This article was downloaded by: [UQ Library]On: 09 November 2014, At: 01:32Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registeredoffice: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK

Soil and Sediment Contamination: AnInternational JournalPublication details, including instructions for authors andsubscription information:http://www.tandfonline.com/loi/bssc20

Effects of Crude and BioremediatedThermal Power Plant Effluents inBrassica JunceaShailu Dalal a & Ramesh Chand Dubey aa Gurukula Kangri University, Department of Botany andMicrobiology , Haridwar, IndiaPublished online: 29 Apr 2011.

To cite this article: Shailu Dalal & Ramesh Chand Dubey (2011) Effects of Crude and BioremediatedThermal Power Plant Effluents in Brassica Juncea , Soil and Sediment Contamination: An InternationalJournal, 20:3, 329-336, DOI: 10.1080/15320383.2011.561085

To link to this article: http://dx.doi.org/10.1080/15320383.2011.561085

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the“Content”) contained in the publications on our platform. However, Taylor & Francis,our agents, and our licensors make no representations or warranties whatsoever as tothe accuracy, completeness, or suitability for any purpose of the Content. Any opinionsand views expressed in this publication are the opinions and views of the authors,and are not the views of or endorsed by Taylor & Francis. The accuracy of the Contentshould not be relied upon and should be independently verified with primary sourcesof information. Taylor and Francis shall not be liable for any losses, actions, claims,proceedings, demands, costs, expenses, damages, and other liabilities whatsoever orhowsoever caused arising directly or indirectly in connection with, in relation to or arisingout of the use of the Content.

This article may be used for research, teaching, and private study purposes. Anysubstantial or systematic reproduction, redistribution, reselling, loan, sub-licensing,systematic supply, or distribution in any form to anyone is expressly forbidden. Terms &Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions

Soil and Sediment Contamination, 20:329–336, 2011Copyright © Taylor & Francis Group, LLCISSN: 1532-0383 print / 1549-7887 onlineDOI: 10.1080/15320383.2011.561085

Effects of Crude and Bioremediated Thermal PowerPlant Effluents in Brassica Juncea

SHAILU DALAL AND RAMESH CHAND DUBEY

Gurukula Kangri University, Department of Botany and Microbiology,Haridwar, India

Crude phenol and cyanides are the major components of the effluents discharged byindustries involved in the manufacture of many synthetic inorganic and organic com-pounds, pharmaceuticals, electroplating units, and thermal power plants.

In this study, an effort was made to use effluents as manure. The effect of variousamendments (10, 40, 70, and 100%) of bioremediated and crude effluents was checkedon plants of Brassica juncea. Roots, shoot lengths, and the mean dry weights weremaximum in the plants irrigated with 10% treated and 10% crude effluent as comparedto the control plants. Total plant phenolics increased with an increase in the amendmentof the effluents in the plants irrigated with bioremediated as well as crude effluents.Applications of lower amendments of treated and untreated effluents in Brassica junceaimproved the chlorophyll levels in the experimental plants and the values obtained weresimilar to the control plants. Effect of bioremediated and crude effluents on antioxidantenzymes of Brassica juncea showed a differential effect. The activity of antioxidantenzymes peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) wasobserved to increase with an increase in the effluent concentration.

Here we demonstrate that the industrial effluents, when bioremediated of theirharmful components, can also serve as a nourishment for plants, which can further helpin the rehabilitation of wastelands.

Keywords Brassica juncea, plant phenolics, chlorophyll, CAT, POD, SOD

1. Introduction

Sources of persistent organic pollutants in the environment are agriculture wastes suchas polychlorinated byphenyls (PCB), polyaromatic hydrocarbons (PHB), and manyorganochlorine pesticides (Neamtu et al., 2009). Apart from these, organic pollutants comefrom various pharmaceutical, pesticide, and heavy electrical industries that discharge wastesrich in xenobiotic compounds like phenols and lethal compounds like cyanides into waterbodies, posing a threat to the aquatic life.

Due to their physical and chemical properties, such hazardous chemicals present inthese effluents not only pollute the water but they also make the land unfit for cultivation byinhibiting plant growth and yield (Sopper, 1993; Fuentes et al., 2004; Huang et al., 1974).

Bioremediation has gained momentum because of the difficulty in disposal methodssuch as direct discharge, land filling, and incineration (Ahlberg et al., 2006). Studies have

Address correspondence to Shailu Dalal, Block no 11/1, Ramni Nagar, Baridih, Jamshedpur-831017, Bihar, India. E-mail: shailydalal@gmail.com

329

Dow

nloa

ded

by [

UQ

Lib

rary

] at

01:

32 0

9 N

ovem

ber

2014

330 S. Dalal and R. Dubey

indicated that not only the microorganisms but also plants have the ability to degradexenobiotic compounds. They have a built-in enzyme system to degrade these harmfulcompounds (Araujo et al., 2006). Among various plants used in phytoremediation processes,the plants of Brassica sp. have been reported as potential highly effective phytoremediators(Singh et al., 2006).

Here we evaluate the effect of crude and bioremediated industrial effluents on thegrowth and biochemical characteristics of Brassica juncea (Indian mustard), a phytoreme-diator.

2. Materials and Methods

2.1 Plant Cultivation

Seeds of Brassica juncea var. hathi patta were obtained from the local seed seller. Theseseeds were surface sterilized using HgCl2 and alcohol (Vincent, 1970) and transferred toautoclaved water agar medium (1%) for germination. Four-day-old seedlings were trans-ferred to earthen pots filled with non-contaminated greenhouse soil, shifted to a greenhouse,and maintained at 25 ± 3◦C. The experiment was divided into two sets. The amendmentsof crude and bioremediated effluents with autoclaved distilled water were carried out atvarious concentrations such as 10, 40, 70, and 100%. The first set of pots was watered withbioremediated effluent while the second set was watered with crude effluent. A control setwas kept and watered with autoclaved distilled water. All the experiments were conductedin triplicate.

For treatment of industrial effluent, the method of Tisnadjaja et al. (1996) was modified.Sterile sawdust was used as a carrier for immobilization of log phase culture of Corynebac-terium sp.DST1. This bacterium was isolated from the wastewater of Ranbaxy, India Pvt.Ltd. The cured sawdust- Corynebacterium sp.DST1 mixture was packed in glass columnsof length 100 cm. Crude industrial effluent was allowed to pass through this column at aflow rate of 2 ml/min. The outpour was monitored for reduced concentrations of phenoland cyanides (unpublished data). It was observed that the initial concentration of phenol incrude industrial effluent was 174.7 mgl−1, whereas after treatment it reduced by approx-imately 93.5% and the obtained value was 11 mgl−1. Similarly, cyanide was removed by85.3% and the value came down to1.8 mgl−1 from 12 mgl−1. Ammonical nitrogen, whichwas as high as 47.5 mgl−1 in crude effluent, came down to 10.19 mgl−1. The pH of the crudeeffluent was highly alkaline and was measured to be 8.4 whereas the pH of bioremediatedeffluent obtained was 7.0, which is considered to be a neutral value.

2.2 Plants Morphological Parameters and Biochemical Analysis

The plants were harvested on the sixtieth day of sowing. These plants were then thoroughlywashed to remove the attached particles of soil. Physical parameters like length of the rootand shoot were taken immediately after harvesting the plants. For dry weight the plantswere dried in the oven at a temperature of 72◦C for 72 hours.

2.3 Measurement of Total Plant Phenolics

Extraction of plant phenol for the estimation of total plant phenolics was done by the methodof Li et al. (2008). The plant samples were ground to fine powder using mortar-pestle andliquid nitrogen. A quantity of 0.02 g of powdered sample was extracted with 400 µl of

Dow

nloa

ded

by [

UQ

Lib

rary

] at

01:

32 0

9 N

ovem

ber

2014

Crude and Bioremediated Effluents 331

100% methanol. The mixture was kept at 40◦C for 24 h. The samples were centrifuged at4500 rpm for 15 minutes at room temperature. The supernatant was collected in a freshtube and was used in the analysis of total plant phenolics. The total plant phenolic wasestimated by the Folin-Ciocalteu method (Singleton and Rossi, 1965).

2.4 Chlorophyll Estimation

The estimation of chlorophyll content was done by the method of Arnon (1949).

