Case of success! Treatment to condition the discharge water in the Petrochemical Industry from hatil's blog

Leading business group in industrial chemical cleaning, with a presence both nationally and internationally. He relies on J. Huesa to be able to find a solution to the treatment of discharge water, generated during the cleaning processes of boilers in a petrochemical industry located in Qatar.

Solution to adapt discharge water

The business group is looking for a solution that adapts the physical-chemical parameters of the discharge water while this system is transportable. Because it must be temporarily located in the desert near the water accumulation basin and the petrochemical plant.

The starting data for the inlet water in the system are as follows:

pH8-9

Input electrical conductivity28,000 micro siemens / cm

DQO12.000 ppm

Iron1.500 ppm

Ammonia Nitrogen2.500 ppm

Electrical conductivity after treatment2,000 micro siemens / cm

Due to the high concentration of dissolved salts, high contamination present in the water, as well as the high values ​​of iron and ammoniacal nitrogen. The state of the water is difficult to characterize and therefore of unique treatment.

Within the technologies applied to the treatment, we can find filtrations with different porous media, ultrafiltration and reverse osmosis.

The treated water balances in the plant are as follows:

CNT: Quantity.

QNT: Nominal working flow.

HFunc: Hours of operation.

QTD: Total working flow.

Subsystems applied to adapt discharge waters

The installation consists of the following subsystems, since in order to achieve the required water quality, given the nature of the inlet water, it must be available:

discharge water

1. Ring filter

The water enters the installation driven directly by a submersible pump, inserted in the bottom of the basin provided by the customer. You will initially access the ring filter, although it has a valve that allows bypassing the system to perform filter maintenance without stopping the system.

2. Mesh filter

The water after passing through the previously arranged ring filter would access the mesh filter. This system, like the previous one, can be manually by-passed.

 3. Turbidex filtrationdischarge water

It will be fed to a battery of 2 turbidex filters with a diameter of 770 mm, with a design treatment flow to each filter of 12 m3 / h. This system is designed to be able to operate both in series and in parallel. At the same time, it can be by-passed individually or in a general way by making the necessary valve opening. In addition, the cleaning of the filters will be carried out by operating time or by pressure difference.

For cleaning, ultrafiltered water accumulated in a 3000 L tank connected in series with another with a 3000 L capacity will be used, adding between the two 6000 L. A differentiated pumping will be available to carry out the washing sequences of the filters.

Each filter will have a set of 5 valves with a single acting pneumatic actuator plus a valve. To perform the By-pass of one of the filters, which are the ones that will perform the hydraulic distribution in the different work and cleaning cycles. The action on the pneumatic actuators will be carried out with 5-way pneumatic solenoid valves. A compressor will be available for compressed air.

The filter washing can be modified in its programming and time through an operator panel located in the electrical panel. non-clog sewage submersible pump

discharge water4.Ultrafiltration.

Ultrafiltration is a pressure-driven process used for the selective removal of suspended matter, particles, large macromolecules, colloidal matter, or microorganisms. This process does not remove ions or dissolved matter as with reverse osmosis. The operating pressure is usually in the range of 0.5 to 6 bar.

Ultrafiltration membranes remove contaminants by a simple size exclusion mechanism (screening or sieving). A pressure difference makes the operation possible. Nominal pore size (pore diameter expressed in microns) or molecular weight cutoff (molecular weight of a solute that is retained by more than 90%, measured in Daltons) are commonly used to characterize Ultrafiltration membranes.

5. Osmosis Inversa.discharge water

Reverse osmosis, therefore, consists of applying a solution of salts in water under mechanical pressure to the concentrate compartment. Until overcoming the osmotic pressure and thus reversing the transit through the semi-permeable membrane in the opposite direction to that which occurs in nature.