agricultural reuse of reclaimed water and uptake of organic compounds: pilot study at mutah...

Available online at www.sciencedirect.com

www.elsevier.com/locate/chemosphere

Chemosphere 72 (2008) 1203–1214

Agricultural reuse of reclaimed water and uptakeof organic compounds: Pilot study at Mutah University

wastewater treatment plant, Jordan

Farah Al Nasir a, Mufeed I. Batarseh b,*

a Faculty of Agriculture, Mutah University, P.O. Box 7, Karak, Jordanb Prince Faisal Center for Dead Sea, Environmental and Energy Research, Mutah University, P.O. Box 3, Karak 61710, Jordan

Received 29 October 2007; received in revised form 17 January 2008; accepted 28 January 2008Available online 8 May 2008

Abstract

The residues of polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorinated benzenes (CBs) and phe-nols were investigated for soil, wastewater, groundwater and plants. The uptake concentration of these compounds was comparativelydetermined using various plant types: Zea mays L., Helianthus annus L., Capsicum annum L., Abelmoschus esculentus L., Solanum

melongena L. and Lycopersicon esculentum L. which were grown in a pilot site established at Mutah University wastewater treatmentplant, Jordan. Soil, wastewater, groundwater and various plant parts (roots, leaves and fruits) samples were extracted in duplicate,cleaned up by open-column chromatography and analyzed by a multi-residue analytical methods using gas chromatography equippedwith either mass selective detector (GC/MS), electron capture detector (GC/ECD), or flame ionization detector (FID).

Environmentally relevant concentrations of targeted compounds were detected for wastewater much higher than for groundwater.The overall distribution profiles of PAHs and PCBs appeared similar for groundwater and wastewater indicating common potential pol-lution sources. The concentrations of PAHs, PCBs and phenols for different soils ranged from 169.34 to 673.20 lg kg�1, 0.04 to 73.86 lgkg�1 and 73.83 to 8724.42 lg kg�1, respectively. However, much lower concentrations were detected for reference soil. CBs were detectedin very low concentrations. Furthermore, it was found that different plants have different uptake and translocation behavior. As a con-sequence, there are some difficulties in evaluating the translocation of PAHs, CBs, PCBs and phenols from soil–roots-plant system. Theuptake concentrations of various compounds from soil, in which plants grown, were dependent on plant variety and plant part, and theyshowed different uptake concentrations. Among the different plant parts, roots were found to be the most contaminated and fruits theleast contaminated.� 2008 Published by Elsevier Ltd.

Keywords: Wastewater; POPs; PCBs; PAHs; Phenols; Jordan

1. Introduction

Jordan with its geographical location in an arid to semiarid environment is characterized by low amounts of wetprecipitation, hot summer and cold winter. Jordan is facinga future of very limited water resources, among the lowestper capita worldwide. Water scarcity is the single mostimportant natural constraint to the country’s economic

0045-6535/$ - see front matter � 2008 Published by Elsevier Ltd.

doi:10.1016/j.chemosphere.2008.01.064

* Corresponding author. Tel.: +962 777215540; fax: + 962 3 2375540.E-mail address: Batarseh@mutah.edu.jo (M.I. Batarseh).

growth and development. All these factors have negativeimpacts on the agricultural activities in the area, althoughJordan soils are characterized by high nutrient content.Therefore, more attention should be paid wastewater reuseas an alternative water resource for irrigation purposes.The annual water consumption in Jordan in 2003 was esti-mated to be around 810 million m3, where 63% is con-sumed by agriculture, 32% domestic, 4% industrial and1% by other activities (MWI, 2004). Wastewater is cur-rently treated in 23 wastewater treatment plants distributedthroughout the country with total influent flow of 93.90

1204 F. Al Nasir, M.I. Batarseh / Chemosphere 72 (2008) 1203–1214

million m3 yr�1 and effluent flow of 75.53 million m3 yr�1.Approximately 60% of the effluent water is currently usedin Jordan for agriculture purposes and groundwaterrecharge.

Mutah University, where the research study has beenconducted, was established in 1981 in Karak governorate.There are two main water sources that supply the campuswith domestic water in addition to the reclaimed water thatis treated at the University wastewater treatment plant.Currently 1100–1200 m3 of domestic wastewater per dayis generated from different activities at the University cam-pus. Reclaimed water is pumped to a storage tank where itis distributed through an irrigation network and reused foragricultural purposes during summer season. However, inthe winter season the excess volume of treated wastewateris discharged into Wadis and used to recharge the nearbygroundwater resources.

Wastewater may contain chemical toxic organic andinorganic components. In addition to the trace metals, itis worth mentioning the impact of chemical pollutioncaused by the conventional ‘‘priority” organic pollutants(POPs), which display persistence in the environment.Acutely toxic, mutagenic and/or carcinogenic compoundssuch as pesticides, PAHs, industrial intermediates, PCBs,phenols, chlorinated phenols, etc. (Hamscher et al.,2002; Batarseh et al., 2003a; Thiele–Bruhn, 2003) are ofprimary concern. These chemical pollutants could reachthe food chain easily in the wastewater used for irrigationpurposes. The irrigation water quality is believed to haveeffects on the soil, crop and the management of water(Shahalam et al., 1998). The use of saline water mayresult in the reduction of crop yield, while water, whichis high in total dissolved solids, may deteriorate the phys-ical properties of the soil with consequent reduction in theyield. Municipal wastewater discharges have been recog-nized as a major source of PAHs, PCBs and phenols(Ng et al., 1997; Jiries et al., 2000; Tor et al., 2003).Chemical composition of waste produced at Mutah Uni-versity laboratories was found to have adverse effect onwastewater quality in terms of trace metals and majorionic composition (Hussein et al., 2000). Furthermore,environmentally significant residues of PAHs were foundfor wastewater, sediments, sludge and plants for wastewa-ter treatment plant in Karak Province (Jiries et al., 2000;Jiries, 2001).

Accumulation of POPs in plants varies by several ordersof magnitude due to several factors such as the differencesin the atmospheric pollution levels, leaf-morphology andphysiology (Franzaring and van der Eerden, 2000). Ininterspecies comparison of PAHs accumulation, it wasfound that plants with higher surface-to-volume ratios playan important role in accumulating more PAHs (Bohmeet al., 1999). Additionally studies have been conducted toevaluate the accumulation of POPs in plants via airbornetransport. For example, for a PAH-to-vegetation mass bal-ance for the NE-USA, it was calculated that the vegetationin the study area scavenges about 4–40% of the total

amount of PAHs emitted (Simonich and Hites, 1994a;Wagrowski and Hites, 1997).

The present work was aimed at investigating the concen-tration of PAHs, PCBs, CBs, and phenols in soil irrigatedwith reclaimed water effluents from Mutah Universitywastewater treatment plant, Jordan. Additionally, theuptake of these compounds was evaluated through study-ing their water–soil-plant system for four different planttypes. Furthermore, the selectivity phenomenon for soil,roots, leaves and fruits are evaluated. The suitability ofthe wastewater effluents was evaluated for agriculturalreuse in terms of toxic organic compounds such asrestricted or non-restricted agriculture practices, given thatthe effluents quantities are 1100–1200 m3 d�1. Finally,examination of the wastewater effluent impact on thegroundwater resources was evaluated.

