Optimization of biological wastewater treatment by micro-flotation at ARA Rhein


ARA Rhein treats industrial and municipal wastewater from the catchment area in Pratteln in a 2‑stage biological process. DAS Environmental Expert GmbH was responsible for building the new two-line flotation system together with the project partner Enviplan®.

With a total of 500,000 pop­u­la­tion equi­val­ents, ARA Rhein is the largest wastewa­ter treat­ment plant of its kind in Switzer­land. The plant cleans ap­prox. six bil­lion litres of in­dus­trial and mu­ni­cipal wastewa­ter in an en­vir­on­ment­ally friendly way. For clean wastewa­ter to be dis­charged into the river Rhine, it must first pass through sev­eral elab­or­ate clean­ing stages. The wastewa­ter treat­ment pro­cess con­sists of mech­an­ical, chem­ical, phys­ical and bio­lo­gical pro­cessing stages, as well as thermal treat­ment of the sewage sludge, formed dur­ing the bio­lo­gical clean­ing pro­cess. The waste heat gen­er­ated dur­ing in­cin­er­a­tion of the sewage sludge is fed as heat­ing en­ergy into the “Grüssen” heat­ing net­work of the com­pany, Elektra Basel­land, with headquar­ters in Li­estal (Switzer­land). This res­ults in sav­ings of ap­prox. one mil­lion litres of fuel oil.

Ex­tens­ive wastewa­ter ana­lyses guar­an­tee the con­sist­ently high qual­ity of the wastewa­ter to be dis­charged. The leg­ally pre­scribed limit val­ues are com­plied with at all times.

An­other ser­vice offered by ARA Rhein is the clean­ing of eas­ily bio­de­grad­able wastewa­ter and the en­vir­on­ment­ally friendly hand­ling of sewage sludge from mu­ni­cipal and in­dus­trial wastewa­ter treat­ment plants. A new waste air concept en­sures the al­most com­plete re­duc­tion of air pol­lut­ant emissions.

Planung Abwasserbehandlung Chemische industrie

Construction of a new flotation system to optimise biological wastewater treatment at ARA Rhein 

The con­struc­tion of the new mi­cro-flot­a­tion sys­tem at ARA Rhein was a joint pro­ject led by DAS En­vir­on­mental Ex­pert GmbH from Dresden. In par­tic­u­lar it in­volved pro­ject en­gin­eer­ing, mech­an­ical equip­ment, and in­stru­ment­a­tion as well as com­mis­sion­ing and op­tim­isa­tion of the mi­cro-flot­a­tion system.