Organopesticides and fertility: where does the link lead to?

Environmental Science and Pollution Research - Organopesticides (OPs) are a group of various synthetic chemicals prevalently used in agriculture and homestead plantations. OPs were originally...     

Mechanism of Navitan Fast Blue S5R degradation by Pseudomonas aeruginosa

The mechanism by which Pseudomonas aeruginosa degraded Navitan Fast Blue S5R was studied using TLC, FTIR, HPLC and GC-MS analysis. Degradation started with the reduction of azo bonds producing metanilic acid and peri acid whose presence was confirmed by HPLC. Aniline, the desulfonated product from metanilic acid and salicylic acid could also be detected by HPLC. GC-MS analysis of the degradation products confirmed the presence of aniline and revealed the presence of beta-ketoadipic acid. Based on these products a probable pathway has been proposed for the degradation of Navitan Fast Blue S5R by Pseudomonas aeruginosa.     

ECONOMIC IMPLICATIONS OF PHOSPHORUS LOADING POLICIES FOR PASTURE LAND APPLICATIONS OF POULTRY LITTER1

ABSTRACT: Non-point source pollution created by agriculture is one of the major issues of intensive production. Recent studies indicate that the eutrophication from agricultural non-point source pollution, especially from phosphorus, is of growing concern. The objectives of this paper are to measure the economic opportunity costs of a proposed phosphorus management policy that targets soils with elevated phosphorus levels and examine the impacts of alternative policies such as Pigouvian taxes on the optimal use of litter. The study focuses on land applications of poultry litter in the Muddy Fork watershed of the Illinois River in Northwest Arkansas. The analysis indicates that restriction of litter applications on soils with elevated phosphorus levels will significantly reduce the net returns generated from forage production, resulting in an environmental policy with a high opportunity cost for producers. An analysis of alternative Pigouvian tax policies shows that a smaller tax per ton of litter applied can achieve the same litter control as that of a larger tax on a per acre basis.     

Threat of heavy metal pollution in halophytic and mangrove plants of Tamil Nadu, India

Mangrove and halophytic plants occur along the coastal areas of Tamil Nadu, south India and these plants have been used in traditional medicine for centuries. Heavy metals are known to pose a potential threat to terrestrial and aquatic biota. However, little is known on the toxic levels of heavy metals found in mangrove and halophytic plants that are used in traditional medicine in India. To understand heavy metal toxicity, we investigated the bioconcentration factors (BCF) of heavy metals in leaves collected from eight mangroves and five halophytes in the protected Pichavaram mangrove forest reserve in Tamil Nadu State, south India. Data presented in this paper describe the impact of essential (Cu, Fe, Mg, Mn and Zn) and non-essential/environmentally toxic trace metals (Hg, Pb and Sn) in mangrove and halophytic medicinal plants. The concentrations of Pb among 13 plant species were higher than the normal range of contamination reported for plants. The average concentration of Hg in the halophytic plants (0.43+/-0.37mug/g) was seven times higher than mangrove plants (0.06+/-0.03mug/g) and it indicated pollutants from industrial sources affecting halophytes more than mangroves.     

Extracellular Biopolymer Production by Aureobasidium pullulans MTCC 2195 Using Jackfruit Seed Powder

In this present paper, statistical screening and optimization of jackfruit seed powder based medium components were investigated for pullulan production from Aureobasidium pullulans. Seven medium variables jackfruit seed powder, K₂HPO₄, yeast extract, (NH₄)₂SO₄, NaCl, MgSO₄·7H₂O and ZnSO₄·7H₂O were screened by employing Plackett–Burman (PB) method. PB method showed jackfruit seed powder, ZnSO₄·7H₂O, K₂HPO₄ and yeast extract were significant. Central composite design of response surface method applied to optimize the significant variables identified from the PB experiment. Statistical analysis of the experimental results showed optimal values were found to be jackfruit seed powder 2 % (w/v), K₂HPO₄ 0.55 % (w/v), yeast extract 0.30 % (w/v) and ZnSO₄·7H₂O 0.006 % (w/v) with maximum pullulan concentration of 18.76 (g/L). Maximum pullulan concentration of 17.95 (g/L) was observed in the validation experiment. This experimental result explained the model was fitted 96 % as compare with the result predicted by response surface method.     

