Polymer flocculant for sludge/wastewater treatments
The polymer flocculant is an essential chemical to improve the dewaterability of sludge. The suspended solids of the slurries are flocculated when the polymer flocculant is dosed in a controlled operation. The flocculation phenomenon is the key to achieving high-rate sludge dewatering. When the flocculation is poor, the recovery of suspended solids into the dewatered sludge cakes also deteriorates.
The coagulants made of soluble aluminum/ferrous/ferric are also often used in the sludge thickening processes. The inorganic coagulants neutralize the electric charge of the negatively charged suspended solids (e.g., organic particles) and create compact and small coagulates. The coagulates have limited electrical repulsive force and are bound to each other accordingly. Compared to the inorganic coagulants, the polymer flocculants create much larger flocs due to their long chains.
The polymer flocculants have better features than the inorganic coagulants in the sludge dewatering processes. The larger flocs built by the polymer flocculants make possible a high-rate sludge dewatering. Fortunately, the recent progress in macromolecule chemistry has substantially reduced the market prices of the polymer flocculants.
Polyacrylamide, the major constituent of the polymer flocculants, has a very limited toxicity compared to the monomer (acrylamide). Based on this feature, the polyacrylamide-based polymer flocculants are used worldwide for sludge dewatering in numerous municipal wastewater treatment plants as well as industrial wastewater treatment plants.
ARK’s polymer flocculants are also polyacrylamide-based and received the highest reputation from the users.
Identifying the relevant polymer flocculant species for your sludge dewatering
The polymer flocculant has a wide variation in its chain lengths and the electric charges. In other words, we can identify the best polymer flocculant among the lineups depending on the properties of the particles present in the slurries.
First of all, a characterization of the slurry suspension is approximately performed in a visual inspection at the site. Based on this, possible polymer flocculants are chosen from the lineups of the chemical suppliers. Since choosing the chemicals requires rich experience, those who are not familiar with sludge dewatering should consult high-quality chemical suppliers, for instance, ARK.
Next, the polymer flocculants are experimentally examined in a set of batch tests to check each optimum dosing. From the examination, the promising polymer flocculant is identified. You may note that too much polymer flocculant may form a highly viscous slurry. This wrong treatment may cause a lowered sludge dewatering performance.
Screening the best polymer flocculant is not easy, particularly for beginners. This is because both chemical species and dosing are highly dependent on the types of sludge dewatering systems as well as the properties of the slurry suspension. ARK is pleased to be rendering screening polymer flocculants to meet your sludge treatments.
