Advanced Materials Research Vols. 726-731

Abstract: TNT-RDX wastewater is hard to biodegrade and highly toxic. The self-made reactor was used to degrade the wastewater, spray and the conditions of droplet diameter, number of nozzle, spray height were clearly observed. The results show that the average COD removal rate of TNT-RDX wastewater was 69.6%.The spray conditions can improve the dispersion of the wastewater and increase the use of the residual ozone in gas phase. Keywords: Spray; TNT-RDX wastewater; ozone; UV; GAC

Abstract: The modified pomelo peel powder was prepared by using chemical modification methods of ZnCl₂ soaking and heating.The removal rate of Pb (II) ion in simulation of wastewater by the modified pomelo peel powder was tested. The effects of pH of wastewater, initial concentrations of Pb (II) ion, adsorbent dosage,temperature and time on adsorption of Pb (II) ion was studied. Results show that when Pb (II) ion initial concentration at 100 mgL^-1, pH of wastewater at 3.5-5.5, adsorption time at 100min, adsorbent dosage at 15gL^-1, temperature at 35°C, the removal rate of Pb (II) ion in simulation of wastewater by the modified pomelo peel powder was more than 95%.

Abstract: Based on the detailed survey on the source and volume of NOx emission over Chengdu Economic Circle, the third-generation air quality model CMAQ is adopted for simulating the density of NOx in the air over Chengdu Economic Circle. The result shows that the hourly concentration, daily mean concentration and annual mean concentration of NOx in air exceed the standard data, and the affected areas respectively account for 0.2%, 0.18% and 0.12% of the total area of the economic circle. Meanwhile, in accordance with the simulation calculation, The NO_X emission of the vehicle exhaust, the thermal power plant and the cement plant are the major NO_X concentration contribution sources in air, contribution rate is amounting to 39.13%, 21.41% and 15.34% respectively. Thus, three main measures to reduce the emission of NOx of Chengdu Economic Circle are proposed as follows: firstly, strengthen the management of vehicle and reduce the emission of NOx by the vehicle; secondly, manage the NOx of the industrial enterprise; flue gas denitrification equipment must be constructed in the thermal power plant and cement manufacturing enterprise, and the comprehensive denitration efficiency of the thermal power plant should be not less than 70% and the comprehensive denitration efficiency of the cement plant should not be less than 60%; thirdly, joint prevention and control measures should be implemented between the cities, so as to reduce the transport of NOx. With the application of the above measures, the emission reductions of NOx can be reduced to 55% of the existing volume, and the concentration of NOx in the air can meet with the Class II of national ambient air quality Standard.

Abstract: The effects of potassium ferrate initial concentration, pH and inorganic salt addition on the stability of potassium ferrate were studied. The results showed that the higher the potassium ferrate initial concentration was, the poor of its stability was. The stability of potassium ferrate improved with the increase of pH. The stability of potassium ferrate got worse with the addition of inorganic salt including sodium silicate, sodium molybdate and sodium phosphate, and the law of the influence of pH on the stability of potassium ferrate was broken.

Abstract: An electrokinetic and magnetic remediation system of polybrominated diphenyl ethers (PBDEs) contaminated soil was built in the laboratory. The characteristics of BDE15 migration under non-uniform electric field and uniform magnetic field were investigated. The results indicated that current and temperature in the soil reached the maximum values 100mA and 14°C respectively in 6h; the moisture content of soil near the cathode and anode was higher than in the middle position; pH values of soil increased gradually from the anode to the cathode and acid-base interface was in the soil area between 3cm from anode and 5 cm from anode; BDE15 mainly enriched in the area 5cm from the anode and reached 22.69μg·g^-1.

Abstract: Tang xian in Hebei Jidong Cement Co., Ltd. flue gas denitrification treatment works, the project uses ammonia as a reducing agent SNCR DeNOx technology. A detailed explanation of the the SNCR process characteristics and system configuration, The analysis for actual operating results of the engineering. The results show: After treatment NOx concentration is less than 200 mg/Nm³, Denitrification efficiency reach 72.82%, Ammonia slip less than 0.9mg/Nm³, Engineering put into operation, About a year reduces emission NOx 1430 tons.

Abstract: How to treat and reuse the excessive sludge effectively and economically has become the most important task in wastewater treatment investigation. It is the significant precondition and key to the follow-up treatment. A new-style cavitator was developed which had ventilation and rotating function to disintegrate excessive sludge cells. These designs could avoid blocking and save energy. The cavitator was used to disintegrate the excessive sludge cells, and the disintegration effect was evaluated by the dissolution rate of the intracellular matters. The operating parameters were optimized through the orthogonal experiments. While the cavitation number was1.8 and the ventilation ratio was 1.4%, the unit energy consumption was 600W/kg. If 1 m³ of excessive sludge was treated for 30 minutes, 1000 MJ of energy would be consumed, which was lower than that of ultrasonic method by 40%. In the first 10 minutes, the average dissolution rate of SCOD was 0.06%/s.

Abstract: The objective of this research is to introduce the main gasoline direct injection vehicle particulate emissions characteristics researches in the world. Many investigations of particulate sizing and number count from gasoline direct injection (GDI) vehicles at different driving cycles were performed. Lots of particulate emissions are measured for FTP-75, NEDC, HWTET, SC03, and US06 cycles and these cycles can reflect different aspects of the particulate emissions. In some papers, both engine-out and tailpipe emissions were measured. Some investigation showed high sensitivity of the particulate number or size distribution to changes with the engine control parameters including A/F, ignition timing, EOI and so on.On the whole, the particulate number during different Driving Cycle is shown along with further analysis of the transient particulate emissions. The cold start process obviously affects particulate formation. Even beyond cold start, the particulate number emissions decrease as the test progresses. The results coming from the particulate measurement system sampling directly from the exhaust showed very rapid increases in particulate emissions during engine transients.

Abstract: Groundwater is widely distributed and stability changed.It is the ideal drinking water with good quality and easy application.As well as, it is an important water supply source of the life, industry and agriculture.However, groundwater pollution can't be ignored in China.In this paper, groundwater pollution,groundwater vulnerability evaluation and groundwater water pollution remediation technologies are reviewed through reading a lot of theses in China and other countries. The groundwater vulnerability evaluation of DRASTIC and based on the GIS technology are mainly introduced. According to the evaluation results, appropriate pollution remediation technologies are taken, so as to protect and repair groundwater. I hope this paper can provide some theoretical suggestions for the sustainable development of groundwater in China.

Abstract: Wastewater from the munitions decomposing process typically contains the widely used explosive-trinitrotoluene (TNT), which is also toxic and mutagenic. Commonly used technologies for degradation of TNT,such as activated carbon adsorption and chemical oxidation, are proved to be feasible but not cost-effective. In this study, the effectiveness of biodegradation of TNT by co-metabolism was evaluated in a hybrid hydrolysis acidification and aerobic membrane bioreactor. After six weeks acclimatization, over 90% TNT was removed with influent TNT concentration ranging between 70-85mg/L. Simultaneously remarkable MLSS concentration increase from 1.4 g/l to 6.9 g/l was observed, which indicated that the acclimatization and incubation of biomass was successful. The membrane effectively prevented loss of sludge and kept large biomass in the reactor, which made the system maintained in a high volume loading rate and low sludge loading rate. The experiment results showed that addition of carbon source was an essential factor in biodegradation of TNT wastewater.