WWTP design in warm climates - guideline comparison and parameter adaptation for a full-scale activated sludge plant using mass balancing.

The ATV-A-131 guideline and the design approach published in 'Wastewater Engineering, Treatment and Reuse (WE)' are widely used for the design of activated sludge plants. They are both based on simplified steady-state assumptions tailored to the boundary conditions of temperate climates. Using design guidelines beyond the designated temperature range may lead to inappropriate results. The objectives of this paper are (1) to summarise temperature relevant differences between ATV-A-131 and WE; (2) to show the related design components; and (3) to demonstrate a procedure for design parameter adaptation for a full-scale activated sludge plant located in a warm climate region. To gain steady-state data required for wastewater treatment plant (WWTP) design according to ATV-A-131 and WE, full-scale plant data were acquired for a period of 6 months as a basis for analyses and adaptation. Mass balances were calculated for the verification of the measurements and for analysing excess sludge production. The two approaches showed relevant temperature related differences. WE default application resulted in lower deviation in the mass balance results for excess sludge production. However, with the adaptation of the heterotrophic decay rates for both approaches and the inert organic and mineral solids fraction additionally for ATV-A-131, a good fit to the observed excess sludge production could be achieved.

MARAPUR--a new process combination for the optimization of MBR.

The MARAPUR concept is a biological wastewater treatment process based on the MBR functional principle. The ultrafiltration of activated sludge takes place in pressure-driven hollow fiber membranes. The vertical membrane modules are installed compactly in a MEGAMODUL. The permeate extraction is accomplished in the cross-flow, which is supported by rinsing aeration. The main process advantages are high filtration performance, excellent operation reliability provided by wastewater fine sieving and reduced cleaning chemicals demand. Wastewater fine sieving with a mesh size of 0.25 mm is an effective measure against membrane clogging by hair and fibers.