Groundwater vulnerability assessment for the Banyas Catchment of the Syrian coastal area using GIS and the RISKE method

Vulnerability assessment to delineate areas that are more susceptible to contamination from anthropogenic sources has become an important element for sensible resource management and landuse planning. This contribution aims at estimating aquifer vulnerability by applying the RISKE model in Banyas Catchment Area (BCA), Tartous Prefecture, west Syria. An additional objective is to demonstrate the combined use of the RISKE model and a geographical information system (GIS) as an effective method for groundwater pollution risk assessment. The RISKE model uses five environmental parameters (Rock of aquifer media, Infiltration, Soil media, Karst, and Epikarst) to characterize the hydro-geological setting and evaluate aquifer vulnerability. The elevated eastern and low western part of the study area was dominated by high vulnerability classes, while the middle part was characterized by moderate vulnerability classes. Based on the vulnerability analysis, it was found that 2% and 39% of BCA is under low and high vulnerability to groundwater contamination, respectively, while more than 52% and 5% of the area of BCA can be designated as an area of moderate and very high vulnerability to groundwater contamination, respectively. The GIS technique has provided an efficient environment for analyses and high capabilities of handling a large amount of spatial data.     

Effect of dimethoate on the immune system of female mice

Abstract

The functional status of the immune system of female mice exposed to a single oral dose of dimethoate (16 mg / kg) was evaluated by assessing cell mediated and humoral immune responses, in addition to the effect of dimethoate on spleen and body weights after different time intervals. The data showed that dimethoate caused a time ‐ depended decrease in spleen weights in the absence of a change in body weights. The immunologic effect of dimethoate to female mice produced a dose‐dependent decrease in the number of the rosette forming cells (total and active erythrocyte rosette). The ability of splenocytes to proliferation in response to mitogens; phytohemagglutinin (PHA) for T cell and lipopolysaccharide (LPS) for B cell were significantly decreased at the different times. As compared to control, a significant decrease in serum total immunoglobulins (Ig) and IgM was found, while IgG was non‐significant deceased. Results of this study also revealed that dimethoate caused a significant decrease in the number of plaque forming cell (PFC / 10⁶ splenocytes) in a time dependent manner.     

Sequential UV-biological degradation of chlorophenols

The sequential UV-biological degradation of a mixture of 4-chlorophenol (CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP), and pentachlorophenol (PCP) was first tested with each pollutant supplied at an initial concentration of 50 mg l(-1). Under these conditions, the chlorophenols were photodegraded in the following order of removal rate: PCP>TCP>DCP>CP with only CP and DCP remaining after 40 h of irradiation. The remaining CP (41 mg l(-1)) and DCP (13 mg l(-1)) were then completely removed by biological treatment with an activated sludge mixed culture. Biodegradation did not occur in similar tests conducted with a non-irradiated mixture due to the high microbial toxicity of the solution. UV treatment lead to a significant reduction of the phytotoxicity to Lipedium sativum but no further reduction of phytotoxicity was observed after biological treatment. Evidence was found that the pollutants were partially photodegraded into toxic and non-biodegradable products. When the pollutants were tested individually (initial concentration of 50 mg l(-1)), PCP, TCP, DCP, 4-CP were photodegraded according to first order kinetic model (r2>99) with half-lives of 2.2, 3.3, 5.7, and 54 h, respectively. The photoproducts were subsequently biodegraded. This study illustrates the potential of UV as pre-treatment for biological treatment in order to remove toxicity and enhance the biodegradability of organic contaminants. However, it also shows that UV treatment must be carefully optimized to avoid the formation of toxic and/or recalcitrant photoproducts and results from studies conducted on single contaminants cannot be extrapolated to mixtures.     

Temporal trends in organophosphorus pesticides use and concentrations in river water in Japan, and risk assessment

We reviewed organophosphorus pesticide use in Japan between 1982 and 2016 using data from the National Institute of Environmental Studies. Organophosphorus pesticide concentrations in river water throughout Japan were taken from the literature, and risk assessments were performed for some organophosphorus pesticides based on risk quotients and hazard quotients. Assessments were performed for 20 common pesticides, including insecticides, fungicides, and herbicides. The amounts used decreased in the order: insecticides?>?herbicides?>?fungicides. Organophosphorus insecticide and fungicide use have decreased over the last four decades, but organophosphorus herbicide use has increased. During this period, annual organophosphorus pesticide use was the highest for chlorpyrifos (105,263?tons/year) and the lowest for glyphosate-sodium (8?tons/year). The ecotoxicological risk assessment indicated that diazinon and fenitrothion posed strong risks to the Japanese aquatic environment, and chlorpyrifos and malathion have moderate risks. None of the pesticides that were assessed posed significant risks to humans. Continued use of organophosphorus pesticides in Japan may cause strong risks to aquatic environments. These risks should be reassessed periodically.     

