Y. ZHANG et al.: EFFECT OF A PHOTOCATALYTIC COMPOSITE COUPLED WITH POTAMOGETOR CRISPUS ...
521–527
EFFECT OF A PHOTOCATALYTIC COMPOSITE COUPLED WITH
POTAMOGETOR CRISPUS ON CONTROL SEDIMENT
PHOSPHORUS
VPLIV FOTOKATALITI^NEGA KOMPOZITA, ZDRU@ENEGA S
KODRAVIM DRISTAVCEM, NA KONTROLO ODLAGANJA
FOSFORJA
Yi Zhang
1*
, Yunli Liu
1,2
, Feng Luo
3
, Zisen Liu
1
, Yilingyun Zou
1,2
, Lingwei Kong
4
,
Dong Xu
1*
, Zhenbin Wu
1
1
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences,
Wuhan 430072, China
2
University of Chinese Academy of Sciences, Beijing 100049, China
3
School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
4
Environmental Research and Design Institute of Zhejiang Province, Hangzhou 310007, China
Prejem rokopisa – received: 2019-07-10; sprejem za objavo – accepted for publication: 2019-12-23
doi:10.17222/mit.2019.267
The treatment efficiency of phosphorus (P) in a sediment with the joint action of a new photocatalytic composite Sr-TiO2/PCFM
and submerged macrophyte was studied for the first time in Donghu Lake, Wuhan, China. The results showed that
Sr-TiO2/PCFM prepared by the sol–gel process exhibited a strong photocatalytic capacity. The dosage of Sr-TiO2/PCFM,
irradiation, operation temperature, reaction time and pH were the principal factors affecting the removal of each sediment P
forms by Sr-TiO2/PCFM. The synergistic effect of Sr-TiO2/PCFM and submerged macrophyte Potamogetor crispus on the
sediment P under irradiation and control conditions showed that the removal rates of each P form have been further enhanced
after irradiation. The unity of Sr-TiO2/PCFM and Potamogeton crispus plays a more important role in removing the sedimental
P than the summation of Sr-TiO2/PCFM and Potamogeton crispus used separately under the irradiation conditions. The results
suggested that the united technology of Sr-TiO2/PCFM and submerged macrophyte could be further applied to the treatment of
endogenous P pollution in eutrophic lakes.
Keywords: Sr-TiO2/PCFM, submerged macrophyte, synergistic effect, sediment P in all fractions, P removal
V jezeru Donghu v Wuhanu na Kitajskem so prvi~ {tudirali u~inkovitost obdelave usedlin fosforja v povezavi z delovanjem
fotokataliti~nega kompozita Sr-TiO2/PCFM v podvodnem rastlinju. Rezultati raziskave so pokazali, da ima Sr-TiO2/PCFM,
pripravljen po Sol-Gel-postopku mo~no fotokataliti~no kapaciteto. Doziranje Sr-TiO2/PCFM, obsevanje, temperatura delovanja,
reakcijski ~as in pH, so glavni faktorji, ki vplivajo na odstranitev fosforja iz vsake usedline z Sr-TiO2/PCFM. Avtorji ~lanka
ugotavljajo, da je sinergisti~ni u~inek Sr-TiO2/PCFM in podvodnega rastlinja iz kodravega dristavca (Potamogetor crispus)na
usedline fosforja pod vplivom obsevanja in pri kontroliranih pogojih dodatno pospe{en po obsevanju. Skupno delovanje
Sr-TiO2/PCFM in kodravega dristavca igra bolj pomembno vlogo pri odstranitvi usedlin fosforja, kot lo~ena uporaba vsakega
posebej v enakih koli~inah in obsevanju. Rezultati {tudije nakazujejo, da se enovita tehnologija Sr-TiO2/PCFM in podvodnega
makrofita lahko uporablja tudi za obdelavo endogene onesna`enosti s fosforjem v evtroficiranih jezerih, to je jezerih, v katerih
poteka pretiran proces razra{~anja biomase (rastlinja, alg itd.).
Klju~ne besede: Sr-TiO2/PCFM, podvodne rastline (makrofit), sinergisti~ni u~inek, usedlina fosforja v vseh frakcijah,
odstranitev fosforja
1 INTRODUCTION
Phosphorus (P) in lakes comes from two sources, i.e.,
the internal release of sediment and the external load.
