1
Application of MOFs on Removal of Emerging Water Contaminants

Nguyen Minh Viet1, Tran Thi Viet Ha2, and Nguyen Le Minh Tri3,4

1 VNU Key Laboratory of Advanced Material for Green Growth, Faculty of Chemistry, VNU University of Science, 334 Nguyen Trai Street, Thanh Xuan, Hanoi, Viet Nam
2 Faculty of Advanced Technologies and Engineering, VNU Vietnam - Japan University, Luu Huu Phuoc Road, Cau Dien Residential Area, Nam Tu Liem District, Ha Noi, Viet Nam
3 Laboratory of Advanced Materials Chemistry, Advanced Institute of Materials Science, Ton Duc Thang University, 758307, Ho Chi Minh City, Vietnam
4 Faculty of Applied Sciences, Ton Duc Thang University, 758307, Ho Chi Minh City, Vietnam

Abbreviated list

AC Activated carbon AOPs Advanced oxidation processes FO Forward osmosis MF Microfiltration MOFs Metal-organic frameworks NF Nanofiltration PPCPs Pharmaceuticals and personal care products RO Reverse osmosis UF Ultrafiltration WWTPs Wastewater treatment plants

1.1 Introduction

1.1.1 Sources of Emerging Water Contaminants

Water is an essential factor that can define the properties of all living species, and there is no doubt that our Earth cannot exist without water. With the rapid development of human society and the economic sector, the types of contaminants are becoming increasingly hard to control. One of the particular concerns is called "emerging contaminants".

Emerging contaminants can be defined as contaminants that have new sources and new pathways to the human body, with novel adverse effects on human health, the environment, and the ecological system. Emerging contaminants are common chemical substances, and modern analytical techniques can detect them. They can be classified depending on their nature, origin, potential effects, or the possible fate of the contaminants. For example, the NORMAN database classified the emerging contaminant into 21 groups with over 700 counted compounds: PPCPs, organic dyes, herbicides and pesticides, industrial compounds/by-products, and nanomaterials [1-5]. These contaminants have been dispersed in wastewater and sewage water via different routes, and lots of them can even be found where they have never been used. Emerging contaminants enter the water environment from different sources, and the origin of the emerging contaminants in the water is often difficult to detect.

One of the primary sources of emerging water contaminants is wastewater treatment plants (WWTPs). Humans use PPCPs, nanomaterials, and food additives in their daily life, and produce a tremendous amount of waste or wastewater, then wastewater moves to WWTPs. It should be mentioned that most emerging contaminants are outside the scope of regulation, or they are not regulated. Besides, current WWTPs are not designed to treat emerging contaminants due to their low concentration. The biosolids obtained after WWTPs are another source of these contaminants.

Other remarkable sources of emerging water contaminants are agriculture and livestock. In modern agriculture, pesticides, herbicides, antibiotics, hormones, etc., are used frequently, introducing the residue chemicals to the environment, including air, soil, and water. The contaminants can be transported between different phases of the environment by spreading, leaching, and runoff.

The landfill, which is the final destination of waste from everywhere, is another source of emerging contaminants. The components of waste are very complex. The leachate from landfill sites consists of emerging contaminants that can come into the groundwater, streams, or WWTPs, leading to adverse environmental and human health effects.

1.1.2 Emerging Water Contaminants Treatment Methods

Identifying the treatment methods for removing emerging contaminants in the water is a priority that must be concentrated on the best practices for ensuring the use of safe water for the community. Recently, many studies have investigated new processes to eliminate emerging contaminants from water, including membrane technology, adsorption, biodegradation, advanced oxidation processes (AOPs), and so on (Table 1.1).

Table 1.1 Summary of advanced treatment technologies for organic pollutant removal.

Technology Target emerging contaminant Removal efficiency Note Ref.

1. Membrane

1. IF

Polysulfone- and polyvinylidene UF membranes Bisphenol A (BPA) and 17ß-estradiol (E2) 75-98%

Polysulfone from Koch

Membrane Systems

[6]

• b) NF

NF-200 and NF-90

Acetaminophen

Phenacetin

Caffeine

18-81%

70-78%

62-93%

[7]

• c) FO

FO: Hydration Innovations (HTI, Albany)

1,4-dioxane

Acetaminophen

Metronidazole

Phenazone

Caffeine

Bisphenol A

Carbamazepine

17a-ethinylestradiol

55-68%

45-89%

70-99%

85-99%

80-99%

40-99%

65-99%

85-99%

[8]

• d) RO

RO: Aromatic polyamide

membrane (Midland, MI)

Ibuprofen

Naproxen

Fenoprofen

Gemfibrozil

Ketoprofen

Acetaminophen

90-99%

95-99%

95-99%

95-99%

95-99%

100%

[8]

2) Adsorption

1. Activated carbon

Commercial AC (PB 170, PB 170-400, PC 1000, WP 235, Carbsorb 28, Cyclecarb 305, W 35, SA Super, LP 39, MP 25 and Hydro XP 17) Atrazine, Diuron (pesticides) 40-75%

Wastewater with an average DOC of 5.6 ± 0.9 mgC/l,

C0 of 6 and 57 ng/l, AC doses of 10 mg/l

[9] Polymer-based spherical activated carbon particles Estradiol (hormone) 96-99% In combination with UF [10] Granular activated carbon

NO3--N

Metoprolol and diclofenac (PPCPs)

95% for NO3--N

80% for PPCPs

Integrate with solid-phase denitrification (SPD) with biodegradable polymer poly-3-hydroxybutyrate-co-hydroxyvalerate (PHBV) [11]

• b) Biochar

Tea-waste biochar Caffeine in aqueous media (PPCPs) 15.4 mg/g-1 Pyrolyzed at 700°C using steam activation (TWBC-SA) Magnetic porous biochar obtained from a biomass garlic skin Paraben, metronidazole, and oxytetracycline (PPCPs) 415, 287, and 822 mg/g-1 for paraben, metronidazole, and oxytetracycline, respectively [12] Biochar (BC) and biomass carbon quantum dots (CQDs) from reed straw Carbamazepine (PPCPs) 96.43% BC and CQDs for the modification MgIn2S4/BiOCl (MB) heterojunction photocatalyst with Z-scheme structure [13]

• c) CNTs

Multiwall carbon nanotube (MWCNT) Ciprofloxacin hydrochloride (PPCPs) 1.7446 mg·g-1 or >88%

Initial ciprofloxacin

hydrochloride concentration of 4 ppm

[14] Commercial multi-walled carbon nanotubes

Chloramphenicol,

thiamphenicol, florfenicol, sulfadiazine, sulfapyridine, sulfamethoxazole, sulfathiazole,

sulfamerazine, sulfamethzine, sulfaquinoxaline, ibuprofen, carbamazepine and diclofenac

Freundlich constant (KF) values were 353-2814 mmol1-n Ln/kg, 571-618 mmol1-n Ln/kg, and 317-1522 mmol1-n Ln/kg for sulfonamides, chloramphenicol, and non-antibiotic pharmaceuticals, respectively [15] Multi-walled carbon nanotubes Tetracycline antibiotics 253.38 mg/g-1

CNTs were synthesized in the CH4/H2 mixture at 700 0C by a chemical vapor deposition method using Co-Mo particles

as...