IWC 12-53 

 

Treatment of Flowback 

– Shale Plays 

Mark Galimberti 

VSep – New Logic Research, 

State College, PA 

ABSTRACT 

Customers have had samples of flow-back water 

resulting from hydro-fracturing of gas wells 

drilled in the Marcellus Shale in Pennsylvania. 

They would like to treat the wastewater to a 

quality suitable for reuse in the fracturing of the 

next well. This re-use water will likely be diluted 

with fresh water. The water is currently being 

hauled off site. 

New Logic has conducted many P-Mode VSEP 

test (pilot mode) to demonstrate the separation 

ability of VSEP. VSEP is a unique membrane 

filtration technology that uses vibration to 

minimize fouling of the filtration media. 

 

OBJECTIVE 

The primary objective of the testing was for the 

VSEP to produce permeate that could be reused as 

frac water. Maximizing the recovery rate was also 

an important objective during this test. 

Maximizing the overall recovery will reduce the 

volume of waste being hauled and thus reduce 

operation costs. There is a natural variation in this 

type of feed material, and the feed conductivity 

will increase over time. The VSEP needs to 

produce consistent results despite this variation in 

feed. 

3.0 Equipment and Set-Up 

NLR provided a VSEP membrane filtration unit 

and periphery equipment. The figure above 

illustrates the basic set up for a VSEP Series LP. 

The VSEP pilot unit was tested in P-mode which 

has 16.7 square feet of membrane area. The Punit was installed with a nanofiltration (NF) 

membrane called NF-270. This membrane was 

chosen based on previous in house lab testing. 

The standard system was run in batch mode in 

which the feed tank is filled with a limited volume 

of feed material and the concentrate line is 

returned to the feed tank. The permeate is 

allowed to leave the system thus concentrating the 

feed tank. Batch mode was chosen as the mode of 

operation for pilot testing in order to handle the 

high TDS of feed and maintain economical flow 

rates. The VSEP set up is shown in Figure 1. 
 IWC 12-53 

 

Figure 1: Examples of VSEP Set up 

4.0 Results 

As part of pilot testing, various operating 

variables were optimized for the best performance 

and economic balance. The operating pressure 

was optimized by collecting permeate flux 

readings at various pressures. The relationship 

between pressure and flux was found to be linear. 

There was no increased rate of fouling or flow 

threshold at higher operating pressures up to 

500psi. The operating pressure chosen was 

480psi. The results are shown in Figure 2. 

0

10

20

30

40

0 50 100 150 200 250 300 350 400 450 500 550 600

Pressure (psi)

Instantaneous Flux (GFD) - Temp. Corrected

Figure 2: Pressure Study 

One case showed a total of 8 batch runs of varying 

feed quality. The first batch was a single pass 

through the membrane with no concentration and 

will not be included in the calculations. The end 

point of each batch was determined by a low 

permeate flux rate or a low feed level (not enough 

feed to pump through the system). A chemical 

pre-treatment of Ferric Chloride and Soda Ash 

was tested but was not successful in reaching 

higher recovery or flux rates and actually 

performed worse than raw feed. The results of the 

instantaneous flux rates for the batch 

concentrations are shown in Figure 3 and Tables 

1, 2, and 3. 

The average performance of the system: 17.2 

GFD and 92% recovery at 20oC and 480psi. The 

average flux is based on the six batches on raw 

feed and these values will be used for system 

sizing calculations. The average flux was 

calculated by fitting an exponential trend line to 

the average flux rates for each batch. The 

equation used for calculating the average flux 

based on percent recovery is: Ave Flux = 31.465e0.6574*%Rec. The average recovery is based on the 

arithmetic mean of the six batches. These values 

will be used for system sizing calculations. The 

results can be seen in Figure 4 and 5. 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

0% 20% 40% 60% 80% 100%

% Recovery

Instantaneous Flux - Temp Corr

Batch #2 - 136.0mS

Batch #3 - 73mS

Batch #4 - 45mS

Batch #5 - 86mS

Batch #6 - Ferric/Soda Ash

Batch #7 - 67.5mS

Batch #8 - 34.5mS

Figure 3: Batch Concentration 
 IWC 12-53 

 

y = 31.465e-0.6574x

R2 = 0.146

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

% Recovery

Average Flux - Temp Corr

Figure 4: Average Flux 

 

Figure 5: VSEP Permeate and Concentrate 

Table 1: Quantitative Results 

*All Flux values are corrected to 20oC 

Table 2: Analytical Results 

Batc

h 

Pressur

e Average Flux %Recovery 

2 480psi 13.3 GFD 91% 

3 480psi 35.9 GFD 94% 

4 480psi 31.4 GFD 80% 

5 480psi 27.8 GFD 93% 

6 480psi 22.7 GFD 43% 

7 480psi 27.5 GFD 96% 

8 480psi 11.0 GFD 98% 

Batc

h Sample pH Conductivity

2 Feed 6.26 136.0 mS 

Permeate 6.99 129.0 mS 

Concentrat

e 

5.63 173.2 mS 

3 Feed 6.27 72.7 mS 

Permeate 6.36 67.3 mS 

Concentrat

e 

6.56 134.3 mS 

4 Feed 6.39 44.7 mS 

Permeate 6.38 43.9 mS 

Concentrat

e 

6.75 69.0 mS 

5 Feed 6.34 86.4 mS 

Permeate 6.25 72.7 mS 

Concentrat

e 

6.62 136.4 mS 

6 Feed 8.52 87.0 mS 

Permeate 7.31 71.6 mS 

Concentrat

e 

7.04 98.1 mS 

7 Feed 6.94 65.7 mS 

Permeate 7.18 63.8 mS 

Concentrat

e 

7.02 123.2 mS 

8 Feed 6.64 34.5 mS 

Permeate 7.74 31.0 mS 

Concentrat

e 

7.17 71.2 mS 
 IWC 12-53 

 