1,2
The accumulation of endogenous P in sediment can
bring great potential risk to eutrophication. Lake sedi-
ments are considered to be the reservoir of P, and the
release of endogenous P in sediments is the main source
of eutrophication, especially in shallow lakes.
3,4
In nutrient-rich shallow lakes, the inputs of exo-
genous P will be brought under control through a variety
of technologies. The internal P load becomes the deci-
sive resource of overburden water P supply after con-
trolling the input of external phosphorus load.
5
Thus, it is
very important to decrease the content of endogenous P
and inhibit the release of endogenous P in sediments.
Various endogenous pollution-control strategies have
been developed, such as dredging,
6
oxidation treatment,
physicochemical sedimentation,
7–9
phytoremediation
10,11
and in-situ sediment capping
12,13
to reduce the release
flux of P from sediment in eutrophic lakes. Submerged
plants have certain inhibitory effects on sediment
resuspension and P release, and uptake and absorb P
from interstitial water and sediment, which is an appli-
cable way to restore the eutrophic water ecosystem.
14
However, the restoration process of P by plants is often
affected by the growing period and surroundings, and
single ecological technologies cannot be applied effect-
Materiali in tehnologije / Materials and technology 54 (2020) 4, 521–527 521
UDK 574.5:669.779:627.8.034.7 ISSN 1580-2949
Original scientific article/Izvirni znanstveni ~lanek MTAEC9, 54(4)521(2020)
*Corresponding author's e-mail:
zhangyi@ihb.ac.cn (Yi Zhang), xudong@ihb.ac.cn (Dong Xu)

ively. At present, a synergistic technology for control
sediment P is urgently needed.
5
Nano-titanium dioxide (nano-TiO
2
) has the advant-
ages of high stability, low toxicity, large specific surface
area and high catalytic efficiency, and is considered as
one of the most practical candidate materials for envi-
ronmental pollution control.
15–18
Nano-TiO
2
thin films
have become a hotspot because of their ease of recycling
and separation.
In our previous studies, porous ceramic filter media
(PCFM) was adopted as the carrier of the TiO
2
film, and
we found that the photocatalytic composite has a great
potential to control the internal P pollution. While little
is known about the remediation effect of sediment P in
all fractions with the synergistic effect of nano-TiO
2
and
submerged macrophytes. To further enhance the single
action of submerged macrophytes and nano-TiO
2
on
sediment P remediation, a Sr-TiO
2
/PCFM (Sr doped into
TiO
2
) photocatalyst capable of responding to visible light
was developed, and the removal effect of each sediment
P forms with the joint effects of Sr-TiO
2
/PCFM and
submerged macrophyte were studied for the first time.
2 EXPERIMENTAL PART
2.1 Study sites and sampling
Donghu Lake is located to the northeast of Wuhan
city, Hubei province, China. The sampling site
(30°33’04.9"N, 114°21’07.1"E) is located on the west
side of Shuiguo Lake (one sub-lake of Donghu Lake),
which is a serious eutrophication area. Surface sediment
samples (0–10cm) and PCFM were collected and ob-
tained.
5, 19
2.2 P fractions
P fractions were employed with the SMT harmonized
protocol, containing five P forms: Fe/Al-P, Ca-P, OP, IP
and TP.
20
The operationally defined scheme was com-
posed of five phosphorus forms: Fe/Al-P (NaOH-extract-
able P, P bound to Al, Fe and Mn oxides and hydro-
xides), Ca-P (HCl-extractable P, P associated with Ca),
organic P (OP), inorganic P (IP) and total P (TP). In a
separate extraction, HCl-extracted inorganic P (IP) and
the residual were treated at 450 °C to decompose the
organic matter and to release the P bound to organic
matter (OP). TP concentration in sediments was deter-
mined by treating the sample at 450 °C, followed by HCl
extraction.
2.3 Batch experiments
2.3.1 Adsorption experiments
A certain amount of Sr/TiO
2
- P C F Ma n d5go f
sediment samples were added and shaken for a period of
time at different pH and temperatures for a stirring
experiment. Chloroform (0.1 %) was added to inhibit the
bacterial activity.
