Abstract

A hydrologically upgraded secondary bush-fallow was used as natural native vegetation riparian buffer to protect water quality of adjacent stream against organic waste pollution by non-point source (NPS) run-off and abattoir wastewater draining from the cattle market/slaughter lots at the upslope of the buffer in Uyo municipality, Nigeria. Buffer site characteristics and soil properties and the quality of the stream water were investigated; and their data were statistically analyzed using Word SPSS version 17. Paired sample t-test and correlations between properties of buffers’s abattoir waste water and stream water were compared. The buffer vegetation was a mix of trees, shrubs and herbaceous plants although, not in a well-structured design. Microbial counts and total organic carbon (TOC) were high on the acidic soil, sufficient for denitrification of soil or root-uptake of nitrate at the market-buffer boundary. Reduction of nitrate across the buffer-floor width was 69 to 82% with removal efficiency from 18 to 57% depending on the buffer section and constituent element of waste, and total microbial reduction across the buffer width was up to 99%. Bush-fallow buffer should be redesigned hydrologically and structurally with grass strip berm at the cattle-market border to increase effectiveness of filtering sediments against the high daily loads of generated organic waste.

Key words: Assessment, effectiveness, abattoir wastewater, cattle-market, bush-fallow riparian buffer, stream water quality.