2.5 Antioxidant Enzyme Assay

Leaf samples (0.3 g) of Brassica juncea were frozen in liquid nitrogen and ground intofine powder with the help of chilled mortar and pestle. The powder of each sample washomogenized with 3 ml of extraction buffer containing 1mM of EDTA in 100 mM ofpotassium phosphate buffer. The slurry was then transferred into microcentrifuge tubes andcentrifuged at 14,000x g at 4◦C for 20 minutes. The supernatant was collected in freshcentrifuge tubes and the pellet was discarded. A part of the supernatant was used for totalprotein estimation and another part was used for studying the enzyme assays.

Protein estimation. The estimation of protein content was done following the method ofLowry et al. (1951) taking Bovine Serum Albumin as standard.

Measurement of enzyme activityPeroxidase (POD) activity. The peroxidase activity was measured spectrophotometrically(Park, 2006) by measuring the amount of production of purpurogallin from oxidation ofpyrogallol by H2O2. The reaction mixture (3 ml) consisted of 2440 µl of phosphate buffer,160 µl of H2O2 (0.5% w/v), 300 µl of pyrogallol (5% w/v), and 100 µl of enzyme extract.The purpurogallin production was measured at an absorbance of 420 nm for 5 minutes. Oneunit of enzyme was defined as the amount of enzyme required to catalyze the productionof 1mg purpurogallin/1 min.

Catalase (CAT) activity. Catalase activity was measured following the method of Beersand Sizer (1951). The 3 ml reaction mixture contained 1 ml of 5×10−3 M solution ofH2O2, 1.9 ml of 0.05 M of phosphate buffer (pH 7.0), and 100 µl of enzyme extract. Themixture was incubated at room temperature for 3 minutes and the disappearance of H2O2

was observed by observing the decrease in absorbance at 240 nm for 5 minutes. One unitof enzyme activity was defined as that which catalyzed the disappearance of 1 µM of H2O2

in one min.

Superoxide dismutase (SOD) activity. SOD activity was measured following the modifiedmethod of Marklund and Marklund (1974). The reaction mixture consisted of 2750 µl ofpotassium phosphate buffer (0.5 M, pH 8.0), 150 µl pyrogallol of 0.2 mM, and 100 µlof enzyme extract. The activity of superoxide dismutase was measured at 420 nm. Oneunit of enzyme activity was defined as the amount of enzyme required to inhibit 50% ofpyrogallol autooxidation.

Dow

nloa

ded

by [

UQ

Lib

rary

] at

01:

32 0

9 N

ovem

ber

2014

332 S. Dalal and R. Dubey

Results and Discussion

3.1 Plant Cultivation

3.2 Plant Morphological Analysis

The average root length (Table 1) was observed to increase significantly by 17.14, 9.985, and9.17%, respectively, in the plants watered with 10, 40, and 70% but decreased by 21.52% at100% concentrations of bioremediated effluent. In case of application of crude effluent, theaverage root lengths of the plants increased by 14.4 and 7.21 at 10 and 40% concentrationlevel but decreased by 21.35 and 58.9% at 70 and 100% level of effluent as comparedto the control plants. Average shoot lengths (Table 1) of plants irrigated with 10, 40, and70% of bioremediated effluents showed a significant increase as compared to the controlplants, but was much affected in the plants irrigated with higher effluent concentration.Similarly, the shoot lengths of the plants irrigated with crude effluent concentration wasnot much affected up to a concentration of 70%, but a significant decrease was noted in theplants growing at 100% concentration of crude effluent. A significant increase in mean dryweights (Table 1) of the plants irrigated up to 40% bioremediated effluent and 10% crudeeffluent was observed. Least biomass was recorded in the plants treated with 100% crudeeffluent, which was 79.85% less than the control. However, the plants growing at 10%bioremediated effluents had maximum, whereas those growing at 100% crude effluents hadminimum average root, shoot lengths, and dry weights, respectively.

