The LODOred product
The state of the art methodologies for sewage sludge reduction are mainly based on a sludge degradation approach, whereas the approach to prevent sludge generation is rarely applied.
The LODOred product has been developed by BIOAZUL, in close cooperation with TTZ-Bremerhaven, to reduce the production of biological sludge generation (surplus sludge) in biological wastewater treatment plants (conventional activated sludge systems, SBR systems). Its efficiency has already been demonstrated in municipal wastewater treatment plants.
LODOred products are a preparation based on a recipe consisting of encapsulation and auxiliary substances in combination with vitamins in aqueous solution. Once added to activated sludge, it enwraps microorganisms and leads to the formation of compact activated sludge flocs as illustrated in Figure 1. These flocs may also incorporate small suspended mineral particles leading to an increase of floc density what is improving simultaneously the settlement abilities in the clarifier.
Figure 2 shows a comparison of microscopic pictures of non-encapsulated activated sludge and microorganisms encapsulated with LODOred. The main purpose of encapsulating microorganisms is influence their metabolism, since a “biological”, highly selective membrane coating is created enabling manipulation of metabolism inside as it is otherwise only possible in membrane bioreactor systems. Therefore, LODOred creates numerous micro membrane bioreactors in a conventional wastewater treatment plant. In addition to this, auxiliary substances in LODOred on the one hand enable immobilisation of enzymes to the flocs and result, in combination with the vitamins, in an intensification metabolism. Other auxiliary substances facilitate or regulate on the other hand mass transfer into and out of the flocs, improving degradation efficiency. The manipulation of the metabolism is aimed to relocate the equilibrium of the microorganisms activities from anabolism, i.e. creation of new cell mass, to catabolism, i.e. generation of additional energy to supply the intensified microbial degradation activity. The consequence is a considerable reduction in surplus sludge generation. LODOred can be allocated to the “prevention methods” as a combination of chemical and biochemical methods. The effects and advantages of LODOred are at a glace:
- Non-hazardous, non-toxic, fully biodegradable product, composed of ingredients of food additives grade
- Reduction of biological surplus sludge / waste generation up to 50 %
- Improvement of sedimentation abilities (SVI)
- More stable biological treatment process
- Improved effluent quality (e.g. BOD, COD, N, P, suspended particles, etc.)
- Biological system less sensitive against shock loads
- Improved dewaterability (reduced polymer consumption, less time for sludge dewatering required, reduced energy consumption, increased equipment lifetime, lower labour costs)
- Less negative environmental impacts by wastes from wastewater treatment