| Popis: |
Industrial wastewater can be highly concentrated and a highly variable byproduct of an industrial process. Industrial waste can have detrimental effects on the natural environment if not treated properly. Various types of waste require specific treatment regimens that are often determined using bench-scale testing. This study explored the treatability and impact on oxygen demand of brewery and cosmetic wastes. Wastes were first characterized to determine important constituents, and for the development of a feeding plan. The cosmetic waste was found to have toxic concentrations of inhibitory substances including heavy metals, sulfate, ammonia, and volatile fatty acids, while the brewery waste proved to be a good candidate for biological treatment. Treatability was evaluated using anaerobic digestion with a single waste stream as feed. The brewery waste was found to be treatable at a variety of retention times in a Continuously Stirred Tank Reactor (CSTR). At a 20 day retention time the organic loading rate was 2.27 kg COD/m³d, and a COD removal efficiency of 85%. The average methane yield for all retention times was 410.6 L /kg COD. The digester being fed the cosmetic waste never achieved stable operation due to inhibitory constituents in the feed and was eventually inactivated. Impact of oxygen demand was evaluated using respirometry in order to determine stoichiometric and kinetic parameters as well as component concentrations and viability of co-treatment using aerobic treatment methods such as activated sludge. The observed biomass yield was found to be 0.19 g VSS/g COD, and the COD/BOD ratio was 1.25; uBOD and the first order rate coefficient were evaluated for specified treatment strategies using non-linear regression. Average COD removal efficiency for brewery waste samples analyzed using respirometry was 80.7%. Respirometric analysis of cosmetic waste indicated that there was a mass transfer limitation as well as an exponential decrease in COD removal efficiency for linear increases in the percent of industrial waste in the sample. Nitrate was also observed as an alternate electron acceptor. In summary brewery waste is readily treatable using biological systems, and further work is needed to develop an effective treatment strategy for the cosmetic waste herein evaluated. |
