Effect of temperatures and pH on methyl violet biosorption by Mansonia wood sawdust

In this study, the effect of temperature on the equilibrium biosorption of methyl violet dye from aqueous solution using Mansonia wood sawdust was studied. The equilibrium biosorption data were analyzed using three widely applied isotherm models; Langmuir, Freundlich and Redlich–Peterson isotherm. The fit of three linear Langmuir isotherm forms, the Freundlich isotherm, and the Redlich–Peterson isotherm were determined using linear and the non-linear methods. Langmuir isotherm parameters obtained from the three Langmuir linear equations by using linear method were dissimilar, except, when the non-linear method was used. Best fits were yielded with Langmuir and Redlich–Peterson isotherms. The methyl violet biosorption was strongly dependent solution pH and percentage dye removal became significant above pH 7, which was slightly higher than the pH_PZC of the sawdust material. In addition, various thermodynamic parameters, such as ΔG°, ΔH°, and ΔS° were calculated. Results suggested that the biosorption was a spontaneous and endothermic process.     

Adsorption Evaluation of Herbicide Iodosulfuron Followed by Cedrus deodora Sawdust-Derived Activated Carbon Removal

The paucity of sorption studies of sulfonylurea herbicide Iodosulfuron has led to the current research for investigation of this imperative phenomena. Iodosulfuron adsorption capacity was evaluated through batch equilibrium experiments in six soil samples collected from distinct geographical regions of Pakistan. Activated carbon prepared from sawdust (Cedrus deodara) was investigated as an economical and sustainable adsorbent for the removal of Iodosulfuron from selected soils. Removal efficiency was studied as a function of contact time and pesticide concentration. Results exhibited a good adsorption capability of Iodosulfuron in different soils. Adsorption coefficient values ranged from 8.9 to 26 mL/g. Soil pH and organic matter greatly influenced the rate of adsorption. The linear adsorption model fitted best with the experimental results. Gibbs free energy values (?17 to ?20 kJ/mol) proposed physisorption and exothermic interaction of Iodosulfuron with selected soils. Analysis of variance and regression displayed a negative correlation of soil pH and K_d (R² = ?0.91) and positive correlation with organic matter (R² = 0.87). A good removal rate for was observed in soils by sawdust-derived activated carbon. Soil properties mainly; pH, organic matter and sand content greatly influenced Iodosulfuron removal phenomena. Biomass-derived activated carbon can thus be utilized as a sustainable remediation tool.     

Mechanical and Morphological Properties of Wood Plastic Biocomposites Prepared from Toughened Poly（lactic acid） and Rubber Wood Sawdust （Hevea brasiliensis）

The present research aims to utilize the acrylic Core-Shell Rubber （CSR） particles to reduce the brittleness in Wood Plastic Composites （WPC） prepared from poly（lactic acid） （PLA） and rubber wood sawdust （Hevea brasiliensis）. Experimental works consisted of two major parts. The first part concentrated on toughening PLA by using CSR particles. Mechanical tests revealed that PLA had become tougher with a more than five times increment in the impact strength when the CSR was added at only 5 wt%. The modified PLA was less stiff with the significant reductions of both elastic and flexural moduli and strengths. The second part focused on producing WPC from the toughened PLA and rubber wood sawdust. The tensile moduli and the strengths of the PLA composites increased with rubber wood content. The composites turned out to be more brittle with reductions of both the impact strength and the tensile elongation at break at all the sawdust contents. Toughening PLA/wood flour with 5 wt% CSR improved both the impact strength and the tensile elongation at break. The toughness enhancement was also depicted by the plastic deformation observed on the surfaces of fractured PLA/CSR/wood sawdust composites.     