2.3.2 Photocatalytic experiments
The photoreactor system was made up of a quartz
beaker reactor (500 mL), a nitrogen pump and a 125-W
high-pressure mercury lamp. Sr/TiO
2
-PCFM and the
sediment were put into a 250-mL KCl solution (0.02 M).
The suspension was irradiated under the high-pressure
mercury lamp for 0.5 h. The visible light was shone
vertically into the solution and the distance between the
illuminant and liquid level was 40cm, and the luminous
flux was 1500 Lm.
2.3.3 Phytoremediation experiments
Potamogeton crispus was sampled from the Donghu
Lake in Wuhan, China. Potamogeton crispus (approxim-
ately 20 cm in length) were planted in the polythene
buckets with a layer of sediment on the bottom.
5
2.3.4 Combined experiments
Potamogeton crispus (approximately 20 cm in
length) was planted into the polythene buckets (diameter
45 cm, height 60 cm). A sediment sample of 8 cm in
thickness and Sr-TiO
2
/PCFM with a certain thickness
were placed in each bucket after the Potamogeton cris-
pus grew stable. The visible light was shone vertically
into the solution and the distance between the illuminant
and the liquid level was 50 cm, the irradiation frequency
was 2 h/d, and the control group was under outdoor
conditions.
3 RESULTS AND DISCUSSION
3.1 Sediment characteristics
The characteristics and compositions of sediments in
Donghu Lake are shown in Table 1.
19
The grain size of
the samples was almost less than 63 mm, and the silt
fraction (4–63 mm) was the main one (79.76 %).
Table 1: Properties and chemical compositions of the sediment
Properties Content
Grain size (%)
<4 ìm 9.26±0.05
4–63 ìm 79.76±0.62
63–400 ìm 6.89±0.02
Major element
(w/%)
SiO2
49.58±0.56
Al2O3 11.46±0.21
Na2
O 23.57±0.38
CaO 12.64±0.16
Fe2
O
3
5.14±0.05
pH 7.39±0.20
TOC (%) 5.22±0.06
P fractions
(mg kg
–1
)
Fe/Al-P 462±13
Ca-P 105±5
IP 553±14
OP 173±6
TP 771±15
Y. ZHANG et al.: EFFECT OF A PHOTOCATALYTIC COMPOSITE COUPLED WITH POTAMOGETOR CRISPUS ...
522 Materiali in tehnologije / Materials and technology 54 (2020) 4, 521–527

3.2 Preparation of Sr/TiO
2
-PCFM
PCFM coated with a nano-Sr/TiO
2
film (Sr/TiO
2
-
PCFM) with a TiO
2
content 11.5 % (w/%) was obtained
as referred to in our previous research.
19
TEM micro-
graphs of the nano-TiO
2
film (Figure 1a) shows that the
film had good surface properties with an average particle
size of 10–20 nm. SEM photographs of the Sr-TiO
2
/
PCFM (fracture surface) (Figure 1b) show that the
compact nano-TiO
2
film was firmly loaded on the sur-
face of the PCFM.
3.3 Removal of sediment P with Sr/TiO
2
-PCFM in
stirring tests
3.3.1 Effect of dosage of Sr/TiO
2
-PCFM
In order to study the effect of the amount on the
removal of P in the sediments by Sr/TiO
2
-PCFM, tests
were conducted under adsorption (no irradiation) and
photocatalytic (irradiation) conditions.
5
The related
results are shown in Figure 2. The increase of the
Sr/TiO
2
-PCFM dosage increased the removal rate of the
sediment P both under adsorption and photocatalytic
conditions (P < 0.05). When the amount of Sr/TiO
2
-
PCFM was 4–6 g, the increased trend of the removal
quantity of sediment P flattens out. The removal quantity
of each P forms (Ca-P, Fe/Al-P, IP, OP and TP) was
16 mg/kg, 188 mg/kg, 218 mg/kg, 70 mg/kg and
305 mg/kg, respectively, as the dosage was 4 g. Under
photocatalytic conditions, the removal quantity of each P
forms was 17 mg/kg, 228 mg/kg, 260 mg/kg, 84 mg/kg
and 360 mg/kg, respectively, and the corresponding
removal rate was 16.2 %, 52.2 %, 47.4 %, 49.7 % and
46.7 %, respectively. It is clear that the removal amounts
of each P form were increased after irradiating with a
high-pressure mercury lamp (P < 0.05).
