国立台湾大学台大工程学刊

Bulletin of the College of Engineering，N.T.U.，No. 86，October 2002，pp. 103–112

國立臺灣大學「台大工程」學刊第八十六期民國九十一年十月第103–112頁

103 廢水污泥於建築工程中之新應用

POTENTIAL REUSE OF WASTEWATER

SLUDGE FOR INNOVATIVE APPLICATIONS IN CONSTRUCTION INDUSTRY

鄭俊華*鄒光耀+方思韵?Joo-Hwa Tay Kuan-Yeow Show Sze-Yunn Hong

簡昭萸?李篤中#

Chao-Yu Chien Duu-Jong Lee

*#教授+助理教授?研究助理?碩士

*+?新加坡南洋理工大學土木與結構工程學院

?#國立台灣大學化學工程學系*#Professor +Assistant Professor ?Project Officer ?Master

*+?School of Civil and Structural Engineering, Nanyang Technological University, Singapore 639798, R.O.S.

?#Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 10617, R.O.C.

Abstract

The large volume of wastewater sludge generated requires enormous landfill space for disposal. Diverting the wastewater sludge from landfill would alleviate the shortage of landfill sites. Thus alternative applications have to be considered for the wastewater sludge diverted away from the landfills. The use of wastewater sludge for the production of construction materials is reviewed in this paper. Wastewater sludge can be used as raw materials for making bricks, concrete filler, concrete aggregates and cement-like materials. Up to 40% of sludge can be mixed with clay for structural bricks making. For use as concrete filler, up to 10% by weight of the cement can be replaced by sludge ash without affecting the strength property. Sludge aggregate made from 100% sludge can be used to replace granite in concrete without any compromise in compressive strength. Cement-like materials made from sludge can be used to replace ordinary Portland cement for up to 20% by weight to produce blended cements without affecting the mortar strength. The study reveals that the reuse of wastewater sludge as construction materials offers a technically feasible alternative for sludge disposal. The properties of each of the products are reported and discussed.

Keywords: wastewater sludge, potential applications,

construction materials.

??

廢水處理程序所產生的大量污泥往往需要甚大面積的掩埋場進行處置，為因應目前掩埋場址日益短缺的問題，必須尋求掩埋之外的處置方式。本篇論文回顧將廢水污泥利用在製造建材原料的一系列研究，包括磚塊、混凝土填充物、混凝土骨材、與似水泥物質等。在混合污泥與黏土製磚時，污泥所佔比例可達重量分率40%；製造混凝土填充物時，重量分率10%的水泥成份可置換為污泥灰，而不影響其強度；污泥製成的骨材可以取代混凝土內的花崗岩材質，而不影響其壓縮強度；污泥製成的似水泥物質亦可取代重量分率20%的一般波特蘭水泥，而不影響製成混合水泥之灰泥強度。本研究顯示，將廢水污泥再利用於建築材料將提供掩埋處置以外的另一技術可行方案，在此也討論各種製品的物性。

????廢水污泥、再利用、建築材料

1. INTRODUCTION

Sludge is generally disposed of through landfilling and spreading on reclaimed land. Incineration can reduce the volume of sludge but the remaining residues still require to be disposed of. All these disposal

104 Bulletin of the College of Engineering, N.T.U., No. 86, October 2002

methods have varying degrees of environmental impact. Increasingly stringent environmental regulations have caused marked increase in the waste disposal requirements. The disposal of sludge from wastewater treatment is thus posing problems of high complexity to any municipality. Hence, there is a need for alternative methods of sludge disposal, such as reutilization that possibly exerts less harmful effects on the environment.

Studies have been carried out by various researchers on possible applications of sludge and sludge ash as building and construction materials. The reuse of wastewater sludge in this aspect would provide good possibilities of alleviating the wastewater sludge in significant quantities. This paper provides a review of studies of the wastewater sludge for use as building and construction materials.

2. BRICKS

The use of municipal wastewater sludge mixed with clay to produce bricks had been reported by Tay [2~4].

