Physico-chemical plant

The physico-chemical wastewater treatments plant allow the removal of polluants, usually poorly biodegradable, present in the water, through the addition of chemicals. These additives, commonly called "reagents", in some pH conditions, react with the pollutants, making them insoluble and favoring their abatement by coagulation, precipitation and or neutralization.

STA designs, build and offers a big choice of technologies and solutions, the aim is providing the optimal solutions from a technical and operational point of view, ensuring the achievement of purification results at the lowest cost. The project and design of the treatment steps of a chemical-physical plant and the suited technology to particular needs is chosen according to the chemical-physical characteristics of the wastewater, as well as the choice of the chemical reagents, their dosages and the reaction times are the most important parameter in order to obtain an efficient chemical purification system. A chemical-physical plant can generally be divided into the following treatment stages:
  • Insolubilization of metal salts in basic solution;
  • Flocculation;
  • Coagulation;
  • Sedimentation / decantation;
  • Neutralization;
  • Final filtration of purified water;
  • Dehydration and sludge disposal.

In the first step the goal is to increase pH to a defined value, to make insoluble salts of metal earlier present in dissolved form, turning into metal hydrates.The following dosage of specific reagents allowes the flocculation of suspended particles with the substance and the formation of flakes.In order to obtain a better settle we add to the effluent a polyelectrolyte that determin the coagulation of the flakes.

In the final separation section the aim is the water clarification and sludge separation, that settles on the bottom of the decanter. The clarified water are sent to a neutralization tank and then to the final treatment as the physical filtration process on quartz / activated carbon.

The sludge are collected from the bottom of the decanter, dehydrated and finally disposed.

The reactions take place sequentially in distinct tanks dimensioned to ensure the right contact times, or in a sequencing reactor with intermittent cycle, a "batch", that incorporates the different steps of treatment in a single basin.

The service of the company is always ready to intervene to guarantee safety, competence and efficacy. STA offers varied and customized formulas with one fundamental objective: provide to the customer a package that combines maximum reliability with lower operating costs, the rapidity of speech with the accuracy of performance, the user will be free by the tasks and issues that it is more appropriate to entrust to specialists.