3.3.2 Effects of reaction time
The effects of reaction time on the P removal from
the sediment by Sr/TiO
2
-PCFM at 20±2 °C under ad-
sorption (no irradiation) and photocatalytic (irradiation)
conditions are presented in Figure 3.InFigure 3, under
adsorption conditions, the removal quantities of each P
form were increased rapidly within 4 h, then continued
to increase at a slow rate (P < 0.05). The removal quan-
tity of each P forms was 16 mg/kg, 190 mg/kg,
218 mg/kg, 72 mg/kg and 303 mg/kg /kg, respectively, as
the reaction time was 8 h.
Under photocatalytic conditions, the removal quanti-
ties of each P form were increased significantly in a
short time and achieved the equilibrium within 4 h. The
removal quantity of each P form was 17 mg/kg,
229 mg/kg, 262 mg/kg, 86 mg/kg and 360 mg/kg, respect-
ively, correspondingly, the removal rate was 16.2 %,
49.6 %, 47.4 %, 49.7 % and 46.7 %, respectively.
3.3.3 Effects of pH on P removal
The operation pH not only influences adsorption
performance, it also influences the photocatalytic
effect.
21,22
The solution pH affects the adsorption effect
by changing the surface properties of the adsorbents.
Meanwhile, the stepwise reduction potential of the
phosphate, and the valence band and conduction band of
TiO
2
change as the pH changes.
23
Thus, the pH was
viewed as an important factor in the process of
Sr-TiO
2
/PCFM treating sediment P.
Y. ZHANG et al.: EFFECT OF A PHOTOCATALYTIC COMPOSITE COUPLED WITH POTAMOGETOR CRISPUS ...
Materiali in tehnologije / Materials and technology 54 (2020) 4, 521–527 523
Figure 3: Effect of reaction time on sediment P removal
Figure 1: a) TEM micrographs of nano-TiO
2
film and b) SEM photo-
graphs of Sr-TiO
2
/PCFM (fracture surface)
Figure 2: Effect of dosage of Sr-TiO
2
/PCFM on P removal

The related results are presented in Figure 4. The
adsorption efficiency of sediment P in all fractions was
the highest under the conditions of adsorption with
strong acid. The adsorption amount of each P form from
the sediment at pH 2 was 19 mg/kg, 207 mg/kg,
243 mg/kg, 78 mg/kg and 340 mg/kg, respectively. The
corresponding adsorption rate was up to 18.1 %, 44.8 %,
43.9 %, 45.1 % and 44.1 %, respectively. The adsorption
amount of each P form decreased at different levels as
the pH increased from 2 to 12 (P < 0.05). The possible
reason was that the isoelectric point pH of the nano TiO
2
was 6.25, the lower pH induced an increase of the
surface positive charge on Sr-TiO
2
/PCFM, which was
beneficial to the adsorption of phosphate ions in sedi-
ments.
Under photocatalytic conditions, the removal effect
of the sediment P in all fractions was influenced more
obviously by pH (P < 0.05). When pH = 2, the removal
quantity of each P form was 20 mg/kg, 256 mg/kg,
292 mg/kg, 93 mg/kg and 403 mg/kg, respectively,
correspondingly, the removal rate was 19.0 %, 55.4 %,
52.8 %, 53.8 % and 52.3 %, respectively. The removal
quantities of each P form were 3 mg/kg, 28 mg/kg,
32 mg/kg, 9 mg/kg and 43 mg/kg, respectively, higher
than in the neutral condition. The possible reason was
that the stepwise reduction potential of phosphate in
acidic conditions was higher than that in neutral and
alkaline, which was relatively easy to be reduced through
photodegradation. While the in-depth mechanisms need
to be further studied and explored.
3.3.4 Influence of operation temperature
Temperature is generally regarded to be an important
factor in adsorption and photocatalytic processes.
