Emmanuel Olisa

Water Quality Assessment of Ex-Mining Lakes in Perak, Malaysia as Alternative Source of Water Supply

This study investigated the water quality of some of the ex-mining lakes in Perak State of Malaysia for possible use as alternative to water supply and compared them to water quality of some of the rivers used for intake of water treatment. A total of twelve (12) water samples were collected for analyses from selected sampling sites. These samples were analyzed for physico-chemical properties, heavy metals concentrations, and organic pollutants concentrations. The analyzed results indicated that average temperature varied from 28.1 oC to 34.1 oC, pH 6.2 to 9.0, EC 55 to 400 μs/cm ,turbidity 5.6 to 74.2 NTU, DO 3.21 to 9.56 mg/l, TDS 36.8 to 268 mg/l, F- 0.017 to 0.182 mg/l, Cl- 0.483 to 3.339 mg/l, Br- 0 to 0.392 mg/l, SO42- 0.051 to 15.307 mg/l, Mg 0.833 to 1.466 mg/l, Na 0.669 to 3.668 mg/l, and Ca 2.85 to 26.77 mg/l. Heavy metals concentrations (mg/l) were: Zn 0.04 to 0.057, Pb 0.019 to 0.075, Cd not detected, Ni 0.013 to 0.105, As not detected to 0.004, and Cu not detected while COD 4 to 51 mg/l. Analyses revealed that all the water samples were turbid and containing slightly high concentration of Pb. Generally, they had common water quality problem. Further work should carry out more tests on other water quality parameters particularly on heavy metals, chemical and biological pollutants at different seasons.

Sorption of Copper and Zinc from Aqueous Solutions by Microwave Incinerated Sugarcane Bagasse Ash (MISCBA)

Industrial wastewater containing toxic pollutants such as heavy metals tends to contaminate the environment once it is release without proper treatment. Heavy metals are toxic to both human and other living organisms. It is necessary to treat industrial wastewater polluted with heavy metals prior to its discharge into the receiving environment. In this study, low cost adsorbent was generated from sugarcane bagasse through incineration. The prepared adsorbent “microwave incinerated sugarcane bagasse ash” (MISCBA) was used in removing copper and zinc from aqueous solution. Parameters of importance such as pH, contact time and adsorbent dosages are studied to investigate their effects on the adsorption of copper and zinc. Maximum adsorption was observed at pH 6.0, contact time of 180 minutes and adsorbent dosage of 10 g/L. Zinc removal follows Langmuir isotherm model with correlation coefficient of 0.9291. Copper adsorption follows both Langmuir and Freundlich isotherm model with correlation coefficient of 0.9181 and 0.9742, respectively. Removal capacities of 38.4 mg/g and 20.4 mg/g were obtained for copper and zinc, respectively. Application of MISCBA as low - cost adsorbent have shown significant outcome in removal of copper and zinc from aqueous solution.

Evaluation of Leachate Characteristics from Different Leachate Ponds in a Semi-Aerobic Landfill

In this study, the performance of a semi-aerobic landfill was monitored through the analysis of leachate composition collected from different leachate ponds; collection pump (CP), equalization pond (EQ) and aerated pond (AP). The landfill site is located in the tropical environment of the central region of Malaysia. Twenty parameters were analyzed and the average values of the parameters for leachate at the CP, EQ and AP, which include; pH (8.24, 8.00 and 8.73), total kjeldahl nitrogen (3987.25, 8744.6, 1927.31 TKN-N), ammonia-N (3726, 3800, 1560 mg/L NH3-N), nitrate (26.7, 33.3, 25 mg/L NO3-N), total phosphorus (0.85, 0.78, 0.92 mg/L PO43-), BOD5 (305, 311.3, 201 mg/L), COD (16100, 14587, 12780 mg/L), BOD5/COD (0.019, 0.021, 0.016), turbidity (405, 735, 940 NTU), colour (3991, 4122, 3412 Pt Co), TSS (109.3, 58, 50.7 mg/L), EC (32.8, 21.9, 37.0 mS/cm) and TDS (21.98, 14.7, 24.8 mg/L) were recorded appropriately. The results realized from the analysis of the three ponds, were compared with previously published data and also the standards specified by the Malaysia Environmental Quality Act 1974. The obtained results indicate that the leachate from the aerated pond could remove some of the pollutants and was more stabilized when compared with the leachate from the pump and equalization ponds. It is also found that the aeration process in aerated pond could enhance the reduction of pollutants in the leachate. The measured leachates would require appropriate treatment methods in order to reduce the pollutants to meet the discharge standard before releasing them into water courses.

Drinking Water Production Using Passive Solar Stills with Different Absorbing Materials

Solar stills as the cheapest options used to desalinate brackish water in areas having freshwater availability limitation. The purpose of this work is to investigate the water production improvement of double slope solar stills using heat absorption materials in the basin. Three similar shapes double slope passive solar stills were constructed to conduct the experiments in tropical climate of Malaysia. Each solar still had a stainless steel trough and a transparent polythene film as basin and cover respectively. Three basins each having 50 cm length, 30 cm width and 8 cm depth were used to keep the fed lake water. 2 cm depths of black soil and sea sand were added in two solar still basins respectively, while the last solar still had only stainless steel trough as basin. Experimental investigations on the solar stills performance showed that the solar still with black soil had a highest output as compared to the solar still yield using sea sand layer in basin or conventional solar still using only stainless steel basin respectively. Some water quality parameters of lake water and produced distilled water were also tested in the laboratory and indicated that the treated water met the WHO standard for drinking.

Landfill Gas Detection in Leachate Pipe: A Consideration for Design Improvement of Leachate Piping and Gas Venting Systems

Landfill provides simple and economic means of solid waste disposal. However, it causes negative effects to the environment due to leachate generation and greenhouse gas emissions. Current trends in landfill design allow aerobic or semi aerobic processes to take place inside the landfill to speed up degradation process and reduce odour. In Malaysia, the semi aerobic system of landfill design is adopted. This paper presents the study of the gas venting system and leachate quality of the semi aerobic landfill. The gas samples were collected from the end of the leachate pipe and the gas vent of a sanitary landfill by the water displacement method. Raw leachate samples from the landfill leachate ponds were collected and the COD of the samples were measured. The concentration of methane gas escaping from the leachate pipe was found to be around 13%. The COD content of the raw leachate was found to be more than 15000 mg/l. The improvement of landfill gas collection in Malaysia is recommended.