The effluent used in this study was the waste of a thermal power plant used to generateelectricity for the manufacture of heavy electrical goods such as large stem and gas turbines,turbo generators, hydro turbines, and generators. This effluent is rich in organic compoundssuch as ammonical nitrogen, phenol, and cyanide. Nitrogen is an important requirement forthe growth and functioning of the plants. Apart from this, phenolics are strong antioxidantsfound in plants. Cyanides, up to a certain concentration, have been reported to be growth

Table 1Effect of bioremediated and crude effluents on growth and total phenolic content of Brassica

juncea plants

Total Root Shoot DryPhenol Length Length Weight

Condition (mg/g) (cm) (cm) (g)

Control 10.02 ± 0.742 6.04 ± 0.872 10.24 ± 0.778 0.13 ± 0.074Bioremediated 10% 10.17 ± 0.685∗∗ 7.29 ± 0.433∗ 13.56 ± 0.763∗ 0.20 ± 0.047∗∗

effluent 40% 12.07 ± 0.771∗∗ 6.71 ± 0.781† 11.64 ± 1.448† 0.14 ± 0.093∗∗

70% 13.80 ± 0.841∗∗ 6.65 ± 0.924† 11.04 ± 1.397† 0.11 ± 0.014∗∗

100% 16.26 ± 0.915∗∗ 4.74 ± 0.621∗ 8 ± 1.945† 0.08 ± 0.018∗∗

Crude effluent 10% 10.57 ± 0.223∗∗ 7.06 ± 0.513† 11.71 ± 1.452† 0.18 ± 0.011∗∗

40% 12.81 ± 0.365∗∗ 6.51 ± 0.741† 10.92 ± 1.321† 0.06 ± 0.016∗∗

70% 15.33 ± 0.426∗∗ 4.75 ± 0.778∗ 9.66 ± 2.175† 0.06 ± 0.017∗∗

100% 16.91 ± 0.472∗∗ 2.48 ± 0.703∗∗ 6.34 ± 1.519∗ 0.02 ± 0.014∗∗

Values are means (n = 3) ± s.e. (∗)Significantly different from the control, ANOVA p < 0.05.(∗∗)Significantly different from the control, ANOVA p < 0.01. (†)Not Significant.

Dow

nloa

ded

by [

UQ

Lib

rary

] at

01:

32 0

9 N

ovem

ber

2014

Crude and Bioremediated Effluents 333

enhancers for the plants (Yu et al., 2006). Increase in the root-shoot lengths at lower dosesof bioremediated effluent may be associated with the high content of organic nutrients,which may have increased the production of growth hormones in the effluent (Chandraet al., 2008). At higher doses the non-degraded residual phenols and cyanides presentin the bioremediated effluent may have stunted the root-shoot lengths. Conversely, inuntreated effluents at 10% concentration the toxicants are diluted below the lethal level butthe organic matter is enough to act as a growth promoter, while at higher concentrationsthe toxic components of the effluent have started acting as a stress factor due to thechemical overload inhibiting the growth of the plants (Mishra and Behera, 1991). Thisthreshold comes at 100% concentration in plants of bioremediated effluent, while at 40%concentration in case of plants crude effluents.

3.3 Total Plant Phenolics

All the experimental sets of plants show a significant increase in the amount of total plantphenolics; the highest value (16.91 mg g−1) was noted at plants growing with 100% crudeeffluents (Table 1). Plants irrigated with higher concentrations of bioremediated effluentsalso showed a significant increase in the total phenolic content because at lower dilutionsthe concentration of the non-degraded contaminants was more, which are factors of stressfor the plants.

Phenolics are present in plants in many forms and are believed to carry out variousfunctions in them. Under environmental stress, an enhancement in the phenylopropanoidmetabolism and the amount of phenolic compounds has been observed to occur (Diaz et al.,2001; Sakihama and Yamasaki, 2002; Grace and Logan, 2000; Lavola et al., 2002).

3.4 Chlorophyll Concentration

Total chlorophyll content of leaves of all the Brassica plants varied with treatment ofdifferent concentrations of effluent (Table 2). At 10% concentration of bioremediated andcrude effluents, chlorophyll a and the total chlorophyll content are statistically equivalentto that of control set. At 40, 70, and 100% of crude effluent concentrations the chlorophyllcontents followed a significant decrease of 33.4, 41.5, and 42.4%, whereas in the caseof the same concentrations of bioremediated effluent the chlorophyll contents were 12.1,38.2, and 40.6% less than the control. Total chlorophyll content was most affected in plantsgrowing with 100% crude effluent.

Cyanides present in the effluent at lower concentration act as enhancer of the plantphotosynthetic pigments and soluble proteins. Thus in lower doses there is a rise in the plantchlorophyll content with respect to the control plants. The result has come in accordancewith the earlier reports (Yu et al., 2007).

