Advanced Materials Research Vols. 396-398

Abstract: Electroplating sludge is always listed as hazardous waste due to the high content of heavy metals. The most economical and available way for disposal of sludge is soil application of sludge compost, and the major limitation in agriculture utilization is the total heavy metal contents and their bioavailability to the soil–plant system. The effect of composting on the speciation of heavy metals in an electroplating sludge was studied, and the potential environmental impacts were also assessed. The electroplating sludge was composted with rice straw and sawdust by static aerobic method at high temperature with forced ventilation. Results showed that the exchangeable species of copper and nickel were significantly decreased after the compost procedure, and the other kinds of species were increased differently. Data in this research indicated that composting can reduce the activity of heavy metals to some extent to achieve the agricultural use.

Abstract: Deep fermentation of brewer's spent grain (BSG) can improve its feeding effectiveness, and it is also an effective way to solve the problem of shortage of proteins source. The interrelated factors affecting the productivity of proteins in fermentation process by effective microorganisms (EM), such as inoculum size, temperature, initial pH and time, were studied and the technique to produce protein feed was also optimized by a serial of single factors and orthogonal design tests. Results showed that the optimal conditions were 4 % of inoculum size, 28 °C of fermentation temperature, 4.0 of initial pH and 3 d of the fermentation time. Under the obtained optimum fermentation conditions, the content of crude proteins increased by 24.48 % and the content of crude fiber decreased by 17.45 % compared with the control experiment. The increased content of proteins indicated the added-value products in animal feed and the significance in its disposal as an environmental problem.

Abstract: The present investigation was conducted to degrade mixed-organic wastes using composting with the optimal parameters of pH, temperature, the ratio of carbon and nitrogen (C/N), moisture and oxygen contents. All these procedures can be carried out within a period of 30 days. After composting, we recorded decreases in total heavy metal contents and ascarid-egg mortality, significant increases of the humus, organic matter, nitrogen, phosphorus and potassium contents and the microorganism numbers in the compost. Furthermore, 6 strains of thermophilic bacterial were isolated from the produced compost. On the basis of their small-subunit ribosomal RNA-encoding DNA (rDNA) sequences and in comparison with authentic strains, the 6 strains were identified as belonging to Paenibacillus polymyxa and Bacillus species and thereby concluded to be the dominant microflora in the composting process.

Abstract: Systematic experiments were carried out with synthetic wastewater in order to investigate the operating conditions and kinetics of wastewater treatment in a three-phase biological fluidized bed reactor. It is found that with the COD loading rate changed stepwise from 3.5 to 11.2 kg COD/m3•d, the reactor can rapidly restore from each impact of COD load and maintain the removal rate for COD at 85% or above, presenting a high flexibility for the variation of organic loading rate (OLR) in the influent. While the operating OLR keeps constant, the increase of influent COD and NH₃-N concentrations will be followed by the correspondingly increased removal rates, so that the COD and NH₃-N concentrations in the effluent keep nearly constant. The batched experiments under different air supply conditions show that there exists an optimal air flow rate at which the most effective treatment can be achieved. Finally, a kinetics model of the continuous treatment process was derived based on mass balance and Monod equations, and the kinetic constants were determined by the experimental data at steady operating OLR.

Abstract: Based on a modified Carrousel oxidation ditch process acclimated with synthetic wastewater，effect of SRT on nitrogen and phosphorus removal occurred in the system was investigated. The results indicated that SRT was prominent to nitrogen and phosphorus removal. The removal efficiency of nitrogen was better with SRT extension and that the removal efficiency of phosphorus was better with SRT shortness. With the operation conditions of water temperature 30°C, SRT 11days, the removal efficiency of TN and TP reached 85.4% and 74.9%, which indicated that nitrogen and phosphorus removals were best.