24,25
The
removal of sediment P by Sr/TiO
2
-PCFM was studied at
different temperatures, ranging from 5 °C to an extreme
high temperature 70 °C under adsorption and photo-
catalytic conditions (Figure 5). As seen from Figure 5,
the temperature has an impact on the removal of sedi-
ment P in the both conditions (P < 0.05). The removal
amounts of each P form increased as the temperature
rises (5–30 °C). Under the adsorption conditions, the
removal quantity of each P forms at 5 °C was 13 mg/kg,
163 mg/kg, 183 mg/kg, 54 mg/kg and 276 mg/kg,
respectively. And the removal amount of each P forms on
PCFM at 30 °C was 16 mg/kg, 189 mg/kg, 220 mg/kg,
71 mg/kg and 308 mg/kg, respectively. The adsorption
amount of sediment P was decreased in different degrees
as the operation temperature rose (P < 0.05). The
removal quantity of each P form at 70 °C was decreased
5 mg/kg, 55 mg/kg, 55 mg/kg, 18 mg/kg and 75 mg/kg,
respectively.
Under photocatalytic conditions, the removal amount
of each P form at 5 °C was 13 mg/kg, 203 mg/kg,
220 mg/kg, 68 mg/kg and 296 mg/kg, respectively, the
corresponding removal rate was 12.4 %, 43.9 %, 39.8 %,
39.3 % and 38.4 %, respectively. When the temperature
rose to 30 °C, the removal quantity of each P form was
increased to 17 mg/kg, 236 mg/kg, 263 mg/kg, 85 mg/kg
and 364 mg/kg, respectively, correspondingly, the re-
moval rate was 16.2 %, 49.8 %, 47.6 %, 49.1 % and
47.2 %, respectively. Under the adsorption conditions,
the removal amounts of all P forms (except Ca-P) were
decreased in varying degrees as the operation tem-
perature rose. It was speculated that the high temperature
promotes the desorption process and Brownian motion,
thus reducing the efficiency of the photocatalytic
reaction.
3.4 Static adsorption tests
For further applying to treat the actual lake with
Sr-TiO
2
/PCFM, static adsorption tests were carried out
with reaction times from0dto22d.Therelated results
are shown in Figure 6. The removal amount of each P
form was not apparent after 18 d (P < 0.05). The adsorp-
tion quantity of each P form on 18d was 11 mg/kg,
136 mg/kg, 154 mg/kg, 52 mg/kg and 218 mg/kg, res-
pectively. Correspondingly, the adsorption rate was
10.5 %, 29.4 %, 27.8 %, 30.1 % and 28.3 %, respect-
ively.
Y. ZHANG et al.: EFFECT OF A PHOTOCATALYTIC COMPOSITE COUPLED WITH POTAMOGETOR CRISPUS ...
524 Materiali in tehnologije / Materials and technology 54 (2020) 4, 521–527
Figure 5: Effect of temperature on P adsorption
Figure 4: Effect of overlying water pH on P removal

The change trends of each P form under photo-
catalytic conditions were similar to that under adsorption
conditions, the reaction equilibrium was achieved at
16 d. The removal quantity of each P forms on 16 d was
13 mg/kg, 159 mg/kg, 181 mg/kg, 63 mg/kg and
254 mg/kg, respectively. The corresponding adsorption
rate reached 12.4 %, 34.4 %, 32.7 %, 36.4 % and 32.9 %,
respectively. The sediment P were reduced efficiently by
Sr-TiO
2
/PCFM.
3.5 The combined effect of Sr-TiO
2
/PCFM and sub-
merged plants
3.5.1 Effects of thickness of Sr-TiO
2
/PCFM on the re-
moval of TP
Tests were carried out with different thickness (1 cm,
2 cm, 4 cm and 6 cm) to investigate the effects of the
thickness of Sr-TiO
2
/PCFM on sediment P removal
under irradiation and outdoor (control group) conditions.
