Authors: Md. Zahangir Alam, Mohammed Saedi Jami, Nassereldeen A Kabbshai andMariatul F Mansor

Bioenvironmental Engineering Research Center (BERC), Department of Biotechnology Engineering, Faculty of Engineering,International Islamic University Malaysia, Gombak, 50728 Kuala Lumpur, Malaysia

Corresponding author: Md Zahangir Alam

E-mail: [email protected];  | Tel: 603-61964571

Abstract

The treatment of sewage treatment plant (STP) sludge by pure bacterial culture was study in lab-scale to evaluate the effective and efficient bioconversion through the process conditions. A 2-level full factorial (24) design with four central points was conducted with the aim of optimization of processes conditions such as temperature, agitation, pH and inoculum for the bioconversion of STP sludge through chemical oxygen demand (COD) removal (response). A second order polynomial model was developed to represent the removal of COD with the variation of different process conditions in the sludge treatment. Analysis of variance (ANOVA) of full factorial design showed a high coefficient of determination (R2) of 0.90 indicating a satisfactory adjustment of the model with the experimental data. The linear and interaction effects among the factors were identified through the p-and t-test. Statistical analysis showed that the agitation and inoculum size have significant effects (p<0.05) on bioconversion of STP sludge (COD removal). The results with the surface response analysis indicated the optimum values of parameters with the minimum content of COD (30mg/L): temperature, 40°C; agitation, 50 rpm; pH, 3; inoculum, 5% (v/v).

Keywords: Statistical optimization, sewage treatment plant sludge, Bioconversion, pure bacterial culture

Authors: Abdul G. Liewa*, Azni Idrisa, Calvin H. K. Wonga, Abdul A. Samadb, Megat Johari M. M. NoorbandAminuddin M. Baki

Departmentof Chemical and Environmental Engineering, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
Department of Civil Engineering, Universiti Putra Malaysia, 43400, Serdang, Selangor, MalaysiacIndah Water Konsortium Sdn Bhd, Kuala Lumpur, Malaysia

Corresponding author: Azni Idris

E-mail: [email protected];  | Tel: +603 89466302

Abstract

This study reports the use of sewage sludge generated from sewage treatment plant (STP) as raw material in a clay brick-making process. The physico-chemical and mineralogical characterization of the sewage sludge and clay were carried out in order to identify the major technological constraints and to define the sludge pre-treatment requirements if necessary. Moreover, the effects on processing conditions and/or on changes of typical final characteristics are also evaluated. Bricks were produced with sewagesludge additions ranging from 10 to 40% by dry weight. The texture and finishing of the surface of sludge-amended clay bricks were rather poor. As for the physical and chemical properties, bricks with a sludge content of up to 40 wt.% were capable of meeting the relevant technical standards. However, bricks with more than 30 wt.% sludge addition are not recommended for use since they are brittle and easily broken even when handled gently. A tendency for a general degradation of brick properties with sludgeadditions was observed due to its refractory nature. Therefore, sludge bricks of this nature are only suitable for use as common bricks, which are normally not exposed to view, because of poor surface finishing.

Keywords: sewage sludge, utilization, claybrick production, physico-chemical, mineralogical characterization

Authors: Yuk San, Liew1, Mat Jusoh, Azman1, E. M Yahaya, Nasehir Khan1, Mohd Sobri, Fatin Afeeqa1, Hj. Ahmad Zaki, Ahmad Taqiyuddin1, Sulaiman, Sharina2, Ayop, Zaliffah2, MohdDom, Norlida2, Thavamani, Satiavathi2, Rohani, Ahmad2, Sulaiman, Tajudin

River Basin Research Centre, National Hydraulic Research Institute of Malaysia (NAHRIM),Lot 5377, Jalan Putra Permai, 43300 Seri Kembangan, Selangor, Malaysia.

Corresponding author: Abdul Wahab Mohammad

E-mail: [email protected], [email protected]; 

Abstract

Flood is one of the natural disasters that affect properties and even people life. There are several methods in preventing water from seeping into building and one of it is the flood wall barrier. There are two types of wall barrier system which are permanent and mobile wall. Permanent flood wall barrier are widely applied in the water prone area. However, the permanent structure may need a huge space and higher cost. For mobile flood wall barrier, it helps avoiding flood from entering the houses and premises especially during flash flood in urban area where the space is limited to build a permanent flood wall. The usage is proven effective compared to the traditional way of using sandbag as flood protective barrier. This flood wall barrier has advantages and disadvantages depending on the place of installation, type of material used and size of the wall itself. The type of flood wall, advantages, disadvantages and failure of flood wall barrier are discussed in this paper.

