THE EFFECTS OF AERATIONAND AGITATION ON THE DEGRADATION OF SAGO EFFLUENT

Ikhwan Fadzli Bin Che Ghazali

Bachelor of Science With Honours (Resource Biotechnology) QIt

495 2004 P17 126 2004

P.KHIDMAT MAKLUMAT AKADEMIK UNIMAS

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Faculty of Resource Science and Technology

THE EFFECTS OF AERATION AND AGITATION ON THE DEGRADATION OF SAGO EFFLUENT

Ikhwan Fadzli Bin Che Ghazali

Bachelor of Science with Honours (Resource Biotechnology)

2004

THE EFFECT OF AGITATION AND AERATION ON DEGRADATION OF SAGO EFFLUENT

IKHWAN F ADZLI CHE GHAZALI

FACULTY OF RESOURCE SCIENCE AND TECHNOLOGY UNIVERSITY MALAYSIA SARA W AK

The Effect of Agitation and Aeration on Degradation of Sago Effluent

Ikhwan Fadzli Che Ghazali

Program Resource Biotechnology Faculty of Resource Science and Technology

University Malaysia Sarawak

ABSTRACT Sago eftluents were produced during sago processing to obtain sago flour. These wastes contain high BOD and TSS. The waste produced was discharge directly without any treatment. This study was carried out to observe the effects of agitation and aeration on the degradation of sago effluent. Sago effluents undergo agitation and aeration treatment for 32 days. Effects of agitation and aeration treatments on filtered and crude sago effluent were observed. At the end of the treatment, both treatments were successful on the removal of BOD and reduction of suspended solids. The BOD level was reduced from 140 mg/L to 69.33 mg/L for filtered sago effluent and 126.67 mg/L to 62.67 mg/L for crude sago effluent under aeration treatment, respectively. The BOD level reduced from 141.33 mg/L to 70.67 mg/L and 128 mglL to 68 mg/L under agitation treatment for filtered and crude sago effluent respectively. The TSS level were also reduced for both aeration and agitation treatment. TSS level for filtered and crude sago effluent is reduced from 6.92 to 5.46 and 24.65 - 14.91 mg/L under aeration treatment for filtered and crude sago effluent, respectively. The T S level for agitation treatment was reduced from 4.88 mg/L to 5.004 mg/L and 22.882 mg/L to 23.6 mg/L for filtered and crude sago effluent, respectively. Through this study, aeration treatment reduced the pollutant parameter efficiently compared to agitation treatment and filtered sago effluent can undergo treatment faster than crude sago effluent.

Keywords: sago effluent, aeration treatment, agitation treatment, BOD, TSS

ABSTRAK Sago efluen ialah hasil buangan yang terhasil ketika proses penghasitan lepllng sago. Hasil bllangan ini mengandungi paras BOD dan TSS yang linggi. Hasil buangan yang lerhasil ini dibllang lerus ke dalam sllngai tanpa me/ailli sebarang rawalan. Kajian ini dijalankan adalah unluk melihal kesan pengudaraan dan penggodakkan ke aias proses degradasi sago eflllen. Sago efluen yang diambit menjalani proses perawalan pengudaraan dan penggodakkan seloma 32 had dan kesan raw alan ke alas sago efluen diperhalikan. Pada akhir proses kajian didapati bahawa kedua - dua rawalan lerseblll lidak kira rawalan pengudaraan mahliPun penggodakkan berjaya merendahkan paras BOD dan TSS dalam sago eflllen. Paras BOD dalam sago efluen berjaya dikllrangkan dari 140 mg/L kepada 69. 33 mglL bagi eflllen yg dilapis dan 126.67 mglL kepada 62.67 mg/L bagi eflllen asal di bawah rawalan pengudaraan manakala 141.33 mglL kepada 70.67 mglL dan 128 mglL kepada 68 mglL bagi rawalan penggodakkan. Paras TSS juga lelah berjaya direndahkan melailli kedua- dua rawalan. Paras TSS lelah direndahkan dari 6.92 - 5.458 dan 24.65 - 14.912 mgl L bagi kedua- dua keadaan efluen di balVah rawalan penglldaraan manakala 4.88 mg/L - 5.004 mglL dan 22. 882 mglL- 23.6 mglL bagi ralVatan penggodakan. Berdasarkan kajian ini, didapali rawalan pengudaraan dapal merendahkan paras BOD dan TSS lebih baik berbanding rawatan penggodakan.

Kala kllnei: sago efluen, rawalan pengudaraan, rawalan penggodakan. TSS, BOD

1.0 INTRODUCTION

Sago palm or Metroxyfon sago which also known as ' rumbia' is commonly distributed in

Southeast Asia. Nutritionally sago product provides only starch and it is the only source of starch

that i perennial. It accumulates large amount of starch in its trunk (Vaughan and Geissler, 1999).