The results are presented in Figure 7. In outdoor
conditions, the removal amount of TP on 120 d was
176 mg/kg as the thickness was 4 cm, correspondingly,
the removal rate was 22.8 %. The removal amount of TP
at 120 d added just 16 mg/kg when the thickness in-
creased to 6 cm. Under irradiation conditions, the
removal amount of TP at 120 d was 192 mg/kg and
202 mg/kg as the thickness was 4 cm and 6 cm,
correspondingly, the removal rate was 24.9 % and
26.2 %, respectively. It is thus clear that the removal
quantity of TP was further improved after irradiation,
especially the first 45 d. The Sr-TiO
2
/PCFM thickness of
4 cm was selected as the optimal dosage to study the
synergistic effect of Sr-TiO
2
/PCFM and submerged
plants on sediment P removal.
3.5.2 The combined effect of Sr-TiO
2
/PCFM and Pota-
mogetor crispus
The removal quantity of sediment P is presented in
Figure 8. The removing rate of Fe/Al-P and IP increased
rapidly within 45 d and then slowly and later flattened at
75 d. The removal quantity of Fe/Al-P, IP, OP and TP by
Y. ZHANG et al.: EFFECT OF A PHOTOCATALYTIC COMPOSITE COUPLED WITH POTAMOGETOR CRISPUS ...
Materiali in tehnologije / Materials and technology 54 (2020) 4, 521–527 525
Figure 7: Effect of thickness of Sr-TiO
2
/PCFM on sediment P
removal
Figure 6: Effect of reaction time of on sediment P removal
Figure 8: Removal effect of sediment P by Potamogeton crispus
Figure 9: Synergistic effect of Potamogeton crispus and Sr-TiO
2
/
PCFM on sediment P removal

Potamogetor crispus on 75 d was 141 mg/kg, 151 mg/kg,
35 mg/kg and 19 3mg/kg, respectively.
The synergistic effects of Sr-TiO
2
/PCFM (thickness
4 cm) and Potamogetor crispus on sediment P under
irradiation and control conditions are presented in
Figure 9. The removal quantity of each P form was
23 mg/kg, 240 mg/kg, 256 mg/kg, 67 mg/kg and
336 mg/kg, respectively, correspondingly, the removing
rate was 21.9 %, 51.9 %, 46.3 %, 38.7 % and 43.6 % in
the control group. Under the irradiation conditions, the
removal quantity of each P form reached 28 mg/kg,
282 mg/kg, 306 mg/kg, 81 mg/kg and 403 mg/kg, res-
pectively. Correspondingly, the removal rate reached
26.7 %, 61.0 %, 55.3 %, 46.8 % and 52.3 %, respect-
ively. It was observed that the removal rates of the
sediment P were further enhanced after irradiation, and
the removal amount of each P forms (except Ca-P)
increased obviously more than the control group
especially within 60 d.
Through comparing the removal effects of each
method, we found that the unity of Sr-TiO
2
/PCFM and
Potamogeton crispus have more remarkable effects on
sediment P removal than the summation of the effect of
Sr-TiO
2
/PCFM and Potamogeton crispus applied
separately under the irradiation conditions. The probable
reasons were that:
1) the irradiation of high-pressure mercury lamp not
only enhanced the photocatalytic efficiency, but also
increased the biomass of the submerged macrophyte;
2) the residual P forms in the sediment that did not
adsorb on the Sr-TiO
2
/PCFM were changed by Potamo-
geton crispus through nutrition partitioning and root
oxygenation, and then the adsorption of residual P on
Sr-TiO
2
/PCFM was promoted;
26
3) the growth of Potamogeton crispus was also
accelerated owing to the trace elements contained in
Sr-TiO
2
/PCFM;
4) the mineralization process of the sediment was
promoted with the help of micro-organisms on
Sr-TiO
2
/PCFM, thus the bioavailability by Potamogeton
crispus was further enhanced.
4 CONCLUSIONS
The control effect of each P form in an eutrophic lake
with the synergistic effect of Sr-TiO
2
/PCFM and
Potamogeton crispus was studied for the first time. The
main contributions of this work are as follows:
1) The compact nano-Sr-TiO
2
film firmly loaded on
the surface of the PCFM, and the average particle size of
TiO
2
was10–20nm.
2) Sr-TiO
2
/PCFM dosage, reaction time, irradiation,
operation temperature and pH were the principal factors
affect the removal of sediment P by Sr-TiO
2
/PCFM.
