Rahul V. Khandare

Development of a bioreactor for remediation of textile effluent and dye mixture: a plant-bacterial synergistic strategy.

The objective of the present work was to develop a plant-bacterial synergistic system for efficient treatment of the textile effluents. Decolorization of the dye Scarlet RR and a dye mixture was studied under in vitro conditions using Glandularia pulchella (Sweet) Tronc., Pseudomonas monteilii ANK and their consortium. Four reactors viz. soil, bacteria, plant and consortium were developed that were subjected for treatment of textile effluents and dye mixture. Under in vitro conditions G. pulchella and P. monteilii showed decolorization of the dye Scarlet RR (SRR) by 97 and 84%, within 72 and 96 h respectively, while their consortium showed 100% decolorization of the dye within 48 h. In case of dye mixture G. pulchella, P. monteilii and consortium-PG showed an ADMI removal of 78, 67 and 92% respectively within 96 h. During decolorization of SRR G. pulchella showed induction in the activities of enzymes lignin peroxidase and DCIP reductase while P. monteilii showed induction of laccase, DCIP reductase and tyrosinase, indicating their involvement in the dye metabolism. High Performance Liquid Chromatography (HPLC), Fourier Transform Infra Red Spectroscopy (FTIR) and High Performance Thin Layer Chromatography (HPTLC) confirmed the biotransformation of SRR and dye mixture into different metabolites. Soil, bacteria, plant and consortium reactors performed an ADMI removal of 42, 46, 62 and 93% in the first decolorization cycle while it showed an average ADMI removal of 21, 27, 59 and 93% in the next three (second, third and fourth) decolorization cycles respectively for the dye mixture within 24 h. Consortium reactor showed an average ADMI removal of 95% within 48 and 60 h for textile effluents A and B respectively for three decolorization cycles, while it showed an average TOC, COD and BOD removal of 74, 70 and 70%, 66, 72 and 67%, and 70, 70 and 66% for three decolorization cycles of the dye mixture (second, third and fourth decolorization cycles), effluent A and effluent B respectively. Degradation of the textile effluents and dye mixture into different metabolites by the consortium reactor was confirmed using HPLC and FTIR. Phytotoxicity studies revealed the non-toxic nature of the metabolites of degradation of dye mixture, effluents A and B by consortium reactor. The developed consortial reactor system performed efficient treatment of the dye mixture and textile effluents, and can be used for treating large amounts of textile effluents when implemented as a constructed wetland by proper engineering approach.

The role of Aster amellus Linn. in the degradation of a sulfonated azo dye Remazol Red: A phytoremediation strategy

Phytoremediation is a novel and promising approach for the treatment of pollutants. This study did explore the potential of Aster amellus Linn. to decolorize a sulfonated azo dye Remazol Red (RR), a mixture of dyes and a textile effluent. Induction in the activities of lignin peroxidase, tyrosinase, veratryl alcohol oxidase and riboflavin reductase was observed during RR decolorization, suggesting their involvement in the metabolism of RR. UV-Visible absorption spectrum, HPLC and FTIR analysis confirmed the degradation of RR. Four metabolites after the degradation of the dye were identified as 2-[(3-diazenylphenyl) sulfonyl] ethanesulfonate, 4-amino-5-hydroxynaphthalene-2,7-disulfonate, naphthalene-2-sulfonate and 3-(1,3,5-triazin-2-ylamino)benzenesulfonate by using GC/MS. Textile effluent and mixture of dyes showed 47% and 62% decrease respectively in American Dye Manufacturers Institute value. BOD of textile effluent and mixture of dyes were reduced by 75% and 48% respectively, COD of industrial effluent and mixture of dyes was reduced by 60% and 75% and TOC was reduced by 54% and 69% respectively after the treatment by A. amellus for 60 h; this indicated that the plant can be used for cleaning textile effluents. Toxicity study revealed the phytotransformation of RR into non-toxic products.

