Agents, polymeric monovalent

Flocculating agents can be simple electrolytes that are capable of reducing the zeta potential of suspended charged particles. Examples include small concentrations (0.01-1%) of monovalent ions (e.g., sodium chloride, potassium chloride) and di- or trivalent ions (e.g., calcium salts, alums, sulfates, citrates or phosphates) [80-83], These salts are often used jointly in the formulations as pH buffers and flocculating agents. Controlled flocculation of suspensions can also be achieved by the addition of polymeric colloids or alteration of the pH of the preparation. 

There are several types of membrane processes used in wastewater treatment in the majority of these the polymeric membrane operates as a filter retaining various species on the feed side while allowing other smaller species to cross. The size of the membrane pores determines the size of species that may be retained. Thus, the membranes with the smallest size pores, called nanofiltration membranes, can retain large ions such as chromate but not the small monovalent species. Ultrafiltration membranes can retain metal ions when combined with large complexing agents. 

The most versatile oxidizing agents are peroxodisulfates, in particular those with monovalent cations such as sodium, potassium, or ammonium. i These peroxodisulfates are water-soluble and the oxidation potential of 2.12 V in acidic medium is sufficient for the oxidative polymerization of EDOT to the positively charged PEDOT polyelectrolyte. Peroxodisulfate has also been used in the form of the free acid, which is, however, less stable than the salts. ... 

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