Low-temperature inhibition of the activated sludge process by an industrial discharge containing the azo dye acid black 1.

A municipal wastewater treatment plant (WWTP) receiving industrial dyeing discharge containing acid black 1 (AB1) failed to meet NH(3) and BOD(5) discharge limits, especially for NH(3) during the winter. Dyeing discharge was combined with domestic sewage in volumetric ratios reflecting the range received by the WWTP and fed to sequencing batch reactors at 22 and 7 degrees C. Analysis of the various nitrogen species revealed complete nitrification failure at 7 degrees C with more rapid nitrification failure as the dye concentration increased.

Design and performance characterization strategy using modeling for biofiltration control of odorous hydrogen sulfide.

Biofilter, dynamic modeling software characterizing contaminant removal via biofiltration, was used in the preliminary design of a biofilter to treat odorous hydrogen sulfide (H2S). Steady-state model simulations were run to generate performance plots for various influent concentrations, loadings, residence times, media sizes, and temperatures. Although elimination capacity and removal efficiency frequently are used to characterize biofilter performance, effluent concentration can be used to characterize performance when treating to a target effluent concentration.

Optimization of biofiltration for odor control: model calibration, validation, and applications.

A dynamic model that describes the biofiltration process for hydrogen sulfide removal from wastewater treatment plant air emissions was calibrated and validated using pilot- and full-scale biofilter data obtained from the Cedar Rapids (Iowa) Water Pollution Control Facilities. After calibration, the model was found to predict the dynamic effluent concentrations of the pilot- and full-scale biofilters well, with the measured data falling within 58 to 80% of the model output values. In addition, the model predicted the trend of the field data, even under field conditions of changing input concentration and at effluent concentrations below 1 ppm by volume.