华南理工大学学报(自然科学版) ›› 2022, Vol. 50 ›› Issue (8): 92-101.doi: 10.12141/j.issn.1000-565X.210726

所属专题: 2022年环境科学与技术

• 环境科学与技术 • 上一篇    下一篇

市政污泥热干化特性及污染物释放规律的实验研究

廖艳芬 邱梦泽 陈顺凯 马晓茜   

  1. 华南理工大学 电力学院,广东 广州 510640
  • 收稿日期:2021-11-16 出版日期:2022-08-25 发布日期:2022-04-08
  • 通信作者: 廖艳芬(1976-),女,教授,博士生导师,主要从事固体废弃物清洁高效利用研究。 E-mail:yfliao@scut.edu.cn
  • 作者简介:廖艳芬(1976-),女,教授,博士生导师,主要从事固体废弃物清洁高效利用研究。
  • 基金资助:
    广东省重点领域研发计划项目(2020B1111380001)

Experimental Study on Thermal Drying Characteristics and Pollutant Discharge Law of Municipal Sludge

LIAO Yanfen QIU Mengze CHEN Shunkai MA Xiaoqian   

  1. School of Electric Power Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China
  • Received:2021-11-16 Online:2022-08-25 Published:2022-04-08
  • Contact: 廖艳芬(1976-),女,教授,博士生导师,主要从事固体废弃物清洁高效利用研究。 E-mail:yfliao@scut.edu.cn
  • About author:廖艳芬(1976-),女,教授,博士生导师,主要从事固体废弃物清洁高效利用研究。
  • Supported by:
    the Guangdong Province Key Field Research and Development Program(2020B1111380001)

摘要:

随着我国经济的发展和城市化进程的加快,污泥产量随着污水处理率的提高而急剧增加,污泥处理处置成为亟待解决的问题。文中以出厂市政污泥为研究对象,对其热干化特性及污染物释放规律进行研究:在100~250 ℃等间隔的7组温度下进行热失重实验,以干燥速率和脱水速率来表征干化特性,实验发现200 ℃为污泥的最佳干化温度。对尾气中的气态污染物进行在线测量,发现除NH3和H2S外,还包含了NO、SO2和HCl等酸性气体,以及CO、CO2、H2、C2H6、C2H4等烃类成分,实验发现温度控制在200 ℃以下有利于抑制气态污染物的释放。实验条件下干化冷凝液为高浓度有机废水,125~250 ℃时pH值集中在8.88~9.17之间,为缓冲体系;COD随温度升高而增大,最高达16 000.0 mg/L。对干化后污泥渣基本燃料特性的检测发现,125~275 ℃下泥渣的碳含量和热值随温度升高而降低,300 ℃时符合低温碳化的部分条件,碳含量和热值增加,这为污泥的能源化提供了思路。结合SEM、BET等手段对泥渣进行表征,发现温度升高可增加泥渣的微孔结构,泥渣整体变得松散疏松,可作为低级吸附剂或建筑原料。文中研究结果为出厂污泥的废物处理及利用提供了一种新的思路。

关键词: 污泥干化, 污染物释放, 低温碳化, 显微结构, 多孔介质, 废物处理

Abstract:

With the development of China’s economy and the acceleration of the urbanization process, the amount of municipal sludge has increased sharply. Sludge treatment and disposal has become an urgent problem to be solved. By taking the sludge from a sewage treatment plant as the research object, this paper studied its thermal drying characteristics and pollutant discharge law. In the study, the thermal weight loss experiment was carried out at seven sets of temperatures at 100 ~ 250 ℃ equidistantly with homemade equipment, and the drying properties were characterized by the drying rate and the dehydration rate. It is found that the best temperature for drying is 200 ℃. Moreover, the gaseous pollutants were measured online with a flue gas analyzer. It is found that, besides NH3 and H2S, the gaseous pollutants also contain acid gases such as NO, SO2 and HCl, as well as hydrocarbon components such as CO, CO2, H2, C2H6 and C2H4. The experiment also finds that the temperature being controlled below 200 ℃ is beneficial to inhibit the release of gaseous pollutants. Under the experimental conditions, the drying condensate is high-concentration organic wastewater, the pH values are concentrated in the range of 8.88 ~ 9.17 at 125 ~ 250 ℃, forming a buffer system; the COD increases as the temperature increases, and is up to 16 000.0 mg/L under the experimental conditions. Through the basic fuel characteristics test results of the dried sludge, it can be found that the carbon content and calorific value at 125 ~ 275 ℃ decrease with the increase of temperature, but at 300 ℃, due to the conditions of low-temperature carbonization, both the carbon content and calorific value increase. This provides ideas for the energy conversion of sludge. Combining SEM, BET and other methods to characterize the sludge, it finds that temperature increase can increase the microporous structure of the dried sludge, the structure of sludge becomes loose, so that the sludge can be used as a low-grade adsorbent or building material. The results in this paper provide a new idea for sludge resource utilization.

Key words: sludge drying, pollutant discharge, low-temperature carbonization, microstructure, porous media, waste treatment

中图分类号: