건조된 하수 슬러지는 콘크리트의 원료가 되는 대체 시멘트가 될 수 있다는 사실이 말레이시아 연구진에 의해 밝혀졌다.

페르타니카 과학기술저널(Pertanika Journal of Science and Technology)에 실린 이번 연구에서 마라기술대학교(Universiti Teknologi MARA) 소속의 연구진은 콘크리트를 만들이 위한 대체 시멘트 물질로 슬러지의 잠재력을 연구했다. 이러한 방식의 하수처리로부터 발생한 슬러지의 처리는 말레이시아에 위치한 폐수 플랜트에 커다란 이슈가 되고 있다.

 

 

 

Dried sewage sludge could be an alternative cement material for concrete, researchers in Malaysia have found.

 

In a study published in the Pertanika Journal of Science and Technology, researchers from Universiti Teknologi MARA investigated the potential of sludge as an alternative cement material for making concrete.

 

The disposal of sludge from sewage water treatment is a big issue for wastewater plants in Malaysia.

 

While studies show that the volume of sludge is expected to rise, disposal options are limited due to stricter environmental regulations including a ban on burying sludge in soil, due to its high heavy metal content that could cause adverse impacts to the environment.

 

Meanwhile, the construction sector is seeking economic and ecological cement replacement materials in order to meet an increasing demand for concrete.

 

To find out, the researchers first produced domestic waste sludge powder (DWSP). The team dried and burnt wet sludge cake to remove moisture and then ground and sieved the dried sludge cake to make DWSP.

 

Using different proportions of DWSP (3, 5, 7, 10 and 15%), the researchers mixed it with cement to produce different types of concrete (normal strength Grade 30 and higher strength Grades 40 and 50).

 

They then compared each DWSP concrete mixture with normal concrete in terms of their compressive strength, water absorption, water permeability and rapid chloride ion penetration (i.e. permeability to salt).

The team found that the compressive strengths of DWSP concrete decreased as the proportion of DWSP increased in concrete mix, with the exception of Grade 40 concrete containing 7% DWSP.

 

Also, both water absorption and water permeability increased as the percentage of DWSP increased. However, normal concrete was more permeable than DWSP concrete of Grade 40, suggesting that DWSP enhanced the durability of this concrete. Additionally, the resistance to chloride permeability increased for concretes with up to 15% DWSP.

The researchers concluded: "Overall, there is potential for using DWSP as a partial cement replacement. However, more detailed research should be conducted to yield methods for producing quality powder.”

 

[출처 = Water World / 2015년 9월 9일]