2. Materials and methods

2.1. Pilot study area

Three replicate plots, 12 m2 square area (3 m � 4 m), foreach type of plant were constructed at Mutah Universitycampus and confined by a soil panel placed in the soil ata 20 cm depth. One pilot plant area was irrigated withwastewater effluents received from Mutah UniversityWWTP, while the other pilot plant area was irrigated withgroundwater received from Mutah University Well andconsidered as a remote reference site. The following plantsspecies were cultivated: Zea mays L., Helianthus annus L.,Capsicum annum L., Abelmoschus esculentus L., Solanummelongena L. and Lycopersicon esculentum L.

2.2. Sampling

Roots, leaves and fruit samples were collected after mat-uration period from the pilot plant areas. Two replicatesout of three were collected, homogenized and stored at�20 �C until time of analysis. Triplicates of soil sampleswere collected from pilot plant areas, sieved for <2 mmand stored at �20 �C until time of analysis. Furthermore,soil samples were collected before caring out the experi-ment and used for physio-chemical soil characterization.Wastewater and groundwater samples were collected onweekly bases using 1 l glass sampling bottles and storedat 4 �C. The toxic organic compounds (PAHs, PCBs, CBsand phenols) were extracted using solid phase extraction(SPE) technique.

2.3. Sample preparation

The wet homogenized samples containing 100 g offruits, leaves or roots and 50 g of soil material were placedseparately into 500 ml Erlenmeyer flask. Extraction wascarried out with 2:1 acetone/water mixture (v:v) overnightusing a horizontal shaker at shaking velocity of220 cycle min�1. After adding 15 g of NaCl and 100 ml

F. Al Nasir, M.I. Batarseh / Chemosphere 72 (2008) 1203–1214 1205

cyclohexane, the mixture was shaken for 1 h, completingthe liquid/liquid partitioning. The organic layer was dec-anted into 250 ml Erlenmeyer flask and dried over 15 gsodium sulfate. 100 ml of the extract were rotary evapo-rated and dissolved in 5 ml of 1:1 ethylacetate and cyclo-hexane mixture (v:v).

The sample was micro-filtered using a polytetrafluoro-ethylene (PTFE) syringe filter before GPC clean up. A5 ml aliquot was added on the top of GPC glass columnpacked with Bio-Beads SX–8 (40 � 3.6 cm) and the elutewas collected from 100 to 360 ml as an analyte fraction.Then, solution was rotary evaporated and concentratedto near dryness under a gentle nitrogen stream. One dropof dodecane was used as a keeper, before the sample wasdissolved in 1 ml of n-hexane. Furthermore, to eliminateother interference substances the samples was cleaned upusing silica gel column. The silica gel was activated at130 �C overnight, and then it was partly deactivated with2% H2O ultrapure (resistivity, 18.2 MX cm), obtained froma Milli–Q water purification system (Millipore Corp.,USA). The chromatographic column was packed with10 g of deactivated silica gel and 1 g of oven dried anhy-drous Na2SO4 on the top of the column. The sample waseluted with 70 ml of a mixture of acetone and hexane(50%:50%). Then, elute was rotary evaporated and concen-trated in a gentle nitrogen stream to 3 ml. The sample wasdivided into three portions each of 1 ml into GC brownvials and analyzed for chlorinated compounds (PCBz,HCBz, PCB congeners), PAHs and phenols using GC/ECD, GC/MS and GC/FID, respectively.

Wastewater and groundwater samples were acidifiedfor pH = 2 and filtrated via simple filtration apparatus.A one-litter sample was transferred subsequently to SPEcolumn of 1000 mg of C18 (Baker, USA), using a VarianSPE apparatus equipped with a vacuum pump (Varian,Australia). The SPE column was preconditioned priorto use using 3 ml of deionized water and 3 ml of acetone.The targeted compounds were eluted with 3 ml of acetoneand elute was concentrated to 200 ll via nitrogen stream.The CBs (pentachlorobenzene (PCBz), hexachloroben-zene, (HCBz), PCB congeners), PAHs and phenols wereanalyzed using GC/ECD, GC/MS and GC/FID,respectively.

2.4. Analysis of PAHs

GC–MS determination was performed using a PerkinEl-mer Clarus 500 gas chromatograph coupled to a PerkinEl-mer Clarus 500 mass spectrometer (MS) with electronionization mode (EI). The split/splitless injection portequipped with autosampler and maintained at 250 �C, splitratio (1:50) and pulse-injection mode. The mass spectrom-eter was operated at the same time in full scan and selectedion monitoring modes (SIM) detecting the M+ ions for 16PAH, and the ionization source was supplied with voltageat 70 eV. A 1 ll of aliquot was injected by the autosamplerwith same split ratio. A DB-5 MS fused silica capillary col-

umn with 30 m length, 0.25 lm film thickness and 0.32 mminner diameter was used as the analytical column (Perkin-Elmer, USA). The oven temperature program was 60 �C(4 min) ramped at 15 �C min�1 to 160 �C, then at3 �C min�1 to 280 �C, and finally held for 10 min. Thetransfer line temperature was maintained at 200 �C andthe source temperature at 180 �C. A grade 6.0 He was usedas carrier gas with flow rate of 1.5 ml min�1. Specific massto charge ratios (m/z) was used to build up the SIM pro-gram for the 16 PAHs.

2.5. Analysis of PCBz, HCBz and PCBs

A Schimadzu GC chromatograph model 2010 equippedwith a 63Ni electron capture detector was used for analysisof PCBz, HCBz, PCB 28, PCB 52, PCB 101, PCB 138, andPCB 180 (Schimadzu, Japan). A 30 m DB–5 fused silicacapillary column with 0.25 lm film thickness and 0.32 mminner diameter was used for the quantification of organo-chlorine compounds (J & W Scientific, USA). Helium(grade 5.5) was employed as carrier gas (1 ml min�1) andnitrogen as make up gas (58 ml min�1). The oven tempera-ture was programmed from 60 �C (1 min) to 160 �C (1 min)at 15 �C min�1, then to 220 �C (5 min) at 5 �C min�1, finallyat 3 �C min�1 to 280 �C (10 min). The injector and detectortemperatures were maintained at 250 �C and 300 �C, respec-tively. The splitless injection volume was 1 ll. SchimadzuPost-Run software was used for data analysis andquantification.

2.6. Analysis of phenols

A Schimadzu GC chromatograph model 2010 equippedwith a flame ionization detector (FID) was used for analy-sis of different phenol compounds (Schimadzu, Japan). A30 m 5% methyl phenyl fused silica capillary column with0.25 lm film thickness and 0.25 mm inner diameter wasused for the quantification of phenol compounds (Qua-drex, USA). A mix standard solution of 10 different phe-nols of 2000 mg l�1 was used as stock standard solution(Supelco, USA). Helium (grade 5.5) was used as carriergas (1 ml min�1), hydrogen and air were used for theFID detector. The oven temperature was programmedfrom 70 �C (1 min) to 185 �C (4 min) at 10 �C min�1. Theinjector and detector temperatures were maintained at200 �C and 250 �C, respectively. The splitless injection vol-ume was 1 ll. Identification of sample peaks (qualitativeanalysis) is performed by comparing the GC retention timewith that of calibration standards and it was acceptedwithin a ±10 s of the retention time of the initial calibra-tion peak. Using the whole profile solves the unexpectedpeak problems and handles shoulders and other chromato-graphic features that might be appeared due to samplematrix effect. The peak area (quantitative analysis) wasemployed to determine the concentration of targeted com-pounds using Schimadzu Post-Run software (Schimadzu,Japan).

