Treatment of High Strength Vegetable Processing Wastewater with a Sequencing Batch Reactor

The feasibility of an aerobic sequencing batch reactor was studied at the lab scale to treat the high organic loading present in two vegetable processing wastewaters. Hydraulic retention time (HRT) was varied to evaluate its effect on the removal efficiency of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and total phosphorus (TP). The results showed that a longer HRT promoted the removal of TP, while the liquid drawn per cycle had a larger effect on the COD removal efficiency. An increase in the COD/TKN and TKN/TP ratio decreased the removal efficiency of TKN and TP respectively. The optimized configuration was able to reduce the wastewater loadings to acceptable sewer discharge limits, making it possible eliminate the sewer surcharge fees

Variation and fate of heavy metals in municipal wastewater treatment plants.

Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1984 .Z975. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.Sc.)--University of Windsor (Canada), 1984

The Development of Technology-supported Approaches to the LO Process for Accredited Engineering Programs

Tracking graduate outcomes is a new requirement for engineering education in Canada.  Working closely with curriculum developers and educational technologists, the School of Engineering at the University of Guelph has shown it is possible to put in place an effective process.  The process requires engaged participants, an open-mindedness and integrated technologies to collect and report the data.  Combining people, process and technology provides a way for data analysis to satisfy accreditation requirements and internal quality education metrics.  This paper describes the approach taken and identifies strengths, challenges, and opportunities to be successful, and support the ultimate goal of curriculum improvement

Hybrid Treatment System to Remove Micromolecular SMPs from Fruit Wastewater Treated with an MBR

Fruit processors want to reduce their environmental footprint by implementing the recycling of treated wastewater. Observations of a membrane bioreactor (MBR) and reverse osmosis (RO) system showed that the RO quickly fouled due to elevated levels of soluble microbial products (SMPs), an inert micromolecular composition in the form of dissolved organic matter (DOM) in the MBR effluent. Bench scale experiments were completed using enhanced coagulation and granular activated carbon sorption. Results showed that enhanced coagulation removed only 20% of the DOM, which was insufficient to protect the RO membrane. However, sorption studies with GAC showed that 98% of the dissolved SMP-DOM could be removed, the fraction of DOM from microbial activities. Results also showed that when enhanced coagulation preceded the sorption stage, GAC column run time could be extended by about 15%. The resulting BMP minimizes RO membrane fouling in the agri-food sector and opens further water recycling opportunities.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Fate of Perchloroethylene in Unsaturated Soil Environments.

Studies were undertaken to evaluate the behaviour of perchloroethylene, PCE, in unsaturated soil to provide remedial actions for minimizing the possible soil and groundwater contamination after a spill. Processes that were investigated included volatilization from water and soil, determination of degradation potential, evaluation of adsorption - desorption isotherms for various granular media and the simulation of a PCE spill on a soil column. Results were then used to calibrate a contaminant transport model. Sandy loam soil, organic top soil, peat moss and granular activated carbon, GAC, were investigated for adsorption - desorption properties. It was determined that the adsorption - desorption processes were well represented by the Freundlich Isotherm. The governing factor in adsorption was the organic carbon content. The higher the organic carbon content, OC, the greater was the adsorption and retention of PCE by the medium. In dividing the Kf coefficient with the oc content, a Koc of 330 L/mg was determined which indicates that PCE has medium mobility in soil. Results on residual saturation values for the four media indicated that peat moss could retain the highest quantity of pure PCE, 7.8 kg/kg, making it ideal for application at a spill site to retain the chemical. Desorption did not increase with a decrease in pH of the aqueous solution. The experiments on volatilization of PCE f~om water in~icated that this rate was rapid and that it was influenced by the area to volume ratio, A/V. The volatilization rate increased with an increase in A/V. The overall liquid film coefficient for the water-air interface was 0.009 m/h. Volatilization from soil was also a function of area to volume ratio. However, it was observed that the QC content of soil influenced the volatilization rate. The volatilization rate decreased with an increase in QC content. The mass flux experiment indicated that submerged PCE followed a first , order mass· transfer rate, with a flux rate of 0.028 kg/m2/d. At the chemical-water interface the overall liquid film coefficient was found to be 0.006 m/h. Equations for the prediction of breakthrough times in soil were determined. The soil properties greatly influenced the penetration distance and the front velocity. Under a 76 mm/d rainfall intensity, the PCE moved at 0.084 m/d and 0.026 m/d in the sandy loam soil and organic top soil respectively. The calibrated contaminant transport model for unsaturated soil prediets the breakthrough time and PCE concentrations. Furthermore, the model and column studies showed that the immiscible phase movement had a significant impact on the PCE concentrations observed in the soil profile

Determining a Bioventing Scale-Up Factor

Bioventing is an increasingly popular means of removing hazardous petroleum products from sites contaminated by industry and underground gasoline storage tanks. A mesoscale bioventing reactor system was used to determine the rate of bioremediation and compared to previous work completed on smaller scale reactors. Ten 4kg reactors with two different soil types were spiked with synthetic gasoline to an initial concentration of 4000mg/kg soil. Vacuum was then applied at a rate of 1mL/min, with sufficient water levels monitored and maintained to induce bioventing conditions. Gas chromatography was used to determine concentrations of synthetic gasoline in soil every two days for each soil type. Results indicate a smaller scale up factor for sandy soils (Delhi), than for clayey soils (Elora). Furthermore it was observed that slower decay rates exist as reactor size increases, suggesting that conservative estimates are needed when transferring lab results to the field