CASE STUDY - BWA FiberTechnology

Problem statement: presence of soluble protein and lack of fibers are the key inhibitors of successful dewatering activity, resulting in low sludge load on centrifuge, high chemical consumption and low centrate quality.

High DS of dewatered sludge to be disposed has been an expectation for a long time, but there is an increasing demand on perfect centrate quality with special concern on microplastic content and suspended solid.

At BWA Lab we have developed a non-ADR, green product on a calcium basis, that enhances your dewatering performance in an enorm way. BWA NanoSMART RED125 is a liquid product that is an excellent tool to pretreat sludge to be dewatered before flocculation agent is added. THERMAL TREAMTENT or higher temperature in thermophilic digester are even increasing the effectivity.

NanoSMART has earned its name and reputation because of its SELECTIVITY. It looks for phenols, proteins and OH groups after entering the sludge. This characteristic and its special fiber content makes it possible to create water outlet channels in the flocs and a structure resistant to shear forces. Fibers in NanoSMART have an iron-oxide coating in a calcium-rich environment, which ensures powerful fixation of microplastics in the dewatered sludge.

The graphs show the two day testing result of BWA Nanosmart RED125 in the Central WWTP in Budapest, where thermophilic digestors operate.

By normal operation BWA NanoSmart RED125 was dosed into the sludge line before the sludge pump of the centrifuges. Due to the shear resistant flocs torque force started to increase immediately. (Blue line in green cloud.) At the new equilibrium in the centrifuge 3%. higher DS was measured with a centrate quality never seen before. The flocculant consumption was then continuously decreased. (Yellow line.) At 20% decrease we arrived to the basis parameters concerning DS and centrate quality.

On day two the sludge load on the centrifuge was increased with fixed specific flocculant consumption (Upper blue line.) We found the limit by 50% increase, but only because of the insufficient capacity of the flocculant solution pump (Yellow line).

A possible positive side effect to be expected is that centrate from the dewatering with increased calcium content entering the anoxic zone of the wastewater treatment plant might play a catalytic role in creating extra basicity and in this way results in a better treatment performance with good sedimentation parameters.

We found that BWA NanoSMART RED125 can be an important tool also in fighting against vivianite and struvite problems in the pipelines. It was noticed that the possible replacement of iron-chloride might decrease the quantity of sludge (DS) reasonably.

We can deliver BWA NanoSMART RED125 in IBCs as a ready to use product, or if you are far away from Hungary, we can offer you BWA NanoSMART BASIS which is a concentrate of fibers with iron-oxid coating and can be easily transferred to BWA NanoSMART RED125 with the assistance of a local chemical distribution partner.