A mixture of dried sludge and clay was ground and crushed into fine pieces by a crushing machine. The crushed mixture was mixed with water and extruded into brick samples. The bricks were dried and then fired in a kiln at a temperature of 1080°C for about 24h. Table 1(a) shows the properties of brick manufactured from sludge. The results indicated that up to 40% by weight of dried sludge could be mixed with clay in making bricks. The surface texture of the bricks was uneven, mainly due to the organic component being burnt off during the firing process.

Table 1 Properties of brick using sludge and sludge ash

Shrinkage (%) % sludge by weight Specific gravity Water absorption %Loss on ignition %

Before firing After firing

(a) Sludge

0.0 2.38

0.03 5.4

4.0

9.91

10.0 2.32

0.74 10.7

4.2

10.15

20.0 2.24

1.37 14.3

3.7

10.84

30.0 2.17

2.58 19.7

4.2

12.26

40.0 1.98

3.63 22.3

4.0

12.87

(b) Industrial sludge

30 2.90

3.3 0.43

20.0

24.8

40 2.89

1.3 0.39

18.8

24.8

50 2.95

23.1 0.45

13.5

–11.2

70 3.13

1.7 0.45

16.1

46.3

80 3.14

0.9 0.45

16.5

41.1

90 3.32

1.4 0.41

13.8

43.5

100 3.34 1.5 0.32

12.0

48.4

(c) Sludge ash

0.0 2.38

0.03 5.4

4.0

9.91

10.0 2.42

0.07 4.9

2.5

9.95

20.0 2.46

0.11 4.8

2.5

9.10

30.0 2.50

1.39 4.7

3.4

9.36

40.0 2.55

1.52 4.7

3.2

9.79

50.0 2.58

1.70 4.6

3.0

10.51

The properties of bricks produced from industrial sludge and marine clay sintered at the temperature of 1050°C are given in Table 1(b) [1]. It was found that, bricks made from 100% sludge and 90% sludge with 10% clay, were prone to develop cracks during firing. The specific gravity decreased and water absorption increased with increasing proportion of clay material, which has a lower specific gravity compared to sludge. However, the 50% clay brick sample has a significantly higher rate of water absorption, which could be attributed to the high porosity of the material. Bricks of all mix proportions, other than 50% clay content, conformed to the specified water absorption limit of 7%. Shrinkage occurs during the processes of both drying and firing. The drying shrinkage increased with increasing clay content, indicating a higher shrinkage rate as the clay content increased. The firing shrinkage on contrary reduced with increasing clay content. Significant expansion can be observed on the 50% clay brick sample as it has a negative shrinkage of 11.2%.

Ash collected after sludge incineration at 600°C was also used to produce bricks [4]. The properties of brick manufactured from pulverized sludge ash are shown in Table 1(c). The maximum amount of pulverized sludge ash that could be mixed with clay to produce good bonding bricks was 50% by weight.

The compressive strength of bricks incorporating sludge or sludge ash is illustrated in Fig. 1. The bricks containing sludge ash exhibited higher strength than those containing dried sludge and industrial sludge. The bricks with up to 10% sludge ash can have strength as high as the normal clay bricks.

Tay．Show．Hong．Chien．Lee：Potential reuse of wastewater sludge for innovative applications in construction industry105

municipal sludge and (b) industrial sludge

3. CONCRETE FILLER

Tay [5,6] demonstrated the use of pulverized sludge ash as filler in concrete. The sludge from sewage treatment works was treated at the temperature of 550°C to remove organic matter. The sludge ash was then pulverized in the laboratory and only the particles finer than 150μm were incorporated into the cement. The results on the chemical compositions of sludge ash shown in Table 2 reveal that the inorganic compounds were chemically inert in nature.

Concrete cubes cast in moulds with internal dimension of 100mm by 100mm were used to study the effect of sludge ash on concrete strength. Effects on the segregation, shrinkage and water absorption of concrete were not significant with up to 40% of pulverized sludge ash. Workability was improved with an increase in replacement of cement by sludge ash. Setting times of the concrete samples with pulverized sludge ash were extended but still remained within the requirements of British Standard BS 12: 1978.

