Advanced Materials Research Vols. 652-654

Abstract: To study the nitrification and denitrification in compartmented biofilm-electrode reactor (C-BER) under limited oxygen, influence of mild electrolysis on nitrogen removal was investigated under low C/N (mole ratios) with dissolved oxygen about 1mg/ L. It was found that nitrogen removal was mainly through simultaneous nitrification and denitrification (SND). C/N ratio was 1, average total nitrogen (TN) removal efficiencies were 33% and 45% for electric current of 5 and 15mA. C/N was 0.5, electric current was 25mA and effluent was recirculated, TN removal efficiency increased to 60%, within which autotrophic denitrification accounted for about 51%. There was about 50% NH3-N reduced under 15mA when C/N ratio was 1, this increased to 70% for 25mA when C/N ratio was 0.5. Nevertheless, TN reduced between anode and cathodes accounted for 64% in all. The experimental results show that both higher electric current and effluent recirculation are good for SND process under oxygen-limited condition, nitrogen removal can be activated by mild electrolysis.

Abstract: The bagasse fly ash (BFA), an industrial solid waste of sugar industry, was used to facilitate the clarification of cane juice. After being grounded, washed, rinsed and dried, the BFA was added into the juice before the clarification process including heating the juice to 60°C, coagulation with magnesium sulfate at pH=11.0, flocculation with PAM, and then settling and filtration. The effect of BFA on purification indexes including turbidity, purity and color value of the clarified juice, and the addition of BFA on the settling and filtration rates were investigated. The results shown that while having little effect on the pufification indexes, the addition of BFA could intensify the solid-liquid separation of the clarification. The gravity settling was significantly improved with the addition of BFA, with an addition at 1.5%, the mud thickening rate at free settling phase was increased from 20.7 mL/min without addition of BFA to 270mL/min and the final mud volume reduced from 48.0% of the total volume to 32.3%, the settling time being about 5 minutes. With the addition of BFA, the filtration rate increased significantly, the filter cake specific resistance was reduced from 562.8 kg·s·m-4 without addition of BFA to 31.2kg·s·m-4 with the BFA addition of 1.5%, making the filtration feasible. The optimum addition of BFA and the pressure drop for the filtration were 1.5% and 0.1MPa respectively.

Abstract: Kitchen waste in general has high water content with various plant required nutrients and organic matters but is non-toxic, and therefore, it is a good composting material. Three different composting methods were applied for experiments twice, which are mechanical aerobic composting, simple bucket composting, and fast composting processor, by using the same source of kitchen waste as the raw composting material. No significant difference was found between the compositions of the two kitchen waste samples. The major components of the two kitchen waste samples of this study were water content (averaged 72.7%), followed by combustible constituent (about 25.6%). The carbon-to-nitrogen (C/N) ratio was between 15 and 25. Since the operation and parameters of these three composting methods were different, the compositions of compost products were different. Among these three composting methods, compost produced by the simple bucket composting method had the highest water content (an average of 25%), while compost by the fast composting processor had the lowest (about 11%). For C/N ratio, compost produced by the fast composting processor had the highest C/N ratio (an average of 26), compost by the mechanical aerobic composting method the second (about 22), and compost by the bucket composting method the lowest (about 12). It is stipulated by the Council of Agriculture that for the miscellaneous types of compost, the C/N ratio should be between 10 and 20 to ensure that the compost has reached maturity. For the germination test, compost produced by the mechanical aerobic composting method had an average of 84%, compost by the fast composting processor had 81%, and compost by the bucket composting method had an average of 95%. Although all three methods can yield compost with a maturity level greater than the minimum requirement (80%), compost produced by the simple bucket method had better maturity. When comparing the three compost samples produced by different methods to the standards given by the Council of Agriculture, only the simple bucket compost qualified all the criteria.

