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One of the most consumed pharmaceutical subgroups across the world is nonsteroidal anti-inflammatory drugs (NSAIDs). However, the dissemination of these compounds to the natural environments through agronomic practices is a serious global problem. The hypothesis of this study is to reveal the transition of selected NSAIDs, paracetamol (PAR), diclofenac (DCF), ibuprofen (IBU), and naproxen (NAP) together with six main metabolites, detected in raw/treated wastewater (RWW/TWW) and sewage sludge generated in an urban wastewater treatment plant (WWTP) to soils and agricultural crops (corn, barley, sunflower, and sugar beet) through two widely applied agronomic practices, irrigation with TWW and application of sewage sludge as soil amendment. In other words, the cycles of 10 NSAIDs have been evaluated by simultaneously monitoring their concentrations in RWW/TWW, sewage sludge, soils, and crops. It was determined that the parent compounds and detected metabolites were treated at quite higher removal efficiencies (93.4 - >99.9%) in the studied WWTP, while DCF was eliminated poorly (7.9-52.2%). However, although it changes seasonally for some compounds, it was determined that the concentrations of almost all investigated NSAIDs increased at the determined irrigation points in the discharge channel (DC) where agricultural irrigations were performed. Apart from that, DCF, NAP, and 2-hydroxyibuprofen (2-OH-IBU) were always detected in sewage sludge seasonally up to about 20.5, 11.3, and 3.7 ng/g, respectively. While 2-OH-IBU was determined as the dominant metabolite in RWW, TWW, and sewage sludge, the metabolite of 1-hydroxyibuprofen (1-OH-IBU) was determined as the dominant compound in soils. Although 1-OH-IBU was not detected in TWW and sewage sludge in any season, detecting this metabolite as a common compound in all investigated soils (up to 60.1 ng/kg) reveals that this compound is the primary transformation product of IBU in soils. It was observed that at least one of the metabolites of IBU (1-OH-IBU and/or 2-OH-IBU) was detected in all plants grown (up to 0.75 ng/g), especially during the periods when both agricultural practices were applied. In addition, the detection of 1-OH-IBU with increasing concentrations from root to shoots in corn grown as a result of both agronomic practices shows that this compound has a high translocation potential in the corn plant. Apart from this, it was determined that PAR was detected in corn (up to 43.3 ng/kg) and barley (up to 16.8 ng/kg) within the scope of irrigation with TWW, and NAP was detected in sugar beet (up to 11.2 ng/kg) through sewage sludge application.
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Esgotos , Solo , Produtos Agrícolas , Anti-Inflamatórios não Esteroides , Águas Residuárias , Diclofenaco , Naproxeno , Acetaminofen , Verduras , AçúcaresRESUMO
Sustainable water recycling and wastewater reuse are urgent nowadays considering water scarcity and increased water consumption through human activities. In 2015, United Nations Sustainable Development Goal 6 (UN SDG6) highlighted the necessity of recycling wastewater to guarantee water availability for individuals. Currently, wastewater irrigation (WWI) of crops and agricultural land appears essential. The present work overviews the quality of treated wastewater in terms of soil microbial activities, and discusses challenges and benefits of WWI in line with wastewater reuse in agriculture and aquaculture irrigation. Combined conventional-advanced wastewater treatment processes are specifically deliberated, considering the harmful impacts on human health arising from WWI originating from reuse of contaminated water (salts, organic pollutants, toxic metals, and microbial pathogens i.e., viruses and bacteria). The comprehensive literature survey revealed that, in addition to the increased levels of pathogen and microbial threats to human wellbeing, poorly-treated wastewater results in plant and soil contamination with toxic organic/inorganic chemicals, and microbial pathogens. The impact of long-term emerging pollutants like plastic nanoparticles should also be established in further studies, with the development of standardized analytical techniques for such hazardous chemicals. Likewise, the reliable, long-term and extensive judgment on heavy metals threat to human beings's health should be explored in future investigations.
