Strategies to enhance the biodegradation of toxic compounds using discontinuous processes

Abstract

This study presents two strategies used to enhance the biological degradation of phenolic wastewaters. In the first one the operation of a sequencing batch biofilter added with granular activated carbon (SBB-AC) was studied. The second strategy presents the results of the automation of a sequencing batch reactor in order to optimize the reaction phase. In this case, the dissolved oxygen was employed to monitor and control the reactor. The results of the SBB-AC system, based on the configuration of the reactor, type and size of activated carbon and size of the packing material, are discussed. The system biodegraded efficiently (total phenol removals as high as 97%) high concentrations (600 mg/l) of a mixture of phenol, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol. Maximal eliminated loads of 4.33 kg COD/m3-d were achieved. For the second strategy, the applicability of an optimal control for a SBR using the dissolved oxygen as the measured variable was demonstrated. When the reactor was operated under the time-optimal control strategy, the degradation time of 4-chlorophenol was reduced. A very satisfactory operation of the reactor was observed, since the removal efficiencies were around 99%.

Treatment of composite chemical wastewater by aerobic GAC-biofilm sequencing batch reactor (SBGR)

“…doi:10.1016/j.jhazmat.2005.03.055 variation in waste strength and composition [8]. SBR has been successfully applied for the treatment of domestic wastewater, medium to low strength wastewater, landfill leachates, simulated dye wastewater, recalcitrant compounds, industrial wastewater and contaminated soils [6][7][8][9][10][11][12][13][14][15][16][17][18]. Reactor configuration is one of the important factors, which governs the performance of any biological system.…”

Biotreatment of Industrial Wastewaters under Transient-State Conditions: Process Stability with Fluctuations of Organic Load, Substrates, Toxicants, and Environmental Parameters

“…8,160 The production of fine chemicals and pharmaceuticals is dominated by batch processes, giving rise to rapid swings in the types and concentrations of organic pollutants appearing in their wastewaters. 27,69,95,202 The latter can be referred to as wastewaters containing "sequentially alternating pollutants" (SAP), with pollutant composition alternating sequentially from one set of compounds to another over cycles of weeks or months. Many of the compounds used in chemical synthesis (e.g., phenols, chlorophenols, aldehydes, long chain fatty acids, aromatic compounds), even though biodegradable, are inhibitory at elevated concentrations.…”

Simulated Acid Azo Dye Wastewater Treatment Using Suspended Grow Th Configured Sequencing Batch Reactor (Sbr) Under Anoxic-Aerobic-Anoxic Microenvironment

“…Interest has been growing worldwide both in scientific research and in practical application of SBR technology. SBR has been successfully applied for the treatment of domestic wastewater, medium and lower strength landfill leachates, simulated dye wastewater's and contaminated soils [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. This communication presents experimental data pertaining to the investigate carried out to treated simulated azo dye wastewater using suspended growth configured sequencing batch reactor (SBR).…”