Pilot-scale biofilter for the simultaneous removal of hydrogen sulphide and ammonia at a wastewater treatment plant

Abstract

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights: A pilot scale biofilter removed H2S and NH3 in a wastewater treatment plant. The biofilter produced small volume of leachate which contains ammonium sulphate. The ammonium sulphate produced can be harvested for further use. AbstractBiofilters are popular for the removal of odours from gaseous emissions in wastewater treatment plants because of their low capital costs and low energy requirements. In an aerobic environment, the microbes in biofilter oxidize odorous gases like hydrogen sulphide (H2S) and ammonia (NH3) to non-odorous sulphate and nitrate. This paper describes a pilot plant biofilter setup at a local waste water treatment plant (WWTP) which has been in continuous operation for more than 150 days, removes both H2S and NH3 at an average removal efficiency of 91.96% and 100% respectively. Unlike a conventional biofilter, the pH of this biofilter was not adjusted by addition of chemicals or buffers and the H2SO4 produced from the biological conversion of H2S is periodically washed down and allowed to accumulate in a concentrated form at the base of the biofilter. NH3 entering at the base is removed, not by biological oxidation, but by the chemical reaction of ammonium with sulphate to form ammonium sulphate. The ammonium sulphate produced in biofilter is washed down and the volume of leachate produced is less than 0.2mL of leachate/L of reactor/day. Estimated cost savings of converting the current chemical scrubber used at the WWTP to a similar biofilter described in this study is included with this paper.

Characterization and evaluation of poplar and pine wood in twin biotrickling filters treating a mixture of NH3, H2S, butyric acid, and ethylmercaptan

“…Similarly, Rabbani et al . reached REs over 90% for H 2 S and NH 3 in an acidified bioreactor because the H 2 S/NH 3 ratio permitted an effective removal of both pollutants by biological oxidation of H 2 S to sulfate and a subsequent chemical reaction of ammonium and sulfate to form (NH 4 ) 2 SO 4 .…”

Use of Biological Methods For Removal of H2S From Biogas In Wastewater Treatment Plants – A Review

“…Microorganisms grow as biofilm on the packing material of the biofilter [16]. The packed bed is usually made up of an inert mate- Porous silica packing [43] TDRP b [44] Bioceramics and polyhedral hollow balls [45] Pozzolan or marble [46] Expanded schist [47] Acid resistant polyethylene (ABB material) [48] a mixture of CH 4 N 2 O, H 3 PO 4 , CaCO 3 and organic binder (20%) b tire-derived rubber particles rial such as a random-dump plastic packing, structured plastic packing, open-pore synthetic foam, lava rock, glass or rock wool, TDRP, glass beads or ceramics. The packing provides the necessary surface for biofilm attachment and for gas-liquid contact.…”

Biofilter for generation of concentrated sulphuric acid from H2S

“…The amount of sulphur that can be recovered from the leachate can be considerable in industrial biofilters that remove H2S which currently produce large volumes of dilute waste stream (Rabbani et al 2015). The recovery of sulphur was explored in a pilot scale study that was recently conducted where H2S was removed from air generated at a wastewater treatment plant using a biofilter similar to the one described in this study (Rabbani et al 2016). The pilot scale biofilter removed H2S from air with a 92 % removal efficiency and produced a very small amount of acidic leachate (0.2 mL L −1 day −1 ), and sulphur was recovered as ammonium sulphate (Rabbani et al 2016).…”

“…Instead of considering this leachate as waste, the leachate can be thought of as a source of sulphur. The notion of recovering nutrients other than sulphur from the leachate of biofilters is not new (Dumont et al 2012a;Jung et al 2005;Rabbani et al 2015;Rabbani et al 2016;Zhang et al 2013). Removal and recovery of elemental sulphur from coal, natural gas and high sulphur crude oils is well-recognised processes, but recovery of sulphur from dilute streams of acid from wastewater treatment plants has not been previously attempted (Babich and Moulijn 2003;Bachmann et al 2014;Jiang et al 2015;Meshram et al 2015;Shu et al 2014).…”