Table 3: Analytical Results – Batch #8 at 98% 

Recovery 

 

5.0 Cleaning 

Chemical cleaning of the membrane is used to 

restore the flux rate. While VSEP can prevent 

colloidal fouling of the membrane and can reduce 

the polarization of rejected materials at the 

membrane surface, like other membranes, it 

cannot avoid chemical bonding type fouling that 

will occur. For this reason, chemical cleaners are 

used to solubilize the foulants and restore the 

membrane. During chemical cleaning, cleaners 

are re-circulated through the membrane system 

and then flushed out. Multiple cleaning cycles are 

used. 

The cleaning procedure used was a two-part 

process. The steps in sequence were: NLR 404 

acid cleaning followed by NLR 505 caustic 

cleaning. The procedure was based on previous 

experience with similar applications. The cleaners 

were used in a 3% by volume solution. After each 

batch run, a cleaning was completed and the 

starting flux on feed was recovered each time. 

When a new membrane is exposed to feed 

material, the membrane will take time to be 

conditioned. Once the membrane is conditioned, 

a new base line can be used for measuring a 

successful cleaning. The effectiveness of the 

cleanings can be seen in Figure 6 and the new 

base line can be seen around 120 GFD. Cleaning 

frequency is estimated after each batch with NLR 

404 and 505. Hot water will need to be available 

for fully effective cleaning. 

NLR 404 is an acidic liquid cleaner designed to 

provide superior and rapid mineral scale cleaning 

of wide range of RO, NF and UF membranes. It 

removes metallic salts such as iron, aluminum, 

barium and strontium sulfate, calcium sulfate, 

calcium carbonate, as well as dyes and polymers. 

NLR 505 is a caustic liquid membrane cleaner 

designed to provide superior and rapid soil 

removal properties. It contains a combination of 

ingredients, which provide cleaning actions that 

include lifting, dispersing, emulsifying, 

sequestering, dissolving and suspending. It 

removes biological and organic materials, silt, 

particulates, colloids, silica and emulsified oil 

from a wide range of RO, NF, UF and MF 

membranes. 

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

New Membrane

Hot Water Flush

NLR 404

NLR 505

Hot Water Flush

NLR 404

NLR 505

Hot Water Flush

NLR 404

NLR 505

Hot Water Flush

NLR 404

NLR 505

Hot Water Flush

NLR 404

NLR 505

NLR 404

NLR 505

GFD @ 25oC

Figure 6: Cleaning Data 

Parameter Permeate Concentrate 

Conductivity 29.44 mS 36.5 mS 

Alkalinity 130 mg/L 225 mg/L 

TDS 17,806 mg/L 21,286 mg/L 

pH 7.35 7.53 

Chloride 17,800 mg/L 14,800 mg/L 

Barium 194 mg/L 352 mg/L 

Calcium 424 mg/L 716 mg/L 

Magnesium 32.0 mg/L 70.8 mg/L 

Strontium 137 mg/L 215 mg/L 
 IWC 12-53 

 

6.0 Summary

Based on the objectives and results presented in 

this report it can be said that we were successful 

in demonstrating the ability of VSEP to treat Fracflow back water. The following is a list of 

process recommendations/results: 

Test Results: 

Membrane: NF-270 

Mode of Operation: Batch Mode 

Average Flux Rate: 17.2 GFD 

Percent Recovery: 92% 

Pressure: 480psi 

Temperature: 20oC 

Cleaner Needed: NLR 404/505 

Cleaning Frequency: Every week, 

Hot water flush every day 

System Sizing Estimates For a process of 28 

GPM: 

EXAMPLE CALCULATION (92% recovery, 

20C): 

28 gal of feed*1440 minutes/day*92% recovery 

rate = 37,094 gallons of permeate generated per 

day 

37,094 gallons of permeate per day / 17.2 GFD * 

24/22 hours (2 hours for cleaning) = 2,353 sf 

2,353 * 1.3 (30% over design) = 3,058 sf needed. 

Module size = 3,058/1500sf = 2.03, therefore, 2 

units needed at 20 C and 92% recovery. 

NF-270 92% Recovery 

Membrane SF 3,058 SF 

VSEP Modules 2 - 84” 1500 SF units 

7.0 System Design Requirements 

Stage Type: 2 - 84” 1500 

VSEP Elastomers: EPDM 

Mode of 

Operation: Batch Drain Cloth: Polyester 

Membrane Type: NF-270 Resin: Epoxy 

Operating 

Temperature: 20 C End Plates: Polypropylene 

Design Pressure: 480psi 

(600max) Membrane Trays: 304 

Feed Flow Rate: 28 GPM Operation: Automated 

Recovery Rate: 92% Pre-treatment: None 

Design Flux Rate: 17.2 GFD 

AVE 

Max Flux After 

Clean: 

140 GFD @ 

200psi 

Cleaning 

Chemicals: NLR 404/505 

Feed Pump Max 

Flow: 

70 GPM @ 

480psi 

Cleaning 

Frequency: 

After every 

week 

Permeate Destination: Reuse as Frac water 

Concentrate Destination: Hauled for disposal 

Some Photos of VSEP units used in 

Flowback Mobile Treatment in 

Pennsylvania: 
 IWC 12-53 

 

Mark Galimberti, mgalimberti@vsep.com