Chemical content and source apportionment of 36 heavy metal analysis and health risk assessment in aerosol of Beijing

The concentration levels of 36 airborne heavy metals and atmospheric radioactivity in total suspended particulate (TSP) samples were measured to investigate the chemical characteristics, potential sources of aerosols, and health risk in Beijing, China, from September 2016 to September 2017. The TSP concentrations varied from 6.93 to 469.18 μg/m³, with a median of 133.97 μg/m³. The order for the mean concentrations of heavy metals, known as hazardous air pollutants (HAPs), was as follows: Mn > Pb > As > Cr > Ni > Se > Cd > Co > Sb > Hg > Be; Non-Designated HAPs Metals: Ca > Fe > Mg > Al > K > Na > Zn > P > Ba > Ti > Cu > Sr > B > Sn > I > V > Rb > Ce > Mo > Cs > Th > Ag > U > Pt. The median concentration of As was higher than China air quality standard (6 ng/m³). The gross α and β concentration levels in aerosols were (1.84?±?1.59) mBg/m³ and (1.15?±?0.85) mBg/m³, respectively. The enrichment factor values of Cu, Ba, B, Ce, Tl, Cs, Pb, As, Cd, Sb, Hg, Fe, Zn, Sn, I, Mo, and Ag were higher than 10, which indicated enriched results from anthropogenic sources. Pb, As, and Cd are considered to originate from multiple sources; fireworks released Ba during China spring festival; Fe, Ce, and Cs may come from stable emissions such as industrial gases. The health risks from anthropogenic metals via inhalation, ingestion, and dermal pathway were estimated on the basis of health quotient as well as the results indicated that children faced the higher risk than adults during the research period. For adults, the health risk posed by heavy metals in atmospheric particles was below the acceptable level.

     

Effects of temperature and relative humidity on the methane permeability rate of biogas storage membranes

Selecting a material for biogas storage membranes is becoming increasingly vital because of the wide applications of biogas storage membranes in biogas plants. Material selection has numerous influencing factors, including gas permeability, strength, density, and so on. Among these, gas permeability has a vital role in biogas storage membranes. In this study, three kinds of biogas storage membranes with the same thickness were selected to investigate the effects of temperature (10, 20, 30, and 40°C) and relative humidity (RH; 0%, 50%, and 100%) on the permeability rate of biogas storage membranes. Results demonstrated that when various membrane samples with the same RH values were tested, temperature exhibited a strong effect on permeability rate. Kinetic analysis showed that the relationship between permeability and temperature agrees with the Arrhenius equation. However, no remarkable variation in methane permeability was observed for membranes with the same temperature but different RH values, thus suggesting that RH nearly has no obvious direct influence on the permeability rate of membranes.     

The effect of municipal sludge compost on the mobility and bioavailability of Cd in a sierozem-wheat system in an arid region northwest of China

The effect of sewage sludge on the mobility and the bioavailability of trace metals in plant-soil systems have aroused wide interested and been widely explored. Based on a wheat-cultivating experiment, the effect of municipal sludge compost (MSC) on the mobility and bioavailability of Cd in a soil-wheat system was studied. With the application of MSC, soil organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) in the soil increased significantly, while concentrations of trace metals (Cu, Zn, Ni, Pb, Cd) were below the China’s minimum thresholds. The application of MSC could improve wheat growth. The application of MSC at the rate of 0.5 % had no significant effect on the chemical fraction distribution of Cd in soil. In two soil treatments, Cd mainly existed in the labile chemical fractions (exchangeable chemical fraction (EXCF) and carbonate chemical fraction (CABF)). However, the application of MSC could reduce accumulation of Cd by wheat. Cd contents in each part of the MSC-applied wheat were significantly less than that of non-MSC-applied wheat. In the tested soils, the extractable concentrations decreased in the order: EDTA > MgCl₂ ≈ NH₄OAc > DTPA. There were no significant differences between soil treatments in the amounts of extractable Cd when the extraction was done under neutral conditions, although significant differences were observed when the extraction was done under alkaline conditions. In this study, the DTPA extraction procedure provided a good indication of Cd bioavailability. Our results suggest that, in the short term at least, amending soils with MSC may benefit crop dry matter production while not increasing the risk of human exposure to Cd through consumption of wheat grown on MSC-amended soils.     

Novel bacterial consortia isolated from plastic garbage processing areas demonstrated enhanced degradation for low density polyethylene

Environmental Science and Pollution Research - This study aimed to formulate novel microbial consortia isolated from plastic garbage processing areas and thereby devise an eco-friendly approach for...     