Table 2 Chemical composition of sludge ash

Element g/kg Ranges Average

Si 80.1 ~ 141.0 102.8

S 62.4 ~ 110.9 80.8

Fe 80.0 ~ 81.3 80.6

Al 42.3 ~ 55.9

50.3

Ca 25.0 ~ 31.0 29.2

Zn 26.4 ~ 27.2 26.8

Cu 18.4 ~ 19.3 18.8

Mg 7.7 ~ 8.1 7.9

K 5.8 ~ 6.4 6.1

Cr 2.8 ~ 3.2 3.0

Na 2.2 ~ 3.0 2.5

Pb 2.4 ~ 2.8 2.5

Ni 1.2 ~ 1.6 1.3

Mn 0.8 ~ 1.5 1.1

The compressive strength of concrete cubes with sludge-ash-blended cement was reduced at all aging times, as the percentages of ash in the cement increased. However, the 28-day compressive strength of concrete cubes with 10% sludge ash in the cement was about the same as the control strength. For 40% sludge-ash- blended cement, the strength fell by about 50%. The 28-day compressive strength of concrete incorporating pulverized sludge ash blended cement is illustrated in Fig. 2.

with sludge ash filler

The results obtained from the study indicated that sludge ash could be used as partial replacement of cement for concrete mixing. However, long-term properties such as durability and volume change should be studied prior to its acceptance as suitable concrete filler. At present, sludge ash could be recommended only for non-structural use such as walkways, pavements and drains.

106 Bulletin of the College of Engineering, N.T.U., No. 86, October 2002

4. CONCRETE AGGREGATES

Industrial sludge that contains little organic materials had been developed into regular weight artificial aggregates [7]. The raw sludge and clay were dried at a temperature of 105°C and pulverized separately to a suitable fineness of particle sizes below 80μm using a mechanical pulverizer, before mixing into paste with water at appropriate proportions. The mixtures were then formed into pellets and sintered at a temperature of 1135°C. The temperature profile of the firing process is shown in Fig. 3. The firing temperature was held at 550°C for an hour to ensure complete removal of organic matters and at 900°C for another hour to reach complete oxidation thus preventing the development of black core. A range of construction aggregates was made from sludge and clay with clay contents of 0, 20, 50, 80, and 100% by mass.

Fig. 3 Firing temperature profile

The chemical contents of the sintered aggregates as reported in Tay [7] are shown in Table 3. The contents of the major elements, iron and silica, in the aggregate made from sludge with 0% clay content were determined to be 20.38% and 9.46%, respectively. The silica and aluminum contents in the aggregates made from 100% clay were determined to be 23.31 and 9.08%, respectively. The levels of chemical contents in the sintered aggregates varied in proportion with the change in sludge and clay contents. The chemical contents of most toxic metals present were reduced after the materials were subjected to elevated temperatures except for mercury, which had a slight increase in sludge. Slight differences in the chemical contents could be resulted from changes in the mass of the materials after firing. Cadmium, which was previously present in the industrial sludge, was not detected in the aggregates after firing.

The chloride contents of sludge and clay materials of 0.23 and 0.25%, respectively, were reduced to values below 0.01% after firing. The reduction of chloride contents could be due to the releasing the chlorides as chlorine gas during the volatilization of chloride- containing organic matter and certain metal chlorides.

The aggregates of different clay content differed in their physical properties. The properties of the aggregates were examined and given in Table 4. The specific gravity of the sintered sludge-clay aggregates reduced with the increase in clay content. The specific gravities of the sludge-clay aggregates were 3.23, 3.08, 2.99, 2.69 and 2.46 at 0, 20, 50, 80 and 100% clay content, respectively. The particle densities of the aggregates were 2.25, 1.84, 1.48, 1.65 and 1.77g/cm3 for the clay contents of 0, 20, 50, 80 and 100%, respectively. The results show that the density of the aggregate varies with increasing clay content, giving the lowest density at 50% clay content.

The porosities of the sludge-clay aggregates were determined at 30.8, 40.3, 50.5, 38.7 and 28.1% for 0, 20, 50, 80 and 100% clay content as shown in Fig. 4. The results show that the porosity varies with increasing clay content with a minimum at 50% clay content. The water absorption values of the sludge-clay aggregates are 0.36, 2.06, 2.80, 2.49 and 1.81% for 0, 20, 50, 80 and 100% clay content.

