Applied Mechanics and Materials Vols. 448-453

Abstract: In recycling cooling system used reclaimed water, the main ions of the reclaimed water must form chemical scales with the increase of temperature and concentrate ratio , In order to control the formation of scale, we must control the fouling ion in the reclaimed water.In this paper the influence laws of Ca²⁺, Mg²⁺, HCO₃^- , SO₄^2-, PO₄^3-, NH₄⁺ , NO₂^- , NO₃^- in reclaimed water on the scale inhibition are researched . The experimental results show that Ca²⁺, HCO₃^- , PO₄^3- in reclaimed water have negative impact on scale and antiscale ;Mg²⁺ and NH₄⁺ have positive effect on scale and antiscale;and SO₄^2-, NO₂^- , NO₃^- hardly affected on scale and antiscale.

Abstract: In current paper, compared to the conventional coagulation, micro-sand (MS) and magnetic powder (MP) ballasted flocculation were investigated during the treatment of micro-polluted surface water by simulating ActifloTM and SiroflocTM process. Under an optimized operation condition, the optimal turbidity, COD_Mn and TP removal, 94.5%, 75.1% and 93.0%, respectively could be achieved by the MP process. In further research, pollutants removal efficiency at various settling time (5, 10, 15, 20 min), flocs two-dimensional fractal dimension and average size were simultaneously studied and the relationship among them was also discussed.

Abstract: A novel modified zeolite bio-filter reactor was used for ammonia removal from drinking water, and inoculated nitrobacteria was combined with modified zeolite in this bio-filter reactor. The effects of various operation factors on the performance of the modified zeolite bio-filter reactor were investigated. The optimum operation conditions of the modified zeolite bio-filter reactor were obtained as follows: a HLR of 0.9 m³/ (m².h), the temperature ranged from 15°C to 30°C, and no-aeration. Under these optimal conditions, the outlet concentration of ammonia was less than 0.5 mg/L, even when an initial ammonia concentration of 6 mg/L.

Abstract: The rules of deep percolation produced by irrigation under maize in the field with greater depth of groundwater are studied. With the maize cultivation in Dalian as an example, 1-D finite element model is built by VADOSE/W using the daily meteorological data in the years with guaranteed rainfall frequency of 75%, 50% and 25% through analyzing the years-long period regional meteorological data. By this model, the field soil water flow in a whole year under the rain-fed, sprinkler irrigation and border irrigation is simulated respectively, and the water balance of 1m-deep root zone is analyzed. The simulation shows that the ratio of deep percolation to the sum of net precipitation and net irrigation water amount is less than 5% under the rain-fed, 5%~9% under the sprinkler irrigation, 7%~13% under the border irrigation respectively. 70%~95% of deep percolation is produced by irrigation and about 13%~28% of net irrigation water amount is lost as deep percolation, as a result, the main reason for deep percolation can be concluded as irrigation in fields.

Abstract: As a heating system of energy saving, environmental protection, comfortable, safe and new-type, low-temperature radiation ground electric heating system has many advantages that other heating ways can not be on a par with such as long service life and free from maintenance within 50 years and has been gradually accepted by broad developers and residents. It has been broadly applied in heat supply in residence, industrial workshop, classrooms and hospitals; warm preservation in pipeline and warming in high tunnel and snow melting in slope road.

Abstract: Through pilot scale test, inspection the effect of treatment of micro-polluted raw water of Kongmu Lake with vortex clarifier accomplished by the addition of coagulant PAC. After the stable operation of the vortex clarifier, in the 30 mg/L of dosage and 6.8 min of flocculation time conditions, the removal of turbidity, NH₃-N, TP, UV₂₅₄ and COD is 94.2%, 22.9%, 84.8%, 45.2% and 78.5%.

Abstract: In order to achieve movement rule of post-mixed water jet outflow field, post-mixed water jet peening nozzle flow field were simulated by FLUENT software, according to their turbulent characteristics, the mathematical model adopted Euler model, turbulence model adopted the standard k ε model. Analyzed the peening pressure and peening standoff distance on the influence of outflow field of liquid-solid two phases-flow axial dynamic pressure and axial velocity, the results show that in different peening pressure, water flow field and pill flow field of axial velocity and the axial dynamic pressure both are symmetrical distribution, and their value increased with the increase of peening pressure to raise, decreases with the increase of peening standoff distance, even, with the increase of length of pill nozzle water flow field of axial velocity decreases, and pill flow field of axial velocity increases. When the peening pressure is 14 MPa, peening standoff distance is 30 mm, length of pill nozzle is 55 mm, maximum axial dynamic pressure of the outflow field is 3.18 MPa, the maximum axial velocity of water flow field and pill flow field respectively are 71.3 m/s and 69.6 m/s.

Abstract: In order to meet the application requirements of visual management and analysis of the information about recycled water use, the spatial database for the City Recycled Water Use is designed and constructed in this paper based on Geodatabase the spatial data model as well as UML and CASE as tools. The View Layer design, Concept design and Logic Design of the database of the recycled water use is explained in details. Then the application of the designed database to implement the Dianchi Lake Basin recycled water use in GIS platform is carried out and parts of the details is described in this paper.

Abstract: In order to prove the rules of bromide ion remove in coagulation treatment stage in drinking water, by carrying out laboratory coagulation test in simulated water and the Songhua River raw water samples, the effects of bromine ion removal by coagulation of PAC, FeCl₃ and the compound ferrous were investigated. The results showed that when the dosage of PAC was 60mg/L, the average removal rate of bromine ion was 50.6% by coagulation in the simulated water samples, and the rate was 44.8% in raw water samples of the Songhua River. In the conditions of FeCl₃ dosage 70mg/L, the average removal rate of bromine ion was 56.1% in the simulated water sample, and the rate was 55.2% in raw water. When Reduce the same turbidity of drinking water, the effect of bromide ions removal by FeCl₃ coagulation was better than that of PAC. When the dosage of compound ferrous (Ferrosilicon ratio of 1:1) as coagulant was 16.8mg/L, the bromide ions removal rate up to 67.6%.

Abstract: In this article, we try to find out the reasons of urban water logging . We will pay attention to the generation process, the affecting factors, and then seek the end solutions to solve the embarrassing situation.