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Poluentes Ambientais , Águas Residuárias , Humanos , Irrigação Agrícola/métodos , Agricultura , Solo , ÁguaRESUMO
The protozoa Cryptosporidium and Giardia are major causes of diarrhea and are commonly found on vegetables in China. They pose a health risk, particularly to immunocompromised individuals, including cancer patients. A quantitative microbial risk assessment of Chinese data evaluated the risks of Cryptosporidium and Giardia exposure arising from the application of surface water and septic tank effluent to agricultural land. Exposure via agricultural produce consumption (consumers) and agricultural practices (farmers) was considered for subpopulations of cancer patients and immunocompetent people in urban and rural areas, and risk mitigation scenarios were modelled. The cumulative disease burdens attributable to cryptosporidiosis and giardiasis were, respectively, 9.68×10-6 and 5.57×10-5 disability-adjusted life years per person per year (DALYs pppy) for immunocompetent people, and 3.14×10-5 and 1.51×10-4 DALYs pppy for cancer patients. Cancer patients were approximately three times more likely to have an individual disease burden than immunocompetent people. The disease burden was higher for consumers than farmers, and higher in rural areas than urban areas (all exceeding the maximum recommended by the World Health Organization). The highest burdens were in provinces of high population, such as Henan, Guangdong, and Sichuan, while the burden associated with human and livestock fecal effluent application was higher than with surface water irrigation. Of the three vegetables studied, lettuce posed the greatest risk, followed by bok choy, while cucumber posed the least risk. Risk mitigation scenario analysis showed that pre-treatment of surface water and feces, and appropriate post-harvest handling of vegetables, including disinfection, cooking, and adequate surface heat treatment (75 °C for 60 s), should be considered when attempting to reduce disease burdens. The methodology and findings of this study are useful for evaluating and reducing the burden of Cryptosporidium and Giardia infections associated with agricultural irrigation and fertilization practices, particularly on cancer patients.
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Criptosporidiose , Cryptosporidium , Giardíase , Neoplasias , Humanos , Giardíase/epidemiologia , Giardia , Criptosporidiose/epidemiologia , Água , População do Leste Asiático , Irrigação Agrícola/métodos , Medição de Risco , VerdurasRESUMO
Climate change poses challenges to agricultural water resources, both in terms of quantity and quality. As an adaptation measure, the new European Regulation (EU) 2020/741 establishes different water quality classes for the use of reclaimed water in agricultural irrigation. Italy is also working on the definition of a new regulation on reclaimed water reuse for agricultural irrigation (in substitution of the current one) that will also include the specific requirements imposed by the European one. Nature-based Solutions (NBS) can be a cost-effective and environmentally friendly way to facilitate water reclamation and reuse. The present study reports the outcomes of a long-term monitoring campaign of two NBS (e.g., a constructed wetland (CW) and a lagoon system (LS)) comparing influent and effluent concentrations of different contaminants (e.g., E. coli, BOD5, TSS, TN and TP) with the threshold values imposed by the new regulations. The results showed that in both the case studies, E. coli (about 100 CFU 100 mL-1) and BOD5 (lower than 25 mg L-1) mean effluent concentration need to be further reduced in reclaimed water to be suitable for unlimited reuse. As a negative aspect, in both the monitored NBS, an increase in TSS mean concentration in the effluent was observed, up to 40 mg L-1 in the case of the LS, making reclaimed water unsuitable for agricultural reuse. The CW has proven to be more effective in nitrogen removal (the effluent mean concentration was 3.4 mg L-1), whereas the LS was better at phosphorus removal (with an effluent mean concentration of 0.4 mg L-1). Based on the results, recommendations were made to further improve the performance of both systems in order to have adequate water quality, even for class A. Furthermore, the capacity of reclaimed water to meet crop water and nutrient needs was analyzed, and total nitrogen removal rate coefficients were calculated for the design of future LSs.