In a separate investigation carried out by Chien [8], aggregates with and without the addition of sodium chloride were fired under the temperature of 1100°C and 1200°C. Sodium chloride was added to the aggregates increasing the amount of sodium by 1.5 times. The specific gravity of the aggregates was then measured and the results are given in Fig. 5.

Both the addition of NaCl and the increase in firing temperature showed effect of reduction in specific gravity, which in turn led to increase in porosity of the aggregates. The result indicates that Na may play a role in bloating the sintered aggregate. The effect of Na in making lightweight aggregates is being examined arising from the finding.

The aggregate strengths were assessed using the aggregate impact test, which measures the aggregates’ susceptibility to impact, with lower value denotes better quality. Results plotted in Figure 6 indicate that the aggregates’ resistance to impact was reduced as the proportion of clay increased. The sintered pellets of up to 50% clay content displayed better aggregate impact values (AIV) of 19.9 to 26.3% as compared with that of 28.3% for the granite aggregates under dry conditions. Under wet conditions, all pellets exhibited better AIV between 18.1 to 27.3% compared to 38.9% AIV for granite aggregates.

Tay ．Show ．Hong ．Chien ．Lee ：Potential reuse of wastewater sludge for innovative applications in construction industry 107

Table 3 Elemental compositions of the sludge-clay aggregates

Clay contents of sludge-clay aggregates %

Chemical content (% by mass)

0 20 50 80 100 Fe 20.38 10.84 6.90 4.92 3.62 Si 9.46 14.95 16.90 20.04 23.31 K 1.89 1.25 1.41 1.55 3.76 Al 4.28 5.16 6.90 8.68 9.08 Ca 2.61 2.14 2.09 1.88 1.86 Cu 2.26 1.53 1.31 0.38 0.10 Zn 0.86 0.87 0.59 0.18 0.02 Mg 1.17 1.25 1.37 1.40 1.50 Ni 0.99 0.93 0.91 1.04 1.60 Na 0.99 0.94 0.89 0.71 0.70 Mn 0.10 0.07 0.04 0.01 0.03 Pb 0.06 0.06 0.04 0.02 0.01 Cr

0.02 0.02 0.02 0.01 0.01 Cd N.D. N.D. N.D. N.D. N.D. Hg 0.0006 0.0006 0.0004 0.0003 0.0002 Cl 0.01 0.01 0.01 0.01 0.01 SO 3

0.17 0.31 0.64 0.92 1.22

Table 4 Physical properties of the sludge-clay aggregates

Granite Clay content of sludge-clay aggregate %

Sludge-clay aggregate

– 0 20 50 80 100

Particle density g/cm 3

2.56 2.25 1.84 1.48 1.65 1.77 Specific gravity 2.63

3.25 3.08 2.99 2.69 2.46 Porosity % 2.66 30.77 40.26 50.50 38.66 28.05 Water absorption % 1.58 0.36 2.06 2.80 2.49 1.81 Aggregate Impact Value

Dry % 28.3 19.9 20.9 26.3 29.1 30.4 Wet % 38.9 18.1 18.3 23.7 26.3 27.3

Fig. 4 Porosity of aggregates at various clay

contents

Fig. 5 Specific gravities of sludge-clay

aggregates with and without NaCl addition fired at 1100°C and 1200°C

108 Bulletin of the College of Engineering, N.T.U., No. 86, October 2002

impact value

Concrete was batched with copper slag grit as fine aggregates, ordinary Portland cement as the binder, and sintered aggregate or granite as coarse aggregates, with a water-cement ratio of 0.5 by mass. The mix proportion of 1 coarse aggregate: 2 fine aggregate: 1 cement by volume was used in producing the concrete samples. An average compressive strength of three specimens was reported.

The performance of the sludge-clay aggregates was evaluated by determining the compressive strengths of the concrete specimens cast from the aggregates. Results of the compressive strengths over a curing period of 28 days are shown in Table 5. The 28th day compressive strengths of the concrete specimens were in the range of 31.0 to 38.5N/mm2. The sludge-clay aggregates of 0% clay content provided a concrete strength of 38.5N/mm2, which was comparable to 38.0N/mm2 achieved of the normal granite aggregate. The densities of concrete specimens made from the sludge-clay aggregates were all lower compared with that of 2680kg/m3 for normal granite aggregate.

