Project Description

Mikroflotation ersetzt Primärbehandlung

The Task

The sewage treatment plant treats domestic and industrial sewage and was a retrofitting project. Using enviplan® technology the plant was upgraded from 80.000 to 130.000 PE in Austria. The former primary sedimentation and rainwater retention system was modernized. After piloting with a mobile enviplan® microflotation unit, the taks was to upgrade primary treatment. enviplan® substituted the entire primary treatment by AQUATECTOR® microflotation to offer minimum TSS, and F.O.G. load to the downstream aerobic biological step.

The Solution

enviplan® has solved this problem by modernising and substituting the primary treatement step with micro-flotation technology. The application of their technology results in a minimum total suspended solids load to the downstream aerobic biological step. It is possible to install technology requiring only very little carbon footprint. The procedure involves micro-flotation technology and iFloat® self-cleaning injectors and valves. The enviplan® microflotation is operated behind a pre-screening and a grease and sand trap.
Microflotation Cells with Microbubble distribution absorbs almost the entire portion of suspended solids, total suspended solids and fats, oils and greases. The pressure of the saturation system operates with compressed air is at about 2,5-3 bar. The specific energy requirement is less than 60Wh/m3 of treated wastewater.

The Advantage

A compact solution offers better effectiveness without additional space requirements plus optimum results in primary treatment with low energy requirements. The microflotation treatment is non-chemical. The footprint of the microflotation tanks is approx. 160m2. Main argument was the maintenance- and clogging-free operation of the iFloat® valve technology.
Project Date: October 2014
Client: Abwasserverband Milstätter See

  • Wastewater treated by Microflotation: max. 3600 m³/h
  • Footprint of Microflotation 15 times smaller than Primary Treatment
  • Energy requirement: ca.60 Wh per m³ Wastewater
  • Increased Capacity of WWTP ca. 30%
  • Removes TSS, F.O.G., BOD and COD upfront biological treatment
  • Microflotation sludge is digested to produce energy
  • WWTP is energy autonomous since startup of microflotation

WWTP Bayer AG, Deutschland

The Task

The Microflotation units with patented  AQUATECTOR® Microfloat® technology were put into operation in the year 1997 at Bayer AG, Uerdingen.They serve the purpose of tertiary and reduction of TSS, COD and turbidity. Here, microflotation replaces sand filtration.

The Solution

The flotation absorbs the waste-water that has already been completely biologically purified immediately after the final clarification. In the microflotation, the waste-water is saturated with compressed air at about 3.5 bar. The small bubbles which occur during the following pressure reduction, mix up with the fine suspended and sludge parts and get to the surface of the liquid. There, a sludge removal system sucks up the floated sludge parts. In the design with two parallel operated round cells of a diameter of 10 m respectively, a non-contacting flotate removal and the pressure re-saturation system AQUATECTOR®, the microflotation technology installed here is a novelty in the purification technology.

The enviplan® microflotation serves as supplementary processing stage for the wide-ranging separation of TSS of the completely biologically purified waste-water of Bayer AG. Beside the further reduction of the cumulative parameter COD, the duty of the flotation is to secure the monitoring values for unfavourable conditions of the purification plant at the outlet. For the wide-spread application of the sand-filtration as processing stage in the purification technology, the flotation represents a high-performance, highly variable and cost-effective processing alternative. The energy requirement of the entire plant lies at < 7,5 Wh per m³ of treated waste-water. About nine million cubic meter of water can be subsequently processed with the new system yearly. Dr. Kuhn as assistant head of factory, responsible for environmental protection: “The pressure reduction flotation ensures that the CSB-value falls further. In it, we are seeing a further contribution in the sense of the Responsible Care”.

Client: Bayer AG Leverkusen

Project Link: Skills Envolved

Input Mikroflotation: 1200 m³/h

  • Input TSS >1000mg/l
  • Discharge <10mg/l
  • Energy requirement: <7,5 Wh per m³ Wastewater