Southern Bangladesh's irrigation and drinking water is threatened by saline intrusion. This study aimed to establish an irrigation water quality index(IWQI) using a geostatistical model and multivariate indices in...Southern Bangladesh's irrigation and drinking water is threatened by saline intrusion. This study aimed to establish an irrigation water quality index(IWQI) using a geostatistical model and multivariate indices in Gopalgan district, south-central Bangladesh. Groundwater samples were taken randomly(different depths) in two seasons(wet-monsoon and dry-monsoon). Hydrochemical analysis revealed groundwater in this area was neutral to slightly alkaline and dominating cations were Na^+, Mg^(2+), and Ca^(2+) along with major anions Cl-and HCO^(3-). Principa component analysis and Gibbs plot helped explain possible geochemical processes in the aquifer. The irrigation wate evaluation indices showed: electrical conductivity(EC)[750 l S/cm, moderate to extreme saline; sodium adsorption ratio(SAR), excellent to doubtful; total hard ness(TH), moderate to very hard; residual sodium bicar bonate, safe to marginal; Kelly's ratio [1; soluble sodiumpercentage(SSP), fair to poor; magnesium adsorption ratio,harmful for soil; and IWQI, moderate to suitable. In addition, the best fitted semivariogram for IWQI, EC, SAR,SSP, and TH confirmed that most parameters had strong spatial dependence and others had moderate to weak spatial dependence. This variation might be due to the different origin/sources of major contributing ions along with the influence of variable river flow and small anthropogenic contributions. Furthermore, the spatial distribution maps for IWQI, EC, SSP, and TH during both seasons confirmed the influence of salinity from the sea; low-flow in the major river system was the driving factor of overall groundwater quality in the study area. These findings may contribute to management of irrigation and/or drinking water in regions with similar groundwater problems.展开更多
Studies in recent years have shown that aquatic pollution by microplastics(MPs)can be considered to pose additional stress to amphibian populations.However,our knowledge of how MPs affect amphibians is very rudimentar...Studies in recent years have shown that aquatic pollution by microplastics(MPs)can be considered to pose additional stress to amphibian populations.However,our knowledge of how MPs affect amphibians is very rudimentary,and even more limited is our understanding of their effects in combination with other emerging pollutants.Thus,we aimed to evaluate the possible toxicity of polyethylene MPs(PE-MPs)(alone or in combination with a mix of pollutants)on the health of Physalaemus cuvieri tadpoles.After 30 days of exposure,multiple biomarkers were measured,including morphological,biometric,and developmental indices,behavioral parameters,mutagenicity,cytotoxicity,antioxidant and cholinesterase responses,as well as the uptake and accumulation of PE-MPs in animals.Based on the results,there was no significant change in any of the parameters measured in tadpoles exposed to treatments,but induced stress was observed in tadpoles exposed to PE-MPs combined with themixture of pollutants,reflecting significant changes in physiological and biochemical responses.Through principal component analysis(PCA)and integrated biomarker response(IBR)assessment,effects induced by pollutants in each test group were distinguished,confirming that the exposure of P.cuvieri tadpoles to the PE-MPs in combination with a mix of emerging pollutants induces an enhanced stress response,although the uptake and accumulation of PE-MPs in these animalswas reduced.Thus,our study provides newinsight into the danger to amphibians of MPs coexisting with other pollutants in aquatic environments.展开更多
基金supported by the project entitled ‘‘Establishment of monitoring network and mathematical model study to assess salinity intrusion in groundwater in the coastal area of Bangladesh due to climate change’’ implemented by Bangladesh Water Development Boardsponsored by Bangladesh Climate Change Trust Fund, Ministry of Environment and Forest
文摘Southern Bangladesh's irrigation and drinking water is threatened by saline intrusion. This study aimed to establish an irrigation water quality index(IWQI) using a geostatistical model and multivariate indices in Gopalgan district, south-central Bangladesh. Groundwater samples were taken randomly(different depths) in two seasons(wet-monsoon and dry-monsoon). Hydrochemical analysis revealed groundwater in this area was neutral to slightly alkaline and dominating cations were Na^+, Mg^(2+), and Ca^(2+) along with major anions Cl-and HCO^(3-). Principa component analysis and Gibbs plot helped explain possible geochemical processes in the aquifer. The irrigation wate evaluation indices showed: electrical conductivity(EC)[750 l S/cm, moderate to extreme saline; sodium adsorption ratio(SAR), excellent to doubtful; total hard ness(TH), moderate to very hard; residual sodium bicar bonate, safe to marginal; Kelly's ratio [1; soluble sodiumpercentage(SSP), fair to poor; magnesium adsorption ratio,harmful for soil; and IWQI, moderate to suitable. In addition, the best fitted semivariogram for IWQI, EC, SAR,SSP, and TH confirmed that most parameters had strong spatial dependence and others had moderate to weak spatial dependence. This variation might be due to the different origin/sources of major contributing ions along with the influence of variable river flow and small anthropogenic contributions. Furthermore, the spatial distribution maps for IWQI, EC, SSP, and TH during both seasons confirmed the influence of salinity from the sea; low-flow in the major river system was the driving factor of overall groundwater quality in the study area. These findings may contribute to management of irrigation and/or drinking water in regions with similar groundwater problems.
基金supporting the financing of this study(Process#307743/2018–7)the granting of research productivity grants to Dr.Malafaia G.(Proc.#307743/2018–7)and Dr.Melo e Silva D.(Process#307652/2018-1)+1 种基金for the scientific initiation scholarships to students Silva A.M.and Luz T.M.In addition,the authors thank the Federal Institute of Goiano(GO,Brazil)granting important financial assistance for the publication of this study(Proc.#23219.000139.2022-17).
文摘Studies in recent years have shown that aquatic pollution by microplastics(MPs)can be considered to pose additional stress to amphibian populations.However,our knowledge of how MPs affect amphibians is very rudimentary,and even more limited is our understanding of their effects in combination with other emerging pollutants.Thus,we aimed to evaluate the possible toxicity of polyethylene MPs(PE-MPs)(alone or in combination with a mix of pollutants)on the health of Physalaemus cuvieri tadpoles.After 30 days of exposure,multiple biomarkers were measured,including morphological,biometric,and developmental indices,behavioral parameters,mutagenicity,cytotoxicity,antioxidant and cholinesterase responses,as well as the uptake and accumulation of PE-MPs in animals.Based on the results,there was no significant change in any of the parameters measured in tadpoles exposed to treatments,but induced stress was observed in tadpoles exposed to PE-MPs combined with themixture of pollutants,reflecting significant changes in physiological and biochemical responses.Through principal component analysis(PCA)and integrated biomarker response(IBR)assessment,effects induced by pollutants in each test group were distinguished,confirming that the exposure of P.cuvieri tadpoles to the PE-MPs in combination with a mix of emerging pollutants induces an enhanced stress response,although the uptake and accumulation of PE-MPs in these animalswas reduced.Thus,our study provides newinsight into the danger to amphibians of MPs coexisting with other pollutants in aquatic environments.