OSMART® Dewatering

The transportation and disposal of treated sewage sludge has one of the highest administrative costs for plant operators. In the last few years, there has been a significant increase in the specific price of transportation and treatment. One of the key processes to contain such costs is sludge dehydration.

The anomalies related to a sub-par control of this process can lead to significant negative impacts on the plant water line, as well as a notable increase in OpEx: foams caused by too much polyelectrolyte; recirculation of treated sludge; sludge humidity higher than optimal; continual need of personnel to manage the operation.

In order to solve these issues, ETC has created OSMART® DEWATERING, the first dehydration compartment controller that does the following:

• automatic dosage of the optimal polyelectrolyte quantities, based on the quantity of TSSs in input, minimizing the waste of chemical products;
• monitor dehydration performance by continuously calculating the dehydrated slugde %TS, thus reducing final sludge production;
• eliminate the negative impacts on the water train and, as a consequence, on the final discharge;
• continuously monitor operating parameters, in particular the %TS concentration of dehydrated sludge, without using very expensive measurement systems;
• reduce the hours for on-site operating personnel managing the dehydration compartment, freeing up resources for other operations activities;
• be informed, remotely and in real time, of the management costs, calculated as a sum of: o sludge disposal costs o energy consumption costs o polyelectrolyte consumption costs
• support the operator in choosing the optimal changes to effect, , based on real-time date, and so minimizing the overall operational cost of sludge treatment

The controller, which is installed on a simple PLC, acquires the signals of extant measuring instruments continuously, monitors energy consumption of the compartment, and processes data with algorithms set up to optimize treatment. It modulates the polyelectrolyte dosing pumps and prevents an overdose or underdose of chemical product.

The system is equipped with a touch screen panel, by which one can visualize the acquired and processed data (e.g. the %TS of dehydrated sludge) and, in particular, be aware of the ongoing effective cost of treatment.

The acquired and processed data is visualized on the OSMART® Dashboard platform, which is available on the web, in real time, 24/7, to the operations personnel. These data can be visualized by any kind of fixed or portable device (smartphone, tablet, PC).

OSMART® DEWATERING is innovative compared to other systems available nationally in Italy, which typically modulate the dosage of polyelectrolyte without providing any indication of the costs of treatment. Our product continuously evaluates some KPIs, such as overall sludge production and energy consumption in the sludge line, which are currently being proposed for reporting by ARERA (Italian Regulatory Authority for Electricity Gas and Water) as part of its Deliberations on Technical Quality.

OSMART® DEWATERING can also be implemented in contexts where a working anaerobic digestion is in place (e.g. civil and industrial treated sludge, O.F.M.S.W. (organic fraction of municipal solid wastes), agricultural and zootechnical waste) by optimizing the the load of recirculated nitrogen at the head of the plant with the liquors produced by sludge dehydration.