Differential fate of metabolism of a sulfonated azo dye Remazol Orange 3R by plants Aster amellus Linn., Glandularia pulchella (Sweet) Tronc. and their consortium

Plant consortium-AG of Aster amellus Linn. and Glandularia pulchella (Sweet) Tronc. showed complete decolorization of a dye Remazol Orange 3R in 36 h, while individually A. amellus and G. pulchella took 72 and 96 h respectively. Individually A. amellus showed induction in the activities of enzymes veratryl alcohol oxidase and DCIP reductase after degradation of the dye while G. pulchella showed induction of laccase and tyrosinase, indicating their involvement in the dye metabolism. Consortium-AG showed induction in the activities of lignin peroxidase, veratryl alcohol oxidase, laccase, tyrosinase and DCIP reductase. Two different sets of induced enzymes from A. amellus and G. pulchella work together in consortium-AG resulting in faster degradation of the dye. The degradation of the dye into different metabolites was confirmed using High Performance Liquid Chromatography and Fourier Transform Infra Red Spectroscopy. Gas Chromatography Mass Spectroscopy analysis identified four metabolites of dye degradation by A. amellus as acetamide, benzene, naphthalene and 3-diazenylnaphthalene-2-sulfonic acid, four metabolites by G. pulchella as acetamide, 3-diazenyl-4-hydroxynaphthalene-2-sulfonic acid, naphthalen-1-ol and (ethylsulfonyl)benzene, while two metabolites by consortium-AG as 2-(phenylsulfonyl)ethanol and N-(naphthalen-2-yl)acetamide. The non-toxic nature of the metabolites of Remazol Orange 3R degradation was revealed by phytotoxicity studies.

Phytoremediation potential of Portulaca grandiflora Hook. (Moss-Rose) in degrading a sulfonated diazo reactive dye Navy Blue HE2R (Reactive Blue 172).

Wild and tissue cultured plants of Portulaca grandiflora Hook. have shown to be able to decolorize a sulfonated diazo dye Navy Blue HE2R (NBHE2R) up to 98% in 40 h. A significant induction in the activities of lignin peroxidase, tyrosinase and DCIP reductase was observed in the roots during dye decolorization. The wild plants and tissue cultures could independently decolorize and degrade NBHE2R into metabolites viz. N-benzylacetamide and 6-diazenyl-4-hydroxynaphthalene-2-sulfonic acid. A dye mixture and a textile effluent were also decolorized efficiently by P. grandiflora. The phytotoxicity study revealed reduction in the toxicity due to metabolites formed after dye degradation.

Bacterial assisted phytoremediation for enhanced degradation of highly sulfonated diazo reactive dye

PurposePhytoremediation is the exploitation of plants and their rhizospheric microorganisms for pollutants treatment like textile dyes, which are toxic, carcinogenic and mutagenic from the effluent. The purpose of this work was to explore a naturally found plant and bacterial synergism to achieve an enhanced degradation of Remazol Black B dye (RBB).MethodsIn vitro cultures of Zinnia angustifolia were obtained by seed culture method. Enzymatic analysis of the plant roots and Exiguobacterium aestuarii strain ZaK cells was performed before and after decolorization of RBB. Metabolites of RBB formed after its degradation were analyzed using UV–Vis spectroscopy, high-performance liquid chromatography (HPLC), Fourier transform infrared (FTIR) and gas chromatography–mass spectrometry (GC-MS). Phytotoxicity studies were performed.ResultsThe consortium ZE was found to be more efficient than individual plant and bacteria. Z. angustifolia roots showed significant induction in the activities of lignin peroxidase, laccase, DCIP reductase and tyrosinase during dye decolorization. E. aestuarii showed significant induction in the activities of veratryl alcohol oxidase, azo reductase and DCIP reductase. Analysis of metabolites revealed differential metabolism of RBB by plant, bacteria and consortium ZE. E. aestuarii and Z. angustifolia led to the formation of 3,6-diamino-4-hydroxynaphthalene-2-sulfonic acid, (ethylsulfonyl)benzene, and 3,4,6-trihydroxynaphthalene-2-sulfonic acid and propane-1-sulfonic acid, respectively, whereas consortium ZE produced 4-hydroxynaphthalene-2-sulfonic acid, naphthalene-2-sulfonic acid and 4-(methylsulfonyl)phenol. The phytotoxicity study revealed the nontoxic nature of the metabolites formed after dye degradation.ConclusionConsortium ZE was found to be more efficient and faster in the degradation of RBB when compared to degradation by Z. angustifoila and E. aestuarii individually.

