Advanced Materials Research Vols. 610-613

Abstract: Dodecyltrimethylammonium chloride was used to modify na-bentonite in Sichuan Yanting. It was studied that the optimal modification conditions of bentonite and its optimum decoloration conditions of crystal violet in dyeing wastewater. The optimum preparation conditions were that the concentration of dodecyltrimethylammonium chloride was 1000mg /L, the preparation temperature was 70°C and the mixing time was 20 minutes. The optimum adsorption conditions for crystal violet were that the pH value was 8, the mixing time was 20 minutes and the dosing quantity of modified bentonite was 15 g/L. The decoloration rate was 85.4% under aforesaid conditions.

Abstract: Disinfection is the essential and final process of municipal wastewater treatment plant. The aim of this study was to investigate the impact of ultrasound on ozone disinfection effect. The results showed that combination of ozone and ultrasound can enhance the disinfection efficiency. After ultrasound combined with ozone treatment (US/O₃) for 5min, a 2.51 log reduction of fecal coliform and a 2.24 log reduction of total bacteria were achieved. As the ultrasound power density increased from 0 to 55 W/L, a 2.59 log reduction of fecal coliform and a 2.36 log reduction of total bacteria were achieved. However, as the power density increased to 99 W/L, the increase in the overall efficiency of disinfection was not obvious. Moreover, with frequency at 20 kHz, 28 kHz and 40 kHz, 2.49, 2.58, 2.62 log reductions of fecal coliform and 2.14, 2.46, 2.51 log reductions of total bacteria were achieved, respectively.

Abstract: The performance of Short-HRT suspended medium bioreactor was investigated to treat the municipal effluent from the chemical-biological flocculation plant. The results showed that under the condition of influent ammonia concentration 9.0-15.0 mg/L, carrier filling ratio 30%, optimal air/water ratio and optimal HRT were 2.0 h and 2.7 h, respectively. The removal efficiency of ammonia is 49.7% with ammonia volume load of 0.058 kg/m3•d. Molecular biological method analysis indicated that bacteria species were abundant and could adapt themselves to varied circumstance in the Short-HRT suspended medium bioreactor.

Abstract: The performance of the municipal wastewater treatment using the Biological Aerated Filter (BAF) was investigated. The optimal operation parameters such as air/water ratio, water temperature, filtration velocity were achieved, and the removal efficiencies of CODCr, NH3 and SS were 80％, 98％, and 95％, respectively at the optimal conditions. The effluent can meet the integrated wastewater discharge standard in China.

Abstract: The regenerative combustion technology has been widely used in the recovery of flue gas waste heat, but the denitration is not considered. This article is based on the comprehensive application of the Selective Catalytic Reduction(SCR) technology and the regenerative combustion technology to recycling waste heat and removing NOx from flue gas. In many industrial heating processes, the temperature of flue gas falls from above 1000°C to the ambient temperature (50°C-100°C) along regenerators, while the temperature window of most catalysts ranges from 200°C to 450°C, meanwhile catalysts and regenerative cells are porous mediums, so the regenerative cells that hold a temperature range for catalytic reactions can be replaced by catalysts, and the waste heat of flue gas can be recovered and the nitrogen oxides can be removed simultaneously.

Abstract: Firstly, several common vertical anti-seepage forms for modern sanitary landfill are reviewed and compared. According to the unreasonable calculation method of the wall thickness in the New Code, this paper proposes a reasonable calculation method of the wall thickness through the two engineering project cases: valley type and plain type landfill, reflecting on the reasonable choice of the vertical anti-seepage forms. For the valley type landfill where the cover layer has a certain thickness, jet grouting pile and post grouting is proposed for the anti-seepage; for the plain type landfill whose foundation is composed of clay or sandy soil, the cement mixing pile is proposed for the anti-seepage.

Abstract: To explore the effect of the electrical degradation of phenolic compounds with TiO₂ under different conditions. The effects of pH, electrode distance, cell voltage, concentration of electrolyte Na₂SO₄ and the initial concentration of phenol were studied for the removal efficiency of phenol. The experiment measured that reacted for 60 min under the conditions that the original solution phenol content is 10 mg/l, the voltage is 15 V, the electrode distance is 1 cm, the electrolyte Na₂SO₄ is 0.2 mol/l, the removal efficiency of the phenol reached 99%.

Abstract: The purpose of this paper is to obtain a start-up of short-cut nitrification systems to treat wastewater with high concentration of nitrogen and phosphorus under laboratory conditions. By starting the nitrification system at room temperature we can achieve the effective accumulation of nitrifying bacteria. Then by increasing experimental temperature and pH, and increasing the concentration of nitrogen and phosphorus in influent, to inhibit the growth of NOB in the systems and promote the accumulation of AOB. So we can make the effluent have a higher concentration of NO2--N. In the stable operation stage we can constantly improve ammonia concentration in the influent, to observe the stability of the each indicators of effluent. This experiment showed that the wastewater with high concentration of nitrogen and phosphorus can better promote the accumulation of AOB, to achieve the effect of short-range nitrification.

Abstract: The effects of fuel quality and pollution control devices on SOF and PAHs emissions in particle matter (PM) for China V heavy-duty (HD) diesel engine fueled with China III, China IV and China V diesel were studied by using soxhlet extraction technique and Gas Chromatography-Mass Spectroscopy (GC-MS) technique. Two engines used were equipped with Diesel Oxidation Convert (DOC)+Diesel Particulate Filter (DPF) and Select Catalytic Reduction (SCR) individually. It is found that the SOF mass fraction in PM rises remarkably and total PAHs concentration declines obviously with the improvement of diesel fuel from China III to China V. However, the 16 components of PAHs distribute similarly for three quality of diesel, the concentrationes of Flu、PA、Ant、FL、Pyr、BaA、CHR reduce obviously, especially Pyr decrease by 95.8%. Moreover, the pollution control device has important effects on SOF and PAHs emissions.

Abstract: Subsurface wastewater infiltration treatment system (SWIS) is a domestic wastewater treatment technology. While the traditional technology has a large floor area, long starting period and low pollutants removal rate. A new biosubstrate that can be applied in SWIS is studied, experiments about its characteristics were performed, and treatment effect was compared. The results show that the biosubstrate has high biological activity, with it, SWIS has shorter starting period, better pollutants removal rate and consequently needs less floor space.