The influence of agro-industrial effluents on River Nile pollution

The major agro-industrial effluents of sugarcane and starch industries pose a serious threat to surface waters. Their disposal in the River Nile around Cairo city transitionally affected the microbial load. In situ bacterial enrichment (50–180%) was reported and gradually diminished downstream; the lateral not vertical effect of the effluent disposal was evident. Disposed effluents increased BOD and COD, and then progressively decreased downstream. Ammoniacal N was elevated, indicating active biological ammonification and in situ biodegradability of the effluents. In vitro, the nitrogen-fixing rhizobacteria Crysomonas luteola, Azospirillum spp., Azomonas spp. and K. pneumoniae successfully grew in batch cultures prepared from the crude effluents. This was supported by adequate growth parameters and organic matter decomposition. Therefore, such biodegradability of the tested agro-industrial effluents strongly recommends their use for microbial biomass necessary for the production of bio-preparates.