Toxic mine drainage from Asia’s biggest copper mine at Malanjkhand,India

This paper has studied the environmental deterioration due to copper mining in Malanjkhand at Central-east India. No data is available on environmental degradation at the studied site although geological aspects are well studied. Mine drainage from the mines is definitively toxic. The site is also undergoing various stages of acid mine drainage (AMD) particularly from the heap leaching sites and the tailing area. AMD impacted water steam and sediment were also analysed. Results show substantial level of contamination of almost all segments of environment. Presence of elevated level of other heavy metal viz. Au, Ag, Pb, Cr, Cd, Fe, Cu and base metals like Na, K in AMD impacted water and sediments is due to metal leaching effect of AMD. Bio monitoring with the help of benthic macro invertebrates and metal accumulation in plants was also carried to know the impact of the toxic drainage. Results prove a very significant impact on the environmental health.     

Population dynamics of vibrio species in the river Narmada at Jabalpur

Several studies on the presence and ecology of various Vibrio sp have been reported in coastal and estuarine waters throughout the world, but there is trifling information available on the distribution of this organism of colossal pathogenic potential in the fresh water riverine environment. Thus, we conducted a multiyearenvironmental study to scrutinize the occurrence of members of genus Vibrio in the largest west flowing river of the Indian subcontinent, which is also the largest river of central India, the Narmada. Statistical analysis was done to reveal major environmental factors controlling the presence of Vibrio sp in the river Narmada. Monthly field samplings were conducted between January 2002 and December 2003 at four different sites in Jabalpur (MP), India. At each site, water samples were taken and physicochemical and bacteriological parameters were measured. The identity of the isolates was confirmed by employing 16S rRNA analysis. The organisms were found to be widely distributed in the river with regular seasonal variations. The density of Vibrio was found to be correlated with temperature, coliforms and other heterotrophic bacteria. Water temperature accounted for most of the variability in the concentration of Vibrio spAs typical fecal pollution indicators may not access public health risk from potential pathogens such as vibrios, hence special monitoring programme for vibrios may adequately be included in the water quality management.     

Ferrate(VI): green chemistry oxidant for degradation of cationic surfactant

Iron in its familiar form exists in the +2 and +3 oxidation states, however, higher oxidation state of iron +6, ferrate(VI) (Fe(VI)O(4)(2-)) can be obtained. The high oxidation power of ferrate(VI) can be utilized in developing cleaner ("greener") technology for remediation processes. This paper demonstrates the unique property of ferrate(VI) to degrade almost completely the cationic surfactant, cetylpyridinium chloride (C(5)H(5)N(+)(CH(2))(15)CH(3).H(2)O Cl(-), CPC). The Rate law for the oxidation of CPC by ferrate(VI) at pH 9.2 was found to be: -d[Fe(VI)]/dt = k[Fe(VI)][CPC](2). Ferrate(VI) oxidizes CPC within minutes and molar consumption of ferrate(VI) was nearly equal to the oxidized CPC. The decrease in total organic carbon (TOC) from CPC was more than 95%; suggesting mineralization of CPC to carbon dioxide. Ammonium ion was the other product of the oxidation. This is the first report in which Fe(VI)O(4)(2-) ion opens the pyridine ring and mineralizes the aliphatic chain of the organic molecule giving inorganic ions.     

Effects of UV-B radiation on the gills of Catla catla during early development

Scanning electron microscopic (SEM) study of gills of Catla catla catla (17-day-old) exposed to UV-B radiation (145?µW?cm^?2 at the water surface) for three different exposure times: 5, 10 and 15?min was conducted. Fish without UV-B exposure served as control. UV-B radiation damaged both gill filaments and lamellae. The intensity of damage was minimal in 5?min exposed fish, followed by 10?min exposed fish and maximal in 15?min. The gill epithelium was severely damaged in 15?min irradiated fish compared to control. Pavement cells (PVCs) were damaged and the numbers of microridges within PVCs decreased. The deep boundary of PVC was not clear. In some area of gill epithelium, PVCs were destroyed and mitochondrion-rich cells (MRCs) were exposed. The 5?min exposure reduced the number of microridges in the PVCs, but the boundary of PVCs was still visible. MRCs in the gill epithelium were not exposed in 5?min exposed fish. The damage to PVCs and subsequent exposure of MRCs in UV-B irradiated fish may hamper respiratory functions and disturb osmoregulation in catla.     

Acute toxicity of ammonia to a freshwater teleost,Labeo bata larvae

Ammonia toxicity tests were performed with Labeo bata (bata) larvae of three different size groups. One hundred percent survival of larvae (500.0?±?4.0?mg) was recorded when exposed to ammonia concentrations of 1.0–13.56?mg?L^?1 at 96?h of exposure. Bata larvae exposed to ammonia concentrations of 15.8–25?mg?L^?1 showed 10–74% mortalities. The 96?h LC₅₀ value for 200 (±5), 250 (±2) and 500 (±4) mg bata larvae were 11.5, 16.8 and 22.5?mg?L^?1 un-ionised ammonia concentrations, respectively. When fish were exposed to different doses of ammonia, behavioural changes immediately occurred even at the lowest dose. At first, the fish became hyperexcitable, the skin darkened and they showed an increased ventilation frequency, fish behaviour became normal, 24?h after exposure. A 96?h LC₅₀ value of un-ionised ammonia showed direct relationship with the increasing size of bata larvae.     

