Management of Chemical Substances in Biosolids

Hiromasa Yamashita*, Masaaki Ozaki
Recycling Team, Material and Geotechnical Engineering Research Group, PublicWorks Research Institute

1. Introduction
Thousandsof

chemicalsubstances

areusedinindustrial

factories,agriculture/aquaculture farms, hospitals and households. Some or most of them aredischarged into sewage and flow into wastewater treatment plants.
Chemical substances recognized as environmental pollution recently and not legally
regulated for environmental protection, such as endocrine disruptors (EDs),
pharmaceuticals and personal care products (PPCPs), are of great concerns fortheir occurrence and fate in wastewater treatment process because it often happensthat sewage is the primary pathway of those substances entering into theenvironment.
Hydrophobic chemical substances tend to be partitioned in biosolids. When theyremained unchanged or retained chemical activity, utilization (especially landapplication) of those biosolids may cause adverse effect on human health andenvironment by exposure.
(In FY2002 the total amount of sewage sludge generated was 2,105 kt of dry solids(DS) and around 14% of this amount (293 kt-DS) was recycled for agricultural use.)
2. Objectives
Our research aims to understand the occurrence of chemical substances inbiosolids and their fate in biosolids treatment/utilization process. We will develop
management method of chemical substances in biosolids, if necessary.
3. Research methods and results
We studied the occurrence and the fate of three categories of chemical substancesin biosolids. The categories and research results are as follows;*1-6, Minamihara, Tsukuba, Ibaraki, 305-8516 Japan- 185 -e-mail: yamasita@pwri.go.jp

(1) Endocrine disrupting chemicals (EDs)Nonylphenols(NPs),nonylphenol

ethoxylates(NPnEOs)

andnonylphenol

polyethoxycarboxylates (NPnECs) were analyzed by LC/MS/MS.
Biosolids composts from 17 cities in Japan contained detectable level of NPs,
NPnEOs and NPnECs.
Anaerobically digested sludge composts contained high concentration of NPs.
NP1-2EO and NP1-2EC were the major contributor to the NPnEOs and NPnECs incomposts, respectively.
Ethoxylates chains of NPnEOs and NPnECs were shortened in biosolids composts
NPs biodegradation decreased under high temperature condition(70 °C)
High temperature operation may suppress the NP degrading microbial activities inthe composting plant.
Degradation

pathwaysofNP2EO-NP2EC-(NP1EC)-degradationor

NP1EO-NP1EC-degradation played major roles in the aerobic degradation ofNPnEOs and NPnECs that remained in biosolids.
(2) Estrogens
Estrone (E1), 17- β estradiol(E2), estriol (E3), ethynylestradiol (EE2) and theirconjugates (both glucronated and sulfated) were analyzed by LC/MS/MS.
Biosolids composts from 17 cities in Japan contained almost no detectable level ofEstrogens.
(3) Pharmaceuticals and Personal Care Products (PPCPs)
We conducted a screening research based on several statistics of PPCPs
production, use and discharge in Japan to develop a priority PPCPs list in biosolids.
We have also developed measurement methods of important PPCPs in biosolids
and have been conducting field survey to understand the occurrence and the fate ofthem.
4. Conclusions
Most of endocrine disrupting chemicals in biosolids were degraded when compostedfor land application. But they were found in some biosolids composts and need to bestudied for effective degradation methods in biosolids utilization/treatment process.
PPCPs research is currently in progress and the necessity of development ofmanagement methods in biosolids will be discussed in the future.

- 186 -

Background Thousands of chemical substances flow into wastewater

treatment plants.

Management of Chemical Substancesin Biosolids

 Sewage is often the primary pathway of newenvironmental pollutions, such as endocrine disruptors(EDs), pharmaceuticals and personal care products(PPCPs), to the environment.
 Hydrophobic species of these chemicals may move tobiosolids. Some hydrophilic species also havetendencies to be absorbed in activated sludge.
 Utilization (land application) of these biosolids may
cause adverse effect on human health and environmentby exposure.