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Irrigação Agrícola , Purificação da Água , Irrigação Agrícola/métodos , Áreas Alagadas , Águas Residuárias , Eliminação de Resíduos Líquidos/métodos , Escherichia coliRESUMO
Water scarcity affects already a large part of the world's population. To overcome this situation, water management is needed, and wastewater reuse must be implemented and included as a new approach. To achieve that objective water quality must comply with the parameters established in the Regulation (EU) 2020/741 of the European Parliament and the Council of the European Union and new treatment solutions have to be developed. The main goal of this pilot study was to evaluate the peracetic acid (PAA) disinfection efficiency in a real wastewater treatment plant (WWTP) in order to accomplish the wastewater reuse objective. To this end, six disinfection conditions were studied, three PAA doses (5, 10, and 15) and three contact times (5, 10, and 15) based on the commonly used disinfection operational conditions in real WWTP. Comparing the Total Suspended Solids (TSS), turbidity, Biological Oxygen Demand (BOD5) and Escherichia coli content, after and before the disinfection step, was possible to conclude that PAA ensures the Regulation (EU) 2020/741 requirements and that the disinfected effluent can be reused for several uses. All the conditions in which the PAA dose was 15 mg/L and the condition with 10 mg/L of PAA with a contact time of 15 min were the most promising, presenting the second highest water quality class achieved. The results of this study illustrate the potential of PAA as an alternative disinfectant for wastewater treatment and, bring it closer to the water reuse objective by presenting several possibilities for water uses.
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Desinfetantes , Purificação da Água , Ácido Peracético , Águas Residuárias , Projetos Piloto , Monitoramento Ambiental , Desinfecção/métodos , Escherichia coli , Purificação da Água/métodos , Eliminação de Resíduos Líquidos/métodosRESUMO
Land use change threatens food security because it may cause the depletion and/or low bioavailability of micronutrients in agricultural soils. Therefore, it is significant to investigate the fate of micronutrients and predict the potential environmental problems. The zinc isotope technique is of particular interest in interpreting soil processes. In this study, Zn isotopic data of soil samples in five profiles based on different land uses were provided, and Zn behavior in different soils was discussed. The isotopic ratios of soil samples in the abandoned orchard, secondary forest, abandoned cropland, and cropland are similar, with the δ66Zn varying from 0.15 to 0.29. However, the samples in shrub grassland show a lower δ66Zn of 0-0.20, which may be affected by anthropogenic sources. For the vertical patterns, the non-cultivated long-rooted plants (i.e., abandoned orchard and secondary forest) show no significant difference in the distribution of δ66Zn, but the patterns of cropland and abandoned cropland samples are reversed. The cropland samples show positive correlations between δ66Zn and Fe2O3 (R2 = 0.90) and MnO (R2 = 0.75), indicating that Fe and Mn oxides preferentially adsorb heavy Zn isotopes on the mineral surfaces. The high affinity between Zn and oxides indicated that the concentration of bio-available Zn in cropland soils was getting lower. As a result, the supplies of micronutrients may be deficient and urged from fertilizer. This study provides a better understanding of Zn cycling in agricultural systems and gives improvements in soil management.
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Poluentes do Solo , Solo , Agricultura , China , Monitoramento Ambiental/métodos , Fertilizantes , Isótopos/análise , Micronutrientes , Óxidos , Poluentes do Solo/análise , Zinco/análise , Isótopos de ZincoRESUMO
Quantitative assessment of the terrestrial water storage (TWS) changes and the major driving factors have been hindered by the lack of direct observations in Inner Mongolia, China. In this study, the spatial and temporal changes of TWS and groundwater storage (GWS) in Inner Mongolia during 2003-2021 were evaluated using the satellite gravity data from the Gravity Recovery and Climate Experiment (GRACE) and the GRACE Follow On combined with data from land surface models. The results indicated that Inner Mongolia has experienced a widespread TWS loss of approximately 1.82 mm/yr from 2003-2021, with a more severe depletion rate of 4.15 mm/yr for GWS. Meteorological factors were the driving factors for water storage changes in northeastern and western regions. The abundant precipitation increased TWS in northeast regions at 2.36 mm/yr. Anthropogenic activities (agricultural irrigation and coal mining) were the driving factors for water resource decline in the middle and eastern regions (especially in the agropastoral transitional zone), where the decrease rates were 4.09 mm/yr and 3.69 mm/yr, respectively. In addition, the severities of hydrological drought events were identified based on water storage deficits, with average severity values of 17 mm, 18 mm, 24 mm, and 33 mm for the west, middle, east, and northeast regions, respectively. This study established a basic framework for water resource changes in Inner Mongolia and provided a scientific foundation for further water resources investigation.