In Malaysia, 90% of the sago planting areas concentrated in Sarawak mainly in Mukah, Igan,

Oya-Oalat and Pusa-Saratok districts. There are 32 mills operating in Sarawak which is supplied

by 19720 ha of sago plantations (Bujang, 1997). The factories are situated mainly near the river

and sago logs are transferred to the factories using rivers before entering several stages in sago

processing such as debarking, pulping, starch extraction, dewatering, drying and packing. Sago

effluent produced during sago extraction consists of liquid and solids form which contain high

Biochem ical Oxygen Demand (BOD) and Suspended Solids (SS) in the range of 1800-7000

mg/L and 4000 mg/L respectively (Chew and Shim, (993). It is acidic, high in organic pollutant

and low in nutrients.

It was reported that sago effluents consisting of sago pith known as ' hampas' and

wastewater was discharged directly to the nearby river without any treatment to decrease the

polluting load. The polluting load is due to the presence of large quantities of hampas with some

starch (Chew and Shim, (993). Discharging sago effluent directly to the river will cause serious

contamination and pollution to the river. According to Bujang et af (1996), the potential threat of

pollution can be hypothesize based on a medium size sago mill in Pusa, Sarawak. At a

consumption rate of 600 standard (1.2m/4 ft) logs/day the mill generated 5 liters/sec (18 tons/h)

and 0.5 liters/sec (1.8 tons/h) of wastewater from the final effluent and the decanter, respectively.

Since the factory opera1 for 12hrs/day, approximately 237.6 tons of wastewater containing 7. I

tons of total solids or ham pas is generated everyday from the processing of the 600 logs. Each log

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would produce 396.7 liters of wastewater containing 1l.9 kg of solids. Thus, in a week,

approximately 1425.6 tons of wastewater (42.6 tons total solids) would have been produced.

In this study, sago effluent obtained from Nitsei Sago Mill Sdn. Bhd, in Mukah was

obtained for analysis. The effects of agitation and aeration on the degradation of sago effluent

were studied. Both filtered and crude sago effluent was treated with aeration and agitation

treatment. By providing environment with high oxygen content, it is hoped that it can help the

microbes to mUltiply and enhance the degradation of sago effluent. Total suspended solids (TSS)

and biological oxygen demand (BOD) analysis was carried out to as a pollutant parameter and to

observe the effectiveness of the treatment on sago effl uent.

2.0 LITERATURE REVIEW

2.1 Sago palm

Sago palm or its scientific name Metroxylon spp. is a very important starch-producing

palm. It is commonly distributed in the Southeast Asia region and probably originated in New

Guinea and Moluccas. Sago grows well in swampy lowlands and humid condition with minimum

care. Sago is fairly salinity tolerant and can withstand occasional flooding by seawater. It can

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grow up to 10 meters height and weight about 1250 kilograms. Sago palm accumulate large

amount of starch in their trunk as it approach the end of their 10 to 15 years reproductive cycle.

Fresh mature sago palm contain 400 kilogram cortex and 850 kilogram pith which normally

contain approx imately 250 kilogram of starch, 425 kilogram of water and 175 kilogram of other

material (Vaughan nd Geissler, 1999).

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2.2 Sago Industry in Malaysia

Sago is a very important source of starch. In peninsular Malaysia, sago industry is small

with a production of 11000 tones of sago production annually from an area of only 4400 hectares

(Chew and Shim, 1993). Sarawak has a total area of 19720 hectares of sago palm including both

semi-wild and cultivated area with annual export of 43000 tones of premium quality flour. In

1994, over 35,000 tones of sago starch and 4180 tones of sago flour were exported procuring

income over RM22 millions and RM2.4 millions for the state of Sarawak (Bujang, 1997). Sago is

an important source of industrial starch for the local food industries as in manufacture of

monosodium glutamate and glucose. It is also has a potential in the animal feed industry, the

manufacture of high-fructose syrup as an alternative to sucrose and gasohol fuel production

(Chew and Shim, 1993). Most of sago factory in Sarawak is located in Mukah, (gan and Oya­

Dalat districts of Sibu which approximately 75% while other in Pusa-Saratok district of Sri

Aman. The number of sago mills has decreased from 86 to 32 due to the closing of small cottage

factories and the establishment of modem factories whilst the production of sago flour has

increased (Chew and Shim, 1993).

2.3 Sago Processing

Most of the starch contained in the central core of soft pale-pink pith of a sago stem and

this core is protected by a layer of fibrous bark. The sago log is transfer by floating it in the river

to the factory which is situated along the river bank. The first step in sago processing is

debarking, fo llowed by splitting the logs lengthwise to facilitate pUlping with a rasper, hammer

mill or chopper. The pulp formed caUed "repos" is past into a sieve with copious amount of

treated ·ver water. Then the starch is washed, dewatered, dried and packed. The waste generated

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