US 11,834,358 B2
Process for treating frac flowback and produced water including naturally occurring radioactive material
Kashi Banerjee, Carnegie, PA (US); Charles Blumenschein, Pittsburgh, PA (US); Hillary Kronebusch, Pittsburgh, PA (US); and Sarah Petrovich, Humble, TX (US)
Assigned to Veolia Water Solutions & Technologies Support, Saint-Maurice (FR)
Appl. No. 17/258,181
Filed by Veolia Water Solutions & Technologies Support, Saint-Maurice (FR)
PCT Filed Jul. 8, 2019, PCT No. PCT/US2019/040779
§ 371(c)(1), (2) Date Jan. 6, 2021,
PCT Pub. No. WO2020/014109, PCT Pub. Date Jan. 16, 2020.
Claims priority of provisional application 62/695,921, filed on Jul. 10, 2018.
Prior Publication US 2021/0163327 A1, Jun. 3, 2021
Int. Cl. C02F 9/00 (2023.01); C02F 1/52 (2023.01); C02F 1/62 (2023.01); C02F 1/66 (2023.01); C02F 5/06 (2023.01); C02F 1/00 (2023.01); C02F 101/00 (2006.01); C02F 101/20 (2006.01); C02F 103/36 (2006.01)
CPC C02F 9/00 (2013.01) [C02F 1/5236 (2013.01); C02F 1/62 (2013.01); C02F 1/66 (2013.01); C02F 5/06 (2013.01); C02F 2001/007 (2013.01); C02F 2101/006 (2013.01); C02F 2101/20 (2013.01); C02F 2103/365 (2013.01); C02F 2209/003 (2013.01); C02F 2209/055 (2013.01); C02F 2209/06 (2013.01); C02F 2209/07 (2013.01); C02F 2209/19 (2013.01); C02F 2301/046 (2013.01); C02F 2301/08 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method of treating frac flowback containing barium, naturally occurring radioactive material (NORM) and hardness employing a dual stage precipitation process to reduce or minimize the production of sludge containing NORM, the method comprising:
A. in a first stage precipitation process:
i. mixing a sulfate source with the frac flowback in a barium sulfate-NORM reaction tank and precipitating barium sulfate and NORM;
ii. after mixing the sulfate source with the frac flowback, subjecting the frac flowback to a solids-liquid separation process to produce a first effluent and a first sludge containing the barium sulfate and NORM;
B. in a second stage precipitation process:
i. adding an alkaline reagent to the first effluent and increasing the pH of the first effluent;
ii. chemically softening the first effluent by precipitating hardness;
iii. after precipitating the hardness, subjecting the first effluent to a solids-liquid separation process and producing a second effluent and a second sludge containing the hardness;
C. recycling the first sludge containing the barium sulfate and NORM and mixing the first sludge with the frac flowback and the sulfate source; and
D. recycling a sufficient amount of the first sludge to maintain the NORM concentration in the second sludge at or below a threshold level.