The present study proposed the use of Chir pine leaves (Pinus roxburghii) to remove As(V) ions from aqueous solutions. The influence of different sorption parameters such as the adsorbent dose, solution pH, contact time, agitation speed, and initial arsenic concentration were studied thoroughly to evaluate optimum conditions. Maximum adsorption has taken place at pH 4.0 while equilibrium was achieved in 35 min. Langmuir, Freundlich, Temkin, Elovich, Dubinin-Radushkevich and Flory-Huggins isotherm models were used to explain the phenomenon. Maximum adsorption capacity of P. roxburghii was 3.27 mg/g that was compared with the capacities of some previous adsorbents used for arsenic removal. Heat of sorption was close to 50 kJ/mol. Adsorption mechanism was explored by Pseudo first- and second-order kinetic models, and it was found that the process followed second order kinetics. The study concluded that the Chir pine leaves can be a good adsorbent for removing As(V) from water owing to the fine adsorption capacity. (C) 2011 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Herbicidal activity of culture filtrates of four Drechslera spp.,namely D. australiensis (Bugnic.) Subram. & B.L. Jain, D.biseptata (Sacc. & Roum.) M.J. Richardson & E.M. Fraser, D.hawaiiensis Bugnic. ex M.B. Ellis, and D. holmii (Luttr.) Subram.& P.C. Jain, prepared in malt extract broth was investigatedagainst parthenium weed ( Parthenium hysterophorus L.) in bothlaboratory bioassays and pots. In laboratory bioassays, the effect oforiginal (100%) and diluted (50%) culture filtrates of the fourDrechslera spp. was studied on parthenium germination and seedlinggrowth in 90 mm diameter Petri plates. Original culture filtrate of allthe four Drechslera species significantly reduced germination, shootlength, shoot fresh biomass, root length, and root fresh biomass ofparthenium seedlings by 43 to 77%, 77 to 82%, 69 to 82%, 90 to 92%, and67 to 83%, respectively, as compared to the control. In pot trials,foliar application of original fungal culture filtrates was carried outon 1-wk and 2-wk old parthenium seedlings. Culture filtrates of all thefour Drechslera spp., except D. holmii, markedly reduced partheniumshoot dry weight. Two-week-old plants were more susceptible to foliarspray than the 1-wk old plants. There was a 13 to 55% and 28 to 65%reduction in shoot dry weight of 1-wk and 2-wk old parthenium plants,respectively, due to culture filtrates of various Drechslera spp. Thepresent study concludes that Drechslera spp. culture filtrates can beused as alternative herbicides for parthenium weed management.

Antibacterial activity of peel essential oils of various Pakistani Citrus species viz. fewtrell’s early [ Citrus reticulata (L.) var. Tangerine], orange [ C. reticulata (L.) var. Mandarin], mousami [ Citrus sinensis (L.) var. Mousami], malta [ C. sinensis (L.) var. Malta], grapefruit ( Citrus paradisi Macf.) and Eureka lemon (Citrus limon L.) were evaluated against food-borne bacteria namely Escherchia coli, Salmonella typhii, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas fluorescence, Proteus myxofaciens, Staphylococcus epidermidis and Streptococcus sp. The peel essential oil yield of the C. reticulata var. Mandarin, C. reticulata var. Tangerine, C. sinensis var. Malta, C. sinensis var. Mousami, C. limon and C. paradisi were 0.32, 0.24, 0.22, 1.21, 0.05 and 0.21%, respectively. The disc diffusion method was used to evaluate the inhibition zones of bacterial growth at two concentrations (5 and 10 ul) of the oil and results were compared with cefipime, a commercial antibacterial agent. Essential oils of C. reticulata var. Mandarin showed highest antibacterial activity followed by essential oils of C. lemon . Essential oils of C. paradise and C. sinensis var. malta exhibited least antibacterial activity. Among the various bacterial species, S. typhii and P. myxofaciens were found most susceptible to various Citrus peel essential oils. Present study concludes that essential oils of C. reticulate var. Mandarin have a broad spectrum antibacterial activity against food spoilage bacteria.

