Biological treatment of actual petrochemical wastewater using anaerobic/anoxic/oxic process and the microbial diversity analysis

Abstract

A novel process integrating anaerobic hydrolysis-acidification (HA) and anoxic/oxic (A/O) reactors was developed to treat the actual petrochemical wastewater, which was operated for more than 8 months, the removal efficiency of COD and NH-N was monitored, and the microbial community was analyzed. The results showed that the effluent concentrations were maintained at around 99 and 1.3 mg/L, with the removal efficiency of 70.6 and 95.4 %, respectively at a total hydraulic retention time (HRT) of 20 h. The major pollutants in the influent were identified as hydrocarbons, aldehydes, heterocyclic matters, amines, alcohols, phenols, ketones, etc. by GC-MS analysis, while only heterocyclic compounds, ketones, and esters were detected in the effluent after HA-A/O treatment. Bacteria belonging to phyla Chloroflexi, Proteobacteria, and Bacteroidetes were highly enriched in the system. The predominant genera in HA, anoxic, and oxic tanks were Anaerolineaceae uncultured and Desulfobacter, Blastocatella and Anaerolineaceae uncultured, Saprospiraceae uncultured and Nitrosomonadaceae uncultured, respectively. The sulfate-reducing bacteria Desulfobacter, Desulfofustis and Desulfomicrobium were detected only in HA reactor. The ammonium-oxidizing bacteria Nitrosomonadaceae and Nitrosomonas and nitrite-oxidizing bacteria Nitrospira were highly enriched in A/O reactor, which is consistent with the good nitrification performance.

Effects of influent C/N ratios and treatment technologies on integral biogas upgrading and pollutants removal from synthetic domestic sewage

“…Recently, more than 90% of the domestic sewage in rural areas was directly discharged into natural waters without appropriate treatment, eventually causing water eutrophication 1 . Many studies indicated that conventional water treatment processes, including oxidation ditch processes 2 , anaerobic-anoxic-axic (A 2 /O) 3 , University of Cape Town (UCT) 4 , Bardenpho, and sequencing batch reactor (SBR) 5 , achieved moderate success in removing pollutants. However, these processes generally entail enormous land requirements, operational costs, complex operations, and large volumes of waste sludge production and are therefore not practicable in rural areas in China.…”

Could Land Abandonment with Human Intervention Benefit Cropland Restoration? From the Perspective of Soil Microbiota

“…In 2016 and 2017, the HII had significant effects on some bacteria that preferred nutritious soil, including Acidobacteria Gp22, OP11, and Saprospiraceae (LDA score > 2, K-W test P < 0.05) [61,62]. In 2018, some bacteria associated with soil nitrogen cycling, including Solibacterales, Thiotrichales, and Piscirickettsiaceae, increased in HII (LDA score > 2, K-W test P < 0.05) [63][64][65].…”

Recovery of resources from industrial wastewater employing electrochemical technologies: status, advancements and perspectives

“…In the rotating biological contactors, the holder is a slowly rotating disk and oxygen is transferred into the wastewater through the rotation of the disk which creates surface turbulence [58,[63][64][65].…”