添加VT菌剂和有机物料腐熟齐对堆肥的影响

通过在高温好氧堆肥中分别添加VT菌剂和有机物料腐熟剂,研究接种3％o的VT菌剂和有机物料腐熟剂促进堆肥的作用效果。结果表明,接种VT菌剂的处理与空白和接种有机物料腐熟剂的处理相比,堆肥初期升温更快;高温期更长;堆肥结束时,C／N降低的多,NO3-N增加的多,NH4-N挥发的少,接种VT菌剂和VT有机物料腐熟剂都可促进有机质的充分降解,缩短堆肥时间,加快堆肥腐熟,提高堆肥肥力。     

低温喹啉降解菌的筛选及降解性能

从吉林石化污水处理厂的活性污泥中驯化、筛选获得一株降解效率高且生长速率快高效耐冷菌,命名为WS-5.该菌能以喹啉作为惟一的碳源、氮源及能源.结合菌体的形态观察、生理生化特性实验及16S rDNA序列同源性对比分析,鉴定菌株WS-5为恶臭假单胞菌(Pseudomonas putida).不同降解条件下的实验结果表明,菌株WS-5的最佳降解条件是投菌量为15％,pH值范围在8～10,摇床转速为100 r/min.最佳降解环境下对200 mg/L的喹啉在132 h降解率达到了85.3％.菌株WS-5对初始喹啉浓度为50、100、200和300 mg/L的初始喹啉浓度分别在36、72、192和262 h内完全降解.这将为今后在低温条件下处理含喹啉废水提供技术指导.     

ALAD genotypes and blood lead levels of neonates and children from e-waste exposure in Guiyu,China

Extensive e-waste recycling activity in Guiyu, China, has been conducted using primitive techniques for the last 20 years, resulting in serious heavy metal environmental contamination. A polymorphic variant of the δ-aminolevulinic acid dehydratase (ALAD) gene has been found to influence lead uptake and, thus, may influence an individual’s susceptibility to lead toxicity. We therefore explored whether the ALAD gene polymorphism affects blood lead levels of newborns and children in Guiyu. A total of 273 newborns and 504 children, and a combination of 2004/2005 and 2006 independent recruitments were used for this study. Umbilical cord blood from newborns (Guiyu/exposed group 189 vs. Chaonan/reference group 84) and venous blood from children (exposed group, 319 vs. Chendian/reference group 185) were collected. Blood lead levels (BLLs) were measured via graphite furnace atomic absorption spectrometry (GFAAS) for all samples, while ALAD genotyping was performed using PCR-RFLP for 273 neonate cord blood and 246 children’s blood. The median BBLs of neonates in exposed group vs. the reference group were 10.50 (2.36–40.78) vs. 7.79 (0.8–19.51) for 2004/2005 and 9.41 (9.28–47.60) vs. 5.49 (0.35–18.68) for 2006, while child mean BLLs were 15.31?±?5.79 vs. 9.94?±?4.05 for 2004/2005 and 13.17?±?5.98 vs. 10.04?±?4.85 for 2006. The genotype frequencies in newborns were 98.90 % for the ALAD-1/ALAD-1 homozygote and 1.10 % for the ALAD-1/ALAD-2 heterozygotes, while the values were 95.93 and 4.07 %, respectively, in children. The allele frequencies of the ALAD-1 and ALAD-2 were 99.45 and 0.55 % for newborns, but 97.97 and 2.03 % for children, respectively. No significant differences in blood lead levels were found between ALAD-1/ALAD-1 and ALAD-1/ALAD-2 either in newborns or in children. The frequency distribution of the ALAD-2 allele in newborns from the exposed group was lower than that of the reference group. There were no significant differences, between the two different ALAD genotypes in the lead load of newborns and children. The frequency distribution of ALAD gene does not influence the blood lead levels of newborns and children in this case, which means that the higher lead burden in the exposed children was possibly influenced by e-waste recycling, but not ALAD genotypes.     

石油炼化企业烟气脱硫技术研究进展

石油炼化企业由于烟气特点、排放特征和减排设施的差别,导致了各炼化企业所采用的烟气脱硫技术的差别较大,尚无成熟、有效、经济的烟气脱硫技术,各炼化企业需要采用的二氧化硫减排技术差别也较大,选用适合炼化企业烟气脱硫的可行工艺技术具有重要现实意义。综合分析了目前国内外已工业化应用的主要烟气脱硫工艺、原理、技术的优缺点以及石油炼化企业烟气脱硫技术的发展趋势,为石油炼化企业烟气脱硫技术研究提供了借鉴和参考依据,并对石油炼化企业未来烟气脱硫技术的研究和选用提出了建议。     