1206 F. Al Nasir, M.I. Batarseh / Chemosphere 72 (2008) 1203–1214

3. Results and discussion

3.1. Analytical data

A multi-analytical method was used for the analysis ofPAHs, PCBs, PCBz, HCBz and phenols in the same extractof groundwater, wastewater, soil and plant samples. Themethod recovery rates for PAHs for soil and plant usingfortified samples, which were spiked with different analytes,ranged from 80% to 116% and from 82% to 110%, respec-tively, with acceptable relative standard deviation RSD%values ranging from 5 to 13. The average recoveries ofPCBs, PCBz and HCBz for soil ranged from 91% to120% with 5–20 RSD%, and for plant from 85% to 125%with 7–18 RSD%. Similar recovery rates were found forgroundwater and wastewater samples. The limits of quan-tification (LoQ) for individual organochlorine compoundswas above 100 ng ll�1 and for PAHs ranged from 0.005to 0.043 lg ll�1. These analytical results were in compara-tive agreement with other recovery rates determined fre-quently for these compounds (Jiries et al., 2000; Batarsehet al., 2003b; Zohair et al., 2006).

SIM mode was used for the determination of the con-centration of PAHs for a standard solution of 16-PAHsand sample extract using external calibration. PCBz,HCBz and PCB chromatograms collected using GC/ECD are presented in Fig. 1a and b, respectively. Finally,phenols chromatograms are presented in Fig. 2a and bfor standard solution of 10 different phenol compoundsand for sample extract, which were collected using GC/FID.

Peak No. Compou

1 Pentachlorobenz2 Hexachlorobenze3 PCB 24 PCB 55 PCB 106 PCB 157 PCB 138 PCB 18

1

3

2

4 5 6 7

4

5

Fig. 1. GC/ECD chromatograms for PCBs, PC

3.2. Groundwater and wastewater

The concentrations of PAHs for groundwater andwastewater samples are shown in Table 1. Generally,higher concentration levels of total PAHs were found inwastewater by 70 folds more than for groundwater. Con-centration of total PAHs in wastewater ranged from174 ng l�1 to 6376 ng l�1, and for groundwater from0.2 ng l�1 to 143 ng l�1. The most abundant individualPAH compounds in groundwater and wastewater sampleswere: pyrene, naphthalene, phenanthrene and fluoranth-ene, reflecting their higher solubility in water comparedto other PAH compounds. They comprised 99% of totalPAHs for wastewater and 81% for groundwater. The over-all distribution a profile of individual PAH compoundsappeared similar for groundwater and wastewater samplesindicating a common potential source. In comparison withprevious studies, PAH concentrations in domestic waste-water samples collected from Thessaloniki WWTP inGreece ranged from 5700 ng l�1 to 11090 ng l�1 (Manoliand Samara, 1999) and pyrene concentrations for threewastewater stabilization ponds in Sweden were in a rangefrom 0.5 lg l�1 to 3.0 lg l�1, similar to our findings (Pax-eus, 1996). A study carried out for groundwater contami-nation caused by landfill leachate in Amman area,Jordan, showed a higher concentration of PAH (2600lg l�1) for groundwater that was due to a different sourceof input (Jiries et al., 2005).

PCBz was found in wastewater in very low concentra-tion (0.30 ng l�1); however, it was not detected in anygroundwater samples. HCBz average concentrations were

nd Retention Time (min)

ene (PCBz) 13.117 ne (HCBz) 15.316 8 17.657 2 18.760 1 21.340 3 23.944 8 25.076 0 27.999

8

a

b

B and HCB, (a) standard and (b) sample.

Peak No. Compound Retention Time (min)

1 o-Cresol 4.586 2 p-Cresol 4.829 3 2,4-Dimethylphenol 5.779 4 2,6-Dichlorophenol 6.565 5 2,3,5-Trichlorophenol 8.319 6 2,4,5-Trichlorophenol 8.653 7 2,3,4-Trichlorophenol 8.801 8 2,3,5,6-Tetrachlorophenol 11.040 9 2,3,4,6-Tetrachlorophenol 11.159

10 4,6-Dinitro-o-cresol 11.839

4

6 10

132

4

56

798

10

a

b

Fig. 2. GC/FID chromatograms for phenols, (a) standard of 10 phenols and (b) sample.

F. Al Nasir, M.I. Batarseh / Chemosphere 72 (2008) 1203–1214 1207

0.17 ng l�1 for groundwater and 0.64 ng l�1 for wastewater,respectively. The total concentration of PCBs ranged from1.98 ng l�1 to 8.29 ng l�1 for groundwater, and from46.42 ng l�1 to 75.40 ng l�1 for wastewater, respectively.The contamination of groundwater with some PCBs cong-eners might reflect a chronic effect due to wastewaterrecharging.

The concentrations of phenol compounds are shown inTable 1. Wastewater samples showed higher concentrationlevels of 25 folds more than for groundwater. Their totalconcentration ranged over 54–90 lg l�1 for wastewaterand 1–4 lg l�1 for groundwater. Among all phenol com-pounds: 2,3,5,6-tetrachlorophenol was found in highestconcentration (42 lg l�1) for wastewater and o-cresol(0.78 lg l�1) for groundwater. Comparing all targetedcompounds, phenols were found in higher concentrationlevels than PAHs and PCBs, this result can be explaineddue to higher solubility of phenols. The concentration ofphenols and chlorinated phenols investigated for effluentsof four biological wastewater treatment plants in Denmarkwere found comparable to those found for the presentwork, the concentration of o-cresol ranged 0.05–11.00 lg l�1, for 2,4-dichlorophenol 0.03–0.33, and for

2,4,6-trichlorophenols 0.06–0.18 lg l�1 (Folke and Lund,1983).

