Effects of β-cyclodextrin on adsorption and desorption of carbofuran in soils of divergent texture

Laboratory studies were conducted to determine the adsorption/desorption equilibrium of carbofuran between four divergently textured soils and distilled water and an aqueous solution of 0.01?mol?L^?1 β-cyclodextrin using a batch equilibrium technique. The determined adsorption isotherms for silt loam soils were of L-shaped, for sandy loam soil S-shaped, in agreement with a Freundlich isotherm. In the presence of β-cyclodextrin, the adsorption of carbofuran to the four soils was lower than with distilled water. Positive hysteresis was observed in all soils with distilled water, negative hysteresis when using a solution of β-cyclodextrin as desorbent. The results indicate the potential use of β-cyclodextrin for remediation of pesticide-contaminated soils.     

Effect of photoperiod and temperature on testicular regression in Channa punctatus

In Channa punctatus testicular regression commonly observed during spawning and postspawing phases of reproductive cycle. In the present study testicular regression was frequently noticed in fish maintained under both long photoperiod-warm temperature (LD 16 : 8-30 degrees C) and short photoperiod-warm temperature (LD 8 : 16-30 degrees C) regimes. Testicular regression was characterized by distortion of cellular boundary of lobules and formation of collagenous capsules containing degenerating germ cells, blood cells and colloidal mass within the lobules. The magnitude of testicular regression was more in fish exposed to short photoperiod regime (R-73.33%, SP-41.67%) than long photoperiod regime (R-50.83%, SP-19.16%) and control group (R-20.83%, SP-16.67%) in both resting (R) and spawning (SP) phases. Further the frequency of testicular regression during resting phase was 73.33% (short photoperiod), 50.83% (long photoperiod) and 20.83% (control) whereas during spawning phase was 41.67% (short photoperiod) 19.16% (long photoperiod) and 16.67% (control). In the present study occurrence of more testicular regression during resting phase than spawning phase may be due to change in the endogenous condition of the fish.     

Assessment of potentially toxic elements in Swiss chard and sediments of Akaki River,Ethiopia

For the determination of 15 potentially toxic elements (V, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Se, Ag, Cd, Sn, Hg, and Pb) in plant and sediment samples of the Akaki River, Ethiopia, inductively coupled plasma–mass spectrometry, inductively coupled plasma–optical emission spectrometry, and a RA-915+ mercury analyzer were applied. Sediment and plant samples were mineralized using a closed-vessel microwave-assisted digestion system. The elemental concentrations varied considerably in plant and sediment samples. The minimum concentration was observed for known toxic elements (As, Hg, and Cd) while the highest concentration was observed for the elements of relatively low toxicity Zn, Mn, and Fe. The concentration of Cr, Fe, Pb, Zn, and As in Swiss chard surpassed the maximum permissible levels at specific sites. At some of the sites, the sediment quality guidelines are surpassed for Cu, Zn, and Pb.     

Inhibitory effect of high soil pH on growth and mineral metabolism of rice and its reversal by zinc

Increasing soil pH retarded growth, tillers and bio-mass production of rice cultivar Sarjoo-52. Application of 10 to 15 kgZn ha(-1) increased the bio-mass by 33 to 41% at pH 8.5 and 27 to 32% at pH 10.3. Panicle length, rachis branches, total spikelets, filled grains, grain size were all adversely affected to the tune of 19, 23, 40, 74 and 21%, respectively by higher soil alkalinity at pH 10.3. Alkalinity resulted in 19, 31 and 65% spikelet sterility which reduced to 3, 21 and 55% at pH 8.5, 9.5 and 10.3, respectively by Zn applied @ 15 kg ha(-1). Grain yield reduced to 50% at pH 10.3 but Zn in general, raised the yield levels by 1.6 to 2.3, times. The chlorophyll decreased by 36 to 50% whereas carbonic anhydrase activities decreased only by 13% due to increase in soil sodicity and alkalinity. Further, increase in pH caused significant decrease in Zn, Ca, Mg, P and K concentrations but phenomenal rise in Na content Zinc application, apart from increasing tissue Zn content, elevated Ca :Na and K :Na ratio resulting in improved growth and yield of rice under soil sodicity and alkalinity.     