The present study reports the biosorption potential of chemically pretreated mycelial biomass of fungus Aspergillus niger van. Tieghem for Cu(II) and Ni(II) ions from aqueous phase. Fungal biomass was pretreated with different types of alkaline/salts (NaOH, NaHCO3, Na2CO3, NaCl & CaCl2,), acids (HCl & H2SO4) and detergent. Pretreatment of biomass with Na2CO3 and NaOH were proved to increase or maintain adsorption efficiency and capacity in comparison to untreated biomass. Pretreatment with NaHCO3, detergent, NaCl and CaCl2 significantly reduce (10-40%) metal sequestering efficiency of the adsorbent. Whereas, acid treatments resulted in drastic loss (80%) in metal uptake efficiency of the biomass. Amongst various pretreatments, Na2CO3 could be use efficiently for the removal of Ni(II) and Cu(II) ions from aqueous solution using A. niger.

This study was carried out to investigate the prospects of using methanolic extracts and residue of wheat (Triticum aestivum L.) for the management of parthenium (Parthenium hysterophorus L.), one of the world's worst weeds.In a laboratory bioassay, the effect of methanol extracts of 1, 2, 3, 4 and 5% (w/v) concentrations of four wheat varieties namely: AS 2002, Inqalab 91, Ufaq and Uqab was studied against the germination and seedling growth of parthenium.Extracts of all the four wheat varieties suppressed germination as well as root and shoot growth of the seedlings.In soil amendment bioassay, dried and chopped wheat straw of the four test wheat varieties was thoroughly mixed in pot soil at 0.5, 1.0 and 1.5% (w/w).Pots were irrigated with tap water and left for one week followed by sowing of seeds in these pots.The effect of residue incorporation of all the wheat cultivars was insignificant on germination of parthenium seeds.However, all the residue incorporation treatments significantly reduced the survival percentage of the parthenium seedlings.Root and shoot growth in terms of length, and fresh and dry biomass were also significantly suppressed by residues of all the four test wheat cultivars.This study concludes that parthenium weed can effectively be managed by amending the soil with wheat residue.

The present study explores the adsorption potential of Pleurotus ostreatus (a macro-fungus) to remove copper, nickel, zinc and chromium from water all together. Different operational parameters such as the effect of pH, biomass dose, equilibrium time, stirring intensity, temperature and initial metal ion concentrations were studied. Maximum adsorption of Ni (II), Cu(II) and Zn(II) took place in the pH range 4.5-5.0, whereas for Cr(VI) ion, best results were achieved at pH 2.5. Nearly 150 mm are required to gain sorption equilibrium. Temperature has no significant effect on biosorption in the range of 20-45 degrees C. The maximum biosorption capacity of fungus was 8.06, 20.40, 3.22 and 10.75 mg g(-1) for Cu(II), Ni(II), Zn(II) and Cr(VI) in that order. FTIR analysis pointed out the involvement of amine (-NH2) and carboxylic (-COOH) groups in the adsorption process. Simple and adjusted Langmuir and Freundlich isotherm models were used to explain the sorption phenomenon. For real effluents of electroplating, biosorption capacities were 2.73, 8.45, 0.88 and 4.45 mg g(-1) for Cu(II), Ni(II), Zn(II) and Cr(VI) ions, respectively. Moreover, used P. ostreatus was recycled repeatedly and used many times to evaluate the adsorption efficacy on reuse, but findings pointed out that capacity decreased, to some extent, on recycling. (C) 2010 Elsevier Ltd. All rights reserved.

Biomass of a wood rotting fungus viz., Schizophyllum commune Fries was utilized for the treatment of electroplating wastewater that contained Cu(II), Ni(II), Zn(II) and Cr(VI) ions. Preliminary batch assays were conducted with synthetic pure metal-bearing solutions. Results obtained showed that among various parameters studied, solution pH between a range of 2.0-6.0 induced negligible uptake at pH < 3.5 and exhibited maximum at around 4.5-5.5 for Ni(II), Cu(II) and Zn(II) ions, while for Cr(VI) ion the highest was evidenced at pH 2.0-2.5. The kinetics of all metal ions was fast and biosorption equilibrium was established in 1 hour with appropriateness of pseudo-second-order. A temperature change in the range of 15–45 ◦ C did not affect the biosorption capacity of the candidate fungus. The biosorption of metal ion increased on elevating initial metal ions concentrations (20-100 mg L -1 ) in the medium. The maximum biosorption capacity of fungus biomass was 9.0, 21.27, 4.83, 18.54 mg g -1 for Ni(II), Cu(II) and Zn(II) and Cr(VI), respectively. The experimental data was best adjusted by Langmuir, Freundlich and modified Langmuir models. Biosorption assays conducted with actual electroplating effluents under pre-optimized conditions revealed efficiency of 72.01, 53.16, 7.08 and 19.87% for Cu(II), Ni(II), Zn(II) and Cr(VI) ions, respectively by candidate biomass.

