EASY RESPIROMETRIC METHODEASY RESPIROMETRIC METHODEASY RESPIROMETRIC METHODDIESEL CONTAMINATED SDIESEL‐CONTAMINATED SDIESEL CONTAMINATED S

Jubany I 1 Corcho D 2 Rovira M 1 Muelle A 2 Martí V 1,3Jubany I. , Corcho D. , Rovira M. , Muelle A. ,Martí V. ,

1CTM Technological Center Foundation Environmental Technology Area (UPC) Av B1CTM, Technological Center Foundation, Environmental Technology Area (UPC), Av. B2 INTRAVAL S L Llull No 109 2nd floor E 08005 Barcelona (Spain)2 INTRAVAL S.L. Llull, No. 109, 2nd floor, E‐08005 Barcelona (Spain)3Department of Chemical Engineering Technical University of Catalonia (UPC) ETSEI3Department of Chemical Engineering, Technical University of Catalonia (UPC), ETSEI

INTRODUCTIONINTRODUCTION

Petroleum hydrocarbon (TPH) contamination in soils is one of the maPetroleum hydrocarbon (TPH) contamination in soils is one of the ma

management practices performed in the last decades The biologicalmanagement practices performed in the last decades. The biological

investment and treatment costs (NFESC, 1996). A useful technique forinvestment and treatment costs (NFESC, 1996). A useful technique for

bi l i l il i h i i h i h b dbiological soil treatment is the respiration technique that can be usedg p q

its potential has not been thoroughly exploited in the soil treatment fieits potential has not been thoroughly exploited in the soil treatment fie

laboratory testing of contaminated soil The method was tested using mlaboratory testing of contaminated soil. The method was tested using m

MATERIALS AND METHODSMATERIALS AND METHODS

Microcosms setupMicrocosms setup

A series of microcosms (Table 1) were set up for the treatment ofA series of microcosms (Table 1) were set up for the treatment ofdiesel contaminated soil (16 7 g TPH/kg d m ) amended ithdiesel‐contaminated soil (16.7 g TPH/kg d.m.) amended withchemical nutrients (NFESC 1996) and a bulking agent (a mixturechemical nutrients (NFESC, 1996) and a bulking agent (a mixturef d d d hi ) id i l i Fof sawdust and wood chips) to provide optimal porosity. Forp ) p p p y

each test an abiotic control (named 0) was also set up (with 4 geach test, an abiotic control (named 0) was also set up (with 4 gHgCl2/kg soil).g 2/ g )

Each microcosmTable 1. Experimental conditions of microcosms

Each microcosmp

consisted on a 1 LBulking agent Nutrients glass jar containingTest Microcosm

g g

(% i t i ht) dditiglass jar containing

(% in wet weight) addition 160 g of the soil‐0 0 A 0 No

160 g of the soilb lki t0 0, A 0 No bulking agent

1 0, A, B, C 10 Yes mixture and added0, A, , C 0 Yes mixture and added( 0 % f2 0, A, B, C 20 Yes water (70 % of

3 0 A B C 30 Yes

(field capacity)3 0, A, B, C 30 Yes field capacity).

Mi k t f 6 k t 20ºC TPHMicrocosms were kept for 6 weeks at 20ºC. TPHs weremeasured at the beginning and at the end of the experimentmeasured at the beginning and at the end of the experiment.

RESULTSRESULTS

The oxygen measurements in the microcosms of Tests 1, 2 and 3The oxygen measurements in the microcosms of Tests 1, 2 and 3Fi 2 h th fil f T t 1 hi h i il t TFigure 2 shows the oxygen profile for Test 1 which was similar to TeThis fact indicated that the contaminated soil without bulking agentThis fact indicated that the contaminated soil without bulking agent

d i bi i l i did h dexpected, oxygen in abiotic control microcosms did not change due tp , yg g

Figure 2 Oxygen profile of microcosms in Test 1 iFigure 2. Oxygen profile of microcosms in Test 1 Figure 3. OUR pr

OUR was calculated for Tests 1, 2 and 3 (Figure 3). The OUR was c, ( g )bacterial activity was taking place in these tests Based on these resbacterial activity was taking place in these tests. Based on these resconditions for bacterial activity. Therefore, it can be stated that tconditions for bacterial activity. Therefore, it can be stated that t

t ti ) f d th b t i l ti it d t t dconcentration) favoured the bacterial activity detected as oxygen reremoval was obtained as higher was the porosity of the mixture (Figuremoval was obtained as higher was the porosity of the mixture (Figu

CONCLUSIONSCONCLUSIONS

An easy respirometric method was developed for testing the bioremediAn easy respirometric method was developed for testing the bioremedi

h d f h f h don the periodic measurement of the air oxygen of jars containing the tested

The method was used to detect the best amendment conditions for thThe method was used to detect the best amendment conditions for th

expensive chemical analyses as TPHs. Results obtained with the respirometp y p

The developed method is a promising method to be used as a tool for smThe developed method is a promising method to be used as a tool for sm

management companies that need cheap and reliable techniquesmanagement companies that need cheap and reliable techniques.

