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Novel technique for recovery of sulphur & nitrogen from odorous air at wastewater treatment plant
Conference paper   Open access

Novel technique for recovery of sulphur & nitrogen from odorous air at wastewater treatment plant

W. Charles, A. Rabbani, A. Kayaalp and G. Ho
International Water Association (IWA) World Water Congress & Exhibition 2018 (Tokyo, Japan, 16/09/2018–21/09/2018)
2018
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Abstract

Biofilters used for the conversion of odorous hydrogen sulphide to odourless sulphate in wastewater treatment plants are known to generate large volumes of unusable weakly sulphuric acidic leachate. This paper presents a novel biofilter that produces small-volume and high-concentration sulphuric acid (H2SO4) as a useful product. The concentrated H2SO4 was produced by washing down the up-flow biofilter with an optimum amount of nutrient solution at pre-determined intervals which created a moisture and pH gradient within the biofilter resulting in an environment at the top favourable for the bacterial conversion of H2S, while concentrated sulphuric acid was accumulated at the base. A lab-scale biofilter based on this concept achieved 95 % H2S removal efficiency with a maximum H2S elimination capacity of 16.3 g/m3/h. Only small volumes (1 mL/L reactor/day) of concentrated sulphuric acid (>5.5 M) was produced after 150 days of continuous operation. A pilot-scale trial at a local WWTP not only achieved similar result to that of the lab-scale trial, but the concentrated sulphuric acid also stripped co-contaminant NH3 from the incoming air resulting in a simultaneous removal of H2S and NH3 with ammonium sulphate as a product in the leachate that can be harvested for further use.

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UN Sustainable Development Goals (SDGs)

This output has contributed to the advancement of the following goals:

#6 Clean Water and Sanitation

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