4. Micropollutant treatment studies with MBR applications

Many analgesics such as ibuprofen, diclofenac, naproxen, and ketoprofen; lipid regulators such as bezafibrate and gemfibrozil; and carbamazepine for antiepileptic drugs were frequently found to be removed at concentrations above 1.0 mg/L in domestic wastewater and in MBR procedures [22].

While the removal rates of microcontaminants in MBR vary from one compound to another, these removal rates, sludge retention time (SRT), biomass concentration, temperature, pH value, class of microcontaminants and hydrophobicity, chemical structure, pKa etc. as well as their physico-chemical properties. The hydrophobic components are removed from the liquid phase by adsorption and, possibly, when the SRT is sufficiently high, to be removed between the biodegradation processes [56–58]. The compactness of the MBR system, the high organic load that can be applied, and the high SRT give good results in removing micropollutant [48]. When the pH value of the wastewater changes, it may affect the removal of micropollutants in the negative direction. On the other hand, the role of pH on sorption has been related with the dissociation of certain micropollutants (through the acid dissociation constant pKa), which can result in the generation of positively charged compounds (prone to interact with the negatively charged surface of sludges) or anions (low interaction). Thus, the cationic species would be adsorbed by van der Waals-type interactions [59].

are roughly divided mechanically into two: recycled (removal of the surface gel and cake layer by aeration or physical backwash) and irreversible (removal of dissolved or colloidal substances in the adsorptive pore accumulation and clogging by chemical cleaning) [53]. MLSS, particle size distribution, soluble microbial by-products, extracellular polymeric materials, viscosity, pore size, porosity, surface energy, electrical charge, hydrophilic/hydrophobic properties parameters are affecting clogging [54]. The formation of cake, which is unavoidable on the membrane surface, is one of the factors that cause the membrane to become contaminated. In a general system, the sidestream of the MBR shows a higher tendency to pollute than the submerged MBR. The reason is that the sidestream MBR needs high pump energy to generate high flux which will cause repetition of pollution when compared to the submerged MBR [37]. Tank reduces production, increases operating and maintenance costs, and requires a special extra cleaning and backwashing. Membrane replacement is challenging. There are more than 10 years of MBR systems. On the other hand, there are many systems that change after 4 years. The main causes are often pollution problems. When contamination is combined with high transmembrane pressure, this contamination is most irreversible, and therefore the chemical cleaning frequency should be increased. This leads to an increase in operating cost by reducing membrane life [51]. The main contributors to energy costs in MBR are sludge transfer, permeate production, and aeration which is often exceeding 50% of total energy consumption. Energy consumption of

for membrane aeration in flat sheet was 33–37% which was higher than in a hollow fiber system. Submerged membranes in MBR reduces the pumping energy requirement to 0.007 kWh/m3 of

Many analgesics such as ibuprofen, diclofenac, naproxen, and ketoprofen; lipid regulators such as bezafibrate and gemfibrozil; and carbamazepine for antiepileptic drugs were frequently found to be removed at concentrations above 1.0 mg/L in domestic wastewater and

While the removal rates of microcontaminants in MBR vary from one compound to another, these removal rates, sludge retention time (SRT), biomass concentration, temperature, pH value, class of microcontaminants and hydrophobicity, chemical structure, pKa etc. as well as their physico-chemical properties. The hydrophobic components are removed from the liquid phase by adsorption and, possibly, when the SRT is sufficiently high, to be removed between the biodegradation processes [56–58]. The compactness of the MBR system, the high organic load that can be applied, and the high SRT give good results in removing micropollutant [48]. When the pH value of the wastewater changes, it may affect the removal of micropollutants in the negative direction. On the other hand, the role of pH on sorption has been related with the dissociation of certain micropollutants (through the acid dissociation constant pKa), which can result in the generation of positively charged compounds (prone to interact with the negatively

focused on two aspects which are reduction of energy demand and membrane fouling [55].

4. Micropollutant treatment studies with MBR applications

, and specific energy consumption

). Future trend of MBR might be

membrane-related modules was in the range of 0.5–0.7 kWh/m3

permeate compared with sidestream membrane (3.0 kWh/m3

in MBR procedures [22].

50 Wastewater and Water Quality

Wastewater temperature also plays an important role. WWTP with an average temperature of 15–20C can be better suited for micropollutants such as in cold countries, which are often below 10C in the USA. Summer and winter affect seasonal temperature changes, microdegradation, and biodegradation [60]. Sorption has been correlated inversely with temperature in the case of the hormone 17α-ethinyl estradiol (EE2), with a reduction of Kd values of 20–25% when the temperature was increased from 10 to 30C [59].

