Structured photocatalytic systems: photocatalytic coatings on low-cost structures for treatment of water contaminated with micropollutants—a short review

Environmental Science and Pollution Research - The persistence of many micropollutants in water and wastewater is of great concern to the contemporary scientific community. Several types of...     

Analysis of the spatial distribution of collectors in dust scrubber based on image processing

The spatial distribution of the collectors in dust scrubber is key in determining the effectiveness of the dust removal process. In the present study, a high-speed camera was used to capture images of the distribution of the collectors. Some of the image information was extracted by image processing, such as the gray mean (GM), the angular second moment (ASM), and the entropy (ENT) from the gray-level co-occurrence matrix of the image. Subsequently, the spatial distribution rules of the collectors were studied by analyzing the spatial proportion, dispersion area, and uniformity and intensiveness of the collectors. It is an intuitive approach and a novel analysis method for the operating state of dust scrubber. The results show that the spatial distribution of the collectors could be better reflected by image processing methods. The dispersion area of the collectors expanded with an increase in the airflow velocity. When the initial liquid level (ILL) was higher, the collectors expanded in an approximate circular shape, and when the ILL was lower the collectors expanded in an approximate sector shape. In general, the variation trend in the spatial proportion enhanced with an increase in ILL and airflow velocity, which is consistent with the uniformity of collectors. When the liquid level was 0?20 mm and the airflow velocity was greater than 6.5 m/sec, the spatial proportion and uniformity of the collectors reached the highest degree. However, the growth rate of the spatial proportion and uniformity of the collectors slowed down and even led to negative growth when the ILL was lower and the airflow velocity was higher. The intensiveness of the collectors was great when the ILL was higher, which was free from the apparent influence of the airflow velocity and the ILL. However, when the ILL was lower, the intensiveness of the collectors was poor, intensifying as the airflow velocity and ILL increased. When the liquid level was ?5?10 mm and the airflow velocity was greater than 8 m/sec, the intensiveness of the collectors reached the highest degree, indicating that a liquid level greater than 0 mm and a higher airflow velocity improved the spatial distribution of the collectors.

Implications: This paper focuses on the spatial distribution of the collectors in dust scrubber. Some of the image information was extracted by image processing, such as the gray mean of the image, the angular second moment, and the entropy from the gray-level co-occurrence matrix of the image. The spatial distribution rules of the collectors were studied by analyzing the spatial proportion, the dispersion area, and the uniformity and intensiveness of the collectors.     

The influences of fly ash on stabilization for Cd in contaminated soils

Soil contaminated with potentially toxic metals (PTMs) has being a global environmental issue, which needs to be addressed on the priority basis. Fly ash (FA) is a kind of low-cost alkaline materials, which has been widely used in remediation of soil contaminated by PTMs, while the effects of FA on the stability for PTMs in contaminated farmland soil are still not clearly evaluated. In this study, cadmium (Cd) contaminated soil samples, collected from Shaanxi (SX), Hubei (HB), and Zhejiang (ZJ) province of China, were amended with FA addition (0, 1%, 2.5%, 5%, and 10% dose), and 1-year changes of Cd availability in soil samples were focused on. In addition, biological assessment method through pot culture was carried out to evaluate the reuse potential of Cd contaminated soils amended by FA. The result indicated that FA had a notable impact on decreasing the Cd mobility of SX soil (sand type), with 18.2~52.1% reduction in the DTPA extractable solution, followed by HB soil with 5.9~16.7% reduction, but no obvious effect of FA on ZJ soil (clay type) was observed. Furthermore, the results of pot experiment revealed that FA application could increase the biomass of Chinese cabbage. However, the DTPA extractable Cd in soils after planation and the Cd accumulation of plant increased. The results revealed that FA was not a promising soil stabilizer to immobilize HMs in Cd contaminated soil, and careful consideration should be given to Cd contaminated soils with FA restoration especially in their using for farmland productive due to the remaining risk of Cd bioavailability. These results also contributed to provide references for similar soil pollution remediation.