石油和天然气开采业危险废物判定要点分析

在油气田开发生产过程中,会产生大量危险废物,如处置不当会造成严重污染,但如何判别危险废物是环境管理中的难点问题。文章分析了石油和天然气开采业生产工艺流程,对石油和天然气开采业的油井、联合站、集输管道产生危险废物的类型、环节进行了分析,可为有关人员对危险废物判定提供参考。     

红浅稠油污水回用锅炉处理技术研究与应用

文章介绍了红浅稠油污水处理站采用的"离子调整旋流反应+216t/h软化水"处理工艺,该工艺创新性的采用了分置式反应罐,将混凝、反应、加药、沉降、颗粒吸附有机结合,优选出高效的污水处理药剂,首次在新疆油田公司污水处理工艺中应用改性纤维束过滤器和216t/h软化水处理装置,优化了各节点的配套工艺,使处理后的污水水质达到回用锅炉水质标准,取得了良好的效果。同时,通过对加药浓度、隔油、反冲洗周期等参数优化,保证了红浅稠油污水回用锅炉处理系统的平稳运行,累计处理回用污水约730万m3,有效地节约了水资源,保护了环境,综合效益显著。     

用微电极测定曝气量对SBR系统中硝化作用的影响

为了研究曝气量对硝化作用的影响,实验采用3个相同的SBR装置,分别在曝气量为4、10和16 L/h的条件下处理人工污水,并采用自制的溶解氧、NO3-、NH4+和pH微电极测定了活性污泥絮体内部微元环境中相应基质的浓度。结果表明,曝气量为4 L/h时,活性污泥絮体内存在厌氧微区,NO3--N浓度减小了,发生了反硝化作用;而曝气量为10 L/h和16 L/h时,活性污泥絮体内发生的都是硝化反应,且NH4+-N浓度的减小量、NO3--N浓度的增大量都随着曝气量的增大而增大,pH随着曝气量的增大而减小。     

高效铁系除臭剂净化制药污泥带滤间恶臭的工程应用研究

在实验室条件下考察了自制高效铁系除臭剂的吸附性能,确定出了最佳工艺条件。将该除臭剂应用于制药厂污水处理污泥带滤间的恶臭气体净化,设计了废气处理量为11 000 m³/h的吸附净化系统。工程实际运行效果良好,H₂S去除率可达97％以上。结果表明：该除臭剂对于处理含硫恶臭气体具有良好的实际应用价值,工业应用前景广阔。     

High nitrite accumulation and strengthening denitrification for old-age landfill leachate treatment using an autocontrol two-stage hybrid process

An autocontrol two-stage hybrid process was developed to treat landfill leachate. Biological nitrogen removal with nitrification and denitrification via nitrite pathway was split into two stages. The first stage was designed for the high nitrite accumulation and was composed of two hybrid bed reactors (Hybrid I and Hybrid II) and a coagulation–flocculation reactor having effective volumes of 120 L and 80 L, respectively. The second stage was designed for strengthening denitrification and included a single 80 L reactor. The carriers of the hybrid bed reactors were composed of fixed multiple flexible carriers and suspended particle carriers. Dissolved oxygen (DO), pH value, oxidation–reduction potential (ORP) and temperature were used as online fuzzy control parameters of the automatic control system. The concentration of nitrite in Hybrid I and Hybrid II could reach 411 mg L⁻¹ and 604 mg L⁻¹, respectively. Ammonia removal has reached maximal rates of 0.061 kgNH₄⁺-N (m³ h)⁻¹ and 0.041 kgNH₄⁺-N (m³ h)⁻¹, respectively. A maximum nitrite removal rate of 0.211 kgNO₂⁻-N (m³ h)⁻¹ was observed during the strengthening denitrification. The running time of one cycle was not fixed and was actually controlled by the system. The results indicated that the running period was more closely related to influent ammonia concentration than influent COD concentration. The aeration times could be shortened and the energy could be saved. The autocontrol two-stage hybrid process is therefore an economical and effective way for landfill leachate treatment.     

The Impact of Sewage Discharge on the Macroalgae Community in the Yellow Sea Coastal Area Around Qingdao,China

The dynamics of macroalgal communities and the impact of sewage on their growth were studied in the tidal zone around Zhanqiao Pier of the Qingdao coastal area, in the northwest of the Yellow Sea, China, from September 2001 to September 2003. The tidal zone of the study area is divided into western and eastern sections by the Zhanqiao Pier. Inorganic nitrogen and phosphorus in seawater showed higher concentrations on the eastern side of Zhanqiao Pier than on the western side, because a sewer drains into the eastern side. The macroalgal communities on each side of the Pier showed an obvious difference due to the effect of this sewage discharge. A total of 47 macroalgal species including 10 greens, 11 browns and 26 reds was identified in this study. The species composition and biomass indicated higher values in the nutrient-rich area on the eastern side of Zhanqiao Pier compared with the nutrient-poor area on the western side of Zhanqiao Pier. Some ephemeral and filamentous species dominated seasonally on the eastern side of Zhanqiao Pier, in contrast to the western side where slow-growing species dominated throughout the year. Nutrient gradients and temperature were considered the main factors affecting the distribution of macroalgae communities in time and space. The results are consistent with the common observation that nutrient-poor areas are dominated by slow-growing rather than ephemeral algal species. Moreover, the species diversity in the whole study area had declined when compared to previous records.