3.5 Antioxidant Enzyme Activity

The activities of the antioxidant enzymes POD, CAT and SOD were also observed in leavesof Brassica juncea plants (Table 3). Plants treated with bioremediated effluents showed anapparent increase in the POD activity; conversely the plants treated with crude effluentsshow an observable inhibition of POD at higher concentrations. It was maximum in theplants irrigated with 100% bioremediated effluent with an increase of 40.9% over thecontrol set.

Dow

nloa

ded

by [

UQ

Lib

rary

] at

01:

32 0

9 N

ovem

ber

2014

334 S. Dalal and R. Dubey

Table 2Effect of various concentrations of crude and bioremediated effluents on total chlorophyll

content of Brassica juncea plants

TotalChlorophyll Chlorophyll a Chlorophyll b

Condition (mg/g leaf) (mg/g leaf) (mg/g leaf)

Control 3.32 ± 0.002 2.66 ± 0.022 0.65 ± 0.001Bioremediated 10% 3.22 ± 0.002† 2.96 ± 0.002† 0.26 ± 0.002∗∗

effluent 40% 2.83 ± 0.001∗∗ 2.60 ± 0.001∗ 0.23 ± 0.002∗∗

70% 2.33 ± 0.002∗∗ 1.88 ± 0.002∗ 0.16 ± 0.001∗∗

100% 1.97 ± 0.0006∗∗ 1.81 ± 0.0006∗ 0.16 ± 0.003∗∗

Crude effluent 10% 3.23 ± 0.007† 2.84 ± 0.007† 0.39 ± 0.002∗∗

40% 2.21 ± 0.001∗ 1.77 ± 0.001∗ 0.43 ± 0.0007∗∗

70% 1.94 ± 0.016∗∗ 1.49 ± 0.016∗∗ 0.45 ± 0.014∗∗

100% 1.91 ± 0.007∗∗ 1.41 ± 0.007∗∗ 0.49 ± 0.049∗∗

Values are means (n = 3) ± s.e. (∗)Significantly different from the control, ANOVA p < 0.05.(∗∗)Significantly different from the control, ANOVA p < 0.01. (†)Not Significant.

It appears that the POD activity is dependent on concentration of pollutants; thus plantsproduce peroxidases to combat oxygen radicals. Rise in toxic components of effluents haveaffected the POD level more than SOD and CAT. Yu et al. (2006) have suggested thesusceptibility of POD more than SOD and CAT. They have also suggested the role of PODas a catalyst that speeds up protoplasm carbonization, which stimulates plant growth. Inthis study the decline in POD in untreated effluents may be one of the reasons for reductionin the plant growth.

The CAT activity in leaves of Brassica plants differed with effluent doses. The CATactivity was maximum in plants growing with 10% crude and bioremediated effluent

Table 3Effects of various concentrations of bioremediated and crude effluents on various enzyme

activity of Brassica juncea plants

POD CAT SODCondition (EU g−1fr.wt) (EU g−1fr.wt) (EU g−1fr.wt)

Control 2701.65 ± 11.627 1.51 ± 0.011 503.02 ± 16.987Bioremediated 10% 2895 ± 50.253∗ 1.83 ± 0.068∗ 674.34 ± 5.152∗∗

effluent 40% 3515.25 ± 28.025∗∗ 1.53 ± 0.021† 688.01 ± 17.894∗∗

70% 3740.41 ± 52.754∗∗ 1.12 ± 0.014∗∗ 813.18 ± 7.199∗∗

100% 4578.15 ± 59.111∗∗ 1.06 ± 0.005∗∗ 1007.56 ± 21.087∗∗

Crude effluent 10% 4527.61 ± 47.819∗∗ 2.03 ± 0.024∗∗ 633.06 ± 3.712∗∗

40% 3441.60 ± 170.366∗∗ 1.82 ± 0.048∗∗ 1216.08 ± 24.901∗∗

70% 3291.45 ± 56.357∗∗ 1.81 ± 0.057∗ 1602.35 ± 15.145∗∗

100% 2891.55 ± 59.238∗ 1.80 ± 0.051∗ 1113.02 ± 1.721∗∗

Values are means (n = 3) ± s.e. (∗)Significantly different from the control, ANOVA p < 0.05.(∗∗)Significantly different from the control, ANOVA p < 0.01. (†)Not Significant versus control.

