Informatics Publishing Limited

P. K. Singh ¹, K. P. Sharma ¹, S. Kumar ¹, S. Sharma ², Subhasini ¹

Affiliations
1 Department of Botany, University of Rajasthan, Jaipur-302 004, Rajasthan, IN
2 Department of Zoology, University of Rajasthan, Jaipur-302 004, Rajasthan, IN

Abstract

Toxic effects of spent wash and crop field soil irrigated with it (hereafter referred to as distillery soil) were examined on 6 species of plants (2 cereals and 4 aquatic macrophytes) and 3 animals (cladoceran, fish and albino mice) by short-term bioassays using end point growth responses and mortality respectively. Seedling emergence was found nil (rice) to low (wheat = 30-40%) in distillery soil, but increased (48-00%) proportionately alongwith their vigor after mixing garden soil. In contrast to distillery soil, toxic effects of even cent percent soil leachate were nil on seed germination while meager (10- 15%) on seedling vigor in both the cereals. Spent wash, however, decreased germination and seedling vigor in both rice (germination = 5-100%; vigor = 2-100%) and wheat (germination = 0-64%; vigor = nil-93%) with an increase in its concentration, though vigor was greater (43%) than control in wheat at 10%. Among aquatic macrophytes, free-floating species (Lemna aequinoctialis and Spirodela polyrrhiza) were found to bemore sensitive than the submerged (Ceratophyllum demersum and Hydrilla verticillata) for spent wash; Lemna being the most sensitive species.

During a detailed study, sensitivity of different test organisms to spent wash (in terms of their EC/LC₅₀ values) was in the order of: Daphnia (EC50 = 0.68%) > Gambusia affinis (LC₅₀ = 1.31%) > Lemna (EC₅₀ = 0.8-6.97%) indicating water flea to be the most sensitive test organism. The toxicity of soil leachate was, however, very low to these test organisms (Gambusia: LC₅₀ = 12.1%; Lemna: EC₅₀ = 46.5-278%) as also noted for cereals. The spent wash exposure not only decreased RBC counts (58-69%) in fish but also altered their morphology (77-97%).

Both food (7-14%) and water (27-45%) intake of albino mice (male) declined in soil leachate treatments (5-20%) alongwith their body (8-17%) and reproductive organ weights (4-63%), except that of prostrate gland weight increasing between 12% and 37%. The sperm counts (78-89%) and their motility (14-23%) also decreased in leachate treatments. Higher toxicity of spent wash may be ascribed to its greater conductivity (32.7mS), COD (54,900ppm) and chlorides (62,00ppm) than the soil leachate (EC = 3.56mS; COD = 2290ppm; chlorides = 220ppm).

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Suresh Kumar ¹, Pawan Kumar ¹, Shweta Sharma ², Pradeep Kumar Sharma ¹, Subhasini ², K. P. Sharma ¹

Affiliations
1 Department of Botany, University of Rajasthan, Jaipur-302 004, Rajasthan, IN
2 Department of Zoology, University of Rajasthan, Jaipur-302 004, Rajasthan, IN

Abstract

The effects of texture, aeration, inorganic (PO₄-P and NO₃-N) and organic (milk whey) nutrients are reported here on degradation and decolourisation of methyl red. The effects have been quantified by comparing UV-visible spectra of untreated and treated 100ppm of the dye in two types of fixed film bioreactors that differed in composition of their solid matrix (one containing gravel only, gravel bed; while the other has gravel + coarse river sand, mixed bed). Methyl red degradation was better in gravel bed reactors in comparison to mixed bed reactors. Aeration improved its degradation in both the types of reactors. Nutrients favoured reduction in bandwidth of spectra in near UV region (hence degradation of benzenoid compounds) in outflows from gravel (non-aerated and aerated) and mixed bed (aerated) bioreactors, while an opposite trend was noted for their OD values in far UV and visible region responsible for the colour. Mixed bed (non-aerated) bioreactor was, however, the exception, where inorganic nutrients, especially NO₃-N improved reduction of bandwidth as well as OD values in the spectra of outflows.

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