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Água Subterrânea , Água , China , Clima , HidrologiaRESUMO
Water scarcity has resulted in extensive wastewater recycling for agricultural irrigation in both Israel and the Palestinian Territories. However, minimal data have been collected regarding perceptions about wastewater recycling between the populations in these two areas. While geographically close and economically linked, these two populations differ in terms of governance, income, and access to technology for wastewater recycling. To address the data gap pertaining to perceptions of wastewater recycling, a survey was administered among a convenience sample of subjects (n = 236) recruited from Eilat, Israel and Bethlehem, West Bank, from May to November 2018. The survey included questions addressing knowledge of water sources, water scarcity, and recycled water; willingness to use recycled water for produce irrigation and household tasks; and demographics. Israeli willingness to use recycled water for various purposes ranged from 8.3% to 55.1%, and more than half of Israeli respondents were willing to serve both raw and cooked produce irrigated with recycled water. Willingness to use recycled water ranged from 28.9% to 41.7% among the Palestinian respondents, and Palestinian respondents were more willing to engage in high-contact uses (i.e. drinking and cooking) than Israeli respondents. Among the Israeli respondents, experience or familiarity with wastewater recycling and water contamination were frequently significantly associated with willingness to use recycled water. In contrast, among Palestinian respondents, personal water contamination experience, home water safety testing, and trust in authorities to monitor recycled wastewater reuse were frequently significantly associated with willingness to use recycled water. Given the likely increasing water stress in both Israel and the Palestinian Territories, as well as the continued evolution of wastewater treatment technologies and the substantial amount of agricultural trade ongoing between Israel and the Palestinian Territories, it is important to identify effective and appropriate outreach and communication strategies to enable successful and acceptable water recycling.
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Árabes , Água , Irrigação Agrícola , Humanos , Percepção , Águas Residuárias/análiseRESUMO
The irrigation channel of the Qishan River is among the most crucial agricultural water resource facilities in Qishan District, Kaohsiung City, Taiwan. The channel was blocked by debris due to flood events caused by Typhoon Morakot in 2009. This study analyzed images captured by an unmanned aerial system to identify channel areas susceptible to sediment deposition and propose measures for reducing the effects of natural hazards on irrigation water resources. The analysis results revealed that the channel was located downstream of the Qishan River; however, debris flows, riverbank landslides, and natural dam breaches deposited sediment in the downstream section, preventing the flow of water. Furthermore, the sediment and driftwood blocked the channel. The channel was also blocked due to a hyperconcentrated flow. Sediment deposition areas and volumes were estimated. On the basis of these results, we suggest that the damaged riverbed groundsills and river tributary banks be restored to inhibit erosion. In addition, subsurface water collection and transfer structures should be constructed to maintain the flow of water during the dry season. The study findings are expected to increase the efficiency of agricultural irrigation water management and prevent natural hazards from affecting water resources.
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Irrigação Agrícola , Monitoramento Ambiental , Sedimentos Geológicos , Cidades , Taiwan , ÁguaRESUMO
Migrating waterbirds moving between upper and lower latitudinal breeding and wintering grounds rely on a limited network of endorheic lakes and wetlands when crossing arid continental interiors. Recent drying of global endorheic water stores raises concerns over deteriorating migratory pathways, yet few studies have considered these effects at the scale of continental flyways. Here, we investigate the resiliency of waterbird migration networks across western North America by reconstructing long-term patterns (1984-2018) of terminal lake and wetland surface water area in 26 endorheic watersheds. Findings were partitioned regionally by snowmelt- and monsoon-driven hydrologies and combined with climate and human water-use data to determine their importance in predicting surface water trends. Nonlinear patterns of lake and wetland drying were apparent along latitudinal flyway gradients. Pervasive surface water declines were prevalent in northern snowmelt watersheds (lakes -27%, wetlands -47%) while largely stable in monsoonal watersheds to the south (lakes -13%, wetlands +8%). Monsoonal watersheds represented a smaller proportion of total lake and wetland area, but their distribution and frequency of change within highly arid regions of the continental flyway increased their value to migratory waterbirds. Irrigated agriculture and increasing evaporative demands were the most important drivers of surface water declines. Underlying agricultural and wetland relationships however were more complex. Approximately 7% of irrigated lands linked to flood irrigation and water storage practices supported 61% of all wetland inundation in snowmelt watersheds. In monsoonal watersheds, small earthen dams, meant to capture surface runoff for livestock watering, were a major component of wetland resources (67%) that supported networks of isolated wetlands surrounding endorheic lakes. Ecological trends and human impacts identified herein underscore the importance of assessing flyway-scale change as our model depictions likely reflect new and emerging bottlenecks to continental migration.
