Anaerobic treatment of industrial and agro-industrial wastewater.

Anaerobic biodegradability tests of selected industrial wastewaters were carried out in batch cultures using anaerobic diffuse sludge obtained from an oxidation pond receiving sisal wastewater. The objective was to assess whether the wastewater types can be treated anaerobically using the above mentioned sludges as an inoculum. The results demonstrated that the diffuse sludge can be used as inoculum for anaerobic digesters treating agro-industrial wastewater. Influence of hydraulic and organic loading conditions on the performance of single-phase Polyurethane Carrier Reactor (PCR) and Upflow Anaerobic Sludge Blanket (UASB) reactor treating sisal wastewater was investigated. The objective was to evaluate the influence of these operational parameters on start-up and process stability of the two reactor types. The results indicated that HRT of 15 hours and the organic loading rate (OLR) of 8 .2 g COD 1-1. d-1 was optimal values for start-up of single phase PCR and UASB reactors treating sisal wastewater with COD removal efficiently of 68 and 79% respectively. Start-up of a UASB reactor treating sisal wastewater was investigated. The objective was to evaluate the influence of sisal wastewater type on granulation and the start-up of UASB reactor inoculated with diffuse sludge adapted to sisal wastewater. The results have shown that the UASB can successfully be started up with inoculum of diffuse sludge obtained from the pond receiving sisal wastewater. Diameter distribution at the end of each loading phase indicated influence of organic and hydraulic loading conditions on granulation. The ranges were between 0.5 to 0.9, 1.9 to 2.4mm for organic loading phase I, II and III respectively. The effect of step-wise increase in organic loading performance of two-phase Polyurethane Carrier Reactor (PCR) treating distillery slop was evaluated. The objective was to evaluate the potential application of anaerobic Two-phase PCR in treating distillery slop and assess the reactor performance with increase in organic loading rate conditions at constant hydraulic retention time. The results indicated a short start-up period for the PCR. The OLR of 63.25 g COD 1-1. d-1 at HRT of 22-23 hours was found to be maximum OLR which could be carried out without compromising reactor performance in terms of COD removal and biogas production.