Hiromasa Yamashita, Masaaki Ozaki
Material and Geotechnical Engineering
Research Group (Recycling)
Public Works Research Institute2

Trends of land application ofsewage sludge in Japan

Objectives
 Understand the occurrence of chemical substances inSludge utilization (kt-DS/year)

1600

biosolids

Land application
1200

Construction material(Cement)
Construction material(Other)

800

400

088 90 92

94 96 98 00

02

Fiscal year(Ministry of Land, Infrastructure and Transport, 2005)

 Understand the fate of chemical substances in biosolids

treatment/utilization process Develop management method of chemical substancesin biosolids, if necessary

FY2002Land application
14% ( 293 kt-DS)
Recycle60% (1,264 kt-DS)
Sewage sludge(2,105 kt-DS)
3

4

Chemical substances in biosolids(1) Endocrine disrupting chemicals (EDs)

Chemical substances
1. Endocrine disrupting chemicals

An example of nonylphenols (NPs)HＯ

2. Estrogens

C9H194-Nonylphenol

3. Pharmaceuticals and Personal Care Products (PPCPs)

An example of nonylphenol polyethoxylates (NPEOs)
HOCH2CH2OCH2CH2Ｏ

C9H19

4-nonylphenol diethoxylate

Nonylphenol polyethoxycarboxylates (NPECs)
56

Chemical substances in biosolids(2) Estrogens (EDs)ＯＨ

Chemical substances in biosolids(3) Pharmaceuticals and Personal Care Products (PPCPs)
Ｏ

O

OH

HumanOH

ON

H
N

NH

O

HOO
NN

OH

HＯ

HＯ
ＯＨ

Ursodeoxycholic acid 128-13-2

Theophylline 58-55-9

Mefenamic acid 61-68-7

Estrone (E1)17 β estradiol (E2)

Veterinary

ＯＨ
ClNOH

OH

OH

N

OH

ＯＨ

OH

NH2Estriol（E3）NH2OH

HＯHＯOHEthynlestradiol (EE2)

O

OH

OH
O

Chlortetracycline 57-62-5

7- 187 -O

OH

O

OH

OO

Oxytetracycline 79-57-2

8

NPCs degradation pathway(1) Endocrine disrupting chemicals (EDs)
Nonylphenolic compounds

R

 NPs

O(CH2CH2O)mCH2CH2OH

4-Alkylphenol polyethoxylate(m=n-1) APnEONPnEO NPnEOs

Activatedsludge
O(CH2CH2O)mCH2COOH
process

Aerobic degradation

 NPnECs
R

R

OCH2CH2OCH2CH2OH

AP2EO
NP2EO

 Occurrence

APnEC
NPnEC

Aerobic degradation

R FateOCH2CH2OH

R

NP1EO
AP1EO

Anaerobicdigestion

OCH2CH2OCH2COOH

AP2EC
NP2EC

Anaerobic degradation

ROH

R

OCH2COOH

Anaerobic degradation

NP1EC
AP1EC

NP

AP

Raw sludge: NPnEOs + NPnECs, Anaerobically digested sludge: NPs

9

NPCs in biosolids composts
in Japan (n=17, LC/MS/MS)
NPs

Occurrence of NPCs
in biosolids composts in Japan

Mixed material

55NPnEOs
NPnECsAnaerobically digested sludge

NPCs7(mg/kg-dry)

Raw sludge

NPCs

37.9 ±25.7 (5.6-90.7 )NPs

21.1±20.5 (4.3-72.6 )NPnEOs 7.6 ±7.8

(1.1-28.9 )NPnECs 9.2 ±8.7(0.2-26.2 )NPnEOs <1.0 mg/kgmg/kg-dry for NP6NP6-15EOs,NPnECs < 1.0 mg/kgmg/kg-dry for NP5NP5-10ECs

NPnEOs (n=1-15)

11

Anaerobically digested sludge
composts contained higher NPs

NPnECs (n=1-10)

12

NPs are dominant in anaerobicallydigested sludge composts
100%

80

p = 0.042 < 0.05, Mann-Whitney's U test

p = 0.0074 < 0.01, Mann-Whitney's U test60

NPs / NPCs (-)

NPs (mg/kg-dry)