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Various highly sensitive and selective analytical methods have been used to monitor metsulfuron-methyl residue in the environment. However, these methods involve costly instruments and complex, time-consuming operations performed in laboratories. Here, a rapid, convenient, and sensitive colorimetric sensor based on anti-aggregation of gold nanoparticles (AuNPs) is demonstrated for the rapid detection of metsulfuron-methyl in agricultural irrigation water. The AuNPs could be induced to aggregate in the presence of melamine and exhibited a distinct color change from wine-red to blue. The aggregation was suppressed by a strong hydrogen-bonding interaction between metsulfuron-methyl and melamine. The differences of the absorbance at 523 nm (ΔA523) and the color change was linearly related to metsulfuron-methyl concentration over the range 0.1â»100 mg/L, as observed visually and by UV-vis (Ultraviolet-visible) spectrometry. The detection limit of the sensor was as low as 0.05 mg/L (signal/noise = 3), and was used to determine metsulfuron-methyl in spiked water and in agricultural irrigation water samples. Recoveries were in the range of 71.2â»100.4%, suggesting that the colorimetric sensor was suitable for the determination of metsulfuron-methyl in agricultural water samples.
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Atmospheric dispersion conditions strongly impact air pollution under identical surface emissions. The degree of air pollution in the Jing-Jin-Ji region is so severe that it may impose feedback on local climate. Reference evapotranspiration (ET0) plays a significant role in the estimation of crop water requirements, as well as in studies on climate variation and change. Since the traditional correlation analysis cannot capture the causality, we apply the convergent cross mapping method (CCM) in this study to observationally investigate whether the air pollution impacts ET0. The results indicate that southwest regions of Jing-Jin-Ji always suffer higher PM2.5 concentration than north regions through the whole year, and correlation analysis suggests that PM2.5 concentration has a significant negative effect on ET0 in most cities. The causality detection with CCM quantitatively demonstrates the significantly causative influence of PM2.5 concentration on ET0, higher PM2.5 concentration decreasing ET0. However, CCM analysis suggests that PM2.5 concentration has a relatively weak causal influence on ET0 while the correlation analysis gives the near zero correlation coefficient in Zhangjiakou city, indicating that the causative influence of PM2.5 concentration on ET0 is better revealed with CCM method than the correlation analysis. Considering that ET0 is strongly associated with crop water requirement, the amount of water for agricultural irrigation could be reduced at high PM2.5 concentrations. These findings can be utilized to improve the efficiency of water resources utilization, and reduce the exploiting amount of groundwater in the Jing-Jin-Ji region, although PM2.5 is detrimental to human health.
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Poluentes Atmosféricos/análise , Poluição do Ar/análise , Produtos Agrícolas/fisiologia , Material Particulado/análise , Transpiração Vegetal , Irrigação Agrícola , China , Tamanho da PartículaRESUMO
The World Health Organization (WHO) has established as a criterion of parasitological quality for irrigation water, ≤ 1 helminth egg/liter, which guarantees the safety in agricultural products. In this study, the presence of parasites in surface water used for irrigation of crops (n = 96) and vegetables (celery and lettuce) (n = 120), from the Former La Ramada irrigation district, was evaluated using conventional and molecular parasitological methods. Our findings showed contamination of irrigation systems in the study area with domestic wastewater, demonstrated by the presence of Ancylostomatidae eggs, Ascaris spp., Hymenolepis spp., Trichuris spp., Capillaria spp., Giardia spp. cysts, and oocysts of Toxoplasma gondii and Cryptosporidium spp. A prevalence of 33% and 23.3% was calculated for helminths and protozoa, respectively in vegetables, representing a possible risk to human and animal health in relation to these parasites. These findings show the need for continuous monitoring of the water quality used for crop irrigation, as well as the safety of food, taking into account the values established in national and international regulations.
