Applied Mechanics and Materials Vols. 178-181

Abstract: Artificial media was used to enrich microbe and improve the water resource quality, therefore trace quantity organic pollutants of 1,2,4-Trichlorobenzene were biodegraded. The result of the experiment showed that, after domestication, the micro association enriched in the assembled medium could remove corresponding trace quantity organic pollutants in some concentration. When the temperature was 30 degree centigrade, the pH was between 6 and 9, the effect was the best about the removal on trace-quantity-organic pollutants water. A strain of bacteria was separated．At the same time, the congener trace quantity organic pollutants could be biodegraded. When the HRT was 6 days, the removal of trace quantity organic pollutants was between 70%～95%. It is evident that the trace quantity organic pollutants of 1,2,4-trichlorobenzene in the source water quality from Meiliang Bay in Taihu Lake can be well degraded by enriched microbes on the artificial media.

Abstract: The process parameters and running effect of A²O-high density sedimentation tank-filter tank process applied in the treatment of municipal sewage were introduced，aiming to provide technical basis for broad application of A²O-high density sedimentation tank-filter tank process. An engineering case was taken as example to describe process flow, process parameters and the size of the structures. The character of the designing was explained along with the discussion of the running effect. The running effort shows that municipal sewage treated by A²O-high density sedimentation tank-filter tank process can meet the requirements of Grand A of Primary standard of Discharge standard of pollutants for municipal wastewater treatment plant（GB189118—2002）.

Abstract: The effects of temperature, pH, precipitation time, reactant concentration, the crystal formation additive on the yield of calcium carbonate precipitation induced by bacillus pasteurii were investigated through orthogonal test. The morphology and structure of the calcium carbonate were characterized by scanning electron microscopic (SEM), Fourier transform infrared spectroscopy (IR) and powder X-ray diffraction (XRD). The results showed that the optimum conditions of calcium carbonate precipitation induced by bacillus pasteurii were temperature of 40oC, pH of 8, precipitation time of 3 d, Ca2+ of 1.5 mol/L, and Mg2+ of 0.05 mol/L. The crystal of calcium carbonate was calcites or mixture of calcites and vaterite. Its morphology and packing density were changed by different external conditions.

Abstract: An expanded granular sludge bed (EGSB) was combined with an anaerobic/anoxic/oxic process (A2/O) to treat piggery wastewater, in which the EGSB was used as a simultaneous methanogenesis and denitrification reactor and the A2/O as an shortcut nitrification reactor. The results showed that: 1) The COD of effluent in anaerobic reactor increased in earlier stage and decreased in later stage with increasing reflux ratios each time, and reached to about 550 mg/L finally. The COD removal efficiencies of the whole process were about 150 mg/L, and almost not affected by different reflux ratios. 2) Simultaneous denitrification and methanogenesis realized successfully after the aerobic effluent recirculated to the anaerobic reactor. The highest nitrite loading reached 1.48 kg/m3.d with constant increase of reflux ratio, while nitrite removal efficiencies were always 100%. 3) Short-cut nitrification was perfored steadily in the whole combined system. When reflux ratios were 50%, 100%, 200%, 300%, respectively, ammonia nitrogen removal efficiencies were all 100%, and total nitrogen removal efficiencies were 52.3%, 53.1%, 68.7%,85.1%, respectively. 4) The first reaction was denitrification when nitrite was recycled to anaerobic reactor, so methane contents were very little in earlier stage with increasing reflux ratios every time, but increased gradually after a period of operation.

Abstract: Effects of coagulation and algae removal was investigated, based on the micro-polluted raw water in the southern China, which was characterized with low-turbidity and high algae-laden. The different removal efficiency by the Ozone, permanganate and Ozone/hydrogen (O₃/H₂O₂) processes was summarized at the pilot study level. The results showed that the pre-oxidation process could enhance the treatment effect. However, compared with the other two processes, the process of O₃ was less effective than either permanganate or O₃/H₂O₂ process.

Abstract: The adsorption of PAEs from aqueous using natural zeolite and CTMAB zeolite was investigated by a batch technique under ambient conditions. Natural zeolite adsorption data were best-fitted to Langmuir and Freundlich equations, while CTMAB adsorption data were best-fitted to Linear equations. The results suggest that the adsorption on CTMAB zeolite involves adsorption process and distribution role and zeolites performs well as reusable materials for adsorption.

Abstract: A denitrifying bacterium aHD7 with nitrate removal efficiency of 91.67% (w/w) in 3 days cultured at 30 °C under stationary conditions was isolated from the activated sludge. The strain was characterized by biochemical tests and 16S rDNA sequence analysis, to be belonging to Pseudomonas. Factors on denitrification ability of aHD7, i.e., pH value, carbon source, C/N ratio, nitrogen source and initial nitrate concentration were investigated. Results showed that this strain could either use nitrate or nitrite as the electron acceptor, and the total inorganic nitrogen removal efficiency for sodium nitrite and potassium nitrate were up to 96.70% (w/w) and 95.93% (w/w) respectively. Denitrification was favored when the pH value was 6-9 and C/N ratio varied from 6 to 8, in which the optimal carbon source was ethanol. The strain had anammox activity, of which the average ammonium utilization rate reached up to 4.56 mg/l/d.

Abstract: Discusses how to making up air to balance indoor air, eliminate the traditional system defects, through in the hearth (under the smoke exhaust ventilator) additional secondary air tuyere. Using the CFD--fluent6.2 simulation software simulates the airflow organization of the kitchen exhaust system if making up air . Analyze the kitchen indoor airflow velocity distribution, and the pressure distribution in the different condition. Setting sizes for 0.06 ~ 0.10 m2 of secondary air tuyere, fill with air 0.162 ~ 0.184 kg/s ,it can avoid lampblack pollutants spilling effectively, reduce the operating energy consumption. After making-up air the kitchen remains negative state. Under the action of differential pressure, outdoor air is sucked into the kitchen so as to achieve the result, form reasonably airflow organization, meet exhaust requirements, get rid of foul gas effectively.

Abstract: This article use several different physical models to describe coupling relationship between indoor and outdoor air contaminants ,analysis the principle of the air filter air purification, discuss all the filters’ roles in improving IAQ.

Abstract: In order to describe the carbon emission situation of Chinese construction sector, this paper calculates the construction sector’s carbon emission and its efficiency of year 1994~2008 based on its energy consumption and economic output. And then the error correction model between the carbon emission and the output of the construction sector is established to predict carbon emission, with the effectiveness of the model proved. Using the error correction model, the long-term and short-term resilience of carbon emission is calculated, which indicates the main driving force of construction sector’s carbon emission is the overall output of construction sector.