The treatment of brewery effluent using an integrated high rate algal ponding system

Cilliers, Anneke (2012) The treatment of brewery effluent using an integrated high rate algal ponding system. Masters thesis, Rhodes University.

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Abstract

The application of high rate algal ponds (HRAP) in the treatment of brewery effluent that met the South African Department of Water Affairs and Forestry's (DWAF) general limits for discharge into a natural water resource of 1998 were tested during a lO-month baseline phase, followed by an 11-month optimization phase. The objective of the baseline phase was to monitor the seasonal performance of HRAPs. The hydraulic retention time (HRT) fluctuated between 11.16 d and 12.00 d in HRAPs. The chemical oxygen demand (COD) increased from 130.12 ± 6.94 mg/L (post-AD), to 171.21 ± 7.99 mg/L (post-HRAP) . The presence of algal cells and evaporation contributed towards an increase in post-HRAP COD. The ammonia (NH,-N) concentration decreased from 46.59 ± 2.47 mg/L (post-AD), to 1.08 ± 0.12 mg/L (post-HRAP). The nitrite (NOz-N) concentration remained below 1.00 mg/L in post-pilot plant AD, post-PFP and post-HRAP effluent. The phosphate (PO,-P) concentration decreased from 29.81 ± 1.39 mg/L (post-AD) to 17.30 ± 1.16 mg/L PO,-P. The objective of the optimization phase was to manipulate the HRT to achieve the maximum treatment rate that met the DWAF general limits for discharge into a natural water resource of 1998. Nitrogen (as NH,-N, NO,-N, NOz-N) removal efficiency was used as an indicator of nutrient removal success. HRT was influenced by season. The optimal HRT for autumn was 4.30 d at a temperature of 20.53·C in HRAP A2 (heated) and 18.96 'C in HRAP B2 (ambient). The optimal HRT for summer was 2.74 d at 29 .90 'C in HRAP A2 (heated) and 26.36 'C in HRAP B2 (ambient). The COD decreased from 152.33 ± 4.85 mg/L (post-AD) to 95.00 ± 3.75 mg/L (post-HRAP A2), and to 100.82 ± 5.93 mg/L (post-HRAP B2). The incoming NH,N concentration decreased from 42.53 ± 1.38 mg/ L (post-AD), to 1.70 ± 0.81 mg/ L (post-HRAP) . The nitrate (NO,-N) concentration post-HRAP was 12 - 14 mg/L. The main methods for NH, -N removal were probably NH,-N volatilization through algal uptake. HRAPs were able to lower nitrogen and phosphorous concentrations to within the DWAF limits under normal operating onditions. It is recommended that HRAP treated brewery wastewater be used for irrigation after salt removal, or alternatively, for groundwater recharge . Regulatory exemptions would be required for higher than permitted COD and EC concentrations to enable these actions.

Item Type:Thesis (Masters)
Uncontrolled Keywords:Algal ponds, Brewery effluent, Treatment, Discharge, Limits, Department of Water Affairs and Forestry, Water, Natural, Resource, Test, HRAPs, Nutrient removal, Irrigation, Groundwater recharge
Subjects:H Social Sciences > HD Industries. Land use. Labour > HD72 Economic growth, development, planning
S Agriculture > SH Aquaculture. Fisheries. Angling
Divisions:Faculty > Faculty of Science > Ichthyology & Fisheries Science
Supervisors:Britz, Pete and Jones, Cliff
ID Code:2972
Deposited By: Philip Clarke
Deposited On:12 Jun 2012 07:57
Last Modified:12 Jun 2012 07:57
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