Azhar Abdul Halim

Ammoniacal nitrogen and COD removal from semi-aerobic landfill leachate using a composite adsorbent: Fixed bed column adsorption performance

The performance of a carbon-mineral composite adsorbent used in a fixed bed column for the removal of ammoniacal nitrogen and aggregate organic pollutant (COD), which are commonly found in landfill leachate, was evaluated. The breakthrough capacities for ammoniacal nitrogen and COD adsorption were 4.46 and 3.23 mg/g, respectively. Additionally, the optimum empty bed contact time (EBCT) was 75 min. The column efficiency for ammoniacal nitrogen and COD adsorption using fresh adsorbent was 86.4% and 92.6%, respectively, and these values increased to 90.0% and 93.7%, respectively, after the regeneration process.

Removal of ammoniacal nitrogen and COD from semi-aerobic landfill leachate using low-cost activated carbon?zeolite composite adsorbent

A carbon-zeolite composite adsorbent has been studied for COD and ammoniacal nitrogen removal in semi-aerobic landfill leachate. The optimum conditions for adsorption in the batch study occurred at pH 7, shaking speed of 200 rpm, and contact time of 105 min. The Langmuir isotherms corresponded slightly better than Freundlich isotherm for both ammoniacal nitrogen and COD removals. The Langmuir adsorption capacities for ammonia and COD were 27.47 mg/g and 22.99 mg/g, while the Freundlich adsorption capacities were 0.4227 mg/g and 0.0642 mg/g, respectively. The overall rate of the ammonia and COD adsorption processes appears to be dominated by chemisorption process.

Poly(Fe-4-vinylpyridine) modified composite graphite paste electrode for the analysis of iron(III)

Abstract An iron(III) selective electrode based on poly(Fe-4-vinylpyridine) modified composite graphite paste was investigated for its characteristics and mechanism of potential determining process. The electrode which was prepared through cathodic polymerization of the monomer 4-vinylpyridine and the Fe(III), showed Nernstian response towards Fe(III) in the 1.58 × 10−6 M to 6.3 × 10−3 M concentration range with slope 60±5 mV decade−1 in solutions of pH 2.5 ±0.5 and in the presence of 0.1 M NaClO4. The mechanism of the electrodes response appeared to follow a redox potential rather than an ion exchange. The steady state response was obtained in 15 s. The electrode was stable in temperature range of 35 ± 10°C. The drift in response was observed to be in the range of 3 ± 1 mV h−1. The electrode displayed high selectivity towards Fe(III), even in the presence of Fe(II). Slight interferences were observed from Br− and F−. The electrode response showed good correlation with selected standard method, AAS, with coefficient, r, equal to 0.96. Experiments on industrial and waste waters, using t-test indicated no significance difference. The electrode remained stable after seventeen days of continued use.

Treatment of automotive wastewater by coagulation-flocculation using poly-aluminum chloride (PAC), ferric chloride (FeCl3) and aluminum sulfate (alum)

A physicochemical treatment (coagulation-flocculation) was applied for automotive wastewater using poly-aluminum chloride (PAC), ferric chloride (FeCl3) and aluminum sulfate (alum) aided by anionic polyacrylamide as flocculant to determine the effectiveness of coagulation method for removal of COD, TSS and heavy metals (Fe, Ni and Zn). The results obtained proved that PAC was comparatively more efficient to FeCl3 and alum. At defined optimum experiment condition (coagulant dose: 70 mg/L, coagulant aid dose: 2 mg/L and pH 7), PAC showed 70% removal for (chemical oxygen demand) COD and 98% of (total suspended solid) TSS. For FeCl3 and alum, the maximum removal for COD were 64% and 54%, meanwhile TSS removal were 91% and 94%. Heavy metals removal using PAC also showed better results in which produced 98% of iron removal, 83% of zinc removal and 63% of nickel removal under optimum condition. The comparison revealed that the use of PAC aided by anionic polyacrylamide produced higher removal for COD, TSS and he...

Adsorption studies of leachate on cockle shells

Sanitary landfills are important means of disposing municipal solid waste in developing countries. However, these landfills are associated with the generation of leachate, which if untreated may pose severe public health risk and may damage the ecosystem in the long term. In this study, cockle shells were explored as an adsorbent media for the treatment of a stabilized landfill leachate. The optimum shaking speed, pH, and dosage for chemical oxygen demand (COD) parameter removal were investigated using the adsorbent media of particle sizes ranging from 2.00 mm to 3.35 mm. Leachate characteristics were then determined. Results indicated that leachate is non-biodegradable with high concentrations of COD (1763 mg/L), ammonia nitrogen (573 mg/L), and biochemical oxygen demand/COD (0.09). The optimum conditions for shaking were determined at 150 rpm according to the adsorption of COD by the media. Optimum pH and dosage was 5.5 and 35 g/L, respectively. The adsorption isotherms indicated that Langmuir isotherm is better fitted than Freundlich isotherm.

