Search

Measurement of the fluxes of pesticides was carried out for a year, ending in March 2009, in the Save catchment, in the vicinity of Toulouse. The hydrograph separation technique was used to evaluate the respective contribution of stormflow and baseflow in transport of 12 pesticide molecules. Transport of over 59% of pesticides and their controlling factors such as total suspended matter (TSM), particulate organic carbon (POC) and dissolved organic carbon (DOC) occurred during storm periods. Hysteresis patterns could be observed in the concentration-discharge relationships only for some molecules between rising and falling periods of the storm hydrograph. Clockwise hysteresis was noticed for low to moderately soluble pesticide molecules and for particulate fractions, which explains the role of surface runoff in pesticide displacement. In contrast, anticlockwise hysteresis was registered for soluble molecules and dissolved fractions, explaining the role of subsurface flows and soil leaching processes. The important role of TSM, POC and DOC in pesticide transport was clearly established. We also came to the conclusion that the role of stormy periods in pesticide movement and their controlling factors worked as a threat to aquatic ecosystems. And there was a positive relation between riverine TSM, POC, DOC and pesticides according to pesticide properties.

This study investigated the contamination and health risk assessment of heavy metals and organophosphorus pesticides in single, double, and ratoon cropping of rice in Mazandaran province, north of Iran. A total of 17 sampling locations in rice farms were selected and soil and rice samples were collected from farms in 5 counties of Mazandaran. Soil and rice samples were then transferred to the lab for further analysis. The concentration of pesticides and heavy metals was then analyzed using gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Mercury was analyzed using a Leco mercury analyzer. Target hazard quotient (THQ), total target hazard quotient (TTHQ), carcinogenic risk (CR), and total carcinogenic risk (TCR) in children and adults were used. Potential ecological risk also was used to test the possible hazards of heavy metals to the environment. Heavy metals concentration in rice and soil samples in different farming steps revealed different levels. THQ showed no considerable risk in consuming contaminated rice to adults and children considered, while TTHQ revealed potential non-carcinogenic risks. Ni had the most carcinogenic risks to target human groups, and TCR showed carcinogenicity for carcinogenic heavy metals in all stations. Findings showed no ecological risks of metals to the environment. In conclusion, rice farmers in Mazandaran use the lands multiple times during the year to increase the performance, function, quality, and quantity of rice, but the possible toxic effects of heavy metals and pesticides on consumers and the environment should not be overlooked., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

In this study, the performance of bench-scale EDR was evaluated using the samples taken from the 1st and the 2nd stage RO from the Brackish Water Reverse Osmosis (BWRO) plant in Eshtehard, Iran. The measurements indicated that original TDS of the aquifer brackish water was equal to 3,229-3,664 mg/L, whereas TDS of the 1st stage RO brine was between 5,500 and 7,700 mg/L, that TDS of the 2nd stage RO brine was in the range of 9,500-10,600 mg/L. A batch bench-scale EDR system of 12 l/h was used with a direct electric current at three different scenarios. In the first, the brine was fed at 20°C (as a reference regulated point). In the second, temperature (14, 20, 26.5°C), and in the third, voltage were changed (6, 12, 18, 24 V) to investigate their influences on performance of the EDR process, while the other operational parameters (feed flow rate, recovery ratio, quality of feed brine)were kept constant. Based on the data analysis using the ANOVA and DUNCAN tests for the second and third scenarios, it was observed that the optimum TDS removal efficiency of the EDR process can be at temperature of 26.5°C and voltage of 18 V. On the other hand, the successful performance of the bench-scale EDR in reducing the 29,000 mg/L TDS and the 45,000 μmhos/cm EC of the 2nd stage brine to 1,716 mg/L (TDS) and 2,640 μmhos/cm (EC) (at 26.5°C and 24V) could be considered as the main achievement of this research. Overall, the hybrid process RO-EDR-RO can be considered as the best technical, environmental and economical scenario for the development of Eshtehard Desalination Plant phase 2 at full scale., Competing Interests: NO.

This study is devoted to optimization synthesis conditions of the N, S co-doped porous graphene via a single step thermal chemical activation process from agricultural wastes such as cabbage waste. To this end, the response surface method (RSM) was considered, and the synthesis parameters were varied in specific ranges. By doing so, the optimum conditions in terms of the best performance in mercury removal was determined which was characterized by TEM, SEM, BET, XRD, XPS, and FTIR techniques. The chosen key process parameters were Activation agent to carbon precursor ratio (A: KOH/C), Reaction time (B: Time), Activation temperature (C: Temperature), and (Dopant to carbon precursor ratio (D: Dopant/C). Each parameter was investigated in 3 levels with lower and upper bounds being A: 2-6; B:30-90 min.; C: 600-800 ˚C; D:2-10. The optimum conditions of the process were determined to be as: A: 2; B: 30 min.; C: 600 ˚C and D: 2. The optimized sample was prepared in repeated runs with reproducible results with Hg vapor adsorption capacity of 2100 µg/g at 40 ˚C and 2266 µg/g at 90 ˚C. In addition to the experiments, DFT calculations were also carried out which elucidated the positive role of N and S co-doping in improving the mercury adsorption intensity., Supplementary Information: The online version contains supplementary material available at 10.1007/s40201-021-00712-y., Competing Interests: Conflict of interestHereby, the authors confirm that there is no conflict of interest., (© Springer Nature Switzerland AG 2021.)