     

Toward quantification of the impact of 21st‐century deforestation on the extinction risk of terrestrial vertebrates

Conservation actions need to be prioritized, often taking into account species’ extinction risk. The International Union for Conservation of Nature (IUCN) Red List provides an accepted, objective framework for the assessment of extinction risk. Assessments based on data collected in the field are the best option, but the field data to base these on are often limited. Information collected through remote sensing can be used in place of field data to inform assessments. Forests are perhaps the best‐studied land‐cover type for use of remote‐sensing data. Using an open‐access 30‐m resolution map of tree cover and its change between 2000 and 2012, we assessed the extent of forest cover and loss within the distributions of 11,186 forest‐dependent amphibians, birds, and mammals worldwide. For 16 species, forest loss resulted in an elevated extinction risk under red‐list criterion A, owing to inferred rapid population declines. This number increased to 23 when data‐deficient species (i.e., those with insufficient information for evaluation) were included. Under red‐list criterion B2, 484 species (855 when data‐deficient species were included) were considered at elevated extinction risk, owing to restricted areas of occupancy resulting from little forest cover remaining within their ranges. The proportion of species of conservation concern would increase by 32.8% for amphibians, 15.1% for birds, and 24.7% for mammals if our suggested uplistings are accepted. Central America, the Northern Andes, Madagascar, the Eastern Arc forests in Africa, and the islands of Southeast Asia are hotspots for these species. Our results illustrate the utility of satellite imagery for global extinction‐risk assessment and measurement of progress toward international environmental agreement targets.     

造纸废水中高效菌群的筛选与鉴定

从再生造纸废水中分离出细菌14株,真菌5株,通过测定菌株的COD去除率,筛选出高效菌株,对其进行形态特征、生理生化特征、16S rDNA或ITS rDNA序列分析,并比较了单个菌株与混合菌的COD去除效果。结果表明:从再生造纸废水中筛选出高效菌株4株,鉴定为巨大芽孢杆菌、施氏假单胞菌、产碱假单胞菌、皮状丝孢酵母;混合菌COD去除能力优于单个菌株,COD去除率可达86.5%。     

4种人工湿地填料的f2噬菌体吸附特性

以无烟煤、钢渣、沸石和镁橄榄石这4种人工湿地填料为研究对象,以f2噬菌体为模型病毒,通过静态和动态吸附试验,考察和比较了4种填料的f2噬菌体吸附效果与特性.静态吸附结果表明,4种填料的f2噬菌体吸附去除效果依次为无烟煤>钢渣>镁橄榄石≈沸石,其中无烟煤对f2噬菌体的吸附过程经历了快、中、慢3个吸附阶段,且随着无烟煤投加量的增加,f2噬菌体去除率逐渐增加,优化的无烟煤投加量为8.0 g(固液比1∶12.5);4种填料的f2噬菌体等温吸附满足Freundlich和Langmuir等温吸附方程;无烟煤和钢渣的f2噬菌体吸附满足准二级吸附动力学,它们的理论平衡吸附量分别为3.35×108PFU·g-1和2.56×108PFU·g-1,与试验条件下得到的平衡吸附量基本一致;液膜扩散过程为无烟煤和钢渣吸附f2噬菌体的速率控制步骤,但不是唯一控制步骤.动态吸附结果表明,吸附柱的f2噬菌体吸附过程经历了适应、吸附、脉冲吸附和动态平衡这4个阶段,达到动态平衡时的f2噬菌体对数去除率大于2.55 lg.     

循环流化床干法脱硫除尘一体化工艺同时脱硝应用研究

目前,由于人类生产生活造成大气污染物日益增长,使国际上对大气污染物中放的控制研究成为热点,本文通过理论计算及工程实例说明了循环流化床干法烟气脱硫除尘一体化工艺同时脱硫脱硝可有效地对电厂大气污染物进行治理。     

浅谈石化企业员工心理健康管理模式的建立

分析了国内外企业员工心理健康管理实施现状,阐述了石化企业引入员工心理健康管理模式的重要性和必要性,提出加强心理健康管理模式建设的建议.