Producing concrete from ... industrial sludge

Sludge from dyeing factories, leather shoes, centralized wastewater treatment . will be treated with odors, adding chemicals to replace sand in concrete production, suitable for making foundation and internal roads , Precast.

This is called 'THS technique' by Dr. Nguyen Hong Binh, Vice President of Ho Chi Minh City Science and Technology Association. Currently, this technique has been piloted at Binh Duong Waste Treatment Enterprise.

Dr. Binh said: 'From the time I was in office (Deputy Director of Ho Chi Minh City Department of Agriculture and Rural Development), I was very interested and had the idea of ​​treating the sludge of industrial factories, but until I retired. done.

The secret of this technique is in some chemicals prepared by Mr. Binh to handle odors and bind sludge, which can replace sand used in concrete production. These chemicals are named BOF1, BOF2 and HSOB.

Waste sludge after being taken up (fresh mud) will be treated with BOF1 and BOF2 chemical odors for about 15 minutes. After that, the initial treated sludge mixture is mixed with cement (ordinary Portland) and HSOB additive compound for concrete.

Use sludge to replace sand for concrete in Binh Duong Waste Experiment.

Dr. Nguyen Hong Binh (the second person from the left), oversees internal concrete pouring at Binh Duong Waste Treatment Enterprise.

HSOB additives have the effect of creating redox reactions, turning toxic substances into more or less toxic and forming inert substances with water.

These chemicals are prepared from commercially available materials. Depending on each type of waste sludge: dyeing, tanning, processing seafood, sludge in concentrated sewage treatment plants, polluted canals and culverts in the city . there will be modulation with billions Different mixing rules for processing. Dr. Binh said, the cost of chemicals to treat one ton of sludge into concrete casting sand is about 1.2 million dong.

Mr. Nguyen Thanh Phong, Deputy Director of Waste Treatment Enterprise, belonging to Binh Duong Province Water Supply and Sewerage Company Limited, said: Currently, this unit applies this technique to treat sludge. of dyeing, tanning, and ash factories from hazardous waste incinerators .

Previously, Binh Duong Waste Treatment Enterprise treated this sludge with a safe burial pit. With organic waste sludge, the unit conducts burning. But when the burning is completed, the unit still has to be buried because this mud cannot burn completely. The unit is conducting a scientific council to evaluate and replace the old treatment method by hardening concrete for infrastructure and precast concrete.

This new approach can turn hazardous waste resources into resources at eight times cheaper than burial or burning. Test results showed that the use of waste sludge instead of sand to make concrete in the way stated in the article meets the environmental safety standards in Vietnam.