污泥处理处置技术研究

污水处理产生的污泥含有丰富的氮、磷、钾和植物生长需要的其他微量元素,可以被人们生产所利用。但是其中含有一些重金属、有害有机物和病原体微生物,堆放时不仅占用很大厂区面积而且会散发出臭气等特点使得污泥不可以不经过处理直接被利用,因此人们对污泥的处理和处置技术研究也越来越重视,经过处理处置后的污泥可以实现资源化、减量化和无害化。     

Thermal removal of PCDD/Fs from medical waste incineration fly ash--effect of temperature and nitrogen flow rate

The fly ash used in this study was collected from a bag filter in a medical waste rotary kiln incineration system, using lime and activated carbon injection followed by their collection as mixed fly ash. Experiments were conducted on fly ash in a quartz tube, heated in a laboratory-scale horizontal tube furnace, in order to study the effect of temperature and nitrogen flow rate on the removal of PCDD/Fs. Results indicated that in this study PCDD/Fs in the fly ash mostly were removed and desorbed very little into the flue gas under thermal treatment especially when the heating temperature was higher than 350 °C, and dechlorination and destruction reactions took important part in the removal of PCDD/Fs. However, in terms of flow rate, when flow rate was higher than 4 cm s⁻¹, destruction efficiency of PCDD/Fs decreased dramatically and the main contributors were P₅CDF, H₆CDF and H₇CDF desorbed to flue gas, the PCDD/Fs in the fly ash decreased with enhanced flow rate.     

Effects of selected metal oxides on the dechlorination and destruction of PCDD and PCDF

OCDD and OCDF spiked silica/graphite based model fly ash containing various copper compounds and metal oxides were thermally treated under oxygen deficient conditions. All copper compounds tested showed a considerable dechlorination/hydrogenation reaction at 260 °C. After 30 min at 340 °C, less than 1% of the spiked OCDD and OCDF was recovered as T₄CDD/F to OCDD/F. Other compounds tested demonstrated a lower rate of dechlorination compared to the copper compounds. However, all other metal oxides showed a small dechlorination effect at 260 °C, which was considerably increased at 340 °C.

The model fly ash containing the different copper compounds or metal oxides showed comparable PCDD and PCDF isomer patterns after thermal treatment. However, small differences were observed among the different tested compounds. The PCDD and PCDF isomer patterns on the model fly ashes were similar to patterns found during dechlorination experiments on fly ashes from waste incineration processes.

Model fly ash containing Ca(OH)₂ exhibited the highest destruction potential, but a low dechlorination potential. In contrast, model fly ash containing any of the remaining compounds tested, was found to predominantly dechlorinate the spiked OCDD and OCDF.     

危险化学品废物销毁设施的通风设计

中国目前还没有危险化学品废物销毁装置的通风设计范例,文章在参考美国标准和中日两国关于日遗化武销毁设施磋商初步成果的基础上,提出了危险化学品废物销毁设施通风的设计思路及污染控制要求。     

国外炼厂污泥无害化处理实践和发展方向

发达国家的炼厂含油污泥土地处置的法令迫使炼厂开发经济有效的方法对炼厂废弃物在最终处置前进行处理．在国外，含油污泥的处理技术发展很快．介绍了国外一些有效的、广泛应用的污泥处理方法，从而能使我们了解国外污犯处理的发展趋势，并为我国污犯处理技术提供借鉴．     

Dechlorination and destruction of PCDD,PCDF and PCB on selected fly ash from municipal waste incineration

The potential of fly ash to dechlorinate and destroy PCDD, PCDF and PCB was tested under oxygen deficient conditions in the laboratory. Specifically, two types of fly ash were compared, originating either from a fluidized bed incinerator using Ca(OH)₂ spray (FA1), or a stoker incinerator without Ca(OH)₂ impact (FA2).

Results from the present study indicate that on FA2 type fly ash, the degradation processes of OCDD, OCDF and D₁₀CB occurred primarily via dechlorination/hydrogenation up to temperature settings of 340 °C. In contrast, FA1 type fly ash was found to effect both dechlorination and destruction of these compounds already at temperature settings of 260 °C.

The dechlorination velocity of PCDD and PCDF did not differ significantly. However, the first dechlorination step of OCDF in the 1,9-position occurred faster compared to the first dechlorination step of OCDD.

The isomer pattern resulting from the dechlorination processes was quite similar on both FA1 and FA2, indicating that differences in alkalinity or elemental composition of the two types of fly ashes do not have a significant influence on the position of dechlorination. PCDD and PCDF dechlorination of the 2,3,7,8-positions was not favoured over dechlorination of the 1,4,6,9-positions on either type of fly ash. In contrast, dechlorination of PCB occurred predominantly on the toxicological relevant 3- and 4-positions.

The dechlorination/destruction processes were completed on both types of fly ash at 380 °C within one hour, which correlates well with results obtained from actual plant operation practices.     

论无害化处理机关事业单位电子办公垃圾

通过对现有机关事业单位办公垃圾分析,提出处理电子办公垃圾的方法及有效治理措施。     

危险废物处理处置技术

危险废物具有腐蚀性、急性毒性、易燃性、反应性和感染性等特点。处理处置危险废物的方法有多种,本文通过对危险废物的特点分析,比较常用的几种处理处置技术方法,最后提出危险废物处理处置的相关建议。     

微塑料污染现状及控制对策

目前,微塑料作为水环境中一种最新型的污染物受到越来越广泛的关注,因不足5mm的微小粒径,使其能够进入环境循环系统从而对环境和人体健康造成极大的威胁。针对微塑料污染问题,本文在对微塑料现状分析的基础上,提出对微塑料控制的对策和建议,积极采取行动,减少微塑料垃圾的产生量,并对已经产生的微塑料进行无害化处理。     

废弃钻井泥浆无害化处理与评价方法的研究

本文简述了废弃钻井泥浆对环境的影响及无害化处理原则,分析了废弃钻井泥浆处理存在的问题,详细论述了废弃钻井泥浆无害化评价标准、浸出毒性评价方法以及分析结果的应用,为废弃钻井泥浆分类贮存、处置和土壤环境修复提供合理化建议。