铜-胺改性ZSM-5吸附剂的制备及其对NOx的净化机理

以ZSM-5分子筛粉体为原料,成型后负载铜盐和有机胺改性,制备出一种高效脱除氮氧化物的吸附剂。通过改变铜盐、有机胺的含量以及铜盐活化温度使吸附剂的性能得到优化,在实验条件下（NO：初浓度1000mg／m^3,气流2．7L／min）床层对NO2动态吸附的透过时间由改性前的3min提高到90min,并使NO气体的释放得到有效减缓。通过动态吸附实验研究了NO释放时间在负载前后的变化,通过X射线光电子能谱（XPS）和红外分析（FTIR）研究了吸附剂表面铜元素、有机基团等在吸附前后的变化规律,提出了可能的净化机理。     

Occurrence and fate of PPCPs and correlations with water quality parameters in urban riverine waters of the Pearl River Delta, South China

The occurrence and fate of eight PPCPs was studied in river waters from upstream to downstream of the three rivers in the Pearl River Delta, China. The correlations of PPCP levels and water quality parameters were also investigated. The analytes of the highest concentrations were caffeine, acetaminophen, and ciprofloxacin. Carbamazepine and erythromycin-H₂O were detected at the lowest concentrations. The highest concentrations of PPCPs were found in the Shijing River, with 865 ng/L caffeine, 339 ng/L acetaminophen, and 304 ng/L ciprofloxacin. In general, the levels of PPCPs in the Zhujiang River were higher at sites where the metropolitan city Guangzhou is located and decreased from the epicenter along the river. Low levels of PPCPs were generally found in the Beijiang River. Positive correlations were found between PPCP levels, total nitrogen, ammonium nitrogen, and cumulative fluorescence excitation-emission matrix (EEM) volume. Among the four PPCPs evaluated (caffeine, acetaminophen, ciprofloxacin, and sulfamethoxazole), caffeine had the best correlations with the correlation coefficients ranging from 0.62 to 0.98. The prediction of PPCP concentrations at specified locations can be substantially simplified.     

Mitigation of nutrient losses via surface runoff from rice cropping systems with alternate wetting and drying irrigation and site-specific nutrient management practices

Resource-conserving irrigation and fertilizer management practices have been developed for rice systems which may help address water quality concerns by reducing N and P losses via surface runoff. Field experiments under three treatments, i.e., farmers’ conventional practice (FCP), alternate wetting and drying (AWD), and AWD integrated with site-specific nutrient management (AWD + SSNM) were carried out during two rice seasons at two sites in the southwest Yangtze River delta region. Across site years, results indicated that under AWD irrigation (i.e., AWD and AWD + SSNM), water inputs were reduced by 13.4?~?27.5 % and surface runoff was reduced by 30.2?~?36.7 % compared to FCP. When AWD was implemented alone, total N and P loss masses via surface runoff were reduced by 23.3?~?30.4 % and 26.9?~?31.7 %, respectively, compared to FCP. However, nutrient concentrations of surface runoff did not decrease under AWD alone. Under AWD + SSNM, total N and P loss masses via surface runoff were reduced to a greater extent than AWD alone (39.4?~?47.6 % and 46.1?~?48.3 % compared to FCP, respectively), while fertilizer inputs and N surpluses significantly decreased and rice grain yields increased relative to FCP. Therefore, by more closely matching nutrient supply with crop demand and reducing both surface runoff and nutrient concentrations of surface runoff, our results demonstrate that integration of AWD and SSNM practices can mitigate N and P losses via surface runoff from rice fields while maintaining high yields.     

响应面法优化克浅十油田废水的混凝沉淀工艺

以克浅十污水处理站原水为研究对象,采用混凝沉淀工艺,探讨优选出的复配混凝剂投加量、助凝剂投加量及静置时间对原水中浊度和总铁去除效果的影响.应用Box-Behnken中心组合实验和响应面分析法,建立混凝剂对处理原水的二次多项式数学模型,确定了混凝沉淀去除原水浊度和总铁的优化工艺参数分别为:复配混凝剂投加量为152.15 mg/L、143.84 mg/L,助凝剂投加量为4.14 mg/L、4.32 mg/L,静置时间为11.77 min、11.22 min.在此工艺条件下回归方程得到的浊度和总铁的去除率预测值与实验值接近,且拟合性良好,误差介于3％～5％之间.通过均值内插法,对比浊度和总铁的多元二次回归方程,推导得出的2组最佳工艺条件均能满足浊度和总铁的去除要求.     

