Applied Mechanics and Materials Vols. 675-677

Abstract: Following the development of national economy, environmental pollution and ecological hazards has been resulted from the pollutant discharge and reclamation etc. So it is very important for evaluating the environmental carrying capacity for guiding the environmental management and control. In this paper, a systematic assessment model with detailed procedure for environmental carrying capacity is proposed, based on the combination of set pair analysis method and cloud theory. The membership degree function obtained from bell function in cloud theory is used for connection degree function in set pair analysis method. The normalization means of membership degree has advantageous of improving the reasonability of membership space. The calibration results of case study work well in Tianjin Binhai New District. This shows the coupled model has advantages of concision, easy-operation and high precision of set pair analysis method, and the randomness and ambiguity of assessment indexes’ membership can be reflected in the assessment procedure by using the cloud theory, so the assessment results are reliable and practical significance.

Abstract: The effect of the air inlet and the air outlet of the strawberry greenhouse are very significant to the microclimate in greenhouse under the conditions of natural ventilation. This paper studied the numerical simulation and experiment of indoor temperature field of the strawberry greenhouse with natural ventilation in different areas of air inlet and air outlet. The impact of the natural ventilation on the microclimate of strawberry greenhouse has been explored. The results indicated that the air velocity and temperature in the air inlet effected on the temperature distribution within the greenhouse, and the temperature near the air inlet was susceptible to the outdoor environmental parameters. The general trend of the variation of the indoor temperature in the greenhouse decreased with increasing the sizes of the air inlet and the air outlet. The overall trend of temperature gradient is similar within the greenhouse.

Abstract: The concentration of suspended solid, oil, HPAM, surfactant, sulfide and silicate colloid was investigated by the simulation aeration and settling experiment. The major factors that influenced the content change of suspended solid were also determined in this study to provide reliable basis for the actual process.By the simulation experiment, the main influence factors that changed the concentration of suspended solid in ASP produced water were the precipitation of HPAM

Abstract: This study investigated the effect of ultraviolet (UV) enhancement and the Fe³⁺-EDTA Complex on the degradation of methylene blue (MB) in Fenton-like system. By studying different variables including H₂O₂ concentration, Fe³⁺-EDTA concentration and pH value，and using MB as a model pollutant, the best experimental conditions was to investigated. Experimental results showed that it is possible to degrade MB wastewater effectively by modified UV-Fenton with Fe³⁺-EDTA at neutral pH. Besides, optimality condition (pH= 7, [Fe³⁺-EDTA] = 2 mmol/L, [H₂O₂] = 10 mmol/L) which were used in the modified UV-Fenton that achieves a removal of over 95% of the MB in 60 min reaction time. Therefore, this new modified Fenton system is an effective treatment for MB wastewater.

Abstract: Many regions of the world are facing the issue of regeneration of large brownfield sites characterized by environmental, social and economic degradation. In order to contribute to the development of innovative regional regeneration models, the paper introduces the successful European strategic project of the Ruhr basin. The irreversible crisis of mining and steel industry sectors, started in 1960 in that area, had brought, within a period of twenty years, to a profound social, economic, environmental decline. Project Emscher Landschaftpark was born in 1989 with the general objective of radically modifying the structure, image and functions that, until then, had characterized the territory of the Ruhr; it was related to a vast area, aimed at a sustainable, long term development and was based on the idea of considering the activities of the Emscher Park as an engine for the economy of the Region. The paper, after describing briefly the characteristics of the project, aims to highlight the main elements that contributed to its implementation.

Abstract: In order to achieve the simultaneous denitrification and dephosphorization from wastewater, the effect of SRT on denitrifying dephosphorylation process was investigated for a long time by using an anaerobic/anoxic sequencing batch reactor (A₂SBR). The results showed that when SRT was controlled at 20 days, removal efficiency of PO₄^3--P was kept at high value and it was higher than 90%, and removal efficiency of NO₃^--N and COD was 90.3% and 80.4%, respectively. A₂SBR process can be operated steadily by using a periodical operation mode of 10min feeding, 2.5 h anaerobic and 3.5 h anoxic followed by 10 min aerobic, 90 min setting and 10 min withdraw. The whole system shows a good performance of denitrification and dephosphorization under a steady operation.

Abstract: Anaerobic ammonium oxidation (anammox) process is a heated researched biotechnology for nitrogen removal in wastewater. The application of the process is limited due to its long start-up time and sensitivity to organic matters. This paper discussed the effects of butyrate on anammox process. The nitrogen removal rate of anammox process was elevated at low butyrate content (1 mmol/L) and decreased at high butyrate content (3 mmol/L). NH₄⁺-N:NO₂^--N:NO₃^--N:butyrate ratio was 1:1.25:0.08:0.04 and 1:7.26:0.10:1.85 when butyrate concentration was 1 mmol/L and 3 mmol/L.

Abstract: The removal of persistent organic pollutants (POPs) in soils at initial concentrations ranging from 20.00 to 321.05 mg·kg^-1 was investigated under different planting patterns, and enhancement mechanisms were analyzed. Results showed that the dissipation of POPs in soils growing Brassica campestris and Medicago sativa significantly exceeded those vegetating single species. During 70-day experiment, about 75.06% of Pyr and 68.22% of BaP was removed from the soils under mixed cropping; while only 31.8% and 64.03% of Pyr and 27.84% and 51.93 of BaP were removed under single rape and alfalfa cropping, respectively. Of all pathways enforcing POPs removal, plant-microbial interactions is the most predominant. These results suggested a feasibility of the establishment of multi-species phytoremediation for improvement of the remediation efficiencies of POPs, which may decrease accumulations of POPs in crops and thus reduce their risks.

Abstract: This Paper introduced the research background and technical features of the simulative experiments in the laboratory with the sorbent of lime solution without lime particles. By means of the effects of various influencing factors on SO₂ removal efficiency were studied carefully. These parameters include gas flow rate (G), inlet SO₂ concentration, liquid-to-gas ratios, the height of the packing and the additive, at the same time menstruating the pH value of the liquid flowing from the tower. To improve desulfurization efficiency of limestone in the wet flue gas desulfurization (WFGD), effect of the hexanedioic acid additive on limestone desulfurization agent were studied. The result shows that this system has advantages of high efficiency, stable, low investment and low circulating cost. The result could give a reference to optimization and will be helpful in selecting desulfurization techniques.

Abstract: Magnetic Nd₂Fe₁₄B activated carbon, a new kind of heterogeneous Fenton catalyst has been synthesis to treat the dyestuff wastewater. The obtained catalysts were characterized by X-raydiffraction (XRD) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of Congo red was evaluated. Experiments show that the Nd2Fe14B activated carbon has hard magnetic properties. The saturated magnetization, remanence and coercive force were 15.93emu/g, 6.0emu/g, and 1313Oe, respectively. The results also indicated that Nd2Fe14B activated carbon has good performance on azo dye Congo red oxidation with heterogeneous Fenton process. Under the optimum conditions ([NdFeB-AC-FC]₀=20g/L, [H₂O₂]₀= 8mmol/L and pH=7.0), Congo red degradation rate could reach 83.4%. The pH had few effects on heterogeneous Fenton process degraded Congo red. The kinetics studied shown that Congo red degraded followed the pseudo-first-order reaction by heterogeneous Fenton process.