Phytoremediation of textile effluent and mixture of structurally different dyes by Glandularia pulchella (Sweet) Tronc.

Plants of Glandularia pulchella (Sweet) Tronc. performed decolorization of structurally different dyes to varying extent because of induction of different set of enzymes in response to specific dyes. Differential pattern of enzyme induction with respect to time was obtained for lignin peroxidase, veratryl alcohol oxidase, tyrosinase and dichlorophenolindophenol reductase during the decolorization of dye mixture, whose combined action resulted in greater and faster decolorization of dyes. HPLC, FTIR and High Performance Thin Layer Chromatography (HPTLC) analysis confirmed degradation of dyes from textile effluent and mixture. HPTLC demonstrated progressive decolorization of dye mixture along with preferential degradation of the dyes. G. pulchella showed reduction in American Dye Manufacturers Institute from 405 to 21 and 418 to 22, in case of textile effluent and mixture of dyes respectively. The non-toxic nature of the metabolites of degraded textile dye effluent and mixture of dyes was revealed by phytotoxicity studies.

Green remediation of textile dyes containing wastewater by Ipomoea hederifolia L.

Wild plant and tissue cultures of Ipomoea hederifolia decolorize Scarlet RR (SRR) dye at a concentration of 50 mg L−1 up to 96% and 90% within 60 and 96 h, respectively. Significant induction in the enzyme activities of Lignin peroxidase, laccase, 2,6-dichlorophenol indophenol reductase, superoxide dismutase, catalase and tyrosinase was found in the plant roots and shoots during decolorization. I. hederifolia was also able to treat a dye mixture and a real textile effluent efficiently with a reduction in the American Dye Manufacturers Institute (ADMI) value (color removal) up to 85% and 88%, BOD up to 65% and 63% and COD up to 62% and 68%, respectively. Detailed anatomical studies of the stem and root cells of I. hederifolia during uptake and degradation were carried out, showing a stepwise and mechanistic degradation of the model dye SRR. Products formed after dye degradation were analyzed by UV-Vis spectroscopy, FTIR, HPLC and HPTLC, which confirmed the phytotransformation of SRR, dye mixture and textile effluent. A possible pathway for the phytotransformation of SRR was proposed based on GC-MS analysis, which confirmed the formation of different metabolites with lower molecular weights. The phytotoxicity study revealed the non-toxic nature of the formed products.

Phytoremediation of a sulphonated azo dye Green HE4B by Glandularia pulchella (Sweet) Tronc. (Moss Verbena)

