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Coagulation and flocculation are an essential component of both the treatment of drinking water and the treatment of wastewater. The coagulant is one of the materials or substances that is added to the water to remove, stabilizes and causes colloidal particles to settle. Chemical coagulants such as aluminum sulphate (alum), ferric chloride, and synthetic polymers are the most commonly used coagulants in the industry due to their efficacy in turbidity removal. However, the use of chemical-based coagulants has had some negative impacts on human health and the environment, such as Alzheimer’s disease, and has produced a high volume of toxic sludge. In order to reduce negative impacts, this led to the discovery of an alternative to the natural coagulant (plant-based) for drinking water treatment. The coagulant used in this study is a combination of fruit waste containing citrus microcarpa peels and papaya seed with a ratio of 80:20 and 40:60. In addition to determining the potential of the composite natural coagulant, the optimal dosage and the effect of the mixing duration are also studied in order to determine the best mixing duration for each stage of the coagulation-flocculation process. Laboratory-scale studies using jar test experiments were conducted on surface water to determine the percentage of turbidity removal. Fruit waste was collected from the UiTM Pulau Pinang cafeteria, dried in the oven for 24 hours at a temperature of 105°C. The optimum dosage of composite natural coagulant is 90 mg/L using an 80:20 ratio of citrus microcarpa peels and papaya seeds with 97% of turbidity removal. The optimum mixing time is determined where the fast mixing time is 180 rpm for 3 minutes, the slow mixing time is 20 minutes with 10 rpm and the settling time is 30 minutes. The study shows that citrus microcarpa peels and papaya seeds have the potential to become effective natural coagulants in the future.

Turbidity is one of the importance of physical water quality parameter in the water treatment process. Aluminum sulfate (alum) and ferric chloride are the most widely groups of chemical coagulant and have been extensively used to remove turbidity. However, there are several flaws relates to the environmental issue and impose health risk to the consumer. Fruit peel waste as a natural coagulant is one of the alternative techniques in minimizing the usage of chemical coagulant in water treatment. This research focused on a combination of ratio 60:40 and 80:20 of citrus microcarpa peels and citrus aurantiifolia peels to act as a natural coagulant for turbidity removal. Furthermore, the effect of mixing duration is determined to establish the optimum mixing duration for the highest turbidity removal. Standard practice using jar test were performed in synthetic turbid water using kaolin. The highest turbidity removal occurred at optimum ratio of 80:20 with 77.6% efficiency removal where the optimum mixing duration was found to be at 120 rpm of rapid mixing at 3 minutes, 50 rpm of slow mixing at 20 minutes and 60 minutes of settling time. The study demonstrated that combination of citrus aurantiifolia peels and citrus microcarpa peels have the potential to be used as natural coagulant for a future alternative in water treatment.

In Malaysia, an increasing rate of the road accident fatalities in rural road has been identified as one of the major concern to authorities and public. One of the systems that has been implemented to ensure that the roads were achieved the required standards of safety is Road Safety Audit (RSA). The RSA (stage 5) guideline very useful to plan major maintenance and improvement by a proactive way of identifying high risk situations so that that they can be eliminated or otherwise treated to reduce the likelihood of accidents or reduce the severity of accidents. It is including the site inspection activity, intersections, traffic signal installations and general traffic management items. This study was developed to evaluate potential unsafe features or operational arrangement that may adversely affect the safety of road user and to justify the risk and severity of crashes that may be attributing to the existing road condition. This study was focused on traffic flow and control that includes the study of traffic signal installation, general traffic management, cross-section and intersection (sight distance). For the RSA inspection, Jalan Berapit at Bukit Mertajam was selected as investigation location in collecting the data of traffic volumes, spot speed, site inspection and qualitative research questionnaire. Besides, extensive preview of previous related research and consolidated by interviews with authorities and industry professionals. The data was analyzed by using SPSS and the site inspection was analyzed by using prioritization method and compared with the Guidelines for the Safety Audit of Roads in Malaysia. All the data obtained need to proceed with an immediate road safety improvement effort to ensure the improvements in term of serviceability and safety of road users. This study may lead to the improvement of road safety on federal road along Berapit to Penanti from the viewpoint of user because it is the main road and its lead to the highway nearby.

The purpose of this study is to establish the complete assessment of flexible pavement maintenance activities carried out from Sungai Petani KM107.90 to Alor Setar KM51.40, Section N2,North South Expressway Northern Region. The assessment includes the visual inspection to determine the rating criteria for each defect found on the flexible pavement and the determination of proper rehabilitation work along Section N2 by referring to Inspection Manual for Pavement Maintenance Management System – PLUS Bhd and OPUS NMM NRO and Buku Panduan Pemeriksaan Penyelenggaraan Bulanan Lebuhraya-Lembaga Lebuhraya Malaysia (LLM). Quality Assurance and Quality Control (QA/QC) practice also been incorporated throughout the assessment as listed in Method Statement in Work Order and Standard Specification for Road Works JKR/SPJ/2008-S4 Fexible Pavement. It is including before, during and after rehabilitation work is implemented. From the visual inspection, cracking recorded the highest percentage of the defect found on north bound with 32%, while south bound recorded as 44%. Both are categorized in rating C condition which require repairs for user comfort which mill and pave method been chosen for repairing works after considering several factors; such as optimum time and cost. A good assessment at defected area will increase the life span of the pavement and minimize the overall maintenance cost.