3) The removal amount of each P form in the
sediment under the optimal photocatalytic conditions
was 20 mg/kg, 256 mg/kg, 292 mg/kg, 93 mg/kg and 403
mg/kg, respectively. Under the optimal photocatalytic
conditions of static tests, the removal amount at 16 d was
13 mg/kg, 159 mg/kg, 181 mg/kg, 63 mg/kg and 254
mg/kg, respectively.
4) The effect of the combination of Sr-TiO
2
/PCFM
and Potamogetor crispus on sediment P in all fractions
under irradiation and control conditions showed that the
removal rates of each P form were further enhanced after
irradiation. The combination of Sr-TiO
2
/PCFM and
Potamogeton crispus demonstrated the higher removal
effect of sedimental P than the summation of Sr-TiO
2
/
PCFM and Potamogeton crispus applied separately
under the irradiation conditions.
Funding
This work was supported by National Natural
Science Foundation of China (No. 51709254), Youth
Innovation Promotion Association, Chinese Academy of
Sciences (No. 2020335) and Zhejiang Provincial Natural
Science Foundation of China (No. LY18E080005).
Acknowledgment
We thank Drs. Qiaohong Zhou, Enrong Xiao and Ms.
Liping Zhang for the experimental design and paper
preparation.
5 REFERENCES
1
J. Lin, Q. Sun, S. Ding, D. Wang, Y. Wang, M. Chen, L. Shi, X. Fan,
D. C. W. Tsang, Mobile phosphorus stratification in sediments by
aluminum immobilization, Chemosphere, 186 (2017), 644–651
2
C. W. Lü, B. Wang, J. He, R. D. Vogt, B. Zhou, R. Guan, L. Zuo, W.
Wang, Z. Xie, J. Wang, D. Yan, Responses of organic phosphorus
fractionation to environmental conditions and lake evolution,
Environ. Sci. Technol., 50 (2016), 5007–50
3
T. H. Kim, J. H. Kang, S. H. Kim, I. S. Choi, K. H. Chang, J. M. Oh,
K. H. Kim, Impact of salinity change on water quality variables from
the sediment of an artificial lake under anaerobic conditions,
Sustainability, 9 (2017), 1429
4
J. Kopá~ek, J. Borovec, J. Hejzlar, K. U. Ulrich, S. A. Norton, A.
Amirbahman, Aluminum control of phosphorus sorption by lake
sediments, Environ. Sci. Technol., 39 (2005), 8784–8789
5
Y. Zhang, F. He, S. Xia, Q. Zhou, Z. Wu, Studies on the treatment
efficiency of sediment phosphorus with a combined technology of
PCFM and submerged macrophytes, Environ. Pollut., 206 (2015),
705–711
6
S. Chen, S. Wang, C. Wu, Sediment removal efficiency of siphon
dredging with wedge-type suction head and float tank, Int. J.