3.3. Soil

The concentrations (lg kg�1 dry weight) of PAHs,PCBs, HCBz, PCBz and phenol residues for soil irrigatedwith wastewater and the reference soil are shown in Table2. Generally, the results showed that higher contaminationlevels of most targeted compounds found for soil, in whichdifferent plants were grown, rather than the reference site(blank soil). The sources of this contamination can beattributed due to wastewater reuse for irrigation. The high-est concentration of PAHs is found for soil related to Okraplant (673 lg kg�1) and the lowest for sunflower(169 lg kg�1) Fig. 3a. The most abundant PAHs were: pyr-ene, fluoranthene and phenathrene. The PAHs profile wascharacterized by low molecular weight PAHs (2–3 ringssystem) rather than those have higher molecular weight(4–6 rings system). These findings were found be in goodagreement with those reported by Kipopoulou et al.(1999) and Tao et al. (2004). Congener PCB 52 was themost abundant among other PCBs for most of analyzed

Table 1PAH, PCBs, HCBz, PCBz and phenols residues for groundwater and wastewater samples

Compound Freshwater (n = 10) Wastewater (n = 6)

Minimum Maximum Mean Standard deviation Minimum Maximum Mean Standard deviation

PAH/abbreviation

Naphthalene/NAP ng l�1 nda 84.97 23.27 32.67 124.66 569.01 291.14 199.60Acenaphthylene/ACY ng l�1 nd 17.13 1.78 4.84 nd 5.50 2.49 1.85Acenaphthene/ACE ng l�1 0.16 4.41 1.11 1.20 nd 3.95 1.39 1.42Fluorene/FLU ng l�1 nd 4.54 0.78 1.24 0.37 19.06 9.37 6.56Phenanthrene/FHE ng l�1 nd 4.80 0.91 1.52 9.48 179.46 103.02 65.56Anthracene/ANT ng l�1 nd 1.35 0.36 0.38 nd 11.42 2.86 4.72Fluoranthene/FLA ng l�1 nd 4.76 1.85 1.79 15.18 123.25 59.57 45.57Pyrene/PYR ng l�1 nd 5.28 1.33 1.66 24.89 5409.30 1976.71 2597.16Benzo[a]anthracene/BaA ng l�1 nd 1.87 0.36 0.61 nd 8.53 1.65 3.39Chrysene/CHR ng l�1 nd 1.97 0.24 0.56 nd 5.85 1.80 2.13Benzo[b]fluoranthene/BbF ng l�1 nd 1.37 0.28 0.39 nd 12.97 2.79 5.05Benzo[k]fluoranthene/BkF ng l�1 nd 1.41 0.22 0.44 nd 2.23 0.82 0.89Benzo[a]pyrene/BaP ng l�1 nd 1.08 0.16 0.36 nd 13.03 3.54 5.09Indo[1,2,3,c,d]pyrene/IcdP ng l�1 nd 3.45 0.49 1.06 nd 2.50 0.82 1.03Dibenzo[a,h]anthracene/DahA ng l�1 nd 2.82 0.49 0.84 nd 8.63 2.37 3.43Benzo[g,h,i]perylene/BghiP ng l�1 nd 1.50 0.25 0.46 nd 1.46 0.32 0.59

Sum PAH ng l�1 0.16 142.69 33.87 33.35 174.58 6376.17 2460.65 2771.51PCBz ng l�1 nd nd nd nd nd 0.68 0.30 0.28HCBz ng l�1 nd 0.84 0.17 0.38 nd 2.36 0.64 1.15PCB 28 ng l�1 nd 8.29 1.98 3.60 nd 4.77 1.61 2.25PCB 52 ng l�1 nd nd nd nd 46.42 70.63 56.06 11.51PCB 101 ng l�1 nd nd nd nd nd nd nd ndPCB 153 ng l�1 nd nd nd nd nd nd nd ndPCB 138 ng l�1 nd nd nd nd nd nd nd ndPCB 180 ng l�1 nd nd nd nd nd nd nd nd

Sum PCBs ng l�1 nd 8.29 1.98 3.50 46.42 75.40 57.67 11.10o-Cresol lg l�1 0.18 1.18 0.78 0.40 0.57 0.76 0.67 0.13p-Cresol lg l�1 nd nd nd nd nd nd nd nd2,4-Dim lg l�1 nd 0.71 0.42 0.28 0.48 0.97 0.73 0.352,6-Dichl lg l�1 nd 0.71 0.21 0.32 nd 1.28 0.64 0.912,3,5-Trichlo lg l�1 nd 0.79 0.16 0.35 nd nd nd nd2,4,5-Trichlo lg l�1 nd 1.74 0.53 0.71 0.59 1.63 1.11 0.742,3,4-Trichlo1 lg l�1 nd 1.04 0.21 0.46 nd nd nd nd2,3,5,6-Tetrachlo lg l�1 nd 0.77 0.31 0.42 nd 84.21 42.10 59.542,3,4,6-Tetrachlo lg l�1 nd nd nd nd nd 1.15 0.57 0.814,6-Dinitro lg l�1 nd 0.64 0.24 0.33 nd 51.97 25.98 36.75Sum phenols lg l�1 1.08 4.03 2.85 1.09 53.80 89.81 71.80 25.46

a nd: not detected.

1208 F. Al Nasir, M.I. Batarseh / Chemosphere 72 (2008) 1203–1214

soil samples, whereas, it was not detected for soil in whichsunflower, corn and tomato were grown. The highest con-centration of PCBs was found for soil related with Okra(74 lg kg�1) and the lowest for corn (0.04 lg kg�1),Fig. 3b. This results support the idea that okra plantsmight uptake the organic pollutants in very low quantitiesas indicated by their concentration in roots, leaves andfruits. In addition, a significant correlation (0.77) wasfound between PAHs and PCBs concentration for all soils,where the plants grown, indicating a common source ofcontamination.

The total concentration of phenols for different soilswere varied from 74 lg kg�1 to 8724 lg kg�1 on dry weightbases, however, no residues of phenols were detected forthe reference site Table 2. This can be attributed due tothe effect of wastewater application for irrigation. Thehighest concentration level of phenols was found for soil

related to okra plants followed by soil related to paprika,sunflower, corn, eggplant and tomato, respectively. Theseresults have to those for PAHs and PCBs in soil and sup-porting the phenomena that okra plants showed the lowestuptake amount of organic contaminants in comparisonwith other plants. Among phenols: 2,4-dinitro-o-cresolwas the most abundant compound followed by 2,3,4,6-tet-rachlorophenol, 2,3,5-trichlorophenol and 2,6-dichloro-phenol. Other phenols were detected in very lowquantities. It is possible to get an idea about contaminationthresholds that could cause risk to either human health ororganisms by comparing the findings for this study with therelevant soil quality standard from the British ColumbiaContaminated Sites Regulation (CSR) (Bright and Healey,2003). For example, the CSR threshold concentrations for:o-cresol (4 lg kg�1), p-cresol (4 lg kg�1), 2,4 and 2,5-dichlorophenols (4 lg kg�1), 2,4,5-trichlorophenol (4 lg

Table 2PAH, PCBs, HCBz, PCBz and phenols residues (lg kg�1 dry weight) for soil samples

Plant scientific name Blank Helianthus annus L. Zea mays L Capsicum annum L. Abelmoschus esculentus L. Solanum melongena L. Lycopersicon esculentum L.Plant popular name Sunflower Corn Paprika Okra Eggplant Tomato