Dow

nloa

ded

by [

UQ

Lib

rary

] at

01:

32 0

9 N

ovem

ber

2014

Crude and Bioremediated Effluents 335

showing 25.4 and 17.9% increase versus the control set. It was observed to decreasesignificantly with an increase in the concentration of bioremediated as well as crude effluent.

This implies that phenols and cyanides may increase the presence of CAT in leaf cells.The reduction in CAT activity in Brassica juncea may be due to the utilization of H2O2 byperoxidase enzyme. This comes in accordance with earlier reports (Gonzalez et al., 2006).

SOD activity followed an increasing trend in all sets of experimental plants. Maxi-mum activity was shown by the plants irrigated with 100% bioremediated effluent with asignificant increase of 50% over the control set. In the crude set of plants the SOD showsmaximum activity at 70% level where it is 68.6% more than the control.

A similar increase in the SOD activity has earlier been observed in the plants of Brassicajuncea growing under a variety of heavy metals (Cakmak and Horst, 1991; Prasad et al.,1999; Qadir et al., 2004). Increase in amount of SOD could be due to de novo synthesis ofenzymatic protein (Allen et al., 1997; Slooten et al., 1995). The increased activities of SODin the plants suggest that the cultivars of Brassica have the potentiality to resist effluenttoxicity.

Conclusion

The study indicates that rehabilitation of waste lands may be done by irrigating themwith bioremediated effluents. Such biologically treated effluents may be of prime im-portance because of their high organic content and reduced chemical overload. It alsorevealed that plants of Brassica juncea, a potentially known phytoremediator, grew wellwith 100% bioremediated effluent and accumulated a considerable amount of phenol. Ourstudy therefore presents a model of combined application of microbial remediation as wellas phytoremediation for effective removal of toxicants from the industrial wastewater.

Acknowledgements

The authors wish to acknowledge the Department of Science & Technology, Govt. of India,for providing financial help to carry out this work and Prof. G.S. Randhawa, the then HODof Dept. Biotechnology, IIT Roorkee, for providing a laboratory facility.

References

Ahlberg, G., Gustafsson, O., and Wedel, P. 2006. Leaching of metals from sewage sludge during oneyear and their relation to particle size. Environ. Pollut. 144, 545–553.

Allen, R. P., Webb, R. P., and Schake, S.A. 1997. Use of transgenic plants to study antioxidantdefenses. Free Radic. Biol. Med. 23, 472–479.

Araujo, B. S. D., Dec, J., Bollag, J. M., and Pletsch, M. 2006. Uptake and transformation of phenolsand chlorophenols by hairy root cultures of Daucus carota, Ipomoea batatus and Solanumaviculare. Chemosphere. 63, 642–651.

Arnon, D. I. 1949. Copper enzymes in isolated chloroplasts. Polyphenol oxidase in Beta vulgaris.Plant Physiol. 24, 1–15.

Beers, R. F. Jr., and Sizer, I. W. 1951. A spectrophotometric method for measuring the breakdown ofhydrogen peroxide by catalase. J. Biol .Chem. 95, 133–140.

Cakmak, I., and Horst, W. J. 1991. Effect of alumunium on lipid peroxidation, SOD, CAT, POXactivities in root tips of Glycine max. Physiol. Plant. 83, 463–468.

Chandra, R., Yadav, S., and Mohan, D. 2008. J. Hazard. Mater. 152, 431–439.Diaz. J., Bernal, A., Pomar, F., and Merino, F. 2001. Induction of shikimate dehydrogenase and

peroxidase in pepper (Capsicum annum L.) seedlings in response to copper stress and its relationto lignification. Plant. Sci. 161, 179–183.

Dow

nloa

ded

by [

UQ

Lib

rary

] at

01:

32 0

9 N

ovem

ber

2014

336 S. Dalal and R. Dubey

Fuentes, A., Liorens, M., Saez, J., Aguilar, I. M., Ortuno, F. J., Juan, F., and Victor, M. F. 2004.Phytotoxicity and heavy metal speciation of stabilized sewage sludge. J. Hazard. Mater. 108,161–169.

Gonzales, P. S, Capozucca, C. E., and Horacio, A. T. 2006. Phytoremediation of phenol from wastew-ater by peroxidases of Tomato hairy root cultures. Enzy Microb. Technol. 39, 647–653.