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Irrigação Agrícola , Produtos Agrícolas , Verduras , Verduras/parasitologia , Colômbia , Animais , Parasitos , HumanosRESUMO
The quality of groundwater is critical to human health. MPs have access to groundwater from the soil, polluted by various agricultural activities. However, to date, there have been no studies on the occurrence of MP in groundwater from an agriculture field without any adjacent sources of contamination, such as nearby landfills. In this study, the occurrence and distribution of MPs in groundwater of an agricultural area in the Haean Basin, Korea, without any definite source of pollution, was examined. MP and groundwater samplings were conducted in the dry season in 2020, the wet and dry seasons in 2021, respectively. In this study, the reliability of MP analysis was improved through good practices from laboratory to field campaigns, collecting large groundwater samples (300-500 L) volumes. Any involvement of plastic materials was avoided during the full procedures as possible and. Detailed investigation was conducted for the distribution of potential plastics sources like mulching, plastic covers, dripping pipes and shading nets, and hydrogeological properties affecting MPs occurrence. Groundwater MP concentrations of 0.02-0.15 particles/L (median = 0.06 particles/L), 0.02-2.56 particles/L (median = 0.43 particles/L) and 0.20-3.48 particles/L (median = 0.83 particles/L) were found in three rounds of sampling that comprised of the exploratory investigation in 2020, the wet season, and the dry season in 2021, respectively. The identified polymer types were polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS) and polyamide (PA). The MPs concentrations showed no statistically significant seasonal variation but revealed an apparent strong positive correlation (r = 0.71) of MPs with the amount of groundwater use. Findings of this study need more clarification from repeated samplings for multiple years. This study reveals the occurrence of MPs in groundwater in Korea for the first time to the best of our knowledge.
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Frequent exchange of surface water and groundwater occurs in arid/semi-arid areas due to high evaporation and intensive irrigation activities, affecting the migration and transformation of per- and polyfluoroalkyl substances (PFASs) and threatening drinking water safety. This study analyzed legacy PFASs and potential precursors in surface water, groundwater, soil, and aquifer solid samples collected from a typical arid area, the Hetao Irrigation District of Northern China, to explore PFASs distribution and transformation between surface and ground. Total PFASs (ΣPFASs) in surface water was 29-232 ng/L, higher than 2-77 ng/L in groundwater. ΣPFASs in soil were 0.29-0.59 ng/g, higher than 0.09-0.27 in the aquifer solids. Regarding horizontal distribution, the concentration of PFASs in groundwater increased in downtowns and the areas recharged with lake water. In terms of vertical distribution, ΣPFASs decreased with the increase of depth, and more PFASs adsorbed on clay particles in the aquifer. The total oxidable precursor analysis showed that 8:2 FT and 4:2 FT were the dominant precursors of PFASs, resulting in an increment of 0.1-4 ng/L PFASs. Hydrogen and oxygen stable isotope compositions suggest similar sources between surface water and groundwater in the study area, while principal component analysis and Bayesian inference also indicate that surface water is an important source of groundwater PFASs. The annual infiltration PFASs to groundwater from Ulansuhai was estimated by the water balance approach to be 9.39 kg. Results highlight the influence of agricultural irrigation activities and lake infiltration on groundwater PFASs in the arid region.