PAHNAP 3.236 4.858 10.642 4.198 210.683 9.660 6.942ACY 0.052 0.010 0.028 0.081 0.498 0.062 0.119ACE 0.022 0.006 0.012 0.121 1.163 0.037 0.016FLU 0.116 0.172 0.492 0.460 5.882 0.439 0.569FHE 0.005 0.004 0.006 0.005 72.243 2.451 6.275ANT 0.255 0.248 0.264 0.157 4.985 0.252 0.520FLA 18.102 21.560 52.678 24.043 11.399 19.350 40.790PYR 105.895 140.038 213.510 158.980 360.151 186.019 192.312BaA 0.125 0.113 0.728 0.272 4.528 0.026 0.214CHR 0.237 0.156 0.492 0.155 0.026 0.097 0.212BbF 0.253 0.320 0.657 0.293 0.435 0.116 0.286BkF 0.171 0.220 0.329 0.088 0.029 0.114 0.180BaP 0.231 0.168 nd0 0.156 0.820 0.073 0.769IcdP 0.536 0.233 0.255 0.652 0.078 0.094 0.804DahA 0.262 0.892 0.928 0.684 0.119 0.070 18.804BghiP 0.181 0.342 0.049 0.065 0.165 0.298 0.151

Total PAH 129.679 169.340 281.069 190.410 673.204 219.157 268.964PCBz nd a 0.015 nd 0.387 0.029 0.010 0.023HCBz nd 0.033 0.018 0.046 0.353 0.005 0.014PCB 28 nd 0.108 0.041 0.077 6.594 0.046 0.158PCB 52 nd nd nd 38.865 59.482 28.179 ndPCB 101 nd 0.318 nd 0.213 7.783 nd 0.262PCB 153 nd 0.309 nd 0.185 nd nd ndPCB 138 nd nd nd nd nd nd ndPCB 180 nd nd nd nd nd nd nd

Sum PCBs nd 0.735 0.041 39.340 73.858 28.225 0.420o-Cresol nd 4.32 nd 4.14 68.48 nd ndp-Cresol nd 15.39 nd 15.28 nd nd nd2,4-Dim nd nd nd nd nd nd nd2,6-Dichl nd 30.79 18.15 nd 38.09 nd nd2,3,5-Trichlo nd 28.49 651.01 14.93 42.37 10.80 43.122,4,5-Trichlo nd nd nd 277.89 39.74 nd nd2,3,4-Trichlo nd 11.96 nd nd 66.66 nd nd2,3,5,6-Tetrachlo nd 59.46 21.67 104.96 204.54 218.97 30.732,3,4,6-Tetrachlo nd nd nd 0.20 34.07 nd nd4,6-Dinitro nd 954.35 135.17 4659.30 8230.46 36.15 ndSum phenols nd 1104.77 826.00 5654.67 8724.42 274.76 73.85

a nd: not detected.

F.

Al

Na

sir,M

.I.B

ata

rseh/C

hem

osp

here

72

(2

00

8)

12

03

–1

21

41209

0

100

200

300

400

500

600

700

conc

. (µ

g/kg

)

Blank

Sunflo

werCor

n

Paprik

aOkr

a

Eggpla

nt

Tomato

soil

PAHs

0

10

20

30

40

50

60

70

conc

. (µ

g/kg

)

Blank

Sunflo

werCor

n

Paprik

a Okr

a

Eggpla

nt

Tomato

soil

PCBs

0

50

100

150

200

250

300

conc

. (µ

g/kg

)

Sunflo

werCor

n

Paprik

aOkr

a

Eggpla

nt

Tomato

roots

PAHs

0

10

20

30

40

50

60

conc

. (µ

g/kg

)

Sunflo

werCor

n

Paprik

aOkr

a

Eggpla

nt

Tomato

roots

PCBs

a b

dc

Fig. 3. Concentration (lg/kg dry weight): (a) PAHs for soil, (b) PCBs for soil, (c) PAHs for roots, (d) PCBs for roots, (e) PAHs for leaves, (f) PCBs forleaves, (g) PAHs for fruits, and (h) PCBs for fruits.

1210 F. Al Nasir, M.I. Batarseh / Chemosphere 72 (2008) 1203–1214

kg�1), 2,3,4,5 and 2,3,4,6-tetrachlorophenol (4 lg kg�1),and 2,4-dinitrophenol (4 lg kg�1). It is valuable here tonote that most investigated soil samples were contaminatedwith either phenols or chlorinated phenols mostly withhigher concentration levels than threshold concentrationsdefined by CSR.

3.4. Roots

The concentration of PAHs, PCBs, PCBz, HCBz andphenols for plant roots are shown in Table 3. The highestconcentration of PAHs was found for paprika roots(295 lg kg�1) followed by eggplant (281 lg kg�1), corn(198 lg kg�1), tomato (156 lg kg�1), sunflower(112 lg kg�1) and okra (106 lg kg�1) Fig. 3c. These resultssupport the conclusion that a similar plant family has sim-ilar uptake trends: as paprika, eggplant and tomato arerelated to the solanacea family. Furthermore, pyreneshowed same trends for all plant roots, while the highestconcentration was found for paprika (250 lg kg�1) and

the lowest for okra (95 lg kg�1). It was found that lowmolecular weight PAHs are more abundant than highermolecular weigh PAHs in all roots, fruits and leaves sam-ples (Wild and Jones, 1992; Kipopoulou et al., 1999). Thehighest concentrations of PCBs were found for Corn(56 lg kg�1) followed by paprika (31 lg kg�1), sunflower(16.5 lg kg�1), okra (9 lg kg�1), tomato (0.30 lg kg�1)and eggplant (0.10 lg kg�1). Among PCB congeners,PCB 52 was the most abundant, while the highest concen-tration was found for corn (56 lg kg�1) Fig. 3d.

Comparing the concentration of phenols, lower levelswere detected for plant roots than their related soils. Thephenols concentration for roots ranged from 222 lg kg�1

to 1728 lg kg�1. The highest concentration was found forpaprika followed by sunflower, corn, eggplant, okra andtomato, respectively. All phenols were detected in differentratios among different plant roots. Therefore, concentra-tion of phenols in plant roots was depending mainly onthe plant type. Comparing the PAHs and phenols results,paprika roots showed the highest uptake amounts. This

0

40

80

120

160

200

conc

. (µ

g/kg

)

Sunflo

werCor

n

Paprik

aOkr

a

Eggpla

nt

Tomato

fruits

PAHs

0

10

20

30

40

conc

. (µ

g/kg

)

Sunflo

werCor

n

Paprik

a Okr

a

Eggpla

nt

Tomato

fruits

PCBs

0

20

40

60

80

100

120

140

conc

. (µ

g/kg

)

Sunflo

werCor

n

Paprik

a Okr

a

Eggpla

nt

Tomato

leaves

PAHs

0

1

2

3

4

5

6

7

conc

. (µ

g/kg

)

Sunflo

werCor

n

Paprik

aOkr

a

Eggpla

nt

Tomato

leaves

PCBs

e f

g h

Fig. 3 (continued)

F. Al Nasir, M.I. Batarseh / Chemosphere 72 (2008) 1203–1214 1211

idea is supported too by a study carried out on carrot rootcultures, which found to be suitable for determining therole of the root matrix in the uptake and further metabo-lism of phenols and chlorinated phenols (de Araujo et al.,2002).

