Microaerobic biodegradation of high organic load wastewater by phototrophic bacteria

  • EI Madukasi
  • G Zhang
Keywords: Biodegradation, environmental pollution, phototrophic bacteria, micronutrients, macronutrient, wastewater treatment, artificial light intensity


High organic strength artificial simulated brewery wastewater (10,000 mgl-1 COD) was used in a batch photo-bioreactor to study the effectiveness of new strain phototrophic bacteria in bioremediation of organic contaminated wastewater. In this work, effects of additions of three individual micronutrients, that is, ferrous, molybdenum and magnesium, and a mixture of micronutrient with urea on the performance of Rhodobacter sphaeroides Z08 in biodegradation of high organic load wastewater under
varied light intensities were investigated. Maximum organic contaminates reduction were 42.3% for ferrous, 36.1% for molybdenum, and 32.3% for magnesium with the corresponding biomass of 989.7, 978.8 and 888.6 mgl-1, respectively. Urea addition increased the wastewater biodegradation potential with the resultant change in carbon to nitrogen ratio (C:N) from initial 200:1 to 200:5. Binary supplement of 26 mgl-1 ferrous and 200 mgl-1 urea to the wastewater readily enhanced the bacteria activity leading to organic contaminates reduction of 67.6%, while optimum pollutants reduction was achieved when binary supplement of urea and ferrous was made under intense radiation of 4000 lumens yielding nearly 80, 48, 90 and 67% reductions of chemical oxygen demand, total phosphorus, total organic carbon and total nitrogen, respectively. In addition, analyses of the resultant biomass and the purified wastewater indicated that major inorganic constituents of the wastewater were assimilated.

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eISSN: 1684-5315