Effect of electrochemical oxidation on biodegradability and toxicity of batik industry wastewater

This study was conducted to investigate the increase in biodegradability and reduction in toxicity level in the batik wastewater treatment. Basically, the wastewater treatment from batik industry contained chemicals especially dyes which are not biodegradable and contains higher toxicity level because of the chemical compartment which comes out during the wastewater discharge and this could lead high risk in health wise to humans and all the aquatic living organisms. Thus, this research was carried to enhance the effectiveness of the electrochemical oxidation method by using the batik wastewater. Optimal parameters such as pH, time, distance between graphite electrodes and sodium chloride (NaCl) concentration as it activates as the electrolyte was done to obtain the removal of BOD, COD and color in the batik wastewater. The research study found that the removal of COD and color was high in the acidic conditions which are pH 5 with the removal of COD, 89.71% and color 93.89%. The ratio of BOD5/ COD success...

Potential of Agro Waste-Derived Adsorbent Material for Colour Removal

The potential of Empty Fruit Bunch obtained from palm oil tree as a low-cost adsorbent is a sustainable approach in wastewater treatment. The objective this study to investigate the capability of EFB for removal colour from natural rubber wastewater as well as the influence of adsorbent dosage, pH, shaking speed and contact time. The results of the analysis show that all selected factors exhibit significant effect on removal of colour. Maximum removal (87.1%) for colour was achieved at 3.5 g of adsorbent dosage, pH 7, 150 rpm of shaking speed, 120 min of contact time. The Langmuir isotherm (R2 = 0.9913) described colour adsorption slightly better than the Freundlich isotherm (R2 = 0.9805), suggesting a monolayer adsorption behavior of the adsorption processes

Micro-Peat as a Potential Low-Cost Adsorbent Material for COD and NH3-N Removal

Micro-peat (M-P) was demonstrated in the present study as a potential low cost natural adsorbent for the removal of COD and ammoniacal nitrogen (NH3-N) from landfill leachate. A series of batch experiments were carried out under fixed conditions and the influence of mixture ratio was investigated. The characteristics of leachate were then determined. Results indicated that leachate is non-biodegradable with high concentration of COD (2739.06 mg/L), NH3-N (1765.34 mg/L) and BOD5/COD ratio (0.09). The optimum ratio for activated carbon (AC) and M-P in the removal of COD and NH3-N obtained were at 2.5:1.5 (87%) and 1.0:3.0 (65%) respectively. The low-cost natural adsorbent used in the present investigation is an attractive alternative to the conventional adsorbent (AC). Thus, M-P can be appropriated for use in leachate treatment that could be cost-effective due its local availability and adsorption property.

An Integrated Approach for Stakeholder Participation in Watershed Management

Water is an essential element for life. However, the rapid urbanization and industrial development in the past decades have put stress on water resources. Water resource management is intended to solve watershed problems on a sustainable basis, and these problems can be categorized into lack of water (quantity), deterioration in water quality, ecological effects, poor public participation, and low output economic value for investment in watershed-related activities. Involvement of stakeholders is of utmost importance to ensure no one is left behind in the sustainable management of water resources. Hence, an integrated approach has emerged as a shift from the structural approach to a nonstructural approach, that is, from engineering-based solutions to community-based solutions, aiming to induce policy-driven institutional change, particularly the coordination and integration of multiple stakeholders toward sustainable watershed management

Coagulation-flocculation in leachate treatment using modified micro sand

Sanitary landfill leachate is considered as highly polluted wastewater, without any treatment, discharging into water system will cause underground water and surface water pollutions. This study was to investigate the treatability of the semi-aerobic landfill leachate via coagulation-flocculation using poly-aluminum chloride (PAC), cationic polymer, and modified micro sand. Leachate was collected from Pulau Burung Sanitary Landfill (PBSL) located in Penang, Malaysia. Coagulation-flocculation was performed by using jar test equipment and the effect of pH, dose of coagulant and dose of polymer toward removal of chemical oxygen demand (COD), color and suspended solid (SS) were examined. Micro sand was also used in this study to compare settling time of coagulation-flocculation process. The optimum pH, dose of coagulant (PAC) and dose of polymer (cationic) achieved were 7.0, 1000 mg/L and 8 mg/L, respectively. The dose of micro sand used for the settling time process was 300 mg/L. Results showed that 52.66% r...