2种烷基多环芳烃对仿刺参CYP450和p53基因表达的影响研究

海洋环境中多环芳烃类(PAHs)主要来源于海洋溢油事故以及沿海石油化工企业的废水排放,国内外大量研究发现海洋中的多环芳烃对海洋生物造成了潜在的生态风险。为了揭示不同浓度多环芳烃类污染物对海参的生态毒理效应,将仿刺参(Apostichopus japonicus)分别暴露于不同浓度的2种烷基多环芳烃3-甲基菲(5、10、100μg·L~(-1))和2-甲基蒽(5、10、50μg·L~(-1))中,检测暴露3 d、7 d和14 d后,3-甲基菲和2-甲基蒽胁迫下仿刺参CYP450和p53基因的相对表达量。结果表明,3-甲基菲和2-甲基蒽胁迫下,仿刺参CYP450和p53基因的表达均对毒物产生了不同程度的响应。与对照组相比,3-甲基菲各处理组对仿刺参CYP450和p53基因的表达均产生显著的抑制作用(P0.05); 2-甲基蒽各处理组对仿刺参CYP450和p53基因的表达影响作用不同,暴露7 d后,2-甲基蒽各处理组对仿刺参CYP450基因的表达表现出抑制作用,对p53基因的表达表现出诱导作用。相同浓度与时间胁迫下,2-甲基蒽对仿刺参CYP450和p53基因表达的影响比3-甲基菲的影响大。上述研究结果表明,3-甲基菲和2-甲基蒽均可不同程度影响仿刺参CYP450和p53基因的表达,且与3-甲基菲相比,2-甲基蒽对仿刺参CYP450和p53基因表达的影响较明显。上述结果为多环芳烃类污染物对仿刺参的生物毒性评价提供了基础数据。     

Numerical analysis of keyhole geometry and temperature profiles in plasma arc welding

In keyhole plasma arc welding (PAW), the formation of the keyhole involves complicated thermo-physical mechanism. The shape and dimensions of the keyhole directly determine the heat deposition along the thickness direction of the test plates, the penetration depth and the weld bead quality. Based on analysis of the forces acting on the weld pool, a keyhole model is established according to the force-balance condition on the keyhole wall. The shape and dimensions of quasi-steady state keyhole are numerically predicted. The keyhole shape and size are used to calibrate some distribution parameters of the combined volumetric heat source which takes into consideration the geometrical feature of welds with larger ratio of penetration depth to width and volumetric distribution characteristic of the plasma heat intensity along the plate thickness direction. The temperature fields on stainless steel plates are numerically simulated. The calculated fusion line at the transverse cross-section of PAW welds are compared with the experimental measurements. It is found that the predicted results are in agreement with the experimental data.     

Response of PM2.5-bound elemental species to emission variations and associated health risk assessment during the COVID-19 pandemic in a coastal megacity

The coronavirus (COVID-19) pandemic is disrupting the world from many aspects. In this study, the impact of emission variations on PM_2.5-bound elemental species and health risks associated to inhalation exposure has been analyzed based on real-time measurements at a remote coastal site in Shanghai during the pandemic. Most trace elemental species decreased significantly and displayed almost no diel peaks during the lockdown. After the lockdown, they rebounded rapidly, of which V and Ni even exceeded the levels before the lockdown, suggesting the recovery of both inland and shipping activities. Five sources were identified based on receptor modeling. Coal combustion accounted for more than 70% of the measured elemental concentrations before and during the lockdown. Shipping emissions, fugitive/mineral dust, and waste incineration all showed elevated contributions after the lockdown. The total non-carcinogenic risk (HQ) for the target elements exceeded the risk threshold for both children and adults with chloride as the predominant species contributing to HQ. Whereas, the total carcinogenic risk (TR) for adults was above the acceptable level and much higher than that for children. Waste incineration was the largest contributor to HQ, while manufacture processing and coal combustion were the main sources of TR. Lockdown control measures were beneficial for lowering the carcinogenic risk while unexpectedly increased the non-carcinogenic risk. From the perspective of health effects, priorities of control measures should be given to waste incineration, manufacture processing, and coal combustion. A balanced way should be reached between both lowering the levels of air pollutants and their health risks.     

居民对室内空气质量安全认知程度的调查研究

为了解山西省城市居民对室内空气质量安全的认知情况和室内空气质量现状,在山西省太原、大同、晋城和吕梁随机选取786户居民进行问卷调查,并对有检测意愿的86户居民进行室内甲醛含量检测.结果表明,山西省居民室内空气质量安全认知得分15.37,得分率为51%;山西省居民平均室内甲醛浓度(0.197 mg/m3)超过国家标准(0.1 mg/m3);四市中太原市的情况最好.山西省居民在室内空气质量安全方面的认知水平和室内空气质量都不高,为保障山西省居民健康,应对山西省城市居民进行室内空气质量安全知识的普及.     

广东省低碳城市评价体系研究

以广东省21个地级市为研究对象,根据低碳发展理念与目标,结合广东省的低碳发展路径,选取与低碳城市发展密切相关的14个基础指标,构建广东省低碳城市评价指标体系进行综合评价。结果表明:(1)广东省低碳城市评价较好的城市主要有广州、深圳、珠海、佛山、惠州等。(2)参与评价的城市得分均较高,整体上具备良好发展势头。(3)排名越靠后的城市,制约指标越多,新能源与可再生能源比例是广东省低碳发展最受制约的指标。(4)单位土地面积碳排放量指标各城市间的反差最大,主要是由于各城市的市域面积不一,能源消费与经济发展不平均而造成的。