Manipulating the Quantity, Quality, and Manner of C Addition to Reduce Soil Inorganic N and Increase C4:C3 Grass Biomass

Applying C to soils has been proposed as a plant community restoration tactic because it has been shown to immobilize inorganic N, which should confer a competitive advantage to slower growing plants that are often key components of the desired plant community. Disparate experimental and survey results have led to questions about the appropriate quality and quantity of C to apply. We conducted a single‐season glasshouse experiment in three soil types to determine how the quality (sugar, sawdust, sugar + sawdust), quantity (1 and 5 kg sugar or sawdust/m²), and mode of application (surface applied or mixed into soil) of C affected soil inorganic N pools, net mineralization rates, and aboveground biomass of coexisting C3 and C4 plant species. Carbon applied as sawdust mixed into the soil resulted in the highest level of immobilization in the short term (6 weeks), but all combinations and rates of sugar and sawdust application resulted in immobilization over this period. In the long term (24 weeks), most amendments immobilized N and suppressed aboveground biomass of the C3 grass, Bromus inermis, but the high rate of sugar resulted in the strongest immobilization and C3 suppression. However, this treatment also maintained the highest soil inorganic N pool at season’s end, which calls into question its effectiveness if longer‐term benefits are desired. Neither net mineralization rates nor soil inorganic N pools were correlated to the ratio of C4 to C3 plant biomass at season’s end indicating that the mechanisms for favorable plant response to C addition are not understood.     

Response of Plant Parasitic and Free Living Soil Nematodes to Composted Animal Manure Soil Amendments

In an outside pot experiment, dry pig manure processed on pine sawdust litter and fermented for seven days by house fly larvae (fermented manure), and pine sawdust applied alone, and in combination with a spring application of inorganic nitrogen fertilizer were used to determine their effects on plant parasitic and free-living soil nematodes on sugar beets (cv. Antek). Non amended soil was used as a control. All treatments with fermented pig manure and sawdust with nitrogen fertilizer decreased number of plant parasitic nematodes and also root-fungal feeding nematodes compared to the untreated control. Sawdust applied alone had no effect on plant parasitic and root-fungal feeding nematode suppression. Free-living nematodes which were mainly bacteriovores and fungivores were significantly more abundant in soil amended with fermented pig manure, while the sawdust had no effect on these nematodes. The effect of all tested treatments on omnivores-predators was rather random, and in general, the number of these nematodes decreased after soil amendment applications compared to the untreated control.     

Assessment of the feasibility of using CCA (copper,chromium and arsenic)-treated and boric acid-treated sawdust as soil amendments

A pot trial was conducted to determine the effects, on plant growth and element uptake, of soil amendment with Cu- Cr- and As-(CCA) treated, or boric-treated sawdust. Three indicator plants (beetroot, white clover, lettuce) were chosen and the trial was carried out at both soil pH 5 and pH 7. Comparisons were made with an untreated sawdust amendment and with a non-sawdust control. Amendment with 10% treated-sawdust (v/v) increased soil concentrations of Cu, Cr, As and B, by 45, 136, 63 and 32 mg kg^-1, respectively. Much of the Cu and B was extractable using standard soil extractants, but extract concentrations of Cr and As were below detection limits. Seeds germinated in all pots, but the boric treatment subsequently proved unsatisfactory as a growth medium for all plants except beetroot grown at pH 7. The CCA treatment had no negative effect on any of the plants at either pH, but yield depression occurred with untreated sawdust. This was attributed to nutrient immobilization by the decomposing untreated sawdust. Plant roots, especially beetroot fibrous roots, in the CCA treatment, concentrated Cu, Cr and As to high levels. Uptake of these elements was generally higher at pH 5 than at pH 7. However, the above-ground parts of the plants, and the beetroot bulbs, i.e. the normal edible parts, had very much lower concentrations. Although Cu was concentrated to some extent in beetroot and clover, the concentrations were below animal toxicity levels, especially at the higher soil pH. B, in contrast, was concentrated in the above-ground portions of the plants, in preference to the roots. These treatments had no important effects on the uptake of major and minor nutrient elements by the plants. Clover nitrogen-fixation was not adversely affected by the CCA treatment, but was totally absent in the boric treatment. These rerults are discussed, and the need to conduct tests on a wider range of edible plants before concluding that amendment with CCA-treated sawdust may be acceptable, is stressed.     

