湿法烟气脱硫废水处理技术探讨

分析了火电厂湿法烟气脱硫装置排水的主要成分、水质特点，叙述了烟气湿法脱硫废水国内外的处理方法和工艺流程。结合笔者实践，提出了一种改进的处理方法，为湿法脱硫废水处理提供了一种有效的途径。     

非均相催化湿式氧化法活性炭再生

使用浸渍法制备的CuO Al2 O3催化剂对吸附苯酚饱和的活性炭进行非均相催化湿式氧化再生研究 ,考察了反应温度、反应时间、催化剂投加量、反应氧分压、投炭量、蒸馏水量对非均相催化湿式氧化再生活性炭的影响结果 ,同时在该实验中得到非均相CuO Al2 O3催化湿式氧化再生活性炭的最佳条件。对催化剂进行了X衍射分析 ,并通过对催化剂的稳定性进行实验 ,得出该催化剂在进行催化湿式氧化再生活性炭的过程中具有较好的稳定性     

Impacts on wetlands of large-scale land-use changes by agricultural development: the Small Sanjiang Plain, China

The Small Sanjiang Plain (SSP), was formerly the largest wetland complex in China, located in the Northeastern part of Heilongjiang Province, China. Home to vast numbers of waterfowls, fish, and plants, the SSP is globally significant for biodiversity conservation. The loss and fragmentation of wetlands as a result agricultural development over 50 years has impacted wetland communities and their biodiversity. We used GIS to inventory large-scale land-use changes from 1950 to 2000, together with other statistical data. We found that 73.6% of the wetlands were lost due to agricultural development. Consequences of these land-use changes included: i) a rapid decline in waterfowl and plant species with the loss and fragmentation of natural wetlands and wetland ecosystem degradation; ii) greater variation in wetland water levels as the result of land-use changes over the years; iii) disruption of the dynamic river-floodplain connection by construction of drainage ditches and levees; and iv) a decrease in floodplain area that caused increased flooding peak flows and runoff. Here we show how these changes affect wetland biodiversity and impact important wetland species.     

城市下水污泥焚烧过程中二次污染物排放特性的试验研究

在0.15 MWt循环流化床燃烧试验台上进行了城市下水污泥与煤的混烧试验,分析了烟气中的二次污染物排放特性.分析结果表明,利用循环流化床焚烧城市下水污泥时,添加辅助燃料(如煤)及改变焚烧条件,不仅可以达到稳定燃烧的目的,而且有利于抑制焚烧中二次污染物(如CO及二恶英等有机污染物)的生成.分析了焚烧污泥污染物的排放特性,为采用焚烧方式处理城市下水污泥提供了基础性试验数据.     

Removal of BTEX vapor from waste gases by a trickle bed biofilter

The system performance of a trickle bed biofilter for treating single and mixed benzene, toluene, ethylbenzene, and o-xylene (BTEX) vapors from waste gases was investigated under different gas flow rates and influent BTEX concentrations. When a single substrate was fed, removal efficiencies of greater than 90% could be achieved for the loads below 64 g benzene/m3/hr, 110 g toluene/m3/hr, 53 g ethylbenzene/m3/hr, and 55 g o-xylene/m3/hr. When a mixed substrate was fed, removal efficiencies of each compound could be above 90% at BTEX loads below 96 g/m3/hr. The trickle bed biofilter appears to be an effective treatment process for removing both single and mixed BTEX vapors with low to high loads. Under similar substrate loads, BTEX vapors were preferentially biodegraded in the order of toluene, benzene, o-xylene, and ethylbenzene. The volumetric removal rates (elimination capacities) of BTEX vapors for a single-substrate feed were higher than those for a mixed-substrate feed under similar substrate loads; these differences were enhanced at higher substrate loads and less significant for a preferred substrate.     