Effective oil removal from water by magnetically driven superhydrophobic and oleophilic magnetic titania nanotubes

Development of efficient techniques to combat the harmful effects of oil spill is an emerging field, where fabrication of new sorbents for selective removal of oil has become a hot topic for environmental scientists. The present study reports the preparation of superhydrophobic/oleophilic magnetic titania nanotubes via a facile hydrothermal method, followed by the treatment with octadecylamine, as potential magnetically driven sorbent for selective removal of oil from water surface. The magnetic nature (superparamagnetism at 300 K) of the nanotubes enabled magnetic removal of the oil-sorbed material from water surface. Wettability test of the material depicted a static water contact angle of 166 ± 1°, indicating its superhydrophobic character. Oil uptake experiments and contact angle measurements revealed its superoleophilicity with maximum oil sorption capacity >1.5 g/g for a variety of oils. In addition to the ease of magnetic removal, the nanotubes possess sufficient buoyancy, high selectivity, and quick rate of oil uptake and is more than five times reusable.     

Histopathological studies and oxidative stress of synthesized silver nanoparticles in Mozambique tilapia (Oreochromis mossambicus)

To evaluate the potential environmental effects of engineered nano metals, it is important to determine the adverse effects of various nanomaterials on aquatic species. Adult tilapia (Oreochromis mossambicus) were maintained in 10 L glass aquaria, and exposed to a graded series of synthesized silver nanoparticles (Ag-NPs) at 25, 50 and 75 mg/L for eight days. The LC₅₀ value was 12.6 mg/L. Reduced activities of antioxidant enzymes and the contents of antioxidants were lowered in the gills and liver of fishes treated with Ag-NPs, which resulted in heavy accumulation of free radicals. Histopathological results imply that the balance between the oxidative and antioxidant system in the fish was broken down during Ag-NPs exposure. The principal concern related with the release of nanomaterials and their smaller particle may change the materials transport and potential toxicity to aquatic organisms compared to larger particles.     

Impact of climate change at species level: a case study of teak in India

In this study, we model the long-term effect of climate change on commercially important teak (Tectona grandis) and its productivity in India. This modelling assessment is based on climate projections of the regional climate model of the Hadley Center (HadRM3) and the dynamic vegetation model, IBIS. According to the model projections, 30% of teak grids in India are vulnerable to climate change under both A2 and B2 SRES scenarios because the future climate may not be optimal for teak at these grids. However, the net primary productivity and biomass are expected to increase because of elevated levels of CO₂. Given these directions of likely impacts, it is crucial to further investigate the climate change impacts on teak and incorporate such findings into long-term teak plantation programs. This study also demonstrates the feasibility and limitations of assessing the impact of projected climate change at the species level in the tropics.     

Electrocatalytic reduction of ortho nitrobenzaldehyde using modified aluminum electrode and its determination

A simple, cost effective and rapid electrochemical method has been developed for the determination of micro level ortho nitrobenzaldehyde（ONB） based on outstanding properties of modified aluminum electrode tin nanorods/anodic aluminum oxide/aluminum（SnNR/AAO/Al） for the first time. The SnNR/AAO/Al electrode was fabricated by a second step anodization, followed by electrodeposition and its electrochemical behavior was investigated in detail. The cyclic voltammetry results indicated that the SnNR/AAO/Al electrode exhibited efficient electrocatalytic activity toward reduction of ONB in the acidic solution. It provides an appreciable improvement of reduction peak for ONB at-0.721 V.Furthermore, various kinetic parameters such as transfer electron number, transfer proton number and standard heterogeneous rate constant were calculated from the scan rates.The electrocatalytic behavior was further exploited as a sensitive detection scheme for the ONB determination by differential pulse voltammetry. Under the optimized conditions, the concentration range and detection limit are 0.1-100 μmol/L and 0.05 μmol/L, respectively,for ONB. The analytical performance of this modified sensor has been evaluated for detection of real sample such as river water and recovery of ONB was achieved all-out up to102.3% under standard addition method.