Can Carbon Addition Increase Competitiveness of Native Grasses? A Case Study from California

There is growing interest in the addition of carbon (C) as sucrose or sawdust to the soil as a tool to reduce plant‐available nitrogen (N) and alter competitive interactions among species. The hypothesis that C addition changes N availability and thereby changes competitive dynamics between natives and exotics was tested in a California grassland that had experienced N enrichment. Sawdust (1.2 kg/m) was added to plots containing various combinations of three native perennial bunchgrasses, exotic perennial grasses, and exotic annual grasses. Sawdust addition resulted in higher microbial biomass N, lower rates of net N mineralization and net nitrification, and higher concentrations of extractable soil ammonium in the soil. In the first year sawdust addition decreased the degree to which exotic annuals competitively suppressed the seedlings of Nassella pulchra and, to a lesser extent, Festuca rubra, both native grasses. However there was no evidence of reduced growth of exotic grasses in sawdust‐amended plots. Sawdust addition did not influence interactions between the natives and exotic perennial grasses. In the second year, however, sawdust addition did not affect the interactions between the natives and either group of exotic grasses. In fact, the native perennial grasses that survived the first year of competition with annual grasses significantly reduced the aboveground productivity of annual grasses even without sawdust addition. These results suggest that the addition of sawdust as a tool in the restoration of native species in our system provided no significant benefit to natives over a 2‐year period.     

Volvariella-treated Eucalyptus sawdust stimulates wheat and onion growth

Conversion of sawdust, a major waste generated by the timber industry, to an agricultural supplement was explored. Beds made with a mixture of Eucalyptus sawdust and soil reduced the chlorophyll content and the growth rate of wheat seedlings. However, following treatment with Volvariella volvaceae and urea, the sawdust in growth beds enhanced both the chlorophyll content and growth of wheat seedlings. Application of treated sawdust to soil increased the biomass of both bulb and foliage of onion. This represents a small beginning in the conversion of an industrial solid waste into a soil conditioner for enhancing agricultural productivity.     

Fermentation of lignocellulosic hydrolysate by the alternative industrial ethanol yeast Dekkera bruxellensis

Aim: Testing the ability of the alternative ethanol production yeast Dekkera bruxellensis to produce ethanol from lignocellulose hydrolysate and comparing it to Saccharomyces cerevisiae. Methods and Results: Industrial isolates of D. bruxellensis and S. cerevisiae were cultivated in small‐scale batch fermentations of enzymatically hydrolysed steam exploded aspen sawdust. Different dilutions of hydrolysate were tested. None of the yeasts grew in undiluted or 1 : 2 diluted hydrolysate [final glucose concentration always adjusted to 40 g l^?1 (0·22 mol l^?1)]. This was most likely due to the presence of inhibitors such as acetate or furfural. In 1 : 5 hydrolysate, S. cerevisiae grew, but not D. bruxellensis, and in 1 : 10 hydrolysate, both yeasts grew. An external vitamin source (e.g. yeast extract) was essential for growth of D. bruxellensis in this lignocellulosic hydrolysate and strongly stimulated S. cerevisiae growth and ethanol production. Ethanol yields of 0·42 ± 0·01 g ethanol (g glucose)^?1 were observed for both yeasts in 1 : 10 hydrolysate. In small‐scale continuous cultures with cell recirculation, with a gradual increase in the hydrolysate concentration, D. bruxellensis was able to grow in 1 : 5 hydrolysate. In bioreactor experiments with cell recirculation, hydrolysate contents were increased up to 1 : 2 hydrolysate, without significant losses in ethanol yields for both yeasts and only slight differences in viable cell counts, indicating an ability of both yeasts to adapt to toxic compounds in the hydrolysate. Conclusions: Dekkera bruxellensis and S. cerevisiae have a similar potential to ferment lignocellulose hydrolysate to ethanol and to adapt to fermentation inhibitors in the hydrolysate. Significance and Impact of the study: This is the first study investigating the potential of D. bruxellensis to ferment lignocellulosic hydrolysate. Its high competitiveness in industrial fermentations makes D. bruxellensis an interesting alternative for ethanol production from those substrates.