Studies have shown that compounds such as ibuprofen and antiseptic powder, methyl paraben, and galaxolide, an analgesic drug in hospital wastewater, do not have significant differences in effluent efficiency with activated sludge processes and MBR. MBR system was found to be efficient for hormones (e.g., estriol, testosterone, androstenedione) and certain pharmaceuticals (e.g., acetaminophen, ibuprofen, and caffeine) with approximately 99% removal [61, 62]. Experimental investigations show that the removal of such compounds from wastewater is 30–50% superior to that of conventional activated sludge process. In addition, the removal efficiencies of some compounds such as mefenamic acid, indomethacin, diclofenac, and gemfibrozil in MBR were 40%, 40%, 65%, and 32–42% [63, 64]. However, biodegradable erythromycin, TCEP, trimethoprim, naproxen, diclofenac, carbamazepine, and nonylphenoxyacetic acid have not been removed [47]. This is comparable to the results of previous studies which indicated very low elimination rates of diclofenac and carbamazepine in WWTP due to their recalcitrant nature processes in Germany. Hydrophilic compounds such as MBRs, acetaminophen, atenolol, iopromide, and sulfamethoxazole (calculated logP <2) (with the exception of sulfamethoxazole (> 62%) are more efficient than hydrophobic compounds. Hydrophobic compounds (calculated log P > 2) can largely be removed by active sludge biosorption in the MBR and in the middle, and longer holding scoops are formed in the bioreactor, resulting in a higher removal yield from the CAS process. However, some hydrophilic microspheres such as carbamazepine and diclofenac tend to be highly resistant to biological degradation in the treatment of CAS and MBR. The retention time of the hydrophilic and persistent micropollutants in the bioreactor is the same as the retention time of hydraulic retention (HRT), as the micropollutants can freely permeate MF and UF membranes. The duration of hydraulic retention in the MBR and the prolongation of the retention time of the sludge are dependent on the compound biosorption of some hydrophobics for the activated sludge, and it can be seen that the pollutants can improve the biodegradation [2, 65].

In the comparison between the two MBR modules used in this study (plate and frame versus hollow fiber), no difference in target compound removal was found [60, 65]. Some results can be negative efficiency. For example, González-Pérez et al. (2017) have worked on the system that has been operated with complex nitrification and ensured that the biodegradable organic material due to circulation is effectively retained [66]. By reducing the concentration increase in the diclofenac (DCF) in the aerobic bioreactor, negative removal efficiencies for DCF have been obtained. This was not observed in the anoxic reactor.

Membrane bioreactor applications for these pollutants in different wastewaters are presented in detail given in Table 4.


configuration

mode/membrane

Volume (L)/

Substrate

MLSS (g SS/L)

Removal (%)

Reference

Organic loading rate

(kg COD/m3.d)

Sulfamed hoxazole

Erythromycin

Carbamazepine

Roxithromyan

Aceclofenac

Naproxen Ibuprofen Ethynilestradiol

Estradiol Naproxen Ketoprofen DiclofenacA DiclofenacB

Levo Betha-V Betha-D

Medro Carbamazepine

Trimethoprim

Sulfamethoxazole

Atenolol

 7 99

FS MBR HF MBR [22]

> Analgesics and

Ibuprofen

anti-inflammatory

99.2

 99.5 53

 drugs

 96

http://dx.doi.org/10.5772/intechopen.75183

6

[70]

99.6

93.4

97.8

Lab scale

3.2 L

PVDF submerged

 1.66 gVSS/L

2.16

g+COD/Lday

hollow fiber membrane model

Pilot-scale PES UF

Hospital effluent

 2 g/L

submerged

(4.7 m3) (FS) membrane Module

(3.6 m3) Hollow fiber (HF)

membrane

External

configuration

ultrafiltration

Microfiltration

 (MF) Flat Sheet

202 C

Real wastewater

 flat sheet


98.7

[1]

Efficient Removal Approach of Micropollutants in Wastewater Using Membrane Bioreactor

20.70

92.26

98.2

 90 95

 > 95

 > 90

90

 > 95

90

 90

 70 30

 60

 > 95

 0

 0

 80

 90

 80

 70

temperature


configuration

Full scale (VRM) Pilot Scale (Clear-box)

PES membrane Plate and frame Anoxic + aerobic

5 L

Real wastewater

 7 – 11 g/L

0.1

grBOD/grMLVSS

25C (

5C)

hollow fiber

(MF)

PVDF Membrane

submerged

mode/membrane

Volume (L)/

Substrate

MLSS (g SS/L)

Removal (%)

Reference

Organic loading rate

(kg COD/m3.d)

temperature

350 L

Syntetic

5 g/L

Full

Pilot

[67]