3.5. Leaves

The concentrations of PAHs, PCBs, PCBz, HCBz andphenols for plant leaves are shown in Table 3. As can benoticed that the PAH concentration levels were dependenton the foliage (leaves) surface area as higher levels of totalPAHs were reported for paprika (147 lg kg�1) and tomato(144 lg kg�1) compared to the corn, eggplant, sunflowerand the lowest for okra (27 lg kg�1), respectively,Fig. 3e. Among the individual PAHs distributions, pyreneshowed the highest concentration level for different plantleaves as follows: tomato, paprika, corn, eggplant, okraand sunflower, respectively. The PAHs profile was domi-nated by low molecular weight compounds (2–3 benzenerings), which occurred at higher concentrations than high

molecular weight compounds (4–6 benzene rings). Thiscan be due to higher solubility of low molecular weightof PAH than the higher molecular weight. These resultswere comparable with other studies worldwide; where sim-ilar concentration levels of PAHs were found for differentplant leaves such as for lettuce, carrot, potatoes and Cab-bage (Voutsa and Samara, 1998; Fismes et al., 2002). Inaddition, the same studies showed that higher concentra-tion of PAHs were reported in soil rather than invegetables.

PCBs were detected in low concentrations for plantleaves, their concentrations ranged from 0.14 lg kg�1 to6.79 lg kg�1, where the highest concentration was foundfor sunflower and the lowest for okra, Fig. 3f. Amongthe individual PCB congeners: PCB 101 was the mostabundant congener. The level of PCBs found in the foliageis mainly due to vapor transport from the soil, rather thanto translocation through the plant (Bacci and Gaggi, 1985).

Phenols concentrations ranged from 349 lg kg�1 to2110 lg kg�1 for different plant leaves. The highest concen-tration level was observed for eggplant and the lowest for

Table 3PAHs, PCBs, PCBz, HCBz and phenols concentration for roots, leaves and fruits

Scientific name Helianthus annus L. Zea mays L. Capsicum annum L. Abelmoschus esculentus L. Solanum melongena L. Lycopersicon esculentum L.Popular name Sunflower Corn Paprika Okra Eggplant Tomato

PAH Roots Leaves Fruits Roots Leaves Fruits Roots Leaves Fruits Roots Leaves Fruits Roots Leaves Fruits Roots Leaves Fruits

NAP 6.37 1.48 2.14 11.71 9.15 7.10 11.19 9.99 1.69 4.54 1.90 5.14 8.74 0.83 12.50 2.40 4.75 1.81ACY 0.27 0.03 11.64 0.08 0.08 0.09 0.17 0.08 0.01 0.08 0.12 0.09 0.06 0.11 0.21 0.10 0.28 0.03ACE 0.08 0.09 0.03 0.12 0.31 0.11 0.14 0.09 0.05 0.12 0.02 0.20 0.12 0.06 0.23 0.05 0.04 0.04FLU 0.12 0.16 0.55 35.76 1.31 0.61 1.06 0.48 0.14 0.40 0.08 0.72 0.82 0.17 0.63 1.96 0.40 0.41FHE 0.01 1.17 3.89 5.49 8.22 4.08 5.65 3.59 0.77 1.85 0.62 3.04 0.69 0.82 4.06 0.00 6.55 0.00ANT 0.47 nd 0.07 0.28 0.08 0.28 0.08 0.02 0.01 0.19 0.04 0.05 0.40 nd 0.23 2.80 0.24 0.17FLA 22.43 0.61 2.28 3.50 2.00 17.10 22.15 1.50 0.53 11.62 0.82 11.94 47.01 1.17 15.56 26.59 3.26 24.49PYR 78.37 20.54 127.66 139.54 39.18 171.80 249.89 44.46 22.92 85.76 23.57 41.96 215.82 38.31 137.33 115.85 119.07 82.48BaA 0.30 0.04 0.10 0.26 0.13 0.05 0.87 0.06 nd 0.19 nd 0.15 0.54 0.15 0.21 0.16 0.30 0.55CHR 0.11 0.04 0.05 0.05 0.03 0.14 0.25 0.02 0.04 0.06 0.05 0.02 0.07 0.11 0.14 0.16 0.09 0.06BbF 0.07 0.04 0.16 0.11 0.18 0.11 0.24 0.14 0.02 0.09 0.01 nd 0.08 0.06 0.11 0.21 0.31 0.03BkF 0.08 0.02 0.02 0.10 nd 0.06 0.16 0.06 0.01 0.07 0.03 0.11 0.10 0.05 0.09 0.12 0.01 0.06BaP 0.00 0.07 0.08 0.22 0.18 0.27 0.48 0.06 0.03 0.20 0.05 0.04 0.22 0.04 0.26 0.26 0.19 0.04IcdP 1.47 nd 0.20 0.55 nd 0.06 2.21 31.74 4.50 0.70 nd 27.18 4.72 nd nd 2.86 0.04 0.30DahA 1.39 15.05 0.07 0.18 nd 0.06 0.31 50.78 nd 0.37 nd nd 0.94 nd 0.67 2.31 9.08 0.54BghiP 0.28 nd 0.09 0.01 nd 0.22 0.10 3.95 nd 0.07 nd 27.60 0.43 4.50 0.19 0.37 0.11 0.00

Total PAH 111.80 39.32 149.01 197.95 60.85 202.12 294.95 147.00 30.71 106.29 27.31 118.23 280.75 46.37 172.41 156.18 144.73 111.01PCBz nd 0.46 nd 0.05 0.09 0.01 0.01 0.08 0.03 0.02 0.08 0.04 0.09 0.08 nd 0.06 0.11 0.00HCBz 0.06 0.16 0.11 4.74 0.15 0.01 0.03 0.08 0.01 0.02 0.06 0.05 0.02 0.01 0.04 0.02 0.62 0.03PCB 28 0.05 0.35 1.71 0.09 nd 0.09 0.25 nd 5.78 0.05 0.03 0.06 0.13 0.06 0.07 0.29 0.25 0.04PCB 52 1.61 nd 1.73 55.76 nd 10.24 31.13 0.95 25.72 7.77 nd nd nd nd nd nd 1.07 ndPCB 101 3.32 4.21 nd 0.17 0.31 nd nd 0.30 nd nd 0.12 nd nd 0.47 nd nd nd ndPCB 153 0.67 nd nd 0.20 nd nd nd nd nd nd nd nd nd nd nd nd nd ndPCB 138 6.06 1.59 nd 0.18 nd nd nd 0.16 nd 0.11 nd nd nd nd nd nd 0.14 ndPCB 180 4.77 0.65 nd nd 0.28 nd nd 0.18 nd 0.08 nd nd nd nd nd nd nd nd