十溴联苯醚共存条件下水中Zn(Ⅱ)的生物吸附

研究了十溴联苯醚(BDE-209)共存条件下嗜麦芽窄食单胞菌对水中Zn2+的吸附特性,并通过对菌体进行失活处理、红外光谱和X-光电子能谱分析,探讨了吸附机理。结果表明,Zn2+的吸附符合Freundlich吸附模式;嗜麦芽窄食单胞菌对Zn2+吸附作用明显,2.5 g/L菌体在2 h时,对初始浓度为2.0 mg/L Zn2+的去除率达92%。BDE-209对菌体吸附Zn2+有一定的抑制作用。各因素对嗜麦芽窄食单胞菌吸附Zn2+的影响程度由大到小依次为:投菌量>pH>BDE-209浓度。菌体对Zn2+的吸附除表面吸附外,还存在跨细胞壁细胞膜的主动运输和积累等作用。菌体中的酰胺基与羟基均参与了Zn2+吸附,而且菌体表面Ca2+与Zn2+发生了离子交换,吸附后Zn2+的价态不变。     

电动力学作用下多溴联苯醚在土壤中的迁移特性

以4,4′-二溴联苯醚(BDE-15)为研究对象,探讨了电极电压、初始土壤pH、β-环糊精加入量、NaCl加入量等工艺条件对多溴联苯醚在土壤中迁移效果的影响。实验结果表明:在电极电压为5~15V范围内,随着电极电压的升高,土壤中BDE-15的迁移效果增强;初始土壤为酸性时、加入β-环糊精或NaCl后,土壤中BDE-15的迁移效果均增强。本实验选择的最佳工作条件为:电极电压15V,初始土壤pH3,β-环糊精的加入量3g,NaCl加入量5g。     

粉煤灰的改性、成型及深度除磷应用

选择合适的改性剂对粉煤灰进行改性,通过有机高分子交联方法对改性粉煤灰进行成型处理,并采用静态吸附法评价改性粉煤灰的深度除磷效果。采用1 g氢氧化铝改性粉煤灰处理100 mL磷质量浓度为10.0 mg/L的模拟废水,磷去除率可达99.70％,处理后模拟废水中磷质量浓度低于0.50 mg/L, 达到GB8978-1996《污水综合排放标准》。成型处理可提高粉煤灰的沉降速率,改善灰水分离效果。经超声再生后的成型氢氧化铝改性粉煤灰的磷去除率仍可达67.9％。     

Regional medical waste management in China: a case study of Shenyang

Medical waste management is of great importance due to its potential environmental and public health risks, especially in developing countries where both financial and technological resources on medical waste management are still lacking. Although many studies have focused on country-scaled medical waste management, few have paid close attention to regional (city-scale) management, particularly in China. This paper fills such a gap by employing a case study approach. Due to its representative nature, Shenyang was selected as the case study. After a review of China’s medical waste management, an empirical study in Shenyang was conducted in order to analyze the current state as well as identify key challenges on regional medical waste management. Based upon the local realities and aiming to better manage medical wastes, an integrated medical waste management framework is developed. Such a platform encourages the establishment of a specific medical waste management authority, a city scaled capacity building program on improving the general public’s awareness, an information platform, application of state-of-the-art technologies, as well as creation of an effective financial system. The combination of such initiatives can significantly improve the overall eco-efficiency of medical waste management at the regional level and should be promoted to other developing cities.     

Spatial variations of concentrations of copper and its speciation in the soil-rice system in Wenling of southeastern China

Copper (Cu) is one of the essential elements for plant growth, while excessive Cu in soils has potential environmental risks. There is little information on spatial variation of Cu in practical paddy fields. This is now important for appropriate agricultural management. The spatial patterns of Cu, its fractions in soils, and its concentrations in rice were investigated in a typical rice production region—Wenling of southeastern China. A total of 96 pairs of rice grain and soil samples (0–15 cm) were collected. The total concentration of Cu and its fractions were very variable, with large skewness, kurtosis, and coefficient of variation (CV) values. Compared to the guideline value (50 mg kg^?1), Cu pollution in paddy fields was observed in the study area. All the measured Cu concentrations in rice were lower than 10 mg kg^?1, suggesting that they remained at a safe level. Spatial analyses including Moran’s I index and geostatistics results indicated that high-high spatial patterns for both Cu in soils and rice were found in the northwest part, which was mainly related to industrial and E-waste dismantling activities. The low-low spatial patterns of Cu in the soil-rice system were located in the south part of study area. The cross-correlogram results indicated that Cu concentration in rice was significantly spatially correlated with total Cu in soils, its fractions, and soil organic matter (SOM), but significantly negatively correlated with pH and electrical conductivity (EC). Most of the selected variables had a clear spatial correlation range with Cu in rice. The ranges of significant spatial correlation (p?<?0.05) could be obtained and further used for dividing agricultural management zones.     

混凝搅拌内部流场数值模拟分析

通过对圆形搅拌容器内部流场的数值模拟,从湍流速度场、湍动耗散率和湍动能3个角度来分析该容器内的二维空间流态变化,及其对混凝过程中颗粒碰撞和絮体成长的影响,针对其不足之处,提出改进模型:方形、圆形挡板、多边形、圆角和方形导流板模型,并分别比较各模型在不同转速下的内部流场的变化。结果表明,在相同截面积的条件下,圆角模型更有利于颗粒的碰撞粘结和絮体的成长。