典型固体废物焚烧飞灰的污染物特性研究

Analysis of Pollution Characteristics of Solid Waste Incinerator Fly Ash in Zhejiang Province

采用成分分析法和毒性监测法系统分析了来源于6类典型固体废物焚烧飞灰的污染物特性.研究表明,6类固体废物焚烧飞灰的主要组成元素有Si、Ca、Al、Fe、K、Na、Cl等.各重金属成分中,Zn是受试飞灰(除LS飞灰)中含量最高的重金属元素,范围在2 100～32 100 mg/kg,均值达9 458 mg/kg;元素Cd、Zn、Cu、Cr、Ni、Pb、As平均值则分别为土壤中的各元素含量的642、127、22、18、15、10、2倍.国标硫酸硝酸法和TCLP浸出程序对飞灰中的重金属浸出率普遍偏低,仅其中2类工业废物焚烧飞灰在TCLP法下超出鉴别限值;虽然受试飞灰中二英类物质(PCDD/Fs)毒性当量均低于危险废物毒性物质含量鉴别(GB 5085.6-2007)有关二英类物质规定,但与浙江省部分地区污染土壤中的平均二英毒性当量进行比较,HZ、WZ、NB、TZ和HUZ飞灰分别为其105、59、401、369和5倍,除LS飞灰外其余5种飞灰的毒性当量值要大大高于加拿大、新西兰和瑞典的土壤中二英的指导值.本研究结果说明不同焚烧厂飞灰化学组成存在很大差异;焚烧废物成分对飞灰中的重金属元素有一定的影响,但焚烧工艺过程是影响固体废物焚烧飞灰中重金属和二英分布和丰度的最主要因素.因此,无论是生活垃圾还是工业危险废物的焚烧飞灰均具有很大的潜在环境风险,处理或利用前必须对其性质进行充分调研.

Pollutants characteristics,especially in components and contents of heavy metals and PCDD/Fs,were chemical analyzed and toxicological evaluated in fly ash from 6 typical kinds of solid waste incinerators in Zhejiang province.The results indicated that the main elements in fly ash were Si,Ca,Al,Fe,K,Na and Cl.Among all kinds of heavy metals,the Zn content was the highest one,whose average was up to 9 458 mg/kg.Meanwhile,the Cd,Zn,Cu,Cr,Ni,Pb and As contents in the fly ash samples were 642,127,22,18,15,10 and 2-fold of those in polluted soil,respectively.The leaching ratios of heavy metals in fly ash concluded according to the HJ/T 299-2007 Procedure were lower than its limitation.However,the leaching ratios from NB and LS sample concluded according to the Toxicity Characteristic Leaching Procedure（TCLP） exceeded its limitation.The TEQ of PCDD/Fs from all samples were lower than the limitation in GB 5085.6-2007,while higher than the soil-limitation in Canadian,New Zealand and Sweden,with 105,59,401,369 and 5-fold in the sample HZ,WZ,NB,TZ and HUZ,respectively.It could be concluded that the components and contents of the pollutants were various from different fly ashes.The components of heavy metals were mainly affected by the type of solid wastes.And the technology of the incinerator played important role in the pollution characteristics in fly ash.Thus,it is of significant meaning to study the particulate pollution characteristics of a certain fly ash before disposal or reuse for the purpose of adequate risk assessment and management.