Sum PCBs 16.49 6.79 3.43 56.40 0.59 10.32 31.38 1.58 31.51 8.01 0.15 0.06 0.13 0.53 0.07 0.29 1.46 0.04O-Cresol nd nd 21.27 28.58 69.05 nd 10.49 3.12 9.44 2.42 23.78 nd 11.65 nd nd 14.54 13.81 ndp-Cresol nd 6.19 nd 2.38 nd nd nd 5.02 nd nd nd nd nd nd nd nd nd 4.322,4-Dim 2.23 75.64 42.17 15.92 5.44 9.10 62.73 nd 5.51 6.57 12.89 15.09 82.97 nd 4.04 22.86 5.44 12.182,6-Dichl 7.06 4.15 nd 133.66 72.41 9.77 nd 10.35 12.18 nd nd 30.37 nd 12.23 4.86 5.99 5.14 4.212,3,5-Trichl 35.89 11.71 11.02 330.88 878.90 25.14 1436.51 5.57 49.01 67.13 91.81 nd 37.52 23.32 10.00 5.52 117.26 16.532,4,5-Trichl 65.60 16.00 22.93 nd 12.74 5.92 28.66 37.30 nd nd 15.75 27.41 32.64 324.10 8.30 38.60 58.23 nd2,3,4-Trichl 46.49 35.05 nd 6.36 26.28 nd 80.42 nd nd 192.41 nd 66.12 nd nd nd nd 10.73 nd2,3,5,6-Tetrachl 132.52 54.62 155.66 127.51 69.48 128.21 81.02 80.93 18.27 26.43 244.71 121.60 302.10 697.60 24.89 89.32 80.19 133.532,3,4,6-Tetrachl 396.10 8.14 nd 9.61 42.19 nd 28.16 25.53 24.12 4.24 nd 84.19 nd nd 15.34 8.29 34.97 164.774,6-Ditro 399.06 199.18 178.16 24.82 nd 36.85 nd 181.00 nd nd nd 28.30 85.83 1052.39 nd 36.60 332.90 53.73Sum Phenols 1084.95 410.68 431.20 679.80 1176.48 214.99 1728.03 348.81 118.53 299.27 388.94 373.10 552.71 2109.65 67.44 221.71 658.68 389.27

1212F

.A

lN

asir,

M.I.

Ba

tarseh

/Ch

emo

sphere

72

(2

00

8)

12

03

–1

21

4

F. Al Nasir, M.I. Batarseh / Chemosphere 72 (2008) 1203–1214 1213

paprika. The distribution of phenols in plant leaves wasdependent on plant type. Comparing the concentrationlevel of phenols, PAHs and chlorinated compounds forplant leaves, it is clear that high amount of phenol com-pounds were found for different plant leaves which maybe attributable to the higher solubility of phenols ratherthan PAHs and PCBs in aquatic environment. Therefore,it is much easier for the plant to uptake phenols from soilthan other organic compounds.

3.6. Fruits

The concentration of PAHs, PCBs, PCBz, HCBz andphenols for fruit samples collected for six different plantsgrown during the study are shown in Table 3. The highestconcentration of total PAHs was found in corn(202 lg kg�1) and the lowest in paprika (31 lg kg�1)Fig. 3g. Most analyzed samples showed similar individualPAHs distribution pattern. Pyrene was the most abundantfollowed by fluoranthene and phenanthrene. The PAHsprofile characterized by high molecular weight wasuniquely detected in fruit samples, however low molecularweight PAHs were more abundant due to their higher sol-ubility. The concentration of PCBs ranged from0.04 lg kg�1 to 32 lg kg�1 with the highest concentrationfound for paprika and the lowest concentration for tomato,Fig. 3h PCB 52 was the predominant congener among theother PCBs congeners in paprika, corn and sunflower,however it was not detected in the other plants. No corre-lation was obtained between PAHs and PCBs in fruitsamples.

The concentration of phenols for plant fruits was variedbetween 67 lg kg�1 and 431 lg kg�1. Sunflower showedthe maximum concentration and eggplant the minimumconcentration. The most abundant phenol compoundsfor fruits are 2,3,5,6-tetrachlorophenol and 2,4-dimethyl-phenol. Comparing the uptake amounts among differentplant parts: fruits showed the lowest uptake quantitiesamong all targeted compounds. Furthermore, the uptakeprofiles were different among all plant types. The applica-tion of plants rich in peroxides were recommended fortreatment of water and soil for bioremediation of phenols(Alder et al., 1994).

Finally, the findings of this study agree with that ofother previous studies, as soil plays an important role inthe global fate of organic pollutants. However, plants playan important role in the global cycling, translocation andfood chain transfer of organic pollutants (Harrad et al.,1994; Chiou et al., 2001; Zhao et al., 2006). In general,the concentration of organic pollutants in the differentplants does not reflect the contamination in the related soil.For example, on one hand the concentration of PAHs insoil related to okra plant was the highest (673 lg kg�1),whereas their concentration in the roots was the lowest(106 lg kg�1). On the other hand, the PAHs concentrationin paprika roots was the highest (295 lg kg�1), although itsrelated soil contained lower concentration (190 lg kg�1),

compared to other plants. The same phenomena wasobserved also for the PCBs, where the highest concentra-tion was for okra related soil (74 lg kg�1) and the lowestfor corn (0.04 lg kg�1). However the highest concentrationof PCBs in roots was found for the corn roots (56 lg kg�1).This result can be explained as plants have different uptakeand translocation behaviors (Zhao et al., 2006). As a con-sequence, there are difficulties to evaluate the uptake andtranslocation of PAHs from soil-roots-plant system (Polderet al., 1995; Gao and Zhu, 2004).

4. Conclusion and recommendations

It can be concluded that the residues of PAHs, PCBsand phenols for soil, wastewater, groundwater and theiruptake by various plant types: Z. mays L., H. annus L.,C. annum L., A. esculentus L., S. melongena L. and L. escu-

lentum L., were investigated successfully in a pilot studyestablished at Mutah University wastewater treatmentplant, Jordan. The contamination with various types oforganic compounds found for wastewater was much higherthan for groundwater samples. Furthermore, the distribu-tion profile of PAHs and PCBs for groundwater and waste-water were similar indicating common potential sources ofpollution.

The concentration levels of all targeted compoundsfound for soil irrigated with wastewater were much higherthan for the reference site indicating a source of contamina-tion due to irrigation with wastewater. The different planttypes showed different uptake concentrations of variousorganic compounds. Roots were found to be the most con-taminated plant part however, fruits are the leastcontaminated.

Generally, organic pollutants might be transferred ortranslocated from the soil irrigated with wastewater andconsequently enter different plant parts. The uptake ratiosare dependent on plant type and the physio-chemical prop-erties of organic compounds. Obviously, this study shouldbe repeated again for a wide spectrum of organic pollutantson a larger scale and extended for a longer period using dif-ferent types of reclaimed water at different locations in Jor-dan. It can be recommended that a national monitoringprogram that can be designed for these types of organiccompounds for soils and crops irrigated frequently withreclaimed water should be initiated. Finally, this studyshowed that reclaimed water is prefer to be used forrestricted agricultural practices.

Acknowledgments

This work was financed by the Higher Council for Sci-ence and Technology HCST, Amman-Jordan. Theresearchers are extending their thanks for anybody whohelped, encouraged or participated in a direct or an indirectway to finish the study.

1214 F. Al Nasir, M.I. Batarseh / Chemosphere 72 (2008) 1203–1214

References

Alder, P.R., Arora, R., Ei Ghaouth, A., Glenn, D.M., Solar, J.M., 1994.Bioremediation of phenolic compounds from water with plant rootsurface peroxidases. J. Environ. Qual. 23, 1113–1117.

Bacci, E., Gaggi, C., 1985. Polychlorinated biphenyls in plants foliage:translocation or volatilization from contaminated soils. Environ. Cont.Toxicol. 35, 673–681.