PurposeThe dyes and dye stuffs present in effluents released from textile dyeing industries are potentially mutagenic and carcinogenic. Phytoremediation technology can be used for remediating sites contaminated with such textile dyeing effluents. The purpose of the work was to explore the potential of Glandularia pulchella (Sweet) Tronc. to decolorize different textile dyes, textile dyeing effluent, and synthetic mixture of dyes.MethodsEnzymatic analysis of the plant roots was performed before and after decolorization of dye Green HE4B. Analysis of the metabolites of Green HE4B degradation was done using UV–Vis spectroscopy, high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), and gas chromatography–mass spectroscopy (GC-MS). The ability of the plant to decolorize and detoxify a textile dyeing effluent and a synthetic mixture of dyes was studied by a determination of the American Dye Manufacturer’s Institute (ADMI), biological oxygen demand (BOD), and chemical oxygen demand (COD). Phytotoxicity studies were performed.ResultInduction of the activities of lignin peroxidase, laccase, tyrosinase, and 2,6-dichlorophenol indophenol reductase was obtained, suggesting their involvement in the dye degradation. UV–Vis spectroscopy, HPLC, and FTIR analysis confirmed the degradation of the dye. Three metabolites of the dye degradation were identified, namely, 1-(4-methylphenyl)-2-{7-[(Z)-phenyldiazenyl] naphthalen-2-yl} diazene; 7,8-diamino-2-(phenyldiazenyl) naphthalen-1-ol; and (Z)-1,1′-naphthalene-2,7-diylbis (phenyldiazene) using GC-MS. ADMI, BOD, and COD values were reduced. The non-toxic nature of the metabolites of Green HE4B degradation was revealed by phytotoxicity studies.ConclusionThis study explored the phytoremediation ability of G. pulchella (Sweet) Tronc. in degrading Green HE4B into non-toxic metabolites.

Enhanced phytotransformation of Navy Blue RX dye by Petunia grandiflora Juss. with augmentation of rhizospheric Bacillus pumilus strain PgJ and subsequent toxicity analysis.

This study reveals the beneficial synergistic phytoremediation potential of Petunia grandiflora Juss. with its rhizospheric bacterial isolate Bacillus pumilus strain PgJ to decolorize reactive Navy Blue RX (NBRX) dye by their active enzymatic machinery. In vitro cultures of P. grandiflora and B. pumilus gave 80.01% and 76.80% while their consortium decolorized NBRX up to 96.86% within 36 h. Significant induction in the enzyme activities of lignin peroxidase (207%), tyrosinase (133%), laccase (161%), riboflavin reductase (78%) were seen in the roots of tissue cultured plants while enzymes tyrosinase (660%), laccase (689%), riboflavin reductase (528%) were induced significantly in the B. pumilus cells. Metabolites of treated NBRX were analyzed using UV-vis spectroscopy, gas chromatography and biotransformation was visualized using high performance thin layer chromatography profile. Metabolites of the dye exhibited reduced phytotoxicity Sorghum vulgare and Phaeseolus mungo and significant reduction in cytogenotoxicity on Allium cepa roots when compared to NBRX.

Bioreactor with Ipomoea hederifolia adventitious roots and its endophyte Cladosporium cladosporioides for textile dye degradation.

In vitro grown untransformed adventitious roots (AR) culture of Ipomoea hederifolia and its endophytic fungus (EF) Cladosporium cladosporioides decolorized Navy Blue HE2R (NB-HE2R) at a concentration of 20 ppm up to 83.3 and 65%, respectively within 96h. Whereas the AR-EF consortium decolorized the dye more efficiently and gave 97% removal within 36h. Significant inductions in the enzyme activities of lignin peroxidase, tyrosinase and laccase were observed in roots, while enzymes like tyrosinase, laccase and riboflavin reductase activities were induced in EF. Metabolites of dye were analyzed using UV-vis spectroscopy, FTIR and gas chromatography-mass spectrometry. Possible metabolic pathways of NB-HE2R were proposed with AR, EF and AR-EF systems independently. Looking at the superior efficacy of AR-EF system, a rhizoreactor was developed for the treatment of NB-HE2R at a concentration of 1000 ppm. Control reactor systems with independently grown AR and EF gave 94 and 85% NB-HE2R removal, respectively within 36h. The AR-EF rhizoreactor, however, gave 97% decolorization. The endophyte colonization additionally increased root and shoot lengths of candidate plants through mutualism. Combined bioreactor strategies can be effectively used for future eco-friendly remediation purposes.