. Both exposure and accumulation levels were consistent over time. Biofilm metal content was highly correlated to the ambient free metal ion concentration for sites of circumneutral pHs for all three metals. When the surface water pH was below 6, biofilm metal content was much lower than at other sites with similar aqueous metal concentrations of exposure. This apparent protective effect of decreasing pH can be explained by proton competition with dissolved metals for uptake binding sites at the surface of the organisms within the biofilm as described by the Biotic Ligand Model principles. The relationships obtained for Cd and Cu were overlapping those observed in previous publications, indicating strong similarities in metal accumulation processes in biofilms over very large geographical areas. Although more data are needed for Ni, our results show that biofilms represent a promising metal biomonitoring tool. Full article

Municipal solid waste landfilling, landfilling process and landfill reclamation result in leachate, which may be dangerous to the environment. Municipal solid waste leachate phytotoxicity tests were performed using the toxicity test and a subchronic toxicity pot experiment by direct application of leachate to reference soil in 5, 25, and 50% concentration for a period of 28 days. White mustard (Sinapis alba L.) seeds were exposed to different leachate dilution. Leachate were collected monthly in 2018 in the period from April to September. Furthermore, pH, conductivity, and dissolved oxygen were measured. The inhibition results on Sinapis alba L. seeds in the tested leachate samples ranged from −18.02 to 39.03%. Lower concentration of leachate showed a stimulating effect (only for Sample 1 and Sample 2 at 5% concentration). It was found out that leachate taken at the landfill is phytotoxic. The results of measurements are based on rainfall which affects the quantity and quality of the leachate. The values of germinated seeds/growing plants from the subchronic toxicity pot experiment ranged from 80 to 104%; therefore, the leachate is considered phytotoxic. However, it was confirmed that leachate may be used for landfill irrigation. Full article

The toxicological effects of nanoparticles mixtures in aquatic organisms are poorly understood. The purpose of this study was to examine the tissue metal loadings and sublethal effects of silver (nAg), cerium oxide (nCeO), copper oxide (nCuO) and zinc oxide (nZnO) nanoparticles individually at 50 µg/L and in two mixtures to freshwater mussels Dreissena bugensis. The mixtures consisted of 12.5 µg/L of each nanoparticle (Mix50) and 50 µg/L of each nanoparticles (Mix200). After a 96-h exposure period, mussels were analyzed for morphological changes, air time survival, bioaccumulation, inflammation (cyclooxygenase or COX activity), lipid peroxidation (LPO), DNA strand breaks, labile Zn, acetylcholinesterase (AChE) and protein–ubiquitin levels. The data revealed that mussels accumulated the nanoparticles with nCeO and nAg were the least and most bioavailable, respectively. Increased tissue metal loadings were observed for nCeO and nCuO in mixtures, while no mixture effects were observed for nAg and nZnO. The weight loss during air emersion was lower in mussels exposed to nCuO alone but not by the mixture. On the one hand, labile Zn levels was increased with nZnO but returned to control values with the Mix50 and Mix200, suggesting antagonism. On the other hand, DNA strand breaks were reduced for both mixtures compared to controls or to the nanoparticles individually, suggesting potentiation of effects. The same was found for protein–ubiquitin levels, which were decreased by nCeO and nCuO alone but not when in mixtures, which increased their levels. In conclusion, the data revealed that the behavior and effects of nanoparticles were influenced by other nanoparticles where antagonist and potentiation interactions were identified. Full article

The management of waste wash-water (WWW) is one of the most significant environmental problems associated with ready-mix concrete production worldwide. The problems are exacerbated should it be disposed of in an inappropriate manner. This study evaluated the potential of WWW recycling in ready mix concrete plants in Jordan. A representative waste wash-water sample (400 L) was collected from a basin in a ready-mix concrete company. A pilot plant on the lab scale was fabricated and installed. The treatment system consisted of a concrete washout reclaimer, wedgebed slurry settling pond, slow sand filtration unit, and a neutralization unit. Water samples were collected from all stages of the pilot plant and analyzed. The collected waste wash-water samples were utilized for replacement of well water (mixing water) at various ratios. Fourteen concrete mixtures were produced and cast, as well as tested at various curing ages (7, 28, and 90 days). The results show that the raw WWW was not acceptable as mixing water even after dilution as it led to significant reductions in concrete compressive strength and low workability. However, the WWW from the settling pond, the filtered WWW and the filtered-neutralized WWW at dilution ratios up to 75% were shown to be potential alternatives to fresh water for ready-mixed concrete. Therefore, the current guidelines for mixing water quality should be revised to encourage the reuse of the WWW. Full article

