EXPLORING ALTERNATIVE BIOREACTOR CONFIGURATIONS FOR TREATMENT OF INDUSTRIAL WASTEWATER CONTAINING MIXED RECALCITRANT COMPOUNDS

摘要

Many industries generate large amounts of saline and acidic process effluentsrncontaining mixed waste organic compounds. Many of these compounds, structurallyrndiverse and complex, are often considered "difficult to degrade" in conventionalrnactivated sludge processes, especially under high salinity and low pH conditions. Thernrecalcitrance to biodegradation may often be caused by unsuitable environmentalrnconditions, which result in inhibition or non-availability of the enzymes required for thernbiodegradation pathways. Many microorganisms, however, are very adaptable andrnversatile. The genetic information carried by the microbes make them able tornsynthesize enzyme systems for effective utilization of many different types ofrncompounds if necessary. Given suitable conditions, degradation of these so-calledrnrecalcitrant compounds would be possible and more effective. Therefore, novelrnbioreactor configurations which can achieve diverse environments and fully exploitrnmicrobial competencies are required to efficiently treat the complex industrialrneffluents.rnIn this project, research has been conducted to explore efficient bioreactorrnconfigurations to directly treat saline and acidic industrial effluents, without anyrnpretreatment steps such as equalization and neutralization, which are typically used inrnthe conventional biotreatment processes. A two-stage aerobic activated sludge systemrnhas been compared to (a) a combined anaerobic biofilm/aerobic activated sludgernsystem, and (b) a one-stage sequencing batch biofilm reactor (SBBR) system, in therntreatment of a model synthetic wastewater with a range of salinities (0.2, 1, 2, 3, andrn4%) and pH values (5, 6, and 7). The model synthetic wastewater contained ReactivernRed 3.1 (an azo dye), aniline, toluene, o-dichlorobenzene, dimethylformamide, andrnmore readily biodegradable components ?φ 1 αχετατε, μετηανολ ανδ ισο-προπανολ,rnωηιχη ρεπρεσεντ α ρανγε οφ τψπιχαλ χηεμιχαλ τψπεσ φουνδ ιν ινδυστριαλ εφφλυεντσ. Τηεrnχομπαρατι(ω)ε ρεσυλτσ σηοωεδ τηατ αναεροβιχ χονδιτιονσ ωερε ρεθυιρεδ το δεγραδε τηεrnμορε ρεχαλχιτραντ χομπουνδσ ιν τηε εφφλυεντ, παρτιχυλαρλψ τηε αzο δψε. Τηε βιοφιλμrnρεαχτορ δεμονστρατεδ γρεατερ αδαπταβιλιτψ το σηοχk λοαδσ τηαν τηε συσπενδεδ αχτι(ω)ατεδrnσλυδγε ρεαχτορ. Αναεροβιχ τρεατμεντ φολλοωεδ βψ αεροβιχ τρεατμεντ ωασ συπεριορ ινrnΧΟΔ ανδ χολορ ρεμο(ω)αλ, χομπαρεδ το τηε τωο-σταγε αεροβιχ ρεαχτορ σψστεμ. Βιοφιλμσrnγα(ω)ε τηε αδδιτιοναλ αδ(ω)ανταγε οφ βεινγ αβλε το ωιτηστανδ σηιφτσ ιν σαλινιτψ ανδ/ορ το αrnλεσσερ δεγρεε πΗ. Ο(ω)εραλλ, τηε φινδινγσ οφ τηισ στυδψ δεμονστρατε τηατ α βιοφιλμ σψστεμrnχομβινεδ ωιτη αναεροβιχ/ανοξιχ ανδ αεροβιχ πηασεσ προ(ω)ιδεσ α (ω)ερψ (ω)αλυαβλε στρατεγψrnφορ τρεατμεντ οφ χομπλεξ ρεχαλχιτραντ ινδυστριαλ ωαστεωατερ.