52 Wastewater and Water Quality

Scale

Diltiazem Acetaminophen

Estrone Carbamazepine

Bezafibrate

Ketaprofen

Furosemide

Atenolol

Propranolol

Diltiazen

Roxithromyan

Clarithromyun

Naproxen

Ciprofloxacin

Levofloxacin

Tetracycline

Triclosan

Triclocarban

Sulfamed hoxazole

> 84%

[68]

Trimethoprim

Ibuprofen

98.12

[66]

Anaerobic reactor+ external / hollow fiber

176 L

Synthetic wastewater

 0,6 g/L 1.7 grCOD/L.d 6,3 – 7.1 gr/L TSS

75 – 77 % VSS

0.83 – 0.98 kgCOD/m2

d

Naproxen Ketoprofen DiclofenacA

DiclofenacB


MF%

 UF %

 [69]

20.70

92.26

98.2

20 – 22 C

Hybrid aerobic MBR

Anoxic+Aerobic+MBR

3,6m3 + 8,8 m3 + 3,5 m3 Flat sheet (MF)

Flat Sheet MF

MFMBR

UFMBR

20 – 22 C

➔ 185 L

➔ 30 L

Synthetic wastewater

 3grVSS/L

400 mgCOD/L

0.4 gr COD/L

Trimethoprim

 50

 40

Hallow Fiber UF

+ PAC

 0 93

[63]

87

68

58

50

57

51

46

97

36

47

52

84

42

 0

 100

10

 100%

 >95%

100

 0

Scale

wastewater

4 C


configuration

mode/membrane

Volume (L)/

Substrate

MLSS (g SS/L)

Removal (%)

Reference

Organic loading rate

(kg COD/m3.d)

Propranolol Hypoglycaemic

Glibenclamide

Lipid regulator and cholesterol

statin drugs Gemfibrozil

Bezafibrate Pravastatin Hydrochlorothiazide

Full-scale

Raw wastewater

 7.5–8.5 g/L

Ibuprofen Diclofenac Carbamazepine

Sulfamethoxazole

Trimethoprim

Estrone,

Estriol BisphenolA

Ibuprofen Diclofenac Paracetamol Carbamazepine

Linuron

 13.4 21.1

55

95.1

17.3

96.7

[72]

http://dx.doi.org/10.5772/intechopen.75183

Lab-scale

Synthetic wastewater

 8.6–10 g/L

> hollow fiber

submerged

 UF modüle

~100

 30 ~100

~100

 60

 24

Efficient Removal Approach of Micropollutants in Wastewater Using Membrane Bioreactor

43

~100

[71]

hollow fiber

 <10

 <10

86.1

 83.1

90.3

 88.2

42.2

 32.5

 95.6

 82.2

 lowering

 agents

77.6

 65.5

temperature


configuration

mode/membrane

Volume (L)/

Substrate

MLSS (g SS/L)

Removal (%)

Reference

Organic loading rate

(kg COD/m3.d)

Naproxen Ketoprofen

Diclofenac Mefenamic Propyphenazone

Acetaminophen

Indomethacin

Anti-histamines

Ranitidine Loratidine Famotidine Anti-epileptic

Carbamazepine

Psychiatric

Fluoxetine Antibiotics

Erythromycin

Sulfamethoxazole

Ofloxacin Trimethoprim

ß-blockers

Atenolol

Sotalol Metoprolol

44.2

 29.5

76.7

53.1

 30.4

 69.5

 66.7

 47.5

 80.8 95.2

 91.3

 78.3

 43.0

 25.2

98.0

 98.0

 drugs

 <10

 <10

 drug

64.6

 47.4

<10

 33.5

44.2

 29.5

 41.4

 39.7

 99.8

 99.9

 64.5

 60.7

40.5

 35.5

65.8

 62.6

43.9

 44.0

90.7

 91.6

54 Wastewater and Water Quality

temperature


configuration

mode/membrane

Volume (L)/

Substrate

MLSS (g SS/L)

Removal (%)

Reference

Organic loading rate

(kg COD/m3.d)

Diclofenac Indomethacin

Acetaminophen

Mefenamic

 acid Propyphenazone

Anti-ulcer agents

Ranitidine Psychiatric drugs

Paroxetine Antiepileptic

Carbamazepine

Antibiotics

Ofloxacin Sulfamethoxazole

Erythromycin

B-blockers

Atenolol Metoprolol

Diuretics

http://dx.doi.org/10.5772/intechopen.75183

Hydrochlorothiazide

Hypoglycaemic

Glibenclamide

Lipid regulator and cholesterol

statin drugs

 47.3

 lowering 57

 agents

 66.3

58.7

65.5

 67.3

 60.5

Efficient Removal Approach of Micropollutants in Wastewater Using Membrane Bioreactor

