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RESUMO Os efeitos das alterações climáticas e a crescente demanda de água para os variados consumos vão levar ao reúso de águas residuárias tratadas (ART). A recarga de aquíferos com ART pode constituir uma alternativa para o restabelecimento de volumes de água subterrânea que poderão ser utilizados para satisfazer parte daquelas atividades, especialmente em regiões de escassez de água ou onde sua qualidade não é adequada para uso. Uma pesquisa de dois anos realizada na estação de tratamento de esgoto de Vila Fernando (Guarda, Portugal) mostrou que as caraterísticas das ART são adequadas para que o efluente seja infiltrado no solo visando à recarga de aquífero. Como a área em estudo é vasta e dada a necessidade de considerar várias restrições técnicas, ambientais e econômicas, foi aplicada uma análise multicritério baseada em Sistemas de Informação Geográfica para encontrar o local mais adequado para a infiltração de ART. Recolheu-se uma amostra de solo para análise, na Quinta de Gonçalo Martins (Guarda, Portugal), tendo os resultados indicado que tal solo apresentava características favoráveis à infiltração de ART.
ABSTRACT The effects of climate change and the increasing demand of water for domestic, industrial and agricultural uses will lead to the use of treated wastewater (reclaimed water). The aquifer recharge with reclaimed water can be an alternative for restoring volumes of water to aquifers, which may afterwards be used to satisfy those demands, especially in regions with water scarcity or where water presents poor quality. A two-year research conducted in the sewage treatment plant of Vila Fernando (Guarda, Portugal) has shown that the characteristics of reclaimed water are adequate to be infiltrated into the soil for aquifer recharge. As the study area for infiltration was very large and it was necessary to consider several technical, environmental and economic constraints, a multi-criteria analysis based on Geographic Information Systems was used in order to find the most suitable site for reclaimed water infiltration. Soil sample was collected at Quinta Gonçalo Martins (Guarda, Portugal) for analysis, and the results have indicated that the site has favorable characteristics for reclaimed water infiltration.
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dichloromethane,since the former four components account for more than 90% of the total HRV,which proposed as the target compounds in risk management of the VOCs.
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Objective To study the concentrations of endocrine disrupting compounds in reclaimed water samples. Methods A solid-phase extraction (SPE)-gas chromatography (GC)-mass spectrometry (MS) analytical method was used for the separation and determination of endocrine disrupting compounds (EDCs) from water samples. The water samples were collected from each process of the reclaimed water plant of Tianjin, China. Important and contrasting EDCs including estrone (E1), 17?-estradiol (E2), 17?-ethynylestradiol (EE2), 4-tert-octylphenol (OP), 4-nonylphenol (NP), bisphenol A (BPA), di-n-butyl phthalate (DnBP), diisobutyl phthalate (DIBP), and di (2-ethylhexyl) phthalate (DEHP) were selected as the target compounds. C-18 solid-phase extraction (SPE) technique was used for the extraction recoveries of target compounds from water samples while ethyl acetate was efficient in eluting EDCs from SPE cartridges. After elution from the SPE column, the t-butyldimethylsilyl (TBS) derivatives of EDCs with N-methyl-N-(tertbutyldimethylsilyl) trifluoroacetamide (MTBSTFA) were analyzed by GC-MS in the selected ion mode (SIM). Results Concentrations of steroid hormones, phenolic compounds and phthalate esters ranged from not detected to 7.01 ng/L, 4.85 ng/L, and 0.03 ?g/L to 23.82 ?g/L, respectively. Conclusion Environmental endocrine disrupting compounds are not completely removed in the process of reclaimed water treatment and will be carried over into the general aquatic environment as it will be reused.
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Objective To study the estrogenic effect of organic extracts of effluent samples from different treatment stages in Tianjin reclaimed water treatment plant. Methods Reverse phase C-18 solid-phase extraction (RP-C18SPE) was used for the extraction of target compounds from water samples. Then, a simplified proliferation test with human estrogen receptor-positive MCF-7 breast cancer cell and recombined yeast assay were applied to assess the estrogenic effect in effluent samples from different treatment stages in Tianjin reclaimed water treatment plant. Results The amount of extracts of reclaimed water inducing the maximum effect in cell proliferation assay was equal to that from 1.00 ml primary water. In recombined yeast assay, the amount of extracts of reclaimed water inducing maximum ?-galactosidase activity was equal to that from 20.00 ml primary water. Conclusion The effluent of reclaimed water treatment plant still shows estrogenic effect though slightly reduced.
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Objective To evaluate the cancer risk from trihalmethanes in the reclaimed water using for road clearing and public garden virescence in Beijing.Methods The reclaimed water samples were collected and the concentration of trihalmethanes was determined,the questionnaires were used to investigate the way and level to exposure to THMs for the occupational workers and general populations respectively when the reclaimed water was used in road clearing and public garden virescence,based on this,health risks assessment method was used to evaluate health affect of THMs in reclaimed water on population quantitatively,in 2003.Results Inbreathe and dermal exposure to THMs in reclaimed water were the main ways of exposure for occupational worker and general populations in road clearing and public garden virescence in Beijing.The major components of THMs in the reclaimed water were TCM,BDCM,DBCM and TBM respectively.Conclusion The cancer risk of the occupational workers and general peoples exposure to THMs is less than 1?10-5,lower than the acceptable level documented by USEPA.
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Objective To study the p53 gene mutation induced by organic extract of reclaimed water used in a city. Methods The organic extract of reclaimed water was collected by C18 solid-phase extraction (SPE) and the 16 kinds of polycyclic aromatic hydrocarbons (PAHs) in the reclaimed water were analyzed using gas chromatography-mass spectrometry (GC-MS). L-02 cells were treated with the organic extract of the reclaimed water at 0.84, 1.68, 3.34 ?l/ml for 24 h. DNA samples for p53 mutation detection was extracted from the cells and subjected to DNA sequencing for detection of mutations in exon 5 of the p53 gene. Results All 16 kinds of PAHs were detected both in input water and reclaimed water. The predominant ones were fluorene and phenanthrene,then naphthalene, acenaphthene, acenaphthylene, anthracene, fluoranthene, pyrene and so on. Total PAHs concentration was 1 777.9 ng/L in the input water and 1380.1 ng/L in the reclaimed water. Mutation in exon 5 within the p53 gene was detected in L-02 cells treated with the organic extract of the water. Conclusion PAHs in water can be removed by sewage treatment technology at present, but the remaining PAHs can still induce the mutation of p53 gene, so using reclaimed water has some potential health impacts, the sewage treatment technology employed today should be improved.