The study demonstrates successful application of industrial sludge and marine clay sintered into hard fused masses as complete replacement of regular coarse granite aggregates in concrete. However, the artificial aggregates were found to have a much higher porosity compared with the normal granite aggregate. The porous nature of the aggregates was found to be influenced by the amount of sodium chloride and the firing temperature. Concrete made from the sludge- clay aggregates had a lower density and hence a higher strength to mass ratio as compared with that produced from conventional granite aggregates. The aggregates made from industrial sludge manifested the attributes required of construction aggregates, and the incorpo- ration of marine clay reduced the particle density of the aggregates, however, the impact resistance of the aggregates was concurrently reduced. The compressive strength test reveals that sintered aggregates, of all sludge-clay combinations are capable

of producing concrete of structural grade between 20 and 40N/mm2.

Table 5 Compressive strengths and densities of the concrete specimens

Compressive strength N/mm2

Day

Aggregate

Concrete

density

kg/m3 3 7 14 28 Clay content %

0 2680

22.0

28.5

32.5

38.5

20 2520

21.0

27.5

30.5

35.5

50 2510

20.0

24.5

28.0

31.0

80 2450

21.0

26.5

29.0

31.0

100 2520 21.0

25.5

29.0

32.5

Granite 2530 22.0 30.0 33.5 38.0 5. CEMENT-LIKE MATERIALS

Research studies had also been conducted by the authors to examine the potential for utilizing digested and dewatered sludge to produce cementitious materials [9~11]. In preparing the cement specimens, the sludge was oven-dried and mixed with limestone powder at various proportions by weight. The mixtures were ground and incinerated in a furnace at different temperatures and for different durations of controlled burning. The ash collected was ground to less than 80μm before being tested for various properties.

The cement specimens were tested for chemical, physical and compressive strength properties. The chemical composition of the sludge cement is listed in Table 6. As a comparison, the chemical composition of ordinary Portland cement is also given. The limiting values [12] stated in Table 6 are to be regarded as valid for the manufacture of cement for general works. The four major oxides of the sludge cement were SiO2, CaO,

Al2O3 and Fe2O3. Most of the chemical compositions of the sludge cement listed in Table 6 were within the limiting values, with the exception for CaO and SO3 contents. The CaO contents were low whereas the SO3 levels were excessive.

Tay ．Show ．Hong ．Chien ．Lee ：Potential reuse of wastewater sludge for innovative applications in construction industry 109

Table 6 Chemical analysis in percent by weight

Component Portland

cement Sludge ash 500°C Sludge cement Limiting value

[2] SiO 2 20.86 20.33 24.55 18 ~ 24 CaO 63.30 1.75 52.11 60 ~ 69 Al 2O 3 5.67 14.64 6.61 4 ~ 8 Fe 2O 3

4.11

20.56

6.26

1 ~ 8

K 2O 1.21 1.81 1.05 < 2.0 MgO 1.04 2.07 2.07 < 5.0 Na 2O 3 0.17 0.51 0.17 < 2.0 SO 3 2.11 7.80 4.88 < 3.0 Loss on

ignition

1.91 10.45 0.30 < 4.0

Physical properties of the sludge cement are given in Table 7. The apparent bulk density was 685kg/m 3. The specific gravity value was 3.33. The sludge cement was rated sound since the soundness test result of 1.9mm was well within the limiting value of 10mm specified by British Standard BS 12: 1978. Based on the pozzolanic activity index result of 67.2%, the cement specimens exhibited low pozzolanic activity. A high water demand property of the sludge cement was indicated by the consistency test result of 82%. The sludge cement was found to be quick setting, with the initial set occurring before the specified 45 min. The final setting times were well within the limiting value of 8 hours.