Abstract: A novel and green method for separating and enriching trace tetracycline(TC) in environment water by phase-separation Floatation has been proposed,the principium was discussed. In this paper,the hydrophobic complex composed of Al(III) and TC was floated into organic phase under the optimal conditions: PH=6.2, the floatation equipment is home-made, The n-propyl alcohol is organic solvent ,sodium chloride is separating phase reagent.The data were obtained by spectrophotometry after floatation; The linear regression equation was A= 2.5759×105C (mol•L-1)－0.2716, The linear ranges were from 5×10-7 to 7.8×10-5 mol·L-1, respectively, with the correlation coefficient (r) better than r=0.9998, The average relative recoveries were 100.1% to 102.3% ,The limit of detection was 3.86×10-8mol·L-1 , It can be applied to analyse the trace TC in water sample ,the results were better.

Abstract: The crude material, corncob, was treated with Cr6+. The product was used adsorbing material of Cr6+. With regard to corncobs, this paper studied the absorption time and modification effect between absorbent and Cr6+ . It could be concluded that the removal ratio of Cr6+ presents an increasing tendency over time and reaches the highest removal ratio at 97% after 250 minutes, which improved 18% compared with unmodified corncob. Besides, it also used branches and peanut shells as comparative materials. Through comparing the test data of three materials, it is found that corncob has a higher absorption rate of Cr6+ than peanut shells at 23% and branches at 11%, which suggests that corncob has the best absorbing effect on Cr⁶⁺.

Abstract: To examine the role of the forest in non-point source pollution control in the Taihu lake region, the soil profile nutrients including nitrate, hydrolyze nitrogen(HN), available phosphorus(AP), total nitrogen(TN), total phosphorus(TP) concentration of 26 forest sample plots along the Xitiaoxi River from upstream to downstream were measured through July to August 2009, the relationship between vegetation type and topographic factors and soil nutrients was analyzed. results show that: (1) All of five soil nutrients concentration decreased with increasing soil depth; (2) Soil nutrients of different soil depth is intermediate variability, the coefficient of variation of AP, TN, HN, TP were increased with the increasing of soil depth, and the coefficient of variation of nitrate was decreased with the increasing of soil depth. (3)Soil HN content under plots with an average tree height above 10m was significantly higher than plots with an average tree height less than 10m; (4) Soil AP, HN, TN, TP content was first decreased and then increased with the increasing of elevation. .In summary, the soil nutrients of different soil depth was found to be closely related to vegetation type, community age, structure, fertilization and topographic features in the upstream of Taihu lake basin.

Abstract: This article deals with measurements of selected waste polymers in the combustion process. The technology of controlled burning occupies an important position in the process of waste disposal. Therefore it is necessary to assess the behaviour of materials in the process of thermal degradation by fire characteristics. An experiment was conducted in accordance with standard STN ISO 871: 2010 Plastics. Determination of ignition temperature using a hot-air furnace. There were studied a mass loss rate of the samples in their degradation and also monitored some products of combustion.

Abstract: For understanding the transport of groundwater existing in the seasonal freezing soil，laboratory test and field monitoring (frozen depth、moisture content and ground temperature in five months) were carried out in Daxinganling. A translocation model is built to analyze water behavior. The result shows that thermal conductivity will increase approximately one percent when temperature decreases 1°C. A transition function is used to prevent non-convergence in the numerical simulation. The simulation proves that the modified numerical simulation can reveal the law of moisture and heat translocation, and further offer guidance in practice.

Abstract: Under 4 different conditions (the smallest air door αpy =1.60, the smaller air door αpy =2.20, the larger air door αpy =3.16 and the largest air door αpy =4.41), the double fire grates boiler designed by the author have been tested. The corresponding result is that the temperature distribution appears similar law in height, depth and width. Secure, stabile and economical operation of the boiler has been realized on the better work state (between condition 2 and condition 3). It will be an important type of straw briquette boiler. It lays foundation for optimization design of burning equipment and running adjustment.

Abstract: The photodegradation of atrazine induced by UV-irradiation in aqueous solution was investigated initially. The affecting factors on the photodetradation were studied and described in details such as atrazine initial concentration, temperature, pH value, exposure intensity, oxidant and co-existing substances. It was found that the atrazine initial concentration had no obvious effect on the photodegradation. With the pH value increasing, photodegradation rates decreased. However, we also observed a positive correlation between the degradation rate of atrazine and temperature, exposure intensity and oxidant while the coexisting organic compounds may decelerate photodegradation of the atrazine in water. In this paper, the degradation products had also been confirmed by using LC-MS.