The microbial community structure of beer wastewater treatment plants with hydrolyze-acidification and SBR process was studied by PCR amplification and denaturing gradient gel electrophoresis (DGGE) based 16S rDNA. Ac...
详细信息
The microbial community structure of beer wastewater treatment plants with hydrolyze-acidification and SBR process was studied by PCR amplification and denaturing gradient gel electrophoresis (DGGE) based 16S rDNA. Activated sludge samples were collected from both hydrolyze-acidification tank and SBR tank at different depth and disposal period. The total DNA was extracted and the 16S rDNA was amplified by universal primer. The microbial community structure was analyzed by denaturing gradient gel electrophoresis, compared with the DGGE band pattern of the screened high efficient bacteria. The PCR products were cloned and sequenced to analyze the microbial community in phylogenic evolution. The DGGE pattern showed that the microbial community in hydrolyze-acidification tank changed with the variation of depth both in microbial structure and population, and at the depth of two-meter the microbial community was relatively rich, the dominant bands were notable. The microbial community in SBR tank at different depths and different disposal periods (precipitation period, inflow period, aeration period) were consistent respectively, but the dominant bands were different. Sequences of y2, 23, 25, 31, h5, 15 yielded high homogeneity with the strains uncultured Thermotogales sp., Comamonas sp. WT OTU1, Agrobacterium tumefaciens, Bacillus subtilis, Bdellovibrio bacteriovorus, Comamonas testosteroni from GenBank. The 16S rDNA sequences of the dominant bands were not completely same with that of the high efficient bacteria, which indicated that the strains screened were not the dominant strains in actual process.
Employing S-15 - bio-toilet as the testing device and pulverized bean stalk particles as the conditioner, an experimental study is made on the aerobic reduction and changes of nutrient content of human feces. The inde...
详细信息
Employing S-15 - bio-toilet as the testing device and pulverized bean stalk particles as the conditioner, an experimental study is made on the aerobic reduction and changes of nutrient content of human feces. The index changes of PH value, organic matter, total nitrogen (TN), total phosphorus (TP) and total potassium (TK) etc. are measured. The results show that using bean stalks as the bio-toilet conditioner has a good treatment effect. The average decomposition rate of the dry weight of the mixture per week is 37.49% ,and the cumulative decomposition rate reaches 95.23%. In the resulting products, the PH value is 7.2, the total amount of organic matter is 71.02% and the content of TN, TP and TK is 3.72%, 1.53% and 4.71%, respectively. The resulting products can be recycled as an efficient organic fertilizer.
p-Aminophenol (PAP), a typical amphoteric compound, has been widely used as raw chemical material and important interrnediate in various fields. To study on the recovery of PAP, an experimental comparison of the ads...
详细信息
p-Aminophenol (PAP), a typical amphoteric compound, has been widely used as raw chemical material and important interrnediate in various fields. To study on the recovery of PAP, an experimental comparison of the adsorption and desorption properties of PAP onto three types of hyper-cross-linked resins in aqueous solutions was performed. This paper focuses on the static equilibrium adsorption and desorption behaviors, the adsorption thermodynamics, the column dynamic adsorption and desorption, and other influencing factors of adsorption, such as temperature and pH values. All the isothermal data fit well to the Freundlich model. The capacity of equilibrium adsorption for PAP on NG-10 is the highest within the temperature range 288K-318K, which may greatly contribute to the advantage in specific surface area, especially the micropore area, of the adsorbent. While in the desorption experiments, NG-9 achieved relative well regeneration efficiency whether by ethanol or by 4% hydrochloric acid. Furthermore, the results of column tests and field applications were also proved that NG-9 was an effective sorbent for the reclamation PAP from wastewater.
The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy *** this study,we used the material flow analysis(MFA)to model the material input and output ...
详细信息
The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy *** this study,we used the material flow analysis(MFA)to model the material input and output of the Wujin District of Changzhou City,Jiangsu Province in *** was revealed that:(1)total material input and material input per capita increased with economic development,while the total material out-put and material output per capita decreased consistently;(2)except for water,the total material input continued to *** of solid materials grew faster than that of gaseous materials,while the total material output *** gas output accounted for the largest pro-portion of the output resulting in primary environmental pollution as burned fossil fuel;(3)water use in agriculture continued with an increasing trend while that in industrial and residential sectors decreased per *** total wastewater discharge and wastewater discharge per capita decreased with a faster decreasing rate of residential was-tewater discharge followed by industrial wastewater discharge;(4)material input per unit GDP fluctuated and material output per unit GDP decreased.A decreasing trend in both water use and wastewater discharge per unit GDP was *** results suggest that the efficiency of resource use in the Wujin District has *** weakened the direct link between economic development and environmental ***,we discussed the harmonic development between environment and *** limitations of MFA’s application were also *** is suggested that effective measures should be taken for the enforcement of cir-cular economic strategies and the construction of a resource-saving economy.
The releasing characteristics of phosphorus, nitrogen compounds, organics, and some metal cations during thermal treatment of excess sludge were investigated. It was found that during heating not only phosphorus, but ...
详细信息
The releasing characteristics of phosphorus, nitrogen compounds, organics, and some metal cations during thermal treatment of excess sludge were investigated. It was found that during heating not only phosphorus, but also nitrogen compounds, organics, and some metal cations could be released in abundance. The maximum orthophosphate (ortho-P) release of about 90 mg/L in concentration was observed at 50℃ in 1 h. Except for volatile fatty acids (VFAs), comparatively little total nitrogen (TN), total organic carbon (TOC), and metal cations were released at the same time. Such results might favor further process of phosphorus recovery. VFAs were considerably released only at 50℃. Acetic, butyric, and propionic acid were the most abundant components in turn and their releasing profiles exhibited good linear relationship with time (R2 = 0.9977, 0.9624, and 0.8908, respectively). The concentrations of Mg^2+ and K^+ increased with time and temperature during thermal treatment, but Ca^2+ decreased. The release of Mg^2+ and K^+ agreed well with TP release (R^2 = 0.9892 and 0.9476, respectively). Temperature in the experimental range had very little impact on the linear relationships, especially of Mg^2+. Moreover, the parameter of mixed liquor suspended solids (MLSS) was found to be an important factor for thermal sludge treatment as the released ortho-P and total phosphorus (TP) at 50℃ increased more than one-fold when MLSS was increased from 4000 to 8000 mg/L.
Based on the experimental research on a pilot units of the chemical-biological flocculation process, the multi-input multi-output (MIMO) model and the multi-input single-output (MISO) model have been built followed by...
详细信息
Based on the experimental research on a pilot units of the chemical-biological flocculation process, the multi-input multi-output (MIMO) model and the multi-input single-output (MISO) model have been built followed by the back-propagation (BP) artificial networks. Trained by the data (water temperatures, flocculant dosages, recycle ratio, CODCr, TP, SS, etc.) from the six different operating modes of the processes, all of the two models achieved convergence well. The data of another two operating modes was used for the model prediction. The relative errors of the MISO model prediction were lower than those of the MIMO model prediction; and all of relative errors from the MISO model prediction were less than 9.0 %. As a result, the MISO model is an easy-to-use modelling tool to obtain a quick preliminary assessment for the effluent quality prediction of the chemical-biological flocculation process.
暂无评论