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Fluorocarbonos , Água Subterrânea , Poluentes Químicos da Água , Fluorocarbonos/análise , Teorema de Bayes , Poluentes Químicos da Água/análise , Solo , Lagos , Água/análise , China , Monitoramento Ambiental/métodosRESUMO
In arid inland irrigated areas, the role of human activities on fluoride enrichment in groundwater is not fully understood. There is an extremely arid climate, high-intensity irrigation, and severe soil salinization in the Hotan Oasis within the Tarim Basin, Northwestern China. In this study, hydrogeochemistry and environmental isotope methods were combined to explore the distribution characteristics and controlling processes of fluoride enrichment in groundwater. The F- concentration in groundwater had a range of 1.12-9.4 mg/L. F- concentrations of all the groundwater samples were higher than 1.0 mg/L (Chinese Standards for Drinking Water Quality), and about 89% were higher than 1.5 mg/L (WHO Guidelines for Drinking Water Quality). High fluoride groundwater was mainly distributed downstream of the river and in the middle of the interfluvial zone. Vertically, the fluoride concentration was higher when the sampling depth was less than 15 m. There was a significant positive correlation between F- concentration and salinity in groundwater. F- in groundwater was mainly derived from river water fluoride, which could be imported to groundwater with infiltration of rivers and irrigation canals as well as irrigation return flow. Anthropogenic inputs may be partly responsible for fluoride enrichment in groundwater. Fluoride accumulated in the vadose zone by strong evapotranspiration and then leached into groundwater with irrigation return flow was the main mechanism of F- enrichment in groundwater in the study area. This work is a clear example of how human activities together with natural processes can affect the chemical quality of groundwater, which is essential to safeguard the sustainable management of water and soil resources inland arid oasis areas.
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Água Subterrânea , Poluentes Químicos da Água , China , Monitoramento Ambiental , Fluoretos/análise , Humanos , Rios , Poluentes Químicos da Água/análiseRESUMO
Treated and untreated wastewater is often used for agricultural irrigation and, despite the many benefits of this practice, it poses the risk of biologically active chemical pollutants (such as pharmaceuticals, like tramadol) entering the environment. The partitioning of tramadol between soil/water at environmentally relevant concentrations is important to understand its environmental toxicity. Kinetics and isotherm sorption studies based on the Organisation for Economic Cooperation and Development (OECD) 106 Guideline were undertaken, ensuring comparability to previous studies. Studies were undertaken in three soils of different characteristics using aqueous concentrations of tramadol from 500 ng L-1 (environmentally relevant) to 100 µg L-1 (comparable to previous studies). Two of the soils presented a significantly (p < 0.05) higher sorption at a lower initial tramadol concentration (5000 ng L-1), compared to 20,000 ng L-1. Hysteresis was observed in all studied soils, indicating the accumulation of tramadol. Higher sorption to soils correlated with higher clay content, with soil/water partitioning coefficients (Kd) of 5.5 ± 13.3, 2.5 ± 3.8 and 0.9 ± 3.0 L kg1 for soils with clay contents of 41.9%, 24.5% and 7.4%, respectively. Cation exchange was proposed as the main sorption mechanism for tramadol to soils when the pH was below tramadol's pKa values (9.41 and 13.08). A comparative kinetics study between tramadol in soil/calcium chloride buffer and soil/wastewater effluent demonstrated significantly higher (p < 0.05) tramadol sorption to soil from wastewater effluent. This has the environmental implication that clay soils will be able to retain tramadol from irrigation water, despite the organic content of the irrigation water. Therefore, our studies show that tramadol soil sorption is likely to be higher in agricultural environments reusing wastewater than that predicted from experiments using the OECD 106 Guideline calcium chloride buffer.