Table 7 Physical properties of the sludge cement [8] Property Sludge

cement

Ordinary

Portland cement Fineness m 2

/kg 113 116

Soundness mm 1.9 0.9 Bulk density kg/m 3 685 866 Specific gravity 3.33 3.16

Consistency % 82 27 Pozzolanic activity

Index with cement

% 67.2 100 Setting time

min

Initial 40 180

Final 80 270

The compressive strength results for 50mm mortar

cubes are shown in Fig. 7. The results indicate that

air-cured cement mortar exhibited the highest strength

obtained at all ages. The 7-day and 28-day strengths

were 5.92N/mm 2 and 6.28N/mm 2

respectively. It may

be noted that ASTM C91 Standard Specification for

Masonry Cement requires 3.45N/mm 2

at 7 days and 6.21N/mm 2

at 28 days. The strength of sludge cement under air curing was adequate for general masonry work. From the investigation, an optimum condition of the mix composition, burning temperature burning duration and curing condition upon highest possible strength development of the cement was determined. It was found that under air curing, the cement specimens with 50% sludge fired at 1000°C for 4h exhibited the highest compressive strength. Before the use of sludge in making masonry binder becomes commercially viable, it is however, necessary to carry out more research work in determining the quality of the mortar based on its air content, water retention characteristics and other long-

term properties.

The sludge masonry binder was also tested as a

partial replacement material for portland cement to produce blended cement [13,14]. The properties of the blended cement were examined at various replacement proportions up to 50%, and the results are given in Table

8.

The water demand of the cement mortar to achieve a standard consistency was observed to increase with the addition of sludge masonry binder, due to its high water

demand property. The increase in water demand was

especially pronounced beyond the replacement of 30%. The soundness ranged from 1.8 to 41.2 and the SG ranged from 3.17 to 3.29. The bulk density of the blended cement, determined to be in the range of 722 ~ 838kg/m 3, decreased with the increasing percentage of sludge binder replacement. The setting times of the blended cement reduced with increasing replacement levels. Compressive strength test results of the blended cements indicates that up to 30% of the portland cement can be replaced by the sludge masonry binder

without deteriorating the strength.

110 Bulletin of the College of Engineering, N.T.U., No. 86, October 2002

Table 8 Properties of blended cements

Sludge masonry binder replacement%

Standard

consistency%

Soundness

mm

Final setting

time h :min

Specific

gravity

Apparent bulk

density kg/m3

Compressive

strength N/mm2

*0 27 0.9 4 : 30 3.16 866 28.20

5 28 1.8 4 : 05 3.17 838 29.31

10 30 7.3 3 : 50 3.17 791 28.80

20 31 8.7 3 : 45 3.20 767 28.62

30 32 9.2 3 : 35 3.25 750 26.84

40 40 27.8 3 : 30 3.28 736 8.12

50 42 41.2 2 : 50 3.29 722 6.32 *Control sample with 100% ordinary Portland cement

6. CONCLUSION

The use of wastewater sludge in the production of construction materials provided satisfactory results. Wastewater sludge and pulverized sludge ash could be used to produce bricks. The maximum percentages of dried municipal sludge and municipal sludge ash that could be mixed with clay for brick making are 40% and 50% by weight, respectively. The compressive strength was 37.9N/mm2 for 40% dried sludge and 69.4N/mm2 for 50% sludge ash. For industrial sludge, the maximum percentage that could be incorporated into marine clay for brick making was 60%, while 30% provide the optimum strength of 31N/mm2.

Pulverized sludge ash was also used as a filler in concrete, without affecting the segregation, shrinkage, water absorption, bulk density, setting times, or compressive strength of the concrete. Sintered aggregates produced from industrial sludge and marine clay at a temperature of 1135°C can be used for complete replacement of regular aggregates in concrete. The 100% sludge pellets were suitable for use in concrete paving blocks or even other structural applications, providing concrete strength of 38.5N/mm2.

The study of using dewatered sludge mixed with limestone to produce cementitious material had determined the optimum condition and mix composition that produced the highest possible strength development of the cement specimens. Under air curing, the cement made from mixtures of sludge and limestone in equal amounts by weight fired at 1000°C for 4h under controlled firing exhibited the highest compressive strength. Evaluation of the mortar cube strength shows that it is possible to produce masonry binder made of sludge that would satisfy the strength requirements of the ASTM standard for masonry cement. The sludge masonry cement can be used to replace up to 20% by weight of ordinary portland cement to produce blended cements without compromise in mortar strength.

REFERENCES

[1] J. H. Tay, K. Y. Show and S. Y. Hong, “The

application of industrial sludge and marine clay in

brick making,” Proceedings of IWA Conference on

Sludge Management Entering the 3rd Millennium,

IWA, Taipei, Taiwan, 25~28 March, 2001, pp.