10DR

40
20
080%
60%

DR

40%20%
0%1234567891

10 11 122345678

9 10 11 12

NPs / NPCs rank

NPs concentration rank

1314

Fate of NPCs in biosolids
composting process

Compost experiment apparatus

 Fate of NPs in anaerobically digested sludge

composting process Fate of NPnEOs and NPnECs in raw sludge

composting process

1516- 188 -NPs biodegradation decreasedin higher temperature
35℃

NP Spike

160%

50℃

140%

NP change

NPnEOs・NPnECs(mg/kg)

180%

NP2EC addition experiment

70℃

120%
100%

NP Spike

80%
60%
40%
20%
0%
036912151821100

NP2EO
NP1EO

NP2EC:
decrease

75

NP2EC
NP1EC

NP2EC→degradation

5025

NP2EO，NP1EO，NP1EC: no change

0240Time (day)In most composting facilities, the composting temperature is expected toexceed 65°C mainly in order to inactivate pathogens

51015Time(d)(N=3, M±SEM)

1718

NP1EC:decrease

100

NP2EO
NP1EO

75

NP2EO addition experiment
NPnEOs・NPnECs(mg/kg)

NPnEOs・NPnECs(mg/kg)

NP1EC addition experiment
NP2EC
NP1EC

NP1EC: degradation
5025

NP2EO，NP1EO，NP2EC: no change

00510

NP2EO
NP1EO

NP2EO:
decrease75

NP2EC: increase

25

NP1EO，
NP1EC:
No change

0150510Time(d)

R

NP2EO
NP1EO

75

NP2EC
NP1EC

O(CH2CH2O)mCH2CH2OH

4-Alkylphenol polyethoxylate(m=n-1) APnEO
NPnEO
Aerobic degradation

NP1EO→NP1EC→degradation

50

20

NP2EO,NP1EO,NP2EC and NP1EC
degradation pathway in biosolids composting

NP1EO addition experiment
NP1EO:
decrease

15(N=3, M±SEM)

NP2EO→NP2EC→degradaion

19100

NP2EC
NP1EC

50Time(d)(N=3, M±SEM)

NPnEOs・NPnECs(mg/kg)

100R

OCH2CH2OCH2CH2OH

Aerobic composting
RAP2EO
NP2EO

O(CH2CH2O)mCH2COOH

APnEC
NPnEC

Aerobic degradation

25R

NP1EC:
increase

嫌気処理

5(N=3, M±SEM)

R

NP1EO
AP1EO

00

OCH2CH2OH

10Time(d)NP1EO，
NP1EC:
No change

Anaerobic degradation

NPnEOs and NPnECs in raw sludge
will be Rdegraded in compostingOH
Anaerobic degradation
process.
NP
AP

15

OCH2CH2OCH2COOH

AP2EC
NP2EC

R

OCH2COOH

NP1EC
AP1EC

Degradation

2122Conclusion (1)Conclusion (2) Biosolids composts from 17 cities in Japan Ethoxylate chains of NPnEOs and NPnECs

contained detectable level of NPs, NPnEOs
and NPnECs
 Anaerobically digested sludge composts
contained high concentration of NPs
 NP1NP1-2EO and NP1NP1-2EC were the major
contributor to the NPnEOs and NPnECs incomposts, respectively

were shortened in biosolids composts
 NPs biodegradation decreased under hightemperature condition(70 °C)
 High temperature operation may suppress theNP degrading microbial activities in thecomposting plant2324- 189 -Conclusion (3)(2) Estrogens (EDs) 1717-βestradiols(E2) Degradation pathways of NP2EONP2EO-NP2ECNP2EC-

 Estrone (E1)(NP1EC)(NP1EC)-degradation or NP1EONP1EO-NP1ECNP1ECdegradation played major roles in the aerobic
degradation of NPnEOs and NPnECs thatremained in biosolids.

 Estriol (E3)
 Ethynlestradiol (EE2)
 Conjugates (G,S)

 Sewage sludge composts from 17 cities in Japan

contained almost no detectable level of Estrogens.
E2E2-diS (β(βestradiolsestradiols-3,173,17-disulfate) was found slightly(0(0-2.7 mg/kg).

2526(3) Pharmaceuticals and Personal Care
Products (PPCPs) Screening Research27- 190 -