Sediment. Res., 25 (2010), 149–160
7
R. Devesa-Rey, N. Fernández, J. M. Cruz, A. B. Moldes,
Optimization of the dose of calcium lactate as a new coagulant for
the coagulation–flocculation of suspended particles in water,
Desalination, 280 (2011), 63–71
8
K. Reitzel, J. Hansen, F. O. Andersen, K. S. Hansen, H. S. Jensen,
Lake restoration by dosing aluminum relative to mobile phosphorus
in the sediment, Environ. Sci. Technol., 39 (2005), 4134–4140
9
M. Yang, J. Lin, Y. Zhan, Z. Zhu, H. Zhang, Immobilization of
phosphorus from water and sediment using zirconium-modified
zeolites, Environ. Sci. Pollut. Res., 22 (2015), 3606–3619
Y. ZHANG et al.: EFFECT OF A PHOTOCATALYTIC COMPOSITE COUPLED WITH POTAMOGETOR CRISPUS ...
526 Materiali in tehnologije / Materials and technology 54 (2020) 4, 521–527

10
H. K. Kwon, S. J. Oh, H. S. Yang, Growth and uptake kinetics of
nitrate and phosphate by benthic microalgae for phytoremediation of
eutrophic coastal sediments, Bioresour. Technol., 129 (2013),
387–395
11
T. Péter, W. Chin, Temperature and Circulation Dynamics in a Small
and Shallow Lake: Effects of Weak Stratification and Littoral
Submerged Macrophytes, Water., 1 (2019) 11, 128, doi:10.3390/
w11010128
12
C. Wang, Y. Qi, Y. Pei, Laboratory investigation of phosphorus
immobilization in lake sediments using water treatment residuals,
Chem. Eng. J., 209 (2012), 379–385
13
H. Yin, K. Ming, Reduction of sediment internal P-loading from
eutrophic lakes using thermally modified calcium-rich attapul-
gite-based thin-layer cap, J. Environ. Manage, 151 (2015), 178–185
14
Y. Zhang, C. Wang, F. He, B. Liu, D. Xu, S. Xia, Q. Zhou, Z. Wu,
In-situ adsorption-biological combined technology treating sediment
phosphorus in all fractions, Sci. Rep., 6 (2016), 29725
15
R. Vinu, G. Madras, Kinetics of simultaneous photocatalytic
degradation of phenolic compounds and reduction of metal ions with
nano-TiO2, Environ. Sci. Technol., 42 (2008), 913–919
16
S. Lorencik Q. Yu, H. J. H. Brouwers, Photocatalytic coating for
indoor air purification: Synergetic effect of photocatalyst dosage and
silica modification, Chem. Eng. J., 306 (2016), 942–952
17
M. Wang, B. Gao, D. Tang, Review of key factors controlling
engineered nanoparticle transport in porous media, J. Hazard. Mater.,
318 (2016), 233–246
18
M. Tasbihi, K. Ko~í, I. Troppová, M. Edelmannová, M. Reli, L.
^apek, R. Schomäcker, Photocatalytic reduction of carbon dioxide
over Cu/TiO2photocatalysts, Research Environ. Sci. Pollut., 25
(2017), 34903–34911
19
Y. Zhang, F. He, D. Kou, D. Xu, S. Xia, Z. Wu, Adsorption of
sediment phosphorus by porous ceramic filter media coated with
nano-titanium dioxide film, Ecol. Eng., 64 (2014), 186–192
20
V. Ruban, J. F. Lopez-Sanchez, P. Pardo, G. Rauret, H. Muntau, P.
Quevauviller, Harmonized protocol and certified reference material
for the determination of extractable contents of phosphorus in
freshwater sediments—a synthesis of recent works, Fresenius. J.
Anal. Chem., 370 (2001), 224–228
21
Y. Zhang, Y. Shao, N. Gao, Y. Gao, W. Chu, S. Li, Y. Wang, S. Xu,
Kinetics and by-products formation of chloramphenicol (CAP) using
chlorination and photocatalytic oxidation, Chem. Eng. J., 333 (2018),
85–91
22
R. Rezaei, M. Mohseni, Impact of pH on the kinetics of photo-
catalytic oxidation of 2,4-dichlorophenoxy acetic acid in a fluidized
bedphotocatalytic reactor, Applied Catalysis B: Environmental, 205
(2017), 302–309
23
S. Maeng, K. Cho, B. Jeong, J. Lee, Y. Lee, C. Lee, K. J. Choi, S. W.
Hong, Substrate-immobilized electrospun TiO2 nanofibers for
photocatalytic degradation of pharmaceuticals: The effects of pH and
dissolved organic matter characteristics, Water. Res., 86 (2015),
25–34
24
J. Zhang, X. Huang, Effect of temperature and salinity on phosphate
sorption on marine sediments, Environ. Sci. Technol., 45 (2011),
6831–6837
25
S. Jellali, M. A. Wahab, R. B. Hassine, A. H. Hamzaoui, L.
Bousselmi, Adsorption characteristics of phosphorus from aqueous
solutions onto phosphate mine wastes, Chem. Eng. J., 169 (2011),
157–165
26
S. Wang, L. Jiao, S. Yang, X. Jin, W. Yi, Effects of organic matter
and submerged macrophytes on variations of alkaline phosphatase
activity and phosphorus fractions in lake sediment, J. Environ.
Manage, 113 (2012), 355–360
Y. ZHANG et al.: EFFECT OF A PHOTOCATALYTIC COMPOSITE COUPLED WITH POTAMOGETOR CRISPUS ...
Materiali in tehnologije / Materials and technology 54 (2020) 4, 521–527 527