Effect of adsorbents coated with titanium dioxide on the photocatalytic degradation of propoxur

Photocatalytic oxidation of pesticides in aqueous media irradiated by UV light is a rapidly growing field of research. Therefore, the treatment technology for degradation of propoxur (an insecticide) using titanium dioxide coated on the supports such as activated carbon, zeolite, brick, quartz and glass beads, was performed in this research. Results show that GAC/TiO2 is the best complexing agent for oxidizing propoxur because of its adsorption properities. The others follow the sequence: plain TiO2 > glass beads > zeolite > brick > quartz. The degradation rate of propoxur with plain TiO2 is higher than that with TiO2/GAC complexing agent. But the mineralization rate of propoxur with plain TiO2 is lower than that with TiO2/GAC complexing agent. However, it can be concluded that using GAC as the support can improve the photocatalytic efficiency.     

Experimental and numerical study of the dispersion of motor vehicle pollutants under idle condition

The aim of the work presented here is to study experimentally and numerically the dispersion characteristics of vehicular exhaust plume at an idle condition in an idealized and simplified environment. The gaseous and particulate concentrations in the exhaust plume of three idling motor vehicles were measured in an isolated environment under calm weather conditions. Despite the difference in the initial concentrations, the pollutants decayed exponentially in all directions.The CFD code PHOENICS 3.3, with the k–ε eddy dissipation sub-model, was used for the numerical simulation. The simulated results match very well with the experimental results close to the source of emission but decay to the ambient concentrations much slower. The effects of the initial emission concentration, exit velocity, exit direction and crosswind intensity have been investigated parametrically. The initial pollutant concentration will increase the local concentrations but the pattern of dispersion remains the same. The exit velocity will increase the momentum of the jet, resulting in a deeper penetration downstream. The exit angle has a stronger influence on pollutant dispersion than both initial pollutant concentration and exit velocity. When the exit angle is 15°, the pollutants tend to spread on the ground region. Crosswind shows a significant effect on the dispersion of the exhaust plume also. It will divert the plume to disperse in the same direction of the wind with limited penetration in the downstream direction.     

Equilibrium and kinetic studies on the adsorption of aniline compounds from aqueous phase onto bifunctional polymeric adsorbent with sulfonic groups

In the present study, a hydrophilic bifunctional polymeric resin (LS-2) with sulfonic groups was synthesized, and the adsorption performance of three aniline compounds, aniline, 4-methylaniline, and 4-nitroaniline onto LS-2 was compared with that on the commercial Amberlite XAD-4. The uptake of the aniline compounds on LS-2 is a procedure of coexistence of physisorption and chemisorption and obeys the pseudo-second order rate equation, while the uptake of the compounds on XAD-4 is merely a physical adsorption and follows the pseudo-first order rate equation. All the isothermal data fit well with the Freundlich model, and the values of K(F) of the compounds adsorbing on LS-2 are much higher than those on XAD-4 suggesting the higher adsorbing capacities on LS-2 than those on XAD-4, which may be attributed to the microporous structure and the polar groups on the network of LS-2 resin. Dynamic adsorption and desorption studies for aniline on LS-2 show that the breakthrough adsorption capacity and the total adsorption capacity are 0.96 and 1.24 mmol per milliliter resin, respectively. Nearly 100% regeneration efficiency for the adsorbent was achieved by 5% hydrochloric acid.     

Degradation of 4-chlorophenol by microwave irradiation enhanced advanced oxidation processes

In this work the synergistic effects of several microwave assisted advanced oxidation processes (MW/AOPs) were studied for the degradation of 4-chlorophenol (4-CP). The efficiencies of the degradation of 4-CP in dilute aqueous solution for a variety of AOPs with or without MW irradiation were compared. The results showed that the synergistic effects between MW and H2O2, UV/H2O2, TiO2 photocatalytic oxidation (PCO) resulted in a high degradation efficiency for 4-CP. The potential of MW/AOPs for treatment of industrial wastewater is discussed.     

农业蔬菜废物处理方法研究进展和探讨

目前我国农业蔬菜废物污染问题正日益加重 ,蔬菜废物和其他固体废物相比具有高含水率、高营养成分和基本无毒害的特性 ,适宜于单独收集处理。本文介绍了国内外蔬菜废物处理方法的研究进展 ,包括好氧堆肥法、厌氧消化法、好氧 -厌氧联合处理法 ,并对这些方法的适用条件进行了论述。同时 ,探讨了接种微生物自然堆沤法的初步研究结果