Abstract: Application of brown hair fiber, ramie fiber, jute fiber and flax fiber to degrade PAHs in water was studied. The experimental results show that the plant fibers which enrich the microbial has better effect of degradation on PAHs in water,and the degradation effects are highly related with plant fiber’s layout density,HRT and aeration rate. The higher the layout density of jute fiver,HRT and aeration rate,the better the effects of decontamination,which means the water quality of effluent meets the GB5749-2006 standard that the total content of PAHs is less than 2000 ng•L-1. Select No11~No14 Tank plant fiber density,6h HRT and 12h aeration,the effect of degradation of PAHs is the best. This result shows that microbial enriched by plant fiber has a good effect of degrading PAHs in water. Plant fibers provide a space as large as possible for indigenous bacteria attached to the growth in water,and also provide a good micro-environment for their biochemical reaction. The indigenous microorganisms attached to the surface of plant fibers rapidly grow to achieve strengthen the natural degradation of the PAHs in water. Except the biodegradable role of plant fiber enrich the microorganisms to degrade PAHs,in addition,there also exists absorption and evaporation effects. Macrocyclic PAHs ring has a more strong hydrophobicity than the small ring,so that in the process of biodegradation,the small ring is more easily to be absorbed by the plant fiber and biofilm surface,and more easily to be degraded. Therefore,plant fiber enriched microbial to degrade PAHs is the main process,then followed by adsorption and evaporation process.

Abstract: A bacterial strain WZS-A which could effective decololorize Safranine T, was screened and isolated from soil sample in Wenzhou. It was preliminary identified as Pseudomonas aeruginosa according to its 16S rDNA gene sequence. The strain WZS-A can use Safranine T as the sole carbon and energy source. The isolate grow optimally at 30°C and pH 7.0 respectively, and its decoloration rate for 250mg/L Safranine T could achieve 90%.

Abstract: The hyperspectral bands sensitive to the disease severity levels of wheat powdery mildew was elucidated in this study. The disease severity levels of wheat powdery mildew were also inverted by the extracting characteristic parameters, which provided a basis for detecting the wheat powdery mildew using hyperspectral data. The spectral data of single leaves was obtained at heading stage, the spectral characteristic parameters and sensitivity of wheat leaves were analyzed qualitatively and quantitatively. The result showed that spectral reflectivity within the visible wavebands (400—760 nm) was increased with the aggravating disease severity levels. The spectral sensitivity reached the maximum value within visible wavebands and the optimal sensitive bands for detecting disease severity levels was 630—680nm. After the spectrum was continuum removal-treated, the absorption position moved to longer wavelength with the aggravating disease severity levels and the disease severity levels showed extremely significant negative correlations with the absorption height, absorption width and absorption area. The linear regression equation has high determination coefficient and low root mean square error using the right AAI as independent variable to establish the model. Moreover, the precision verification test also showed that the model performed best in monitoring wheat powdery mildew. In conclusion, disease severity levels of wheat powdery mildew could be inverted effectively by hyperspectral technology, which provides the foundation for detecting wheat powdery mildew.

Abstract: Continuous processing in the microreactor represents a novel way for the safe and expedient conduct of high energetic nitration. Apart from handling benefits,nitration in microreactors proceed under precisely controlled conditions providing improved yields and selectivity. This paper studied the nitration of toluene in the microglass reactor using concentrated nitric acid as the nitrating agent and SO₃H-functional ionic liquids, Lanthanide(iii) trifluoroacetate as recyclable catalysts. We described a mild, efficient process for the nitration of toluene.

Abstract: Abstract. Two applied synthesis techniques of bentazone were introduced including the disadvantages. Innovative adjustments were developed to eliminate the produce of waste water in isatoic anhydride route, and determined as: DMF as the solvent of o-amino-benzoyl isopropylamine preparation, based on certain treatments bentazone sodium salt solution as the product, soda lime as hydrolysis reagent to eliminate phosphorus oxychloride. With 95% recycling rate of 2-methyl pyridine, in the sodium salt aqueous solution, bentazone was prepared from isatoic anhydride with the yield of 85.5% and purity of 98%.