Johnson-Ettinger蒸气入侵风险评估模型参数修正研究

Johnson-Ettinger蒸气入侵模型(J-E模型)作为目前应用最广泛的评价蒸气入侵潜在风险的筛选工具,其模型预测结果的准确性影响蒸气入侵风险的判断。通过对J-E模型进行敏感性分析,发现对其预测结果影响较大的参数依次为土壤毛细管层含水率、空气交换指数、封闭空间的体积以及毛细管层的厚度。基于以上分析结果,提出采用美国环境保护局(US EPA)推荐的饱和含水率对毛细管层含水率进行修正,毛细管层厚度采用VG方程描述的水分特征曲线拐点处的毛细管压头进行修正。修正后的J-E模型预测结果与三维数值模拟的计算结果较为吻合,两者的差距不到1个数量级。     

代谢组学方法在生态毒理学中的应用进展

代谢组学方法越来越多地用于研究有机体与生态环境的相互作用。近年来,该方法已被应用于化学物风险评价和野生动物的疾病诊断,成为环境科学,特别是生态毒理学中充满活力的研究方向之一。本文介绍了应用于代谢组学研究的核磁共振波谱和质谱2种检测技术,着重讨论了生态毒理学研究中代谢组学方法在生物标志物的发掘和毒性评价,以及有机体对环境影响因子的代谢响应、野生水生动物疾病的诊断和监测等方面的应用。这些代谢组学在生态毒理学领域的应用将促进对有机体与环境相互作用的认识。     

广州地区农田土壤中有机氯农药残留分布特征

以网格法在农田土壤中均匀布点,采集土壤样品75个,对广州地区农田土壤中有机氯农药含量及分布状况进行了研究。结果表明,试区土壤有机氯农药的检出率为100％,表明广州地区农田土壤中有机氯农药残留现象普遍存在。六六六（HCHs）和滴滴涕（DDTs）的平均含量分别为42．75μg/kg、52．76μg/kg,含量范围分别在1．35—803．72和2．73—1036．90μg/kg。与国内不同区域的同类研究相比,广州地区土壤的有机氯残留水平较高。在不同利用类型土壤中,有机氯残留状况有所差异,六六六在水稻土中残留量最高,而滴滴涕在菜园土中含量最高。     

Leaching toxicity and heavy metal bioavailability of medical waste incineration fly ash

The aim of this study was to provide a comprehensive risk assessment for medical waste incineration fly ash from another aspect through various leaching methods. The differences and connections between leaching concentrations achieved via the toxicity characteristic leaching procedure (TCLP), the physiologically based extraction test (PBET) and the sequential extraction procedure were also described. Heavy metal contents of the used medical waste incineration fly ash were 1.7–31 times higher than that from Japan, indicating poor medical waste management in China. The fly ash leaching concentration in the TCLP test exceeded the regulation value and can be characterized as hazardous waste under current regulations. However, the PBET concentrations were only 1/10 of the TCLP value or even lower, and the calculated ingested contents of all heavy metals were lower than tolerable daily intake, demonstrating that TCLP might have overestimated the environment risk to some degree. The leaching metal content of TCLP ranged from exchangeable to residual forms, and the leaching percentage varied from 7.75 to 92.55 %, while the content for PBET was equal to or lower than the exchangeable form.     

皮革废水处理中絮凝沉降工艺的改进与应用

以皮革污水处理中的絮凝沉降工艺为研究对象,研究了聚丙烯酰胺（PAM）用量、聚合氯化铝铁（PAFC）用量及污水pH值对COD去除率的影响。结果表明,污水pH值是影响絮凝沉降效果的关键因素,将污水pH调节为7.0后,即可用0.4 mg·L-1的PAM与1 g·L-1的PAFC实现54%的COD去除率。同时研究了活性炭及硅藻土对污泥膨胀的应急处理效果,当添加量均为1 g·L-1时,活性炭能够在1 h时迅速使沉降比下降20%,而硅藻土虽见效较慢,但其长时间的沉降效果远好于活性炭（能够在8 h时使沉降比下降64%）,说明两种物质的投加时机应有所不同。以上研究成果应用于皮革污水处理厂后,提高了污水处理效果,并取得了明显的经济效益。     

Study on preparation and microwave absorption property of the core-nanoshell composite materials doped with La

Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve -24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption.     

危险废物鉴别监测现状、问题及建议研究

危险废物鉴别技术是危险废物监管中重要的技术支撑。现有的危险废物鉴别技术在危险废物监管中发挥了巨大的作用,但在实际鉴别工作中,还存在一些不足。对危险废物鉴别工作现状进行了具体阐述,同时指出了危险废物名录灵活性不够、危废鉴别标准项目待梳理、鉴别时间周期长、采样数大等存在的问题,并针对性提出解决问题的工作建议。     

深圳市典型溶剂使用源VOCs排放特征、治理现状与减排对策

为强化工业企业VOCs的综合整治,选取工业经济发达的深圳市作为研究区域,通过实地调研和现场检测的方式探讨了橡胶和塑料制品行业、印刷行业、表面涂装行业、电子元件制造业等典型溶剂使用源的VOCs排放特征和末端治理现状,并就源头替代和末端管理提出了具体的减排对策。结果表明：深圳市典型溶剂使用源VOCs的平均排放量为表面涂装（51.8 t/a）>电子元件（36.5 t/a）>印刷（21.0 t/a）>橡胶塑料（17.4 t/a）,不同排放规模的橡胶塑料企业和印刷企业对各自行业的排放贡献较为均匀,而排放量>300 t/a的涂装企业、电子企业对各自行业的贡献率则分别占63.9%、44.9%;受水性原料替代和末端治理设施等控制政策的影响,四大行业固定排放源VOCs组分以OVOCs为主（排放量占比为76.8%~97.0%）,特征污染物为甲醛和乙醛;四大行业末端工艺类型均以UV光解、水喷淋、活性炭吸附的低效组合工艺为主,占比约51.4%~69.6%;评估结果显示,所测试的典型组合工艺中,78%的设施平均处理率均低于35%,治理方案缺乏针对性、运行管理缺乏规范性是造成溶剂使用源VOCs末端削减率偏低的主要因素。因此,为控制未来溶剂使用源VOCs排放量,应当推动源头排放控制从“底线约束”向“先进带动”持续转变;末端治理应统筹考虑技术可行性和管理有效性,确保实现行业VOCs排放总量的高效削减。

     

汽车排气污染及控制对策

综合介绍了我国汽车产业的发展，汽车污染物排放及危害，以及国内外对汽车排气污染的控制，总结了我国汽车排气污染控制与国外的差距，从而提出了我国汽车排气污染控制对策。     

迭鞘石斛抗肿瘤作用研究

体外培养SMMC-7721和HL-7702细胞,以不同浓度的迭鞘石斛多糖、醇提物、水提物作为药物组,并设生理盐水组作为阴性对照,5-Fu组作为阳性对照,MTT法分别测定处理24h、48h、72h后的吸光度值,计算药物对细胞生长的抑制率.荷瘤小鼠分别腹腔注射迭鞘石斛3种提取物,连续注射10d,d11眼眶静脉取血,测定血清中MDA含量及SOD活力变化.体外实验发现浓度为160μg/mL的迭鞘石斛多糖作用48h,对SMMC-7721细胞的生长抑制作用最强,且对HL-7702细胞的毒害作用较小.体内实验发现,迭鞘石斛多糖能显著增强荷瘤小鼠血清中SOD活力(P<0.01),降低MDA含量(P<0.01).研究表明,迭鞘石斛多糖是一种具有潜力的抗肿瘤天然药物.图1表2参8