Advanced Materials Research Vols. 955-959

Abstract: An oil/water separator with inlet component, perforated plates and coalesence internals was designed in this paper. The influence of the perforated plates on the flow field and the structures of coalesence component on the oil/water separation were simulated by commercial software FLUENT. The results show that the perforated plates can prevent turbulence and eliminate back-mixing flow effectively. And the flow field uniformity was the best,when the distance between the two plates was 140mm.The separator with inclined plates had the highest separation efficiency of the three structures.

Abstract: The effect of Phanerochaete chrysosporium (Pc) on the characteristics of humic substances (HS) was investigated during composting of agricultural wastes. The dynamic changes of HS, fulvic acid (FA), humic acid (HA) and the humification index (HI) were monitored during a 60-day composting. The results showed that the formation of FA was not obviously influenced, while HA formation was improved by the inoculum of Pc. During the composting process, HI increased from 0.28, 0.29 to 2.23 and 3.17 in the control and the treatment, respectively. This result indicated that Pc could significantly enhance the degree of HS aromatization (P<0.05). This research helps to know the contribution of Pc to the formation of HS during composting and provide some useful information for the development of efficient methods to increase the content of HS in the composting.

Abstract: The aim of this study was to assess the effects of the addition of sewage sludge compost (SSC) on the properties of aeolian sandy soil by measuring electric conductivity (EC),pH value,bulk density,field capacity,total N(TN),total P(TP),organic matter (OM),available N,available P and available K.Seven treatments were included in this experiment,the SSC was applied at rates of 0,2,5,10,15,20,25 kg·m^-1.The results showed that the physichemical properties changed greatly with the addition of SSC to the soil. As for physical properties of the soil, bulk density decreased gradually, the field capacity increased significantly compared with CK,As for chemical properties, pH changed inapparently, the concentration of OM and other nutrients were positive correlated with SSC dosages. It was concluded that the addition of SSC could enhance the soil’s fertility and improve the soil’s physical structure,it was an effective disposition way for sewage sludge to be used as the organic fertilizer in soil.

Abstract: The generations of agricultural and forestry wastes (AFWS) are increasing rapidly with developments of agriculture and forestry in China, and AFWS are commonly treated by composting. The objective of this work was to explore the effect of different microbial agents on biodegradation of AFWS. Three microbial agents in the research were Phanerochaete chrysosporium(PC) , Coriolus versicolor (CV) and GP (agent developed from laboratory with high lignocellulose degradation ability). All the composts inoculated the different microbial agents matured in 58 days. Compared with CK(without exogenous micro agent), composts with micro agents inoculated increased the duration of high-temperature fermentation period, reduced the maturity time, and increased lignocellulose degradation rate. PC and GP inoculated to AFWS produced the higher quality compost with respect to C/N ratio, GI, pH, total organic carbon (TOC) content, and humic acid content.

Abstract: A series of anaerobic digestion experiments on straw stalk mixed with pig dung was carried out at mid-temperature (35°C) by using the self-designed continuous stirring tank reactor (CSTR) in different organic load rates (OLR). Anaerobic digestion indexes, such as pH, ammonia-nitrogen, volatile fatty acid (VFA), total alkalinity, quantity of gas production and production rate of methane under the different organic load were studied and the aerogenic capability of the system and its stability were analyzed, so as to find the optimal organic load rate for anaerobic digestion reaction. The results show that: (1) With the OLR increases from 0.5-2.0g VS/(L·d) step by step, the pH value is always maintained 6.7-7.2; the average daily gas-production quantity is 869-3232 mL; the average ammonia-nitrogen concentration in the anaerobic digestion process has kept 522-850mg/L; the VFA concentration has remained between 1520-3420mg/L; the average total alkalinity is among 2152-2441mg/L . (2) The anaerobic digestion system is stable when the OLR increases from 0.5-2.0g VS/(L·d), and the optimal organic load rate is 1.5g VS/(L·d) for volume fraction of methane.

Abstract: The fly ash has a wide range of particles size and has a large amount of unburned carbon. As a raw material, the presence of the large particles and the unburned carbon will reduce the quality of the product. How to improve the utilization of fly ash has become one of focus points. In this work, hydrocyclone was adopted for classification after decarburization in a flotation column. Hydrocyclone showed a very good classification performance. In overflow, the particles were all smaller than 85μm. About 97.34% of the particles were smaller than 25 μm. Different fly ash content was selected to investigate its influence on the decarburization. The results showed that it made no obvious differences.

Abstract: A novel process was proposed to extract copper from the ammonia leaching solution of copper-covered iron needle. Under the condition of the content of P507 50%, phase ratio 1:2, reaction time 1min, room temperature, the extraction percentage of copper can reach 98%. Under the condition of H₂SO₄ concentration 3mol•L^-1, phase ratio 3:1, reaction time 1min and room temperature, the total stripping percentage of copper can reach 99%, and the stripping solution concentration was 60g•L^-1. The qualified CuSO₄•5H₂O product was obtained after evaporating and crystallizing from the solution.

Abstract: Copper is used to remove vanadium from crude TiCl₄ in titanium sponge production which produces large wash water containing vanadium and copper. The precipitate containing copper and vanadium was formed from the wash water by oxidization and neutralization treatment. The vanadium in the precipitate can be recovered by NaOH leaching, after that, the cake containing copper was formed. The leaching of copper from the cake was investigated by H₂SO₄. Under the optimum leaching conditions (58% H₂SO₄ leaching for 30 min. at room temperature with a pulp density of 28.6%), the copper leaching could reach 90.4%.

Abstract: First, through implementing a U₂₄ (6³) uniform design trial with 3 factors at 6 levels on temperature, heating time and water addition ratio as the main influencing factors of hydrothermal process and analyzing the physicochemical characteristics, the process parameters were optimized in this research. Then, the impacts of the hydrothermal process on the performance of sterilization, de-oiling and dewaterability were studied. It showed that the highest nutrient value of the product appears on condition that the temperature, heating time and water addition ratio were 120 °C, 80 minutes and 30% respectively. Additionally, hydrothermal treatment can kill bacteria thoroughly and affect the dewaterablity of the garbage markedly. Furthermore, hydrothermal process improved the de-oil performance of the garbage, and the optimal conditions for de-oil was the temperature 160 °C and heating time 80 minutes.

Abstract: Gentamicin bacteria residue contains high organic compound. The technology of thermochemical conversion can effectively solve the problem of bulk gentamicin residue disposal, research on pyrolysis kinetics of the reaction is the basic work for thermochemical conversion . In this paper, Pyrolysis experiments were carried out in a thermogravimetric analyzer under inert conditions and operated at different heating rates (5, 10, 20 K/min).Two different kinetic models, the iso-conversional Ozawa–Flynn–Wall (Ozawa) models and Satava method were applied on TGA data of gentamicin residue to calculate the kinetic parameters including activation energy, pre-exponential factor and Mechanism function. The results showed that: gentamicin bacteria residue lost most weight of it between 100-650 °C , about 74.23% of the whole sample can decompose under high temperature. The pyrolysis function for gentamicin residue should be G(α) =[-ln(1-α)]³.