Keywords: Flood, mobile flood wall barrie

Authors: Che Fauziah Ishaka, Rosenani Abu Bakara and Rosazlin Abdullah

Department of Land Management, Faculty of Agriculture, UniversitiPutra Malaysia, 43400, Serdang, Selangor, Malaysia
Institute of Biological Science, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia

Corresponding author: Che Fauziah Ishak

E-mail: [email protected];  | Tel: +603-8947 4938

Abstract

A field experiment using a block design was set up from 1995-1999. Soil at this site is the well-drained Bungor Series, clayey, kaolinitic, isohyperthermic Typic Paleudults. The treatments for the first cycle are no sludge application, inorganic N (ammonium sulfate) at 140 kg N ha-1and sludge application rates at 150, 300, 450 and 600% of recommended fertilizer N rate of 140 kg N ha-1. No sludge was applied during the second cycle. During the third, fourth and fifth cycle, the treatments were similar with the exception that the rates were reduced to 100, 200, 300 and 400% of the recommended fertilizer N rate. The method of the sequential extraction procedure used in this study is the modified version of Yang and Kimura [1]and Chlopecka et al. [2]as put forward by Salas et al. [3]. The forms of heavy metals are water soluble, exchangeable, carbonate bound, Fe-Mn oxides bound, organically bound and the residual form. Soil samples at 0-20 cm depth from the plots with different treatments and four replications were collected after each corn harvest.The concentration of Cd, Cu, Pb, Ni and Zn in grain even in the highest sludge treatments (approximately 1%) in the five cycles were still below the maximum permitted concentration (fresh weight basis) as stipulated by the Malaysian Food Act 1985. There is however, an increase in the accumulation of Cu and Zn in the soil, and for Cd and Pb, the trend is not yet visible. As for the fractionation study, for soil Ni and Zn, the most predominant form was the residual form. Soil Cd and Pb were found mostly in the exchangeable form. Soil Cu was dominant in the organically bound form. For all these heavy metals, the water soluble fraction is less than 5% of the total heavy metal content. From the correlation study, Zn uptake by maize grain showed positive correlation with water soluble form. There were relationships between copper uptake in grain and the carbonate, organic and residual form. Meanwhile, there were relationships between Ni uptake by the grain and the Ni associated with the Fe-Mn oxides, organic and residual form. No correlation was done between Cd and Pb uptake with these metals fractions in the soil because the concentrations inthe grain were very low.

Keywords: sewage sludge, heavy metals, fractionation, correlation, corn grain uptake

Authors: S. W. Howa, J. H. Sina, S. Y. Y. Wonga, P. B. Limb, A. M. Arisb, G. C. Ngoha, T. P. Curtiscand A. S. M. Chua

Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
Indah Water Konsortium Sdn Bhd, No. 44, Jalan Dungun, Damansara Heights, 50490, Kuala Lumpur, Malaysia

Corresponding author: Adeline Chua Seak May

E-mail: [email protected];  | Tel: +603-79675291

Abstract

Biological nitrogen removal is a common process to remove ammonia (NH3) and nitrate (NO3-) from domestic wastewater. The denitrification step in biological nitrogen removal process requires sufficient amount of biodegradable organics. Previous wastewater characterization study in the Klang Valley region suggested that our wastewater has low soluble biodegradable organics. Particulate settleable solids (PSS) in the wastewater made up the major portion of chemical oxygen demand (COD) in the wastewater. We hypothesized that the warm wastewater temperature (30 ± 2ºC) may accelerate PSS hydrolysis in wastewater. The hydrolysis of PSS may provide slowly-biodegradable chemical oxygen demand (sbCOD) for denitrification. This study aimed to investigate the potential of utilizing sbCOD for denitrification in treating wastewater in the Klang Valley. We sampled wastewater and sludge from six WWTPs across Klang Valley region. We characterized the fractions of COD in the wastewater by fractionation experiments. The PSS hydrolysis kinetic coefficients weredetermined at tropical temperature (30 ± 2ºC) by oxygen uptake rate (OUR) experiment. The wastewater samples was low in readily-biodegradable COD (rbCOD), which made up 3 –40% of total COD (TCOD). Most of the biodegradable organics was in the form of sbCOD (15–60% of TCOD). The amount of biodegradable COD (rbCOD + sbCOD) in the wastewater was sufficient for denitrification. The PSS hydrolysis rate was 3 times higher than that at 20ºC. The high PSS hydrolysis rate may provide sufficient sbCOD to achieve effective biological nitrogen removal performance for the wastewater in the Klang Valley region.

Keywords: Biological nitrogen removal; particulate settleable solids; hydrolysis; COD fractionation

Authors: Chin Boon Ongaand Abdul Wahab Mohammada, ba

Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti KebangsaanMalaysia, 43600 UKM Bangi, Selangor, MalaysiabCentre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

Corresponding author: Abdul Wahab Mohammad

E-mail: [email protected];  | Tel: 03-8921 5080

Abstract

Despite water scarcity leading to wastewater reclamation and reuse, there are still many considerations for the ongoing utilization of reclaimed water. Among the factors, social aspect is paramount for reuse success. This paper presented a study on the reclaimed water quality using a membrane based (Ultrafiltration (UF)/Reverse Osmosis (RO)) pilot plant for water reuse and also identified the factors that will influence public and industries acceptance towards the use of recycled treated water from sewage treatment. Moreover, factors which will affect industries willingness to use reclaimed water for industrial purpose were also studied. Technically, the performance of UF/RO system was excellent. The RO permeate water quality was able to meet WHO drinking water standard. The key results based on the surveys showed that there are positive responses from the public provided that the quality of reclaimed water meets the standards. In this work, cost seems to be the main issue for industries consideration compared to public uses.

Keywords: Industries acceptance, public acceptance, reclaimed water, sewage, reverse osmosis