WP-1: PANDIT DEENDAYAL ENERGY UNIVERSITY, GANDHINAGAR, GUJARAT

1. Development of solar power (DC) driven Electro coagulation (EC) unit with increased life span and low running cost:

• Performance of a DC power runs EC cell integrated with a spouted bed bioreactor and an adsorption packed column to treat highly contaminated refinery wastewater. The best results were achieved when EC was used as a pre-treatment step to reduce the contaminant loads prior to the following treatment steps. The challenge with the EC technology is to resolve the problems associated with the unreliable/short lifetime of the unit and high operating costs which will be addressed in the proposed project.​

​

2. Development of solar power (DC) driven Electro dialysis (ED) unit with increased life span, high recovery ratio and low running cost:

• ED selectively removes dissolved solids, based on their electrical charge, by transferring the brackish water ions through a semi permeable ion exchange membrane charged with an electrical potential.Because of the corrosive nature of the anode compartments, electrodes are usually made of titanium and plated with platinum. Its life span is dependent on the ionic composition of the source water and the amperage applied to the electrode. Large amounts of chlorides in the source water and high amperages reduce electrode life. Development of solar power (DC) driven Electro dialysis (ED) unit with done with increased life span, high recovery ratio and low running cost.

​

3. Design of high recovery and low cost Adsorption unit:

• Treated water from EC and ED processes is passed through Adsorption unit. Major Disadvantages which will be addressed in the proposed scheme of Adsorption process are:  Product recovery possibly requiring a special, expensive distillation  Adsorbent progressively deteriorating in capacity as number of cycles increases  Adsorbent regeneration requiring a steam or vacuum source  Relatively high capital cost  Relatively high steam requirements to desorb high-molecular-weight pollutants.

​

4. Design and construct advanced prototypes to demonstrate and evaluate desalination powered from variety of thermal energy sources:

• The proposed system will have EC followed by ED and Adsorption Unit followed by Multi- effect distillation and thermal- reverse osmosis process (Fig. 2, 2a & 2b). Effluent water will first be treated in EC unit where most off suspended solids formed flock and get separated from water. This treated water will then be sent to ED unit. After treatment in ED the water is sent to Adsorption unit for further treatment. Finally the water will be recycled to the unit or will pass through thermal energy driven RO unit to make it potable. Sequence and module of operation will be decided as per the customer based choice and feasibility. Finally the treated water will be sent to MED unit or Thermal RO plant (Fig. 2a & 2b).These two processes are thermal energy driven and will deliver potable water that can be used for drinking purpose.

​

5. Design and development of wind powered reverse osmosis process with Continuous variable transmission (CVT) gear train arrangement for high recovery ratio:

• A wind mill will be designed to deliver a range of rpm using wind farm software and this will be directly coupled with RO module using a CVT gear train arrangement in between. The CVT arrangement will deliver a mechanical advantage as and when it is required that lead to high recovery ratio.

• MED process is based on recycling of latent heat of steam (once produced steam is recycled using its latent heat) and condensate is recovered at every stage. The fellow PI Mudgal has successfully demonstrated 3- effect, 6- effect and 10- effect MED unit successfully. This make the process economic. Proposed RO process is also thermal energy driven- based on isothermal Rankine cycle. Mudgal and Philip has shown possibility of thermal energy driven RO system [8]. An expanding fluid (steam in our case) is sent to cylinder piston arrangement and through a linkage mechanism (that produces required mechanical advantage) the force is transferred to RO membrane to pass the polluted water through it. At advance stage some organic fluids may also be tried to run the unit using Organic Rankine Cycle (ORC).

​