RESUMEN
Aim: This study aims to investigate the ability of laccase producing fungal strains Cladosporium uredinicola GRDBF21 and Bipolaris maydis GRDBF23 isolated from decaying wood bark in decolouration and detoxification of tannery effluent. Methodology: Fungal strains from decaying wood bark samples were isolated by serial dilution technique followed by single spore isolation method. The selected fungal isolates were investigated for their laccase enzyme production. Their effect on physio-chemical properties of tannery effluent collected from final effluent drainage of a leather-tanning factory in Chrompet, Chennai, Tamil Nadu, India was analysed. Toxicity of treated and untreated tannery effluent was analysed by seed germination test. Results: The lignolytic and constitutive producers of laccase enzyme, C. uredinicola GRDBF21 and B. maydis GRDBF23 exhibited a tolerance index of 1.2 and 1.5, respectively, at 60% effluent concentration. The isolates were able to increase pH and reduce colour, turbidity, total suspended solids and electrical conductivity of the effluent. Besides observing a decrease in the BOD and COD levels, there was also a reduction in the sodium and hexavalent chromium content. C. uredinicola GRDBF21 and B. maydis GRDBF23 treated effluent showed a seed germination percentage of 66.6% and 76.6%, respectively. The untreated effluent completely inhibited the seed germination. Interpretation: The study confirms that the fungal species C. uredinicola GRDBF21 and B. maydis GRDBF23 could be effectively used in decolouration and detoxification of tannery effluent.
RESUMEN
Tannery effluent contributes significantly to pollution of the environment. In this study, phytotoxic and genotoxic effects of tannery effluent and chromium (Cr) were investigated in Allium cepa. For this purpose, tannery effluent was collected from “Up flow Anaerobic Sludge Blanket” (U.A.S.B) Jajmau, Kanpur. A. cepa were exposed to various concentrations of tannery effluent (0.0, 3.125, 6.25, 12.50, 25.0%) and Cr (0.0, 1.0, 2.0, 4.0, 8.0 mg l-1) for 48 and 168 hr. The perusal of data revealed that the physico-chemical characteristics of tannery effluent viz. pH (8.5), EC (11.94 dSm-1), BOD (499 mg l-1), COD (1382 mgl-1) and Cr content (2.32 mg l-1) were much higher than the prescribed permissible limit for industrial effluent discharged into inland waters. These substances provoked phytotoxic and genotoxic effects in A. cepa. Total chlorophyll and protein content in leaves of tannery effluent and Cr treated plants decreased significantly in dose-duration dependent manner. A maximum decrease of 86.29 and 84.26% in total chlorophyll and 81.27 and 76.16% in protein content was observed after 168 hr of exposure while carotenoid content increased up to 6.25% effluent and 2.0 mgl-1Cr treatment and decreased further. In all treated plants, a significant (p>0.05) reduction in root length, mitotic index (MI) and induction in chromosomal (CA)/mitotic (MA) aberration and micronuclei (MNC) were observed as compared to unstressed plants. A maximum reduction of 81.15 and 79.71% in MI, and induction of 6.8 and 4.8% in CA, 29.24 and 26.66% in MA and 0.52 and 0.43% in MNC were found at 12.50% effluent and 4 mgl-1 Cr treated plants as compared to unstressed plants, however at highest effluent and Cr concentration both the plants showed pyknosis condition after 168 hr.
RESUMEN
Aquatic macrophytes have been widely studied because of their capability of absorbing contaminants from water and their subsequent use in biomonitoring. This study presents a comparison of Cr accumulating potential of submerged aquatic plants viz Vallisneria spiralis and Hydrilla verticillata. These plants were treated with various concentrations of treated tannery effluent collected from UASB, Jajmau, Kanpur under repeated exposure in controlled laboratory conditions in order to assess their maximum bioaccumulation potential. The maximum accumulation of 385.6 and 201.6 μg g-1 dry weight was found in roots of V. spiralis and the whole plants of H. verticillata, respectively at 100% concentration after 9th day of effluent exposure. The chlorophyll and protein content of both species decreased with increase in effluent concentration and duration. At highest concentration and duration a maximum reduction of 67.4 and 62.66% in total chlorophyll content, 9.97 and 4.66% in carotenoid content and 62.66 and 59.36% in protein content was found in V. spiralis and H. verticillata respectively. Anatomical studies in both V. spiralis and H. verticillata was carried out to assess the effects of metal accumulation within the plants. Changes in the anatomical structures of both plants exhibits the capacity of these species to act as indicator of effluent toxicity. The high accumulation potential of Cr by both plants revealed their capability to remove pollutants from effluent.
RESUMEN
The various dilution levels of treated tannery effluent (T.E.) (10, 25, 50 and 100 %) and Cr 6+ (0.5, 2.0, 5.0 and 10 ppm) were used in experiment to know their effect on seed germination, seedling growth, pigments and enzymes content in Black gram (Phaseolus mungo Roxb.). Chromium is known as the main toxic component of tannery effluent so its various concentration were given to know their effects. For the recovery of plant damage, protective value of 10 and 25 ppm of zinc, potassium and iron sulphate were also given with 50 % treated tannery effluent and 10 ppm Cr 6+ levels in separate petridishes. The different concentrations of tannery effluent and Cr 6+ showed significant reduction in germination percentage, seedling growth (plumule and radicle length, number of lateral roots, fresh and dry weight, and moisture %) and pigments (chlorophyll, pheophytin and carotenoids) with increase in concentrations. The lower doses of tannery effluent (10%) and Cr 6+ (0.5, 2 and 5 ppm) slightly increases the pigments concentration. The amylase activity and total sugar contents were also significantly decreased while catalase and peroxidase activity showed significant increase with rise in concentrations of treatments. The lower concentrations of tannery effluent (dilution 10 and 25%) and Cr 6+ (0.5 and 2 ppm) showed significant increase in total protein contents while decrease at higher concentrations. The zinc, potassium and iron treatments led to recover the damage caused by chromium and tannery effluent in all parameters. In recovery treatments zinc showed highest and significant recovery in maximum parameters. Iron also showed almost similar effect to the zinc while potassium showed minimum recovery.