Adsorption is an effective method in treating heavy metals of wastewater. The presence of high dissolved Copper (Cu) and Zinc (Zn) concentration in industrial wastewater contribute to the decoloration of water and can cause health problems for long-term exposure to these heavy metals. This studies investigate eggshell as an alternative adsorbent. The effects of contact time, initial metal concentration and adsorbent dosage were studied in batch experiments. The Cu and Zn concentrations were analysed triplicate using Spectrophotometer (Model: DR 2800). The result shows that more than 90% removal of Cu and Zn occurred at optimum contact hours of 60 minutes and 120 minutes respectively while optimum initial concentration was 1 ppm for Cu removal and 2 ppm for Zn removal. Based on the present results, the application of the eggshell is a potential and economic treatment for excessive Cu and Zn content in wastewater treatment plant.

This research aimed to determine the suitability of citrus fruit peel waste namely as Citrus Aurantiifolia (key lime) and Citrus Microcarpa (kasturi lime) to act as a natural coagulant for water turbidity removal. The performance of these two coagulants was assessed in terms of turbidity removal using jar test experiments for synthetic low turbid water. The results indicated that the optimum dosage and turbidity removal for Citrus Microcarpa and Citrus Aurantiifolia was found at 30 mg/l with 75.6% turbidity removal and 60 mg/l with 74 % turbidity removal, respectively. Citrus Aurantiifolia showed higher removal efficiency as compared to Citrus Microcarpa. The study demonstrated that both citrus fruit peel waste has the potential to be use as a substitute for chemical based coagulant for a future alternative in water treatment.

Illumination level is an important thing in our daily life. Therefore, it is necessary for the building or any infrastructure to achieve the minimum recommendations of illumination. This case study was focus on the evaluation of illumination level at public transit infrastructure which is Pengkalan Sultan Abdul Halim Ferry Terminal. The aim of this study is to evaluate either the illumination level in selected area is comply to the standard of Panduan Teknik JKR or not. Field measurement was conducted, and the reading of lux meter were recorded. The illumination level of the selected location is in good condition during the day. The walkways area achieved 100% of recommendation standard followed by waiting area is about 85%. Only ticket counter in satisfactory level with 86.20% and only 13.80% achieved the minimum requirement. Only walkways achieved 65.4% of satisfactorily standard and 34.6% in bad condition for the night situations. The bad condition of illumination at ticket counter and waiting area during the night. The 100% of the area are in bad condition which is dangerous to the users. From the results, it is suggested to do routine maintenance to improve the illumination level and achieve the minimum requirement of standard.

In this study, tea waste (TW) is investigated as a low cost adsorbent for the treatment of Mn(II) and Zn(II) in synthetic wastewater. Experimental design, the variables are the adsorbent dosage (0.5g, 1.0g, 1.5g, 2.0g, 2.5g and 3.0g) and contact time (20, 40, 60, 80, 100 and 120 minutes). The percentage of heavy metal ions removal in the solution are measured using DR2800 Spectrophotometer. Adsorption Isotherm and Adsorption Kinetic modelling are applied to further prove the correlation of the experimental data obtained for the removal of Mn(II) and Zn(II). The equilibrium data satisfactorily fitted into Langmuir Isotherm model for both Mn(II) and Zn(II) with R2 value of 0.9906 and 0.9854, respectively. Based on the result, TW is capable to adsorb more than 90% of both Mn(II) and Zn(II) at optimum dosage of 2g/100ml. The kinetic studies show that the absorption mechanisms satisfied the Pseudo-Second-Order model and have the best equilibrium data with R2 value of 0.9998 and 1.0000 for Mn(II) and Zn(II), respectively. The maximum adsorption achieved at 60 minutes for Mn(II) and 80 minutes for Zn(II). Thus, the Langmuir Isotherm and Pseudo-Second-Order Kinetic models proved that TW is capable of being an efficient and effective adsorbent for Mn(II) and Zn(II) removal in synthetic wastewater.

In Malaysia, the productions of waste from various sources keep increasing annually. This problem can cause our nation to face serious problem regarding with the process in handling waste handling process at landfill. By recycling agricultural waste is the one of effective method to reduce the waste damping on landfill. The agricultural waste such as eggshell and coconut shell not commonly being used as stabilizing material as lime and cement in pavement design, but the mineral composition contain shows their own ability to strengthen the weak subgrade soil. Thus, the aimed for this study is to investigate the effectiveness mixture of eggshell powder (ESP) and Crushed Coconut Shell (CCS) on soil performance for subgrade layer. The combination of constant 3% ESP with the various percentage of CCS, 2%, 4%, 6% and 8% is evaluated by conducting Standard Proctor Test (SPT) and California Bearing Ratio (CBR) test. The results obtained shows the maximum CBR value achieved at 4% of CCS along with constant 3% ESP.