Spremljanje učinkovitosti odstranjevanja bisfenolov iz odpadne vode v komunalni čistilni napravi

Vehar, Anja (author), Žgajnar Gotvajn, Andreja (mentor), Heath, Ester (co-mentor)

Bisfenoli se kot monomeri pogosto uporabljajo v industriji v proizvodnji epoksi smol in polikarbonatov. Imajo skupno strukturo dveh povezanih fenolnih obročev in so potencialni motilci endokrinega sistema. Literaturni podatki navajajo njihovo prisotnost v različnih okoljih, kot so površinska voda, sedimenti, odpadna voda in odpadno blato. Zaradi obstoječih podatkov o njihovi potencialni toksičnosti, pa bi poleg bisfenola A, morali nadzorovati tudi uporabo njegovih nadomestkov (npr. bisfenol S in bisfenol F). V predloženi raziskavi smo spremljali pojavnost bisfenola A in 15 njegovih nadomestkov v komunalni čistilni napravi s tehnologijo čiščenja odpadne vode z aktivnim blatom. Najprej smo razvili in validirali analizno metodo za določitev 16 bisfenolov v trdni fazi aktivnega blata, ki temelji na ekstrakciji na trdno fazo in plinski kromatografiji sklopljeni z masno spektrometrijo. Na komunalni čistilni napravi, ki za čiščenje uporablja šaržne biološke reaktorje, smo na različnih mestih odvzeli kompozitne vzorce in jih analizirali. Izmerjene koncentracije bisfenolov smo preračunali v masne tokove in izračunali njihovo odstranitev in adsorpcijo na primarno in sekundarno blato. Ocenili smo tudi emisije teh snovi v okolje z iztokom iz čistilne naprave in odlaganjem odpadnega blata. Rezultati so pokazali, da so bili vsi bisfenoli v očiščeni odpadni vodi, razen bisfenola A (79 ng L-1), bisfenola S (20 ng L-1), bisfenola BP (3 ng L-1), 2,2'-bisfenola F (3 ng L-1) in bisfenola AP (2 ng L-1), prisotni pod mejo kvantifikacije, kar pomeni, da se je iz odpadne vode odstranilo od 29 % (bisfenol AF) do 94 % (2,4'-bisfenol F, bisfenol E) bisfenolov. Adsorpcija bisfenolov na primarno in sekundarno blato je bila od 2 % (bisfenol E, bisfenol BP) do 45 % (2,2'-bisfenol F), v iztoku iz čistilne naprave pa je ostalo od 3 % (2,4'-bisfenol F) do 52 % (bisfenol P) bisfenolov. Najvišje dnevne emisije smo izmerili za bisfenol A, ki so znašale 1,48 g dan-1 v iztoku iz čistilne naprave ter 4,63 g dan-1 v anaerobno stabiliziranem blatu. Rezultati kažejo, da koncentracije bisfenolov v odpadnem blatu niso zanemarljive, zato jih je potrebno spremljati in upoštevati njihove emisije v okolje.

• Language: Slovenian
• Keywords: bisfenoli, čiščenje odpadne vode, masne bilance, odpadno blato
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2021
• PID: 20.500.12556/RUL-130286
• COBISS.SI-ID: 82233859
• Publication date in RUL: 13.09.2021

Secondary language

• Language: English
• Title: Monitoring of bisfenols removal efficiency in municipal wastewater treatment plant

Abstract

Bisphenols have been widely applied in the industry as monomers in epoxy resins, and polycarbonate production. They all share a common structure of two hydroxyphenyl functionalities and are potential endocrine disruptors. Their presence in different environments, such as surface waters, sediments, wastewaters, and sludge has already been reported. Since the existing data about their potential toxicity, besides bisphenol A, also the use of its alternatives (e.g., bisphenol S, bisphenol F) should be monitored. In the following research the occurrence of bisphenol A and his 15 substitutes in a municipal wastewater treatment plant with a technology of wastewater treatment with activated sludge was monitored. First, an analytical method for the determination of 16 bisphenols in the solid phase of activated sludge, based on solid-phase extraction and gas chromatography coupled with mass spectrometry, was developed, and validated. Composite samples from different compartments of a municipal wastewater treatment plant that uses sequencing batch reactor technology were sampled and analysed. Concentrations of bisphenols were recalculated into mass flows, and their removal rate from wastewater and their adsorption to primary and secondary sludge was determined. In addition, their emissions into the environment via effluent release or sludge disposal were evaluated. Results showed that all the bisphenols in the effluent from wastewater treatment plant, except bisphenol A (79 ng L-1), bisphenol S (20 ng L-1), bisphenol BP (3 ng L-1), 2,2’ bisphenol F (3 ng L-1), bisphenol AP (2 ng L-1), were present below the limit of quantification, which means that the removal of bisphenols from the aqueous phase ranged from 29% (bisphenol AF) to 94% (2,4'-bisphenol F, bisphenol E). Adsorption to primary and secondary sludge ranged from 2% (bisphenol E, bisphenol BP) to 45% (2,2’ bisphenol F) and the remaining bisphenols in the effluent from wastewater treatment plant from 3% (2,4’ bisphenol F) to 52% (bisphenol P). The highest daily emissions via effluent release and sludge disposal were measured for BPA and were up to 1.48 g day-1 and 4.63 g day-1, respectively. Results show that the concentrations of bisphenols in sludge are not negligible, and for that reason their emissions into the environment should be monitored and considered.

• Keywords: bisphenols, mass balances, sludge, wastewater treatment