A nationwide river survey conducted by the Ministry of Land, Infrastructure and Transport. (MLIT) confirmed the existence and spread of natural estrogen and ...
EVALUATION OF THE RIVER WATER TREATMENT FACILITIES FOR REDUCTION OF ESTROGENIC COMPOUNDS Norihide NAKADA1), Koya KOMORI1), Yutaka SUZUKI1), Hiroyuki KAWANO2), Yukio NAGATO2), Hiroaki TANAKA3) 1)
Water Environment Research Group, Public Works Research Institute, Tsukuba, Ibaraki 305-08, Japan 2) Kanto Engineering Laboratory, Ministry of Land, Infrastructure and Transport Government of Japan, Matsudo, Chiba 270-2218, Japan 3) Research Center for Environmental Quality Control, Kyoto University, Otsu, Kyoto, 520-0811, Japan Keywords: river water treatment facilities, endocrine disrupter, estrogen, estrogenic activity, aerated gravel contact oxidation process INTRODUCTION A nationwide river survey conducted by the Ministry of Land, Infrastructure and Transport (MLIT) confirmed the existence and spread of natural estrogen and endocrine disrupters (EDs), in river water1). These compounds are substances of concern because of their estrogenic effects on fish in the water environment. Our previous study2) confirmed that river water treatment facilities (RWTFs) equipped with an aerator effectively remove estrogen and EDs, although the main purpose of an RWTF is to remove organic substances (e.g., BOD, COD) on the riverside. However, about 70% of RWTFs operating in Japan are not equipped with aerators. Thus, we evaluated RWTF, particularly those without an aerator, for the removal of estrogen and EDs. METHODS The survey was carried out from October 2003 to January 2004 at five RWTFs (Table 1). All of these treatment plants use gravel as the contact media, but only facility A is equipped with an aerator. Water was sampled at the inlet and outlet points of each facility as grab samples, and the temperature and pH were measured on site. In a laboratory, concentrations of suspended solids (SS), biochemical oxygen demand (BOD), and total organic carbon (TOC) were measured. Nonylphenol (NP)-related substances and estrogen were analyzed by HPLC and LC/MS/MS, respectively. Additionally, estrogenic activity was measured using DNA recombinant yeast. Table 1.
Details of surveyed river water treatment facilities (RWTFs) Yes
Retention time (h) 2.1 – 2.8
Daily capacity (m3/d) 216,000
L18 x W85 x D4.3 x 2 tanks
No
1.25
78,000
C
L21.5 x W121 x D2.6 x 2 tanks
No
1.25
43,000
D
L7.35 x W57 x D3.7 x 1 tank L5.0 x W64 x D3.7 x 2 tanks L5.0 x W68 x D4.4 x 4 tanks x 3 series
No
0.5 – 1.0
52,000
No
0.5
259,000
RWTF ID A
Scale of contact oxidation tank (m) L28 x W125 x D3.5 x 5 tanks
B
E
Aerator
RESULTS AND CONCLUSIONS The average values indicating the removal efficiency of RWTF with or without aeration are shown in Figure 1. The concentration of 17β-estradiol (E2) was below its detection limit in all samples. The results clearly show that the removal efficiency in RWTF with aeration is higher than that without aeration for all substances, except nonylphenoxy acetic acid (NPEC). A previous study also reported that in the facilities,aeration effectively removed NP and estrogen2). In the RWTFs without aeration, negative removal efficiencies were frequently observed for many target compounds, especially in facility E, which had the shortest retention time and the largest daily capacity, and the removal efficiencies were varied, as shown in Figure 1. For RWTFs without aeration, higher removal efficiencies were correlated with longer retention time, which suggests that longer retention time is necessary if the facility is to be used to remove estrogen and EDs. with aeration
without aeration*
100 Removal efficiency (%)
80 60 40 20
n.d.
0 -20 -40 -60
NP
NPEO NPEC BPA
E1
E2
YES
SS
BOD
TOC
Figure 1. Removal efficiencies of endocrine disruptors, estrogens, estrogenic activity, SS, BOD and TOC in river water treatment facilities in Japan. NP: nonylphenol; NPEO: nonylphenol polyetoxylate; NPEC: nonylphenoxy acetic acids; BPA: bisphenol A; E1: estrone; E2: 17ß-estradiol; YES: estrogenic activity; SS: suspended solid; BOD: biological oxygen demand; TOC: total organic carbon; n.d.: not detected. *Averages of data for each facility for B, C, D, and E.
REFERENCES 1)
Ministry of Land, Infrastructure and Transport, MLIT: Report on FY 2001 fact-finding study on endocrine disruptors in water environment (2002) (in Japanese) 2) Komori, K., Miyamoto, N., Tanaka, H., Sato, C., Hayashi, K., and Horiuchi, S.: Reduction of the Estrogen-like Substances and Estrogen-like Activity in the River Water Treatment Facilities. ABSTRACTS -International Association for Great Lakes Research 46th Annual Conference & International Lake Environment Committee 10th World Lakes Conference-International Association for Great Lakes Research, p.81 (2003.06.)