In a pot study, effect of 5 and 10% (w/v) aqueous straw extracts of allelopathic rice (Oryza sativa L.) variety 'Super Basmati' was investigated on growth. yield, nodulation and arbuscular mycorrhizal (AM) colonization of 8 mungbean [Vigna radiata (L.) Wiczek] cultivars (AUM-19, AUM-27, AUM-38, AUM-7375, N-2, N-5, N-8 and N-9). The 10% extract significantly enhanced the shoot and root dry biomass of cv. AUM-27. Contrarily, 5% extract decreased the shoot biomass in cv. N-8 and 10% extract reduced the root biomass in cv. AUM-7375. The 5% extract increased both number and biomass of nodules in cv. AUM-19, while 10% extract decreased them in cv. N-9. The 5 or 10% extract increased the grain yields in AUM-19, AUM-27, AUM-38 and AUM-7375. Conversely, these extracts decreased the grain yields in cv. N-9. The 10% rice extract markedly enhanced the mycorrhizal colonization in N-5, N-8 and N-9 cultivars. The study concluded that for better grain yield under rice allelopathic stress, AUM cultivars of mungbean Should be cultivated.

This study evaluated the in vitro antifungal activity of aqueous, methanol and n-hexane shoot extracts (0, 1, 3 and 5%) of three rice varieties (Basmati-385, Basmati-386 and Basmati Super) against two phytopathogenic fungi [Ascochyta rabiei (Pass.) Lab. and Macrophomina phaseolina (Tassi) G. Goid]. Aqueous and n-hexane extracts significantly suppressed the in vitro growth of M. phaseolina. The aqueous and n-hexane extracts of different rice varieties caused 21-52% and 18-60% reduction in growth of M. phaseolina, respectively. However the effect of methanol extracts was non-significant. A. rabiei proved less susceptible to these extracts as compared to M. phaseolina. Only 1% aqueous extracts of Basmati 385 and Basmati 386 significantly declined the growth of this fungus, while, all other extracts either had insignificant effect or stimulated the fungal growth.

The present study reports the effect of viral infection on arbuscular mycorrhizal colonization in three weed species namely Ageratum conyzoides L., Croton sparsiflorus Morong and Malva parviflora L. Percentage of mycelial, arbuscular and vesicular colonization was recorded on the bases of presence or absence of these structures in twenty 1 cm root pieces. Extent of mycorrhizal colonization was recorded as cm/100 cm of root length. Arbuscular and vesicular infections were quantified by counting these structures per cm of root length. Mycorrhizal infestation was invariably absent in healthy plants of all the three test weed species. Moderately diseased plants of all the three weed species exhibited mycorrhizal colonization. In M. parviflora mycorrhizal colonization and especially the number of vesicles was increased with increase in disease severity. However, in rest of the test weeds, the plants showing severe viral infections did not harbour any mycorrhizal colonization.

article extends the study on the removal of Cr(III) ions by utilizing Basidiomycetous fungus viz., Pleurotus ostreatus (Jacq.) Quelet from aqueous solution. To predict the biosorption performance of the test fungus with actual wastewater of tannery, laboratory assays were conducted with synthetic pure metal- bearing solutions. Oven dried biomass of test fungus was utilized to evaluate the effect of pH, stirring intensity and initial metal ion concentrations. Results revealed optimum pH 4.5, stirring intensity 150 rpm, with increase in removal rate on increasing metal ion concentrations (4-20 mgL -1 ) in the medium. The Langmuir and Freundlich models use to check the distribution of metallic ions between liquid and solid phase adequately described all experimental data on sorption capacity of the test fungus. On exposure of fungal biomass in tannery effluents 55% of biosorption efficiency for Cr(III) ions was obtained. To amplify this potential for prospective commercialization of biotechnology through the test fungus, the production of fungus was carried out on the economically cheaper substrates viz., rice straw, wheat straw and cotton waste. The results clearly indicated among the agro-wastes (colonized) best removal efficiency was recorded for wheat straw (80-90%). Due to the low cost involved and simplicity of the technique, wheat straw colonized with P. ostreatus could be utilized as an excellent biosorbent for removal of Cr(III) ions from tannery wastewater containing low concentration of the metal.