In this survey a new route has been developed the preparation of poly (amidoamine) generation 6 (PAMAM-G6) dendrimer functionalized Fe 3 O 4 /SiO 2 nanoparticle and was used for arsenite (As (III)) adsorption. SiO 2 was first grafted onto the surface of Fe 3 O 4 to formation a core-shell structure. Then the introduction of epoxy rings were done by hydrolysis of methylsilane groups of 3-Glycidoxypropyltrimethoxysilane (GPTMS) on OH groups of SiO 2 and afterwards, PAMAM-G6 reacted with epoxy rings of GPTMS to obtain a multiamino magnetic adsorbent. The as-prepared nanocomposite was characterized by TEM, Zeta potential, FESEM, VSM, FTIR, Raman and XPS techniques. The effects of reaction time from 5 to 50 min, initial As (III) concentration in the range of 1-10 mgL -1 , initial adsorbent concentration in the range of 10-50 mgL -1 and initial pH in the range 3-8 were studied. The resulting of kinetic and isotherm models displays high adsorption affinity (233 mg/g) for As (III) and the adsorbent can reach the adsorbent can reach the adsorption equilibrium at a neutral pH (7). The As (III) loaded nanocomposite could be separated readily from aqueous solution by magnetic and regenerated simply via NaOH. The study of the adsorption procedure showed that the pseudo-second order kinetics and Langmuir isotherm well-fitted with the experimental data of As (III) adsorption onto nanocomposite., Competing Interests: Conflict of interestThere is no conflict of interest., (© Springer Nature Switzerland AG 2020.)

The in situ evaluation of the genotoxic impact of the Karaj River was performed using the comet and micronucleus (MN) assays in erythrocytes, liver, gill and kidney of indigenous brown trout, Salmo trutta fario from three different stations, including Varangerud, Asara and Purkan. The results showed that DNA damage significantly increased in sampled fish erythrocytes, liver and gill from low levels in the upstream river (Varangerud) via intermediate levels in downstream (Purkan) to high levels in the middle of the river (Asara), correlating with the river increasing pollution gradient. Gill was the most sensitive tissue followed by blood and liver. Kidney did not respond to the genotoxic gradient of the river. MN test (as a complementary assay) of liver cells of fish was a sensitive biomarker of genotoxic exposure. MN test in blood, gill and kidney did not reflect the genotoxic condition of the river., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: Spatial assessment of traffic noise pollution intensity will provide urban planners with approximate estimation of citizens exposure to impermissible sound levels. They could identify critical noise pollution areas wherein noise barriers should be embedded. The present study aims at using the Geographic Information System (GIS) to assess spatial changes in traffic noise pollution in Tehran, the capital of Iran, and the largest city in the Middle East., Material and Methods: For this purpose, while measuring equivalent sound levels at different time periods of a day and different days of a week in District 14 of Tehran, wherein there are highways and busy streets, the geographic coordination of the measurement points was recorded at the stations. The obtained results indicated that the equivalent sound level did not show a statistically significant difference between weekdays, and morning, afternoon and evening hours as well as time intervals of 10 min, 15 min and 30 min. Then, 91 stations were selected in the target area and equivalent sound level was measured for each station on 3 occasions of the morning (7:00-9:00 a.m.), afternoon (12.00-3:00 p.m.) and evening (5:00-8:00 p.m.) on Saturdays to Wednesdays., Results: As the results suggest, the maximum equivalent sound level (Leq) was reported from Basij Highway, which is a very important connecting thoroughfare in the district, and was equal to 84.2 dB(A), while the minimum equivalent sound level (Leq), measured in the Fajr Hospital, was equal to 59.9 dB(A)., Conclusions: The average equivalent sound level was higher than the national standard limit at all stations. The use of sound walls in Highways Basij and Mahallati as well as widening the Streets 17th Shahrivar, Pirouzi and Khavaran, benchmarked on a map, were recommended as the most effective mitigation measures. Additionally, the research findings confirm the outstanding applicability of the Geographic Information System in handling noise pollution data towards depicting noise pollution intensity caused by traffic., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)