456–461.

[2] J. H. Tay, “Sludge and incinerator residue as

building and construction materials,” Proc.

lnterclean '84 Conf., Singapore, 1984, pp. 252–261. [3] J. H. Tay, “Sludge as brick making material,” Proc.

on New Directions and Research in Waste

Treatment and Residual Management, Vancouver,

Canada, Vol. 2, 1985, p. 661.

[4] J. H. Tay, “Bricks manufactured from sludge,” J.

Environ. Eng. Div., Am. Soc. Civ. Eng., Vol. 113,

1987, pp. 278–283.

[5] J. H. Tay, “Properties of pulverized sludge ash

blended cement,” Materials J., Am. Concrete

Institute, Vol. 84, 1987, pp. 358–364.

[6] J. H. Tay, “Sludge ash as filler for Portland cement

concrete,” J. Environ. Eng. Div., Am. Soc. Civ.

Eng., Vol. 113, 1987, pp. 345–351.

[7] J. H. Tay, K. Y. Show and S. Y. Hong, “Concrete

aggregates made from sludge-marine clay mixes,”

Journal of Materials in Civil Engineering, ASCE,

Vol. 14, No. 5, Oct. issue, 2002 (in print).

[8] C. Y. Chien, “Sintered industrial sludge as coarse

aggregates,”Master’s Thesis, Department of

Chemical Engineering, National Taiwan University,

2001.

[9] J. H. Tay and K. Y. Show, “Properties of cement

made from sludge.” J. Environ. Eng. &. Div., Am.

Soc. Civ. Eng., Vol. 117, 1991, pp. 236–246. [10] J. H. Tay and K. Y. Show, “The use of

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material,”J. Water Environ. Research, Vol. 64, No.

1, 1992, pp. 6–12.

[11] J. H. Tay and K. Y. Show, “Manufacture of cement

Tay．Show．Hong．Chien．Lee：Potential reuse of wastewater sludge for innovative applications in construction industry111

from sewage sludge.” Journal of Materials in Civil

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19–29.

[12] O. Labahn, Cement Engineers’ Handbook,

Bauveriag, Berlin, Germany, 1983.

[13] J. H. Tay and K. Y. Show, “Innovative civil

engineering material from sewage sludge:

bio-cement and its use as a blended cement

material,” Journal of Materials in Civil Engineering, ASCE, Vol. 6, No. 1, 1994, pp.

23–33.

[14] J. H. Tay and K. Y. Show, “Resource recovery of

sludge as building and construction materials — a

future trend in sludge management,” J. Water

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259–266.

鄭俊華 (Joo-Hwa Tay) 加拿大多倫多大學環境工程博士，現任新加坡南洋理工大學土木與結構工程學院環境與水資源工程研究所所長，以及該校環境工程研究中心主任，專長為廢棄物回收與再利用、有害廢棄物管理、生物科技於廢水處理之應用、膜過濾技術、高級氧化程序技術、污泥處置等。

鄒光耀 (Kuan-Yeow Show) 新加坡南洋理工大學環境工程博士，現任現任新加坡南洋理工大學土木與結構工程學院環境與水資源工程研究所助理教授，專長為廢棄物於建築材料之應用、廢水處理、厭氧消化程序等。

方 思 韵 (Sze-Yunn Hong) 新加坡南洋理工大學環境工程碩士，現任現任新加坡南洋理工大學土木與結構工程學院環境與水資源工程研究所研究助理。

112 Bulletin of the College of Engineering, N.T.U., No. 86, October 2002

簡昭萸 (Chao-Yu Chien) 民國66年生，國立台灣大學化學工程研究所碩士，論

文主題為「工業污泥燒結製作骨材之研究」。

李篤中 (Duu-Jong Lee) 民國51年生，國立台灣大學化學工程研究所博士，曾任

元智大學化學工程學系副教授與國立台灣大學化學工程學系副教授，現任國立台灣大學

化學工程學系教授，專長為沸騰熱傳遞與污泥處置。

收稿日期90年9月29日、接受日期90年11月29日

Manuscript received September 29, 2001, accepted November 29, 2001