强化混凝法处理煤气冷凝水

以包头钢铁(集团)有限责任公司高炉煤气冷凝水为处理对象,采用强化混凝法进行静态混凝沉淀对比实验。实验结果表明,当聚合氯化铝加入量为20mg/L、高分子纳米除氯剂加入量为2.0mL/L时,处理后出水SS小于10mg/L,浊度小于10NTU,氯离子去除率在80%以上,而且对废水中的其他离子也有一定的去除效果,出水水质基本接近工业冷却循环水回用指标。     

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.     

Vehicle routing for the eco-efficient collection of household plastic waste

Plastic waste is a special category of municipal solid waste. Plastic waste collection is featured with various alternatives of collection methods (curbside/drop-off) and separation methods (source-/post-separation). In the Netherlands, the collection routes of plastic waste are the same as those of other waste, although plastic is different than other waste in terms of volume to weight ratio. This paper aims for redesigning the collection routes and compares the collection options of plastic waste using eco-efficiency as performance indicator. Eco-efficiency concerns the trade-off between environmental impacts, social issues and costs. The collection problem is modeled as a vehicle routing problem. A tabu search heuristic is used to improve the routes. Collection alternatives are compared by a scenario study approach. Real distances between locations are calculated with MapPoint. The scenario study is conducted based on real case data of the Dutch municipality Wageningen. Scenarios are designed according to the collection alternatives with different assumptions in collection method, vehicle type, collection frequency and collection points, etc. Results show that the current collection routes can be improved in terms of eco-efficiency performance by using our method. The source-separation drop-off collection scenario has the best performance for plastic collection assuming householders take the waste to the drop-off points in a sustainable manner. The model also shows to be an efficient decision support tool to investigate the impacts of future changes such as alternative vehicle type and different response rates.     

The kinetic stability of colloid-associated plutonium: settling characteristics and species transformation

The colloid-associated plutonium-239, as the dominant species of Pu in natural environment, was formed through sorption of Pu onto in situ colloids. In case of chemical perturbations present in pore water, the fate and transport of Pu would be therefore impacted by changes in sorption affinity of Pu for the colloid surfaces. The present study reveals that colloidal ²³⁹Pu exhibited the kinetic stability in two respects. First, in situ colloids isolated from the vadose zone sediments at Lop Nor, when in contact with solutions of high ion concentrations or low pH, were significantly aggregated and then exhibited fast settling. Kinetics settling characteristics were described by the parameters, including settling index and characteristic time. Second, Pu dissociation from colloid surfaces occurred immediately after the introduction of Na⁺. However, the dissolved species was still unstable and had the potential for re-association with the fraction of colloids that had not settled out from the suspensions due to small size and then remained in suspension. This implies that Pu sorption sites on initial colloids were changed to the sites of suspended colloids.     

Chronic exposure to contaminated drinking water stimulates PPAR expression in mice livers

Mice were fed with source water (SW) and tap water (TW) for 90 d to evaluate hepatotoxicity induced by the drinking water. Histopathologic observation showed no obvious damage to hepatic tissue in the SW and TW groups. However, microarray analysis indicated that the SW and TW exposures affected many metabolic pathways, among which PPAR (peroxisome proliferator-activated receptors) signaling was most susceptible. Immunohistochemical staining demonstrated that both PPAR-α and PPAR-γ were significantly increased in the exposure groups compared to control. Enzyme-linked immunosorbent assay revealed that PPAR-α expression level was increased from 23.37±0.53 ng g(-1) liver weight in control group to 26.60±1.43 ng g(-1) liver weight in SW group and 27.68±1.10 ng g(-1) liver weight in TW group (p<0.05). For PPAR-γ, the expression level was also significantly enhanced from 0.83±0.07 ng g(-1) liver weight in control group to 1.11±0.20 ng g(-1) liver weight in SW group and 1.16±0.07 ng g(-1) liver weight in TW group (p<0.05). The SW and DW posed no obvious hepatotoxicity on mice and PPAR-α/-γ could be used as a novel biomarker to assess public health risk induced by slightly contaminated drinking water.     

土壤石油污染环境容量的评估与模拟研究

文章基于对某滨海油区环境和生态进行调研分析的结果,选择一般参数法、综合估值法和数值模拟法三种方法对土壤石油污染的环境容量进行评估和模拟研究。研究分析了污染物在土壤中的时空分布,预测分析污染物迁移趋势和范围,综合探讨了研究区土壤石油污染的环境容量,可为制订有关环境标准和加强土壤石油烃排放管理提供技术依据和参考。     

Burial of terrestrial and marine organic carbon in Jiaozhou Bay: different responses to urbanization

Organic geochemical proxies (OC, OC/TN, δ¹³C, and lignin oxidation products) were measured in a 271 cm long sediment core collected from central Jiaozhou Bay, northern China, to study the response of terrestrial and marine organic carbon burials to the surrounding urbanization. Terrestrial organic carbon content was constantly low from the bottom of the core to ~150 cm depth, indicating a stable and low level of terrestrial input before urbanization. Thereafter, it increased up to ~20 cm depth, suggesting that increased human activities and land-use changes during urbanization likely enhanced the flux of terrestrial organic carbon to the bay. Overall, 5–38% of the total organic carbon was terrigenous, which was derived from a mixture of woody and non-woody angiosperms and moderately degraded. Marine organic carbon content did not increase notably during urbanization. It increased from the bottom of the core to ~180 cm and stayed at high levels until it decreased in the top 20 cm. It was affected by multiple factors, including grain size and nutrient composition. These results demonstrate the different influences of urbanization on terrestrial and marine organic carbon cycles and suggest the importance of discriminating between these two organic carbon pools in the reconstruction of their historical changes.     

基于三维荧光光谱特征峰的水体有机污染物综合指标检测

对来源不同一的32个水样进行三维荧光光谱的测定,并用5种典型有机物的荧光特征峰A(腐殖酸类)、C(腐殖酸类)、B(络氨酸类)、T1(色氨酸类)、T2(色氨酸类)进行了单一和组合式建模,发现对于来源不同一的水体的总有机含碳量(TOC)、化学耗氧量(COD)的检测采用这种提取特征峰建模的效果并不理想.该研究说明,依据典型特...