Batarseh, M., Kreuzig, R., Bahadir, M., 2003a. Residue analysis oforganic pollutants in sediments from the Amman/Zarqa area inJordan, part I: development of analytical method and distributionPattern of PAH. Fresen. Environ. Bull. 12, 972–978.

Batarseh, M., Kreuzig, R., Al-Nasir, F., Bahadir, M., 2003b. Residueanalysis of organic pollutants in sediments from the Amman/Zarqaarea in Jordan, part II: organochlorine compounds. Fresen. Environ.Bull. 12 (9), 979–983.

Bohme, F., Welsch-Pausch, K., Mclacchlan, M., 1999. Uptake of airbornesemivolatile organic compounds in agricultural plants: field measure-ment of interspecies variability. Environ. Sci. Technol. 33, 1805–1813.

Bright, D.A., Healey, N., 2003. Contaminant risks from biosolids landapplication: contemporary organic contaminant levels in digestedsewage sludge from five treatment plants in Greater Vancouver, BritishColumbia. Environ. Pollut. 126, 39–49.

Chiou, C.T., Sheng, G., Manes, M.A., 2001. Partition-limited model forthe plant uptake of organic contaminants from soil and water.Environ. Sci. Technol. 35, 1437–1444.

De Araujo, B., Charlwood, B., Pletsch, M., 2002. Tolerance andmetabolism of phenol and chloroderivatives by hairy root cultures ofDaucus carota L. Environ. Pollut. 117, 329–335.

Fismes, J., Perrin-Ganier, C., Empereur-Bissonnet, P., Morel, J.L., 2002.Soil-to-root transfer and translocation of polycyclic aromatic hydro-carbons by vegetables grown on industrial contaminated soils. J.Environ. Qual. 31, 1649–1656.

Folke, J., Lund, U., 1983. Occurrence of low- and high-chlorinatedphenols in municipal sewage before and after passing throughbiological treatment plants. J. Chrom. 279, 189–198.

Franzaring, J., van der Eerden, L., 2000. Accumulation of airbornepersistent organic pollutants (POPs) in plants. Basic Appl. Ecol. 1, 25–30.

Gao, Y., Zhu, L., 2004. Plant uptake, accumulation and translocation ofphenanthrene and pyrene in soils. Chemosphere 55, 1169–1178.

Hamscher, G., Sczesny, S., Hoper, H., Nau, H., 2002. Determination ofpersistent tetracycline residues in soil fertilized with liquid manure byHPLC with electrospray ionization Tandam mass spectrometry. Anal.Chem. 74, 1509–1518.

Harrad, S.J., Sewart, A.P., Alcock, R., Boumphrey, R., Burnett, V.,Duarte-Davidson, R., 1994. Polychlorinated biphenyls (PCBs) in theBritish environment: sinks sources and temporal trends. Environ.Pollut. 85, 131–146.

Hussein, H., Alali, A., Jiries, A., Aharonian, Gh., 2000. Chemicalevaluation of wastes produced from a Jordanian University, a casestudy. Waste Manag. Res. 18, 94–98.

Jiries, A., Rimawi, O., Lintelmann, J., Batarseh, M., 2005. Polycyclicaromatic hydrocarbons (PAH) in topsoil, leachate and groundwaterfrom Ruseifa solid waste landfill, Jordan. Int. J. Environ. Pollut. 23,179–188.

Jiries, A., Hussan, H., Lintelmann, J., 2000. Determination of polycyclicaromatic hydrocarbons in wastewater, sediments, sludge and plants inKarak Province, Jordan. Water Air Soil Pollut. 121, 217–228.

Jiries, A., 2001. Chemical evaluation of treated sewage effluents in Karakprovinces and its suitability for irrigation purpose. Pakistan J. Biol.Sci. 4, 1400–1402.

Kipopoulou, A.M., Manoli, E., Samara, C., 1999. Bioconcentration ofpolycyclic aromatic hydrocarbons in vegetables grown in an industrialarea. Environ. Pollut. 106, 369–380.

Manoli, E., Samara, C., 1999. Occurrence and mass balance of polycyclicaromatic hydrocarbons in the Thessaloniki sewage treatment plant. J.Environ. Qual. 28, 176–187.

MWI, 2004. Ministry of Water and Irrigation, Annual Report 2004,Amman, Jordan.

Ng, K.C., Poi, G., Pauh, C.M., Castro, V.De., Rogers, P.L., 1997.Monitoring of phenols in wastewater by HPLC. Environ. Monit.Assess. 44, 433–436.

Paxeus, N., 1996. Organic pollutants in the effluents of large wastewatertreatment plants in Sweden. Water Res. 30, 1115–1122.

Polder, M.D., Hulzebos, E.M., Jager, D.T., 1995. Validation of models onuptake of organic chemicals by plant roots. Environ. Toxicol. Chem.14, 1615–1623.

Shahalam, A., Zahra, B.M.A., Jaradat, A., 1998. Wastewater irrigationeffect soil, crop and environment: a pilot scale study at IRBID, Jordan.Water Air Soil Pollut. 106, 425–445.

Simonich, S.L., Hites, R.A., 1994a. Importance of vegetation in removingpolycyclic aromatic hydrocarbons from the atmosphere. Nature 370,49–51.

Tao, S., Cui, Y.H., Xu, F.L., Li, B.G., Cao, J., Liu, W.X., Schmitt, G.,Wang, X.J., Shen, W.R., Qing, B.P., Sun, R., 2004. Polycyclicaromatic hydrocarbons (PAHs) in agricultural soil and vegetablesfrom Tianjin. Sci. Total Environ. 320, 11–24.

Thiele-Bruhn, S., 2003. Pharmaceutical antibiotic compounds in soil: areview. J. Plant Nutr. Soil Sci. 166, 145–167.

Tor, A., Cengeloglu, Y., Aydin, M.E., Ersoz, M., Wichmann, H., Bahadir,M., 2003. Polychlorinated biphenyls (PCB) and polycyclic aromatichydrocarbons (PAH) in wastewater samples from the sewage sludgesystem of Konya-Turkey. Fresen. Environ. Bull. 12, 732–735.

Voutsa, D., Samara, C., 1998. Dietary intake of trace elements andpolycyclic aromatic hydrocarbons via vegetables grown in an indus-trial Greek area. Sci. Total Environ. 218, 203–216.

Wagrowski, D.M., Hites, R.A., 1997. Polycyclic aromatic hydrocarbonsaccumulation in urban, suburban, and rural vegetation. Environ. Sci.Technol. 31, 279–282.

Wild, S.R., Jones, K.C., 1992. Organic chemicals entering agriculturalsoils in sewage sludges: screening for their potential to transfer to cropplants and livestock. Sci. Total Environ. 119, 85–119.

Zhao, X., Zheng, M., Zhang, B., Zhang, Q., Liu, W., 2006. Evidence forthe transfer of polychorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans from soil into biota. Sci.Total Environ. 368, 744–752.

Zohair, A., Salim, A.B., Soyibo, A.A., Beck, A.J., 2006. Residues ofpolycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls(PCBs) and organochlorine pesticides in organically-farmed vegeta-bles. Chemosphere 63, 541–553.