Sequential anaerobic and aerobic treatment of pulp and paper mill effluent in pilot scale bioreactor

In the present study sequential anaerobic and aerobic treatment in two step bioreactor was performed for removal of colour in the pulp and paper mill effluent. In anaerobic treatment, colour 50%, lignin 62%, COD 29%, absordable organic halides (AOX) 25% and phenol 29% were reduced in eight days. The anaerobically treated effluent was separately applied in bioreactor in presence of fungal strain, Paecilomyces sp., and bacterial strain, Microbrevis luteum. Data of study indicated reduction in colour 80%, AOX 74%, lignin 81%, COD 93% and phenol 76 per cent by Paecilomyces sp. where as Microbrevis luteum showed removal in colour 59%, lignin 71%, COD 86%, AOX 84% and phenol 88% by day third when 7 days anaerobically treated effluent was further treated by aerobic microorganisms. Change in pH of the effluent and increase in biomass of microorganism's substantiated results of the study, which was concomitant to the treatment method.     

Evaluation of existing equations for temporal scour depth around circular bridge piers

Scour is defined as the processes of removal of sediment particles from water stream bed by the erosive action of activated water, and also carries sediment away from the hydraulic structures. Scour is the main cause of pier failure. Numerous equations are available for estimating temporal and equilibrium scour depth. The present study describes the phenomenon of temporal scour depth variation at bridge piers and deals with the methods for its estimation. The accuracy of six temporal scour depth equations are also checked in this study. After graphical and statistical analysis, it was found that the relationship proposed by Oliveto and Hager (J Hydraul Eng (ASCE) 128(9):811–520, 2002) predicts temporal scour depth better than other equations. Three equations of equilibrium time of scour are also used for computing equilibrium time. Equilibrium time equation proposed by Choi and Choi (Water Environ J 30(1–2):14–21, 2016) gives better agreements with observed values.     

Evaluation of fodder quality of straw of different landraces of rice (Oryza sativa L.) under cultivation in the Kumaun Region of Indian Central Himalaya

Thirty landraces of rice collected from various locations, across an elevational gradient (1150–2400 m asl), in Kumaun, Central Himalaya and VL-206 (a high-yielding variety recommended for rainfed mountain area) have been evaluated, both in terms of quantity and nutritional quality of straw. Data were collected to estimate the percentage share of fodder in the overall biomass produced. The total biomass harvested at maturity was taken as productivity. In view of the severe scarcity of fodder in hill regions, particularly during winter months, straw was also examined for quality-linked biochemical parameters and dry matter digestibility (DMD) of fodder. The Crude Protein (CP) values ranged from 2.21% (Nandhani) to 6.33% (Dalbadal), and in saceo DMD (nylonbag technique) was highest in Kaladur (48.84%) and lowest in Kantolia (32.25%). While the CP in VL206 was within the range recorded for various landraces (3.61%), DMD value (27.29%) was lower than that of all the landraces tested. In saceo DMD data indicate that the fodder quality of landraces is better than that of the introduced variety. The values for neutral detergent fibre (NDF) ranged from 63.64% (Sabhawati) to 78.46% (Chhotiya) among the rainfed landraces, while in the irrigated landraces, Thapchini had more NDF (87.50 %), as compared to Kantolia (73.88%) and VL206 (74.91%). Values for the acid detergent fibre (ADF) varied from 42.70% (Danbasmati) to 54.58% (Nandhani) in the rainfed group; ADF was slightly higher in Thapchini (49.41%) in comparison to Kantolia (47.19) and VL206 had the highest (56.80%) ADF content. The observed differences with respect to straw productivity, chemical composition and in saceo DMD in various landraces, even when grown under similar conditions at one place, clearly indicate the richness of the gene pool of rice being maintained, through cultivation, in the Kumaun hills. It may be mentioned that agriculture in the hills is biomass based, and livestock form an integral component of subsistence farming.     

Experimental study of solar energy–based water purifier of single-slope type by incorporating a number of similar evacuated tubular collectors

Environmental Science and Pollution Research - This research paper deals with the experimental investigation of solar energy–based water purifier (SEBWP) of single-slope type by incorporating...