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Poluentes do Solo , Tramadol , Adsorção , Irrigação Agrícola , Cloreto de Cálcio , Argila , Organização para a Cooperação e Desenvolvimento Econômico , Solo/química , Poluentes do Solo/análise , Águas Residuárias/química , ÁguaRESUMO
Inland freshwater ecosystems are of increasing concerns in global methane (CH4) budget in the atmosphere. Agricultural irrigation watersheds are a potential CH4 emission hotspot owing to the anthropogenic carbon and nutrients loading. However, large-scale spatial variations of CH4 concentrations and fluxes in agricultural catchments remain poorly understood, constraining an accurate regional estimate of CH4 budgets. Here, we examined the spatiotemporal variations of dissolved CH4 concentrations and fluxes from typical freshwater types (ditch, reservoir and river) within an agricultural irrigation watershed from Hongze catchment, which is subjected to intensive agricultural and rural activities in Eastern China. The dissolved CH4 concentrations and fluxes showed similar temporal variations among the three freshwater types, with the highest rates in summer and the lowest rates in winter. The total CH4 emission from this agricultural irrigation watershed was estimated to be 0.002 Gg CH4 yr-1, with annual mean CH4 concentration and flux of 0.12 µmol L-1 and 0.58 mg m-2 d-1, respectively. Diffusive CH4 fluxes varied in samples taken from different freshwater types, the annual mean CH4 fluxes for ditch, reservoir and river were 0.31 ± 0.06, 0.71 ± 0.13 and 0.72 ± 0.25 mg m-2 d-1, respectively. Among three freshwater types, the CH4 fluxes were the lowest in ditch, which was associated with the lowest responses of CH4 fluxes to water dissolved oxygen (DO), nitrate nitrogen (NO3--N) and sediment dissolved organic carbon (DOC) concentrations in ditch. In addition, water velocity and wind speed were significantly lower in ditch than in reservoir and river, suggesting that they also played important roles in explaining the spatial variability of dissolved CH4 concentrations and fluxes. These results highlighted a need for more field measurements with wider spatial coverage and finer frequency, which would further improve the reliability of flux estimates for assessing the contribution of agricultural watersheds to the regional and global CH4 budgets.
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Irrigação Agrícola , Ecossistema , Nitratos , Reprodutibilidade dos Testes , Água Doce , Metano/análise , Carbono/análise , Dióxido de Carbono/análise , Nitrogênio , China , Água , OxigênioRESUMO
In this study, a fixed-mix stochastic fractional programming (FSFP) method is developed for balancing the water-allocation conflict between upstream hydropower generation and downstream agricultural irrigation. FSFP has advantages in dealing with ratio-objective problem under uncertainty, reflecting the dynamic and stochastic characteristics over a long-term planning context, as well as analyzing interrelationships between system efficiency and violation risk of water-allocation target. Then, FSFP is firstly applied to Tuyamuyun reservoir in the lower reach of Amu Darya River basin (Central Asia), where multiple scenarios based on different hydropower-generation targets and inflow levels are examined for identifying the complex relationship between hydropower generation and crop irrigation. Major findings and managerial insights can be summarized as: (i) with the reduction of reservoir inflow, water allocation for downstream agricultural irrigation would decrease by 30.4% once the minimum demand is satisfied, and hydropower generation should be higher priority for pursuing higher marginal benefit; (ii) with the shrinking water supply and rising hydropower-generation target, cotton planting should be firstly restrained due to its high water demand and grape planting is encouraged; (iii) under extreme water scarcity (i.e., low and very-low inflow levels), low-level hydropower generation target (i.e., α = 0.45) is desired for meeting the food requirement in the study basin; (iv) for alleviating the water shortage during dry seasons, it is recommended that water storage should be conducted in autumn and winter, and water release for crop irrigation should be implemented during spring and summer. These findings can help managers identify sustainable water-allocation schemes for agricultural irrigation and hydropower generation against water shortage, environmental destruction and energy insecurity in arid regions.
Assuntos
Irrigação Agrícola , Recursos Hídricos , Irrigação Agrícola/métodos , Ásia , Água , Abastecimento de ÁguaRESUMO
The European Commission's draft regulation for minimum requirements for water reuse in agriculture addresses microbial and basic water quality parameters but does not consider the potential impacts of chemicals of emerging concern (CECs) on human and environmental health. Because insufficient data prevents the quantitative characterisation of risks posed by CECs in treated wastewater (TWW), this paper presents a framework, which combines data and expert judgement to assess likelihood of occurrence and magnitude of impact. An increasing relative scale is applied where numeric values are pre-defined to represent comparative levels of importance. Subsequently, an overall assessment of the level of risk is characterised by multiplying together allocated scores, to obtain a single discrete overall score per CEC. Guidelines to support implementation of the framework as far as soil (the initial receiving compartment and pathway to further protected targets) are developed and applied. The approach is demonstrated through its application to clarithromycin, where results indicate that - under the considered scenario - there is limited possibility of its occurrence in soil in a bioavailable form. The role of a qualitative risk assessment approach is considered and the opportunity for its outputs to inform future research agendas described.