Grace, S. C., and Logan, B. A. 2000. Energy dissipation and radical scavenging by the plant pheny-lopropanoid pathway. Phil. Trans. R. Soc. Lond. 355, 1499–1510.

Huang, C., Bazzar, F. A., and Vanderhoff, L. N. 1974. The inhibition of soybean metabolism bycadmium and lead. Plant Physiol. 54, 122–124.

Lavola, A., Julkunen-Tiitto, R., Delarosa, T. M., Lehto, T., and Aphalo, P. J. 2000. Allocation ofcarbon to growth and secondary metabolites in birch seedlings in UV-B radiation and CO2

exposure. Physiol. Plant. 109, 260–265.Li, H. B., Wong, C. C., Cheng, K. W., and Chen, F. 2008. Antioxidant properties in vitro and

total phenolic contents in methanol extracts from medicinal plants. LWT-Food Sci. Technol. 41,385–390.

Lowry, O. H., Rosenbrough, N. J., Farr, A. L., and Randall, R. J. 1951. Protein measurement withfolin-phenol reagent. J. Biol. Chem. 193, 265–275.

Marklund, S., and Marklund, G. 1974. Involvement of the superoxide anion radical in the autoxidationof pyrogallol and a convenient assay for superoxide dismutase. Eur. J. Biochem. 47, 469–474.

Mishra, R. N., and Behra, P. K. 1991. The effect of paper industry effluent on growth pigment,carbohydrate and protein of rice seedlings. Environ. Pollut. 72, 159–162.

Neamtu, M., Ciumasu, I. M., Costica, N., Costica. M., Bobu, M., Nicoara, M. N., Catrinescu, C.,Van Slooten, K. B., and De Alencastro, L. F. 2009. Chemical, biological, and ecotoxicologicalassessment of pesticides and persistent organic pollutants in the Bahlui River, Romania. Environ.Sci. Pollut. Res. Int. 1, 76–85.

Park, S. 2006. Study of an enzyme activity in extracts of Ginkgo biloba .eaves. Bull. Korean. Chem.Soc. 27, 1885–1887.

Prasad, K. V. S. K., Pardha Saradhi, P., and Sharmila, P. 1999. Concerted action of antioxidantenzymes and curtailed growth under Zn toxicity in Brassica juncea. Environ. Exp. Bot. 42,1–10.

Qadir, S., Qureshi, M. I., Javed, S., and Abdin, M. Z. 2004. Genotypic variation in phytoremediationpotential of Brassica juncea cultivars exposed to Cd stress. Plant Sci. 167, 1171–1181.

Sakihama, Y., and Yamasaki, H. 2002. Lipid peroxidation induced by phenolics in conjunction withaluminium ions. Biol. Plantarum. 45, 249–254.

Singh, S., Melo, J. S., Eapen, S., and D’souza, S. F. 2006. Phenol removal using Brassica junceahairy roots: Role of inherent peroxidases and H2O2. J. Biotechnol. 123, 43–49.

Singleton, V. L., and Rossi, J. A. 1965. Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents. American J. Enol. Viticul. 16,144–153.

Slooten, L., Capiiau, K., VanCamp, W., Van Montagu, M., Sybesma, C., and Inze, D. 1995. Factorsaffecting the enhancement of oxidative stress tolerance in transgenic tobacco overexpressingMn-SOD in the chloroplast. Plant Physiol. 107, 737–750.

Sopper, W. E. 1993. Municipal Sludge Use in Land Reclamation. Lewis Publishers, Berlin.Vincent, J. M. 1970. A Manual for Practical Study of Root Nodule Bacteria. Blackwell, London.Tisnadjaja, D., Gutierrez, N. A., and Maddox, I. S. 1996. Citric acid production in a bubble-column

reactor using cells of the yeast Candida guilliermondii immobilized by adsorption onto sawdust.Enz. Microbiol. Technol. 19, 343–347.

Yu, X., Trapp, S., Zhou, P., Xiaoying, P., and Xi, C. 2006. Response of weeping willows to linearalkylbenzene sulphonate. Chemosphere. 64, 43–48.

Yu, X. Z., Gua, J. D., and Liu, S. 2007. Biotransformation and metabolic response of cyanide inweeping willows. J. Hazard. Mater. 147, 838–844.

Dow

nloa

ded

by [

UQ

Lib

rary

] at

01:

32 0

9 N

ovem

ber

2014