In arid and semi-arid regions, planting drought-tolerant species is the most useful strategy in the reclamation of degraded soils. In the present study, we evaluated the effect of simulated drought by polyethylene glycol (PEG-6000) on seed germination and seedling growth of three desert plants such as Atriplex canescens, Salsola kali and Zygophyllum fabago. Seeds were subjected to water stress to drought stress by PEG at five stress levels (0, −1, −4, −8, −12, −14 bars). Germination of Z. fabago was completely inhibited at an osmotic potential of −8, −10 and −12 bars and the germination of A. canescens was inhibited only at −14 bar. In contrast, S. kali responded positively to high levels of stress and our results showed the highest final germination percent (71.75, 54 and 18.25%) under three-drought stress −8, −12 and −14 bars, respectively. In addition, increasing PEG concentration adversely affected the germination rate and seedling vigor index as well as the root and shoot length of species. Under high stress levels, S. kali achieved a higher germination rate and seedling vigor index compared to Z. fabago and A. canescens. Among species, S. kali was the only one able to develop roots and shoots at −14 bar. Therefore, S. kali could be considered as a promising plant for the rehabilitation of degraded soils at risk of desertification. Full article

The rainwater chemistry within the Metropolitan Area of Monterrey (MAM) was studied during a one-year period (January 2019–January 2020) in seven sampling sites. The metal concentration of Zn, Fe, Cd, Cu, Ni, and Mn was analyzed in bulk samples and the toxicity potential (TP) was calculated for each metal. A canonical correspondence analysis (CCA) was applied to identify the relationship between environmental variables and metals concentrations. An average of 26.6 ± 10 mm of rainfall was obtained. A mean pH of 7.2 ± 0.3 and a mean electrical conductivity of 177.8 ± 8.7 µS cm⁻¹ were observed. The average concentration of metals in all sites follows a descending order of Fe> Zn > Mn > Cu > Ni > Cd. The university site shows the highest averages of Fe, Zn, Cu, and Mn, which is attributed to its proximity to the metallurgical industry. The TP value of Cd reflects a risk in all sites and Fe only for the Universidad, Obispado, Pastora, and Santa Catarina sites, using as a reference value the Environmental Protection Agency (EPA) Drinking Water Regulations and Mexican norm NOM-127-SSA1-1994. The CCA analysis showed that only Ni and Cd had a strong correlation with the environmental variable of relative humidity of air. Full article

Groundwater quality deterioration and overexploitation constitute two critical environmental issues worldwide. In this study, with the aim to achieve a groundwater sustainability purpose, a preliminary hydrogeochemical survey is conducted in the Flamouria basin, Pella prefecture, Northern Greece using available and collected data. For this purpose, chemical analyses of groundwater, springs, and surface water were collected and analyzed with three electrical resistivity tomographies (ERTs). A Groundwater Quality Index (GQI), along with a nitrate susceptibility assessment is applied within the porous aquifer. The water quality analysis along with GQI application showed excellent water quality for potable and irrigation use however highlighted future issue for irrigation utilization as the high alkalinity and total dissolved solid (TDS)could generate excessive soil salinization. Moreover, the application of a methodology for the identification of “Nitrate Vulnerable Zone” called the Protection from Natural and Anthropogenic sources (PNA) highlighted the natural susceptibility to nitrate pollution of the porous aquifer, especially in the central part of the area where most agricultural activity is localized. The work further confirmed how the proposed elaboration could represent an easy and widely applicable hydrological assessment where there is also limited data available. Full article

We examine decision-making, shared authority, and pluralism as key characteristics for the effective co-management of natural resources. Drawing on the concept of network governance, we complement this approach by studying localized practices of governance that support existing and compensate for missing aspects in the regulation. The regime of territorial use rights for fisheries (TURF) in Chile is a recognized example of large-scale co-management that has given rise to local organizations that manage and exploit benthic resources. Based on multi-sited qualitative fieldwork across five regions, we analyze practices with respect to two governance objects: the deterrence of illegal fishing and the periodic assessment of the fisheries’ biology fields. Our analysis shows that local fisher organizations have institutionalized informal practices of surveillance and monitoring to fill in the gaps of existing regulations. Although fisher organizations and consultants—the so-called management and exploitation areas for benthic resources (AMERB)—have managed to operate the TURF regime, they depend on the government to enforce regulations and receive public subsidies to cover the costs of delegated governance tasks. We suggest that governance effectiveness could benefit from delegating additional authority to the local level. This would enhance the supervision of productive areas and better adaptation of national co-management regulations to the specific geographical context. Full article