Long-term management of PFAS contaminated water using constructed floating wetlands: Opportunities, limitations, and implementation considerations

Figures & data

Figure. 1. Schematic diagram of the proposed PFAS control process.

Figure. 2. Factors influencing PFAS removal via plants, microorganisms, and plant growth media.

Table 1. Uptake rate (µg/g of plant tissue) of PFASs by wetland species in hydroponic studies.

Species	Initial concentration (each - µg/L)	Initial concentration (each - µg/L)	PFBA	PFPeA	PFHxA	PFHpA	PFOA	PFDA	PFTeDA	PFBS	PFHxS	PFOS	4:2 FTS	6:2 FTS	GenX	Ref.
Justicia procumbens	R	10,000	0.2	0.15	0.15	0.25	0.5			0.15	0.6	2.7		<0.1	0.6	(Zhi et al., 2022)
	S (L)		0.5	0.4	0.5	0.5	0.4			0.5	0.5	0.6		0.2	0.7
Alisma orientale	R	1000					1.8					9.5				(Wang et al., 2020)
	S (L)						0.54(1.37)					0.25(0.96)
Alisma orientale	R	50					0.7					4				(Wang et al., 2020)
	S (L)						0.3 (0.02)					0.8 (0.1)
Echinodorus horemanii (submerged)	R	20					1	5	45	0.3	1.2	5				(Pi et al., 2017)
	S (L)						0.8	2.4	1.6	0.7	0.8	1.1
Aster indicus	R	10,000	0.4	0.2	0.1	<0.1	0.2			0.2	0.3	1.8		<0.1	0.3	(Zhi et al., 2022)
	S (L)		0.5	0.2	0.1	<0.1	<0.1			0.2	0.1	0.1		<0.1	0.2
Canna indica	R	50					3					34				(Wang et al., 2020)
	S (L)						0.3 (0.1)					0.3 (0.1)
Cyperus alternifolius	R	50					1					9				(Wang et al., 2020)
	S (L)						1.5 (0.9)					2.1 (0.8)
Cyperus papyrus	R	50					1					7				(Wang et al., 2020)
	S (L)						0.2(0.02)					0.3 (0.2)
Baumea articulata	R	10					0.04					0.11				(Awad, Brunetti, et al., 2022)
	S (L)						0.08					0.07
Juncus effusus	R	66–660	<2	<2	<2	<2	<3			<2	<3	1.6–5	<2	<2	<2	(Qian et al., 2023)
	S (L)		1–5	1.0–5	0.5–3	0.5–3.5	0.5–3.5			1–5	0.5 − 4	0.5–2.5	1–4.5	0.5–3.5	1–5.5
Juncus krausii	R	10	<1		<3	<2	<15			<3	<8	125-680				(Zhang et al., 2019)
	S (L)		1–6		4.0–22	1.0–8	5.0–35			1–17	1.0–18	25–200
Lemna minor	R	2–200					0.02					0.06				(Awad, Brunetti, et al., 2022)
	S (L)						0.06					0.05
Lemna minor with aeration	R	2–200														(Zhang & Liang, 2020)
	S (L)		< 0.6	< 0.6		< 0.6	<1.0			< 0.6	< 0.6	0.3–4
Thalia dealbata	R	50														(Zhang & Liang, 2020)
	S (L)		< 0.9	< 0.9		< 0.9	1.3			< 0.9	< 0.9	7
Phyllanthus urinaria	R	10,000					2					13				(Wang et al., 2020)
	S (L)						1.5 (1.1)					0.8 (0.4)
Arundo donax	R	50	0.9	0.7	0.2	0.25	0.5			0.1	0.5	4.5		<0.1	0.8	(Zhi et al., 2022)
	S (L)		0.8	1	1	1.1	0.9			0.9	1.1	1.1		0.5	1.3
Phragmites australis	R	50					1.2					7.5				(Wang et al., 2020)
	S (L)						0.9 (0.4)					0.9 (0.4)
Bromus diandrus	R	500 − 1,000					1.4					9				(Wang et al., 2020)
	S (L)						0.5 (0.1)					0.9(0.05)

Table 2. Correlation between PFAS bioaccumulation and translocation factors and plant physiological characteristics.

Parameters	Plant type	PFAS species	Plant root										Plant shoot					Ref
			L	PA	SA	Di	SA/L	ProR	LipR	Ep	Co	Va	SA_S	ProS	LipR	ProS/ProR	LipS/LipR
Croot^a	Ferns	Vary	+	+	+	–	+	N	N	–	N	–						(Qian et al., 2023)
	Weed	Vary	N	N	N	N	N	+	+	N	N	N	N					(He et al., 2023)
RCFs	Vegetable	PFOS&PFOA						+	–									(Wen et al., 2016)
BCFroot	Ferns	Vary	+	+	+	–	+	N	N	N	N	–						(Qian et al., 2023)
	Weed	Vary	+	N	N	N	N	+	+	N	N	N	–					(He et al., 2023)
	Weed	Vary				−							–					(Zhi et al., 2022)
Cshoot	Weed	Vary	N	N	N	N	N	+	+	N	N	N	–					(He et al., 2023)
SCFs	Vegetable	PFOS&PFOA												+	N			(Qian et al., 2023)
BCFshoot	Weed	Vary	N	N	N	−	−	+	+	N	N	N	−					(He et al., 2023)
	Weed	Vary				–							–					(Zhi et al., 2022)
TF	Ferns	Vary	N	N	N	−	N	N	N	N	N	+						(Qian et al., 2023)
	Vegetable	PFOS&PFOA														+	N	(Wen et al., 2016)
	Ferns	Vary						N	N									(Qian et al., 2023)
	Weed	Vary	N	N	N	–	–	N	N	N	N	N	N					(He et al., 2023)

^a L: root length; P_A: project area; S_{A_R}: root surface area; D_i: average diameter; SA/L: surface area per unit length; Pro_R and Lip_R: root protein and lipid content; Pro_S and Lip_S: shoot protein and lipid content; Ep: the thickness of epidermis; Co: cortical thickness; Va: the thickness of vascular column; S_{A_S}: shoot surface area; RCFs: root concentration factors; SCFs: shoot concentration factors; C_root and C_shoot: bioconcentrations in root and shoot respectively; BCF_root and BCF_shoot: bioaccumulation factor in root and shoot respectively; TF: translocation factor; +: positive correlation was reported; −: negative correlation was reported; N: no correlation was reported. Presented data from previously reported studies from wetland and non-wetland species.

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