Monitoring toxicity of an azo dye methyl red and a heavy metal Cu,using plant and animal bioassays

Toxicities of an azo dye methyl red and a heavy metal copper (Cu) were quantified, using growth and mortality as end points, in four plant species and three animal species by subjecting them to short-term (4 days for animals, 10 days for plants) static bioassays. Lemna aequinoctialis Welwitch (EC₅₀: 7–16 ppm) was found to be the most sensitive species for methyl red, Ceratophyllum demersum L. (EC₅₀: 25 ppm) and Lactuca sativa L. (EC₅₀: 56 ppm) were intermediate, while Oryza sativa L. shows reduction in seedling vigor (9–27%) of <50%, being the least sensitive amongst the tested plant species. Methyl red toxicity is almost 3–5-fold higher in growing medium (pH = 5.8–6.0), even at high nutrient levels, while Cu toxicity is higher in nutrient-poor alkaline medium at alkaline pH (8.3–8.7; EC₅₀: Ceratophyllum = 104–200 ppb; Lemna = 100–170 ppb) compared to nutrient-rich acidic medium (pH = 5.4–5.7; EC₅₀: Ceratophyllum = 2600–3175 ppb; Lemna = 4350–4715 ppb). Rice tolerance (EC₅₀: 6500 ppb) was found to be higher than hydrophytes while lettuce was most tolerant to Cu. Fish sensitivity toward the test chemicals was almost parallel to Ceratophyllum and Lemna [Gambusia affinis Baird and Gerard (LC₅₀: 250 ppb for Cu) and Poecilia reticulata Peters (LC₅₀: 24 ppm for methyl red)]. Similar to the plants, dye toxicity increased markedly (LC₅₀: 7 ppm) in the acidic medium (pH = 6.0). Amongst the tested organisms, Daphnia was found to be most sensitive to methyl red (EC₅₀: 6 ppm) while its sensitivity to Cu (EC₅₀: 230 ppb) was similar to hydrophytes and fish. Initially, the combination of dye and Cu (at their sublethal concentrations) had additive effects in duckweed, while dye concentration ruled afterward. These results indicate that hydrophytes and animals are equally sensitive toward the test chemicals. Dye toxicity in hydrophytes and fish was pH dependent, while in the case of Cu, it is related to the nutrient status of the growth medium of plants.     

Development and validation of a spectrophotometric method for soil adsorption study of malathion on three Indian soils

In view of the widespread use of pesticides in agriculture and its associated toxic effects on environment and human beings, the fate of these chemicals in soil is of major concern. The pesticide adsorption process is one of the major factors affecting its persistence and movement in the soil. With a view of studying the fate of malathion in soil, the adsorption of this insecticide was studied on three Indian soils by using batch equilibrium method. To carry out the adsorption study, a new simple, sensitive, and rapid method was developed, based on microwave-assisted alkaline hydrolysis of insecticide to the dimethyl dithiophosphate and its subsequent reaction with copper(I) perchlorate in acetonitrile. On mixing the reagents, a yellow color developed, which was stable for 120?min and was measured at 419?nm. The adsorption of malathion was studied by using Freundlich's adsorption equation and n _f values were observed less than 1 in all the soils. The leaching behavior of the insecticide was studied in terms of ground ubiquity score, which was below 1.8, classifying malathion as non-leacher pesticide, and hence it is not hazardous.     

Applications of natural polysaccharide-based beads for slow release herbicide formulation

This work deals with the use of polysaccharide-based beads for controlled release of the herbicide atrazine. This article discusses the release of the herbicide atrazine from neem-alginate-clay-based beads. Formulation characteristics such as entrapment efficiency, bead size, and diffusion mechanism for release of atrazine have been evaluated.     

Synthesis and characterization of an ion exchanger based on tamarind kernel powder and its application for removal of some metal ions from industrial effluents

A resin synthesized from tamarind kernel powder possesses high selectivity for metal ions. Distribution coefficients for some metal ions has been determined by the batch method. The influence of pH on ion exchange capacity and K _d value of metal ions were studied. The resin has been characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, chemical composition and ion exchange capacity (IEC). The selectivity order is Pb²⁺?>?Cu²⁺?>?Fe²⁺?>?Zn²⁺?>?Ni²⁺. Removal of metal ions from the aqueous solution and from effluents of a steel mill has been studied.     

Sorption and leaching behavior of hexaconazole as influenced bysoilproperties

Sorption and leaching behavior of hexaconazole in four different soils (alluvial, red, laterite, and black) was studied using a batch equilibration technique. The values of the Freundlich adsorption constant 1/n_ads ranged from 0.75 to 0.85 for all four soils, showing strong non-linear behavior. Upon stepwise desorption with CaCl₂ solution (10 mmol·L^?1), release of hexaconazole was maximum with the first elution, the amount decreasing with each subsequent one. The leaching behavior under saturated flow conditions was also studied with soil columns packed in polythene tubes. The mobility of hexaconazole was maximum in sandy loam and minimum in black soil.