REFERENCESREFERENCES• NFESC (1996). Biopile design and construction manual. TM‐2189‐ENV. Naval Facilities Engineering Se( ) p g g g

D FOR THE OPTIMISATION OFD FOR THE OPTIMISATION OFD FOR THE OPTIMISATION OF SOIL BIOREMEDIATIONSOIL BIOREMEDIATIONSOIL BIOREMEDIATION

Bases de Manresa 1 E 08242 Manresa (Spain)Bases de Manresa, 1, E‐08242 Manresa (Spain) 

B Av Diagonal 647 E 08028 Barcelona (Spain)B, Av. Diagonal, 647, E‐08028, Barcelona (Spain) 

ain environmental problems in Spain due to bad industrial and wasteain environmental problems in Spain due to bad industrial and waste

treatment is one of the most cost‐effective treatments due to its lowtreatment is one of the most cost effective treatments due to its low

the determination of bacterial activity in biological processes like thethe determination of bacterial activity in biological processes like the

l h O i i h h i l Hto relate the O2 consumption with the contaminant removal. However2 p

eld This work shows a low cost and easy respirometric method for theeld. This work shows a low‐cost and easy respirometric method for the

microcosms experiments with hydrocarbon‐contaminated soilmicrocosms experiments with hydrocarbon‐contaminated soil.

Respirometic method:Respirometic method:

Throughout the experiment, the oxygen of the air chamber ofThroughout the experiment, the oxygen of the air chamber ofthe jars as periodicall meas red b introd cing an o genthe jars was periodically measured by introducing an oxygenprobe into the jars through a hole in the lid which was sealedprobe into the jars through a hole in the lid which was sealedi h i l i (Fi 1) Th l f h iwith insulating tape (Figure 1). The slope of the air oxygeng p ( g ) p yg

concentration with time (d(O %)/dt) was used to calculate theconcentration with time (d(O2%)/dt) was used to calculate theoxygen uptake rate (OUR in mg O2/d kg d.m.) using Eq. 1.yg p ( g 2/ g ) g q

2 7421∙ V d(O %)Eq 1OUR =

2.7421∙ Vair d(O2%) Eq. 1OUR = ∙M dtM dt

V is the volume of air in each jarVair is the volume of air in each jar(in L) and M is the dry weight of(in L) and M is the dry weight ofth il (i ) i th ithe soil (in g) in the microcosm.

Figure 1. Air chamber oxygenFigure 1. Air chamber oxygen measurement of a microcosm setup.measurement of a microcosm setup. 

clearly showed oxygen consumption due to the biological activity.clearly showed oxygen consumption due to the biological activity.t 2 d 3 N li ibl ti d t t d i T t 0est 2 and 3. Negligible oxygen consumption was detected in Test 0.

t and without added nutrients had no capacity to degrade TPHs Ast and without added nutrients had no capacity to degrade TPHs. Ash i hibi i f b i l i ito the inhibition of bacterial activity.y

f l f d i f lrofile of Tests 1, 2 and 3.  Figure 4. Percentage of TPH removal

clearly higher in Tests 2 and 3 than in Test 1 indicating that highery g g gspirometric results experimental conditions in Test 3 were the bestspirometric results, experimental conditions in Test 3 were the bestthe increase of the mixture porosity (due to higher bulking agentthe increase of the mixture porosity (due to higher bulking agent

i ti t Thi fi d ith TPH d t i hi h TPHespiration rate. This was confirmed with TPH data since higher TPHure 4)ure 4).

ation potential of hydrocarbon‐contaminated soil. The method was basedation potential of hydrocarbon contaminated soil. The method was based

d l bd soil using an oxygen probe.

e biotreatment of a hydrocarbon‐contaminated soil without the need fore biotreatment of a hydrocarbon contaminated soil without the need for

ric method were in agreement with results obtained with TPH analysis.g y

mall scale screening tests previous to pilot or industrial treatments for wastemall‐scale screening tests previous to pilot or industrial treatments for waste

ervice Center.