Atmospheric air pollution associated with macrophyte and algal-based wastewater stabilization ponds in Kumasi, Ghana.

Abstract

Domestic wastewater treatment is strongly recommended for developing countries because of the high incidence of enteric disease and its associated high mortality rates. In Ghana, waste stabilization ponds have been recommended for urban centres. Macrophyte-based ponds have also been recommended because of their economic importance. The large scale environmental effects on air quality of these ponds are yet to be fully explored. The study was carried out by measuring the amount of hydrogen sulphide and ammonia volatised from the ponds 4 times in each month during the study. Sludge accumulation after 451 days of pond operation was also measured. The results showed that the ammonia and hydrogen sulphide concentrations in the air around the treatment plant where the pilot plant was mounted was above the WHO recommended guidelines. The study further showed that, the anaerobic pond had the highest production of ammonia and hydrogen sulphide. Sludge accumulation was also highest in the first ponds of each treatment system followed by the subsequent ponds in series. It is therefore recommended that operators of the treatment plants must be protected from the hydrogen sulphide and ammonia gases by planting odour absorbing plants as well as employing the appropriate nose masks.