Effects of 5-year application of municipal solid waste compost on the distribution and mobility of heavy metals in a Tunisian calcareous soil

It is obvious that the application of solid waste compost improves the soil fertility. These wastes, however, may also have some negative effects on the agricultural environment due to their metal content. This research aimed at evaluating the influence of Tunisian municipal solid waste compost and farmyard manure on some chemical properties and the distribution of heavy metals in a calcareous Tunisian soil (clayey–loamy soil). A field plot experiment, without vegetation, was installed since 1999 at the experimental farm of the Agronomic National Institute of Tunis (INAT) in the region of Mornag (20 km south of Tunis, Tunisia). During 5 years, the field received yearly the following treatments: 0, 40, 80 and 120 t/ha of municipal solid waste compost and 0, 40 and 120 t/ha of manure. The fractionation of heavy metals in the soil was evaluated after 5 years using a sequential extraction procedure. The application of the two amendments was found to increase the content of organic matter, the total nitrogen content and the electrical conductivity, whereas it slightly decreased the soil pH. The addition of manure did not have a significant effect on the accumulation of heavy metals in the soil, whereas compost application increased the total concentration of heavy metals in the soil. The distribution of heavy metals between the different fractions in untreated and treated soils showed the residual fraction to be dominant, followed by the fraction bound to Fe and Mn oxides. The amount of Cu bound to the organic fraction increased with the application rate, which is probably caused by the formation of organic complexes. For the other metals, the increase of the association with organic matter is very limited. The application of compost moreover increases the amount of Zn associated with Fe and Mn oxides. The “Mobility Factor (MF)” was quite low and did not change after the 5-year application of the two organic amendments. It always remained lower than 10%, although for Cd it amounted to 17%.     

Mango performance as affected by the soil application of zeolite and biochar under water salinity stresses

This study was carried out during two consecutive seasons, 2020 and 2021, on 12-year-old mango (Mangifera indica L.). cv. Ewaise grown in region Idku, El Beheira Governorate, Egypt. The trees were planted at 5?×?4 m apart and grafted on “Sokary” root stock to study the influence of zeolite and biochar on growth, yield, and fruit quality of “Ewaise” mango cultivar irrigated by agricultural drainage water. The trees were treated by the following treatments: zeolite or biochar solely at 1, 2, and 3 kg for tree and their different combinations such as 1 kg zeolite?+?1 kg biochar; 1 kg zeolite?+?2 kg biochar; 1 kg zeolite?+?3 kg biochar; 2 kg zeolite?+?1 kg biochar; 2 kg zeolite?+?2 kg biochar; 2 kg zeolite?+?3 kg biochar; 3 kg zeolite?+?1 kg biochar; 3 kg zeolite?+?2 kg biochar; and 3 kg zeolite?+?3 kg biochar as well as control zero soil application. The obtained results showed that the soil application of zeolite or biochar gave a positive effect on improving the soil characteristics which reflects on the tree trunk thickness, shoot length and thickness, number of inflorescences, yield in kg per tree, and fruit quality. The greatest positive effect on the previous mentioned parameters was obtained by the combined application of the soil application of 2 kg zeolite?+?3 kg biochar; 2 kg zeolite?+?2 kg biochar; 3 kg zeolite?+?2 kg biochar; and 3 kg zeolite?+?3 kg biochar over the rest-applied treatments or control in the two seasons.

     

Climate change and adoption of sustainable land management practices in the Niger basin of Benin

Due to the important role that the agricultural sector plays in sustaining growth and reducing poverty in developing countries, the adoption of practices that have the potential to simultaneously improve agricultural productivity while minimizing environmental impacts is essential. This paper examines the determinants of farmers’ perceptions of climate change and subsequent adoption of sustainable land management practices in the Niger basin of Benin. Binary and multivariate probit models are applied in a two‐stage regression procedure to cross‐sectional data collected through a survey of 545 randomly selected farm households in 28 villages. The findings indicate that there are substitutabilities among three pairs of sustainable land management practices being used by the farmers. Climate change perception is positively related to land tenure, experience in farming, number of relatives, tractor use, and membership in farmers’ organizations, and negatively related to household size, remoteness, and plough use. Moreover, the findings reveal that the uptake of land management practices is related to assets, land tenure, education level of the household head, remoteness, social network, non‐irrigated land size, having a farm located near a river/lake/stream, tractor and plough use, being a subsistence farmer or not, and memberships in farmers’ organizations. The adoption of sustainable land management practices could be encouraged through improving access to markets, adequate roads, and technologies, as well as by promoting membership in farmers’ organizations.     

Kinetics and thermodynamics studies of cobalt,strontium and caesium sorption on marble from aqueous solution

Adsorption onto solid phases plays an important role in the transport of radionuclides and contaminants in the environment. Radionuclides in radioactive waste have been considered to be hazardous pollutants, and their migration with groundwater is strongly affected by sorption on the geologic media. Therefore, the knowledge of radionuclide sorption is of great importance in the management of radioactive wastes. A series of batch sorption experiments were conducted separately to investigate sorption and transport behaviour of cobalt, strontium and caesium on and through marble. Batch-mode kinetic and equilibrium studies have been carried out at different temperatures. Sorption experimental data were analysed by kinetic and isotherm models. Based on the results obtained, it can be concluded that the marble is an economic and efficient retaining material for environmental hazardous migration and/or leakage of some radionuclides. Therefore, this study could be used as a starting point to establish and consider that rock as a reactive barrier around the disposal facilities at the nuclear activity centres.     

Distribution and assessment of heavy metal toxicity in sediment cores from Bizerte Lagoon,Tunisia

To examine the state of pollution of Bizerte Lagoon which is exposed to intense anthropogenic pressure, two sediment cores were taken at two sites, one undergoes the dual effects of both marine waters arriving from the Mediterranean Sea through the Channel, and also of freshwater from the Tinja River; the other core is located at the center of the lagoon where water depth is maximal (12 m). Heavy metal concentrations in the two cores were assessed, with calculated enrichment factors and geo-accumulation indexes. Core sediments were also studied for chemical speciation and their monosulfide contents were measured. Results from enrichment factors and geo-accumulation indexes show an accumulation of Cd, Zn, Cr, and Pb, while chemical speciation revealed a risk only from Cd and Mn. Comparison of sequential extraction values with those of acid volatile sulfides revealed that non-toxic effects may be caused by any of the studied metals in the sediment.