1-undecanol DFT study DLLME-SFO EOCs determination Guarani aquifer HPLC-UV PBDE advanced oxidation processes biocides biosorption boron doped diamond boron-doped diamond electrode budesonide chemical oxygen demand chlorinated intermediates continuous liquid–liquid extraction density functional theory disinfection by-products doxazosin maleate electrochemical degradation electrochemical oxidation emerging contaminants emerging organic contaminants environmental samples flame retardants fractional distillation gas chromatography-mass spectrometry graphene quantum dots groundwater hormones