Biofilter for Odour Control

BIOF BI OFIL ILTE TER R FO FOR R ODOUR CONTROL

INTRODUCTION  H2S is highly toxic, odorous and poisonous It is produced from 

Petroleum refining

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Waste water treatment

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Paper and pupl manufacturing

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Food processing

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 H2S removal is crucial in every odour abatement

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Several chemical and physical process are used for removal !hey are less effective and more expensive

Why Bioflter ????? It uses microorganisms to remove undesirable components 

"ow operation cost

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"ow maintenance re#uirement

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"ow energy re#uirement

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 $o secondary pollution

LITERATURE REVIEW 

“Performance of Biofilter for the Removal of Hydrogen

 Sulphide Odour”; %ehman, & ' , Faroo#i I H and (yub S In this paper laboratory scale experiments were performed to evaluate the feasibility of biofilters for the removal of H 2S from wastewater treatment plant waste air )ompost was used as media in biofilter )arried out in six different  phases, by increasing H2S concentrations gradually It was concluded that the  biofilter, used in the study, was more efficient for low contaminant concentrations 



“Biofiltration: An Innovative Air Pollution ontrol

!echnology "or #O $mi%%ion%”; *ero "eson and (rthur

+ Winer  Thi !"!er #ie$ the hitory "%& '(rre%t t"t( o) *iofltr"tio%+ o(tli%e it (%&erlyi%, 'ie%tif' "%& e%,i%eeri%,

!ri%'i!le+

"%&

&i'(e

the

"!!li'"*ility o) *ioflter )or " $i&e r"%,e o) !e'if' e-iio% o(r'e .



“&icro'ial 'iofiltration technology for odour a'atement”;

Sonil $anda, Praash -umar Sarangi and .ayanthi (braham

!his report describes the generation of odorants from different sources and their possible degradation by suitable microbial cultures In addition, comparisons among physiochemical and  biological methods for odour abatement have been discussed  $evertheless, the type of biofilter, its pacing material and other reaction conditions for an effective biofiltration have also been considered

OBECTIVE 

!o design a biofilter and determine operational parameters necessary to optimi/e the performance



(lso to study the effect of operational  parameters on 2  removal efficiency

ETODOLO67

Schematic representation of an open single0  bed biofilter system

A typical biofilter configuration 

Water sprinler system to apply moisture directly to

the filter media surface 

!he typical depth of biofilter media is 1 m



+any different media types include soil, compost,

sand, shredded bar, peat, heather, volcanic ash, and a mixture of these components 



!he growth and activities of the microorganisms is

dependent on •

absence of toxic materials

•

 ample inorganic nutrients

•

 optimum moisture conditions,

•

 appropriate temperatures

•

 neutral pH range

ECANI (s odorous gas passes through biofilter 2  processes occur simultaneously 

Sorption  (dsorption 3 (bsorption4



5io conversion

Organic Pollutant + O2 ─> CO2 + H2O + Biomass

DEI6N :ARAETER

!he depending factors in the biofilter design are 6 

7olumetric flow rate of air to be treated

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Specific air contaminants and their concentration

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+edia characteristics

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5iofilter si/e

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+oisture control

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+aintainence



)ost

AIR ;LOW RATE 

"iterature values for biofilter airflows range from 8889 to 88829m:s and are typically 8819 to 882 m:s

EDIA CARACTERITIC )ritical properties of media material include6 

Porosity

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+oisture holding capacity

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 $utrient content

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Slow decomposition

EDIA CARACTERITIC ;rganic mixture for odour removal  biofilters ranges from approximately 

 !ime that the air is in contact with biofilter media

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!aen as =02< seconds 

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5eyond 2< seconds there is no apparent effect

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>5)!? 7olume of media:(irflow rate

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!he actual contact time is usually less than >5%!

OITURE CONTENT Inade#uate moisture 

(llow the media to dry out

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@eactivate the microbes



 )reate cracs and channelling of air

%esults in reduction of filter efficiency

OITURE CONTENT !oo much moisture cause 

 )hannelling



"imit oxygen flow

!hus create anaerobic /ones in the biofilm

OITURE CONTENT %ecommended moisture content for  biofilters range from A80B9C wet basis



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;ptimal moisture content is 980B9C

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+oisture content C4 ? mass of water4: mass of water D mass of dry pacing4 x 188

 TE:ERATURE 

+icroorganisms tolerate a temperature range of =80E8F

CONTROL O; ! 

!he pH in compost filters is typically  between= and  In some cases the biodegradation of air  pollutants can generate acidic by0products %educes filterGs removal efficiency Hence add buffers lie lime

AINTAINENCE @ifferent areas that re#uire maintenance are 

+oisture content

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Weeds

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%odents

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(ssessment of pressure drop

COT 

)ost for installation of fans, media ductwor ,plenum and labour to construct

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 +aintenance cost

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;peration cost

 DEI6N TE: For given airflow rate and >5%! 

+edia 7olume 7m 4 ? (ir flow rate 4 x >5%! J : B8

If area is not limited select a suitable depth @m 

'nit (ir flow rate ?  : (m

DEI6N TE: 

'nit Pressure @rop

'P@4 ? 2 x  C of 7oids 4 x 'nit air flow rate 

!otal Pressure @rop ? 'P@ x @ m

>xpected !otal pressure drop and (ir flow rate can be used to select exhaust fan 

RE;ERENCE () “Performance of Biofilter for the Removal of Hydrogen  Sulphide Odour”; %ehman, & ' , Faroo#i I H and (yub

S, Int . >n viron %es,