Intermedia transport of organic compounds in biological wastewater treatment processes

Abstract

Organic compounds present in many industrial effluents are transported to varying extents to the gaseous or solid phase, in addition to potential biodegradation, during treatment. Knowledge of the fate of such compounds is critical for making valid policy and engineering decisions regarding issues such as the disposal of sludges, effluent toxicity, and emissions to the ambient air. To quantify the relative distribution of the fate of selected groups of compounds, a mathematical model is presented which describes the intermedia transport mechanisms including volatilization, solids sorption, and biodegradation. The extent of removal via each modeled pathway is a function of the physical properties of the speci$c compound and the process design and operational parameters of the system.

Integrated model for predicting the fate of organics in wastewater treatment plants

“…Potential applications of the Fate Model include: (1) assessment of VOC emissions from wastewater treatment plants; (2) determine acceptability of various aqueous wastes for treatment at central facilities; (3) evaluate pretreatment requirements prior to discharge to the sewer system; (4) establish local limits; ( 5 ) predict concentrations of toxics in sludge which impact disposal options; (6) predict fate of new chemicals in biological treatment plants; and (7) provide a general basis for estimating the effect of operating parameters on removal of toxic organics during treatment.…”

Monitoring and Modeling VOCs in Wastewater Facilities

“…They have been used to predict emissions for air permitting purposes (72). Many models have been developed, but not all are computer-based (59,46,50,(73)(74)(75)(76)(77)(78)(79). They include equations that describe the VOC removal mechanisms described above with differing degrees of refinement relating to mass transfer assumptions and methods of calculating rate coefficients.…”

“…NOCEPM, PAVE, SIMS, and WA-TER 7 are based on industrial waste- CHEMDAT 7 (also known as WATER 7) Developed by R. L. The calibration of overall fate models is costly; this can limit their applicability, although proponents have shown significant success in the predictive qualities of their models. The NOCEPM model can predict the fate of VOCs typically found in pulp and paper wastewater treatment systems (73,87). The FATE model has been validated at pilot-scale and at POTWs (75).…”

Volatile Organic Compound Emission Rates from Mechanical Surface Aerators: Mass-Transfer Modeling

“…The emission of volatile organic compounds (VOCs) from municipal and industrial wastewater treatment facilities has been identified as one of major air pollution sources and caused great concern. In wastewater treatment facilities, VOCs emit from wastewater collection systems as well as many treatment units. − Most VOC emission problems occur in the aeration basins where oxygen is transferred into wastewater by aeration devices such as mechanical surface aerators and diffused aeration systems. This aeration process was once viewed as one good method to remove the VOCs from wastewaters .…”