Wastewater treatment

Problem

The currently increasing gap between the amount of sewage produced and the amount of sewage that is effectively treated before discharge into receiving water bodies seems to have 5 major causes:

 

1. Wastewater treatment is a money losing activity and not affordable for most people.

2. Wastewater treatment yields no useful, sellable product.

3. Wastewater treatment consumes a significant amount of electricity for aeration. However, electricity allocation to many other activities is given a higher priority.

4. Due to rapid population growth, existing wastewater treatment plants are frequently overloaded with respect to their design capacity consequently leading to sub-optimal performance and high failure rates.

5. The conventional centralized treatment model obligates a complex, costly and slow decision-making process that leads to the implementation of sub-optimal solutions.

 

Solution

The proposed technological solution is derived from modern progress in environmental biotechnology, process monitoring, communications technology, and data science. The solution features data intensive process development. The system should include phototrophic, anaerobic and anoxic bioprocesses, reutilization of existing wastewater treatment plant infrastructure and remote monitoring.

Depending on local conditions, the concept can be implemented as nodes in an existing sewer network, as a renovation of an existing centralized plant or as a new construction.

 

Value proposition

The plant can be energy positive and water can be recovered for productive uses. The system offers lower Capex and Opex compared to conventional alternatives. An attractive Public Private Partnership model is possible. Treated water, electricity and other products can be profitably exported according to the local conditions.

 

Energy positive wastewater treatment project outline

The subject of the energy positive wastewater treatment plant (WWTP) has been studied for many years. In a conventional WWTP, more than 50% of the potential energy (enthalpy) contained in the incoming solids leaves the system in activated sludge units. Improving the energy balance is not just about digesting sewage sludge, cogeneration with internal combustion engines, sludge incineration and optimizing the electricity consumption of a conventional WWTP. Rather, it is a question of designing a new model of wastewater treatment plant and including new processes, high-throughput anaerobic processes (anaerobic filter, for example), biotechnologies based on the cultivation of algae and cyanobacteria, membrane filtration and constructed wetlands. A new financially profitable WWTP is possible. The path to market is through pilot and demonstration projects in the field.

Fate of influent solids calorific value through a conventional wastewater treatment plant

Wastewater treatment plant optimization using neural networks

A wastewater treatment plant is a system of sub-processes that includes complex interactions between the physico-chemical quality of incoming wastewater, effluents, constructive and electromechanical parameters, biological processes, and daily and seasonal variations. A numerical monitoring and simulation tool would help efforts to optimize the operation of a WWTP. Numerical models have demonstrated their ability to identify complex, non-linear systems and estimate parameters. Unlike conventional numerical models which attach great importance to biological parameters, an approach based on the identification of a few important and easily measured operating parameters could lead to better control of WWTPs. The following example describes the use of neural networks in the field of wastewater.

 

• Sakiewicz, P.; Piotrowski, K.; Ober, J. & Karwot, J. Innovative artificial neural network approach for integrated biogas – wastewater treatment system modelling: Effect of plant operating parameters on process intensification. Renewable and Sustainable Energy Reviews, Elsevier BV, 2020, vol. 124.

Value addition to dairy waste streams

The system includes all the mechanical components and the automation required to transform whey and wastewater into economically valuable products at the cheese dairy. The development method includes data acquisition during on-site trials, the creation of a neural network model, and simulation to determine optimal values for construction and operation parameters.

 

• Inputs: raw whey, all wastewater (e.g. from washing)
• Outputs: lactic acid, protein concentrate, biogas, wash water, wastewater