94.0

 -

 drugs

89.7

95.0

 64.6

 74.8

 99.6

 46.6

87.4

temperature


configuration

mode/membrane

Volume (L)/

Substrate

MLSS (g SS/L)

Removal (%)

Reference

Organic loading rate

(kg COD/m3.d)

Sulfamethoxazole

Ketoprofen 17β-estradiol

17αTriclocarban

Naproxen Bisphenol A

Sulfamethoxazole

Nonylphenol

Atrazine Hormones Acetaminophen

Ibuprofen

Caffeine

Others Aceclofenac

 50

[49]

 0 80

> 95

> 95

Carbamazepine

Diclofenac

Enalapril

Trimethoprim

Analgesics

Naproxen Ketoprofen

Ibuprofen

99.8

91.9

 and

anti-inflammatory

99.3

 drugs

[22]

low

99

 99 99

Good

[60]

Flate and frame- type

1 m3/d

Domestic wastewater

> hollow fiber

A pilot-scale MBR

21 L

Municipal,

and industrial

wastewater

 hospital,

> flat-sheet membranes

submerged

Flat- sheet

21L

Real wastewater

(municipal,

and industrial)

 hospital

(20

 2 C)

(MF) membrane

submerged

 MBR

 99.3

4.4

 91.9

90.4

40.1

ethynilestradiol

 93.5 >98.4

 99.4

70.5

 91.9

56 Wastewater and Water Quality

temperature


configuration

mode/membrane

Volume (L)/

Substrate

MLSS (g SS/L)

Removal (%)

Reference

Organic loading rate

(kg COD/m3.d)

Carbamazepine

0

0

23.6

34.2

100

100

100

0

20-40

 [76]

Tramadol

Naproxen

Propanolol

Ibuprofen

17b-Estradiol

Triclosan

Gemfibrozil

Laboratory-scale

Pilot-scale

Anoxic+Aerobic

 MBR

 Anoxic (13.8 L) Aerobic (11.7 L)

hollow fiber Ultrafiltration

membrane

(18 3 C)

 MBR

Feed tank (50 L)

2.15 gCOD/L/d Anoxic (4.1 0.5 and

Atenolol

Pilot

Full Scale

[77]

Sulfamethoxazole

> 80

> 80

> 60

> 80

> 90

> 90

> > 80

> > 90

> > > 90

> > > 90

> > > > 90

> > > > 90

> > > > 60

> > > > 70

> > > > > 20

0

 20

 60

> 90

> 90

Efficient Removal Approach of Micropollutants in Wastewater Using Membrane Bioreactor

0

0

 80

> 90

> 30

> 90

> > 90

> > 90

> > 0

 30

> > 90

> > 90

> > > 90

> > > 90

> > > > 90

> > > > 90

http://dx.doi.org/10.5772/intechopen.75183

 60

 60

> > 90

 50 59

Caffeine

Naproxen

Ibuprofen

Paracetamol

Trimethoprim

Primidone

Diclofenac

Gemfibrozil

Carbamapazine

DEET

Diuron

Polyparaben

Amtriptyline

Estrone

Androsterone

Etiocholanolone

Triclosan

Triclocarban

Table 4.

Membrane

 bioreactor applications

 for

micropollutants

 in various

wastewaters.

2.7 0.3 g/L) Aerobic (2.4 0.8 g/L

(MLSS))

 Amelotin (AMTN)

> MBR (15 L)

temperature


configuration

Full-scale flat sheet

MBR Concept A

10 C

10 g/L 10 g/L

10 C

MBR Concept B

Hospital effluent

mode/membrane

Volume (L)/

Substrate

MLSS (g SS/L)

Removal (%)

Reference

Organic loading rate

(kg COD/m3.d)

Gemfibrozil

Bezafibrate Clofibric acid

Pravastatin

Ibuprofen Carbamazepine

Diclofenac

 <20 <20

Concept

Concept

[74]

A

Paracetamol

Ibuprofen Ketoprofen

Naproxen

Caffeine Tetracycline

Atenolol Bisoprolol Metoprolol

Sotalol Furosemide Hydrochlorothiazide

Pilot-scale MBR

1.3 m3

Hospital

less than 13 g/L

 Diclofenac Sulfamethoxazole

Trimethoprim

wastewater

hollow fiber

PVDF

 27.5

 2.4

0

[75]

0

0

16.3

 5.6

18.8


 -33.0

 20.1

41.9

 21.7

70.8

 69.1

>95

 >95

99.7

 99.5

>97

 90.2

90.1

 81.3

>99

 98.5

>99

 >99

B

>80

[73]

 71.8 90.8

95.8

89.6

58 Wastewater and Water Quality

temperature
