Journal of Environmental Treatment Techniques  
2020, Volume 8, Issue 3, Pages: 967-970  
J. Environ. Treat. Tech.  
ISSN: 2309-1185  
Journal web link:  
Study of Eco-Processed Pozzolan Characterization as  
Partial Replacement of Cement  
Raihana Farahiyah Abd Rahman , Hidayati Asrah , Ahmad Nurfaidhi Rizalman , Abdul K.  
Mirasa , M A A Rajak  
Faculty of Engineering, Universiti Malaysia Sabah, 88400 Jalan UMS, Kota Kinabalu, Sabah, Malaysia  
Preparatory Centre for Science & Technology, Universiti Malaysia Sabah, 88400 Jalan UMS, Kota Kinabalu, Sabah, Malaysia  
Received: 11/01/2020  
Accepted: 16/06/2020  
Published: 20/09/2020  
Eco-processed pozzolan (EPP) is a sustainable product recycled from spent bleaching earth (SBE). It is recently used as a blended cement.  
The pretreatment method of palm oil generates SBE as waste material in the refinery plant. Despite sending the SBE to the landfill, which  
can lead to environmental pollution, it is extracted to produce sustainable products. The physical, chemical, mineralogical, and microstructural  
characteristics of EPP were analysed. Furthermore, the conventional cement was substituted with 20% of EPP by cement mass in mortar.  
The compressive strength of mortar containing EPP was determined for the assessment of strength activity index (SAI) of EPP. EPP consists  
mainly of silica (SiO  
2 2 2 3 2 3  
), and the value of SiO , aluminium oxide (Al O ), and iron oxide (Fe O )combination was 68.98% which is more than  
0%. According to the ASTM C618 standard, EPP could be categorised in the Class C pozzolan. The major crystalline phase of EPP was α-  
quartz. Based on the micrograph image, EPP possesses some relatively spherical, irregular shaped, and agglomeration of its particles. At an  
early curing age, the compressive strength of the mortar was increased with the inclusion of 20% of EPP. A high value of SAI can be reached  
by mortar specimen with 20% of EPP.  
Keywords: Eco-processed pozzolan, Pozzolan, Strength activity index  
Palm oil fuel ash (POFA) [5], milled waste glass powder [6],  
clay brick powder [7], sugarcane bagasse ash [8], and fly ash [9]  
have been investigated to be used to substitute conventional  
cement in mortar and concrete. Because of its high percentage of  
Crude palm oil refinery plant generates spent bleaching earth  
(SBE) for approximately more than 2 million tonnes per year  
globally [1]. Malaysia is known to produce a huge number of  
palm oil fruits. In the pretreatment process which is in the  
degumming and bleaching of crude palm oil stage, bleaching  
earth is added to produce refined palm oil. SBE is one of the  
products of crude palm oil refining process. In Malaysia, the SBE  
from a refinery plant is often sent to the landfills [2]. The SBE  
disposal at landfills can affect the greenhouse gas (GHG)  
emission due to the natural anaerobic degradation. Recently,  
EcoOils’ company provides a solution to recycle SBE to produce  
sustainable products. Eco-processed pozzolan (EPP) is one of the  
extracted products from SBE. The sustainable products extracted  
from SBE are shown in Figure 1.  
Recently, EPP has been used as blended cement. From the  
previous studies, research on EPP as a pozzolanic material is  
limited. Waste products with pozzolanic characteristics are  
utilised in concrete to substitute cement, thus minimising the use  
of cement [3]. The use of pozzolanic material to replace cement  
silica (SiO  
concrete [5]. The reaction of SiO  
), POFA has a high potential to substitute cement in  
in pozzolanic material with the  
calcium hydroxide produces more CSH gel. The CSH gel will  
make the hardened paste denser and enhance its strength and  
durability [10]. In this study, the properties and the strength  
activity index (SAI) of EPP were investigated. At 7 and 28 days  
of curing, ordinary Portland cement was substituted with 20% of  
EPP by cement mass in mortar to assess the SAI of EPP.  
Materials and methods  
In this study, the EPP was collected from EcoOils, Lahad  
Datu. The EPP is as shown in Figure 2. The particle size of EPP  
was measured by using laser diffraction particle size analyser.  
The chemical oxides, mineralogical, and microstructural  
characteristics of EPP were investigated by using X-ray  
fluorescence (XRF), X-ray diffraction (XRD), and scanning  
electron microscope (SEM), respectively. The ordinary Portland  
cement was substituted with 20% of EPP by cement mass in  
could minimise the release of carbon dioxide (CO ) from the  
cement industry because the production of cement contributes to  
%7% of global CO emissions [4].  
Corresponding author: Raihana Farahiyah Abd Rahman, Faculty of Engineering, Universiti Malaysia Sabah, 88400 Jalan UMS, Kota  
Kinabalu, Sabah, Malaysia. Email: