Ahmad Md. Noor

Cure characteristics, tensile properties and swelling behaviour of recycled rubber powder-filled natural rubber compounds

The effect of recycled rubber powder (RRP) on cure characteristics, tensile properties and swelling behaviour of natural rubber (NR) compounds was investigated in the concentration range of 0 to 50 phr. Results indicate that the minimum torque and Mooney viscosity of the natural rubber compounds increase with increasing RRP loading whereas the scorch time and cure time exhibit a decreasing trend. Increasing RRP loading also gives natural rubber compounds better resistance towards swelling and reduces the elongation at break but the tensile stress, M100 (stress at 100% elongation) and M300 (stress at 300% elongation), increases slightly. However, the tensile strength increases up to 10 phr of RRP and then decreases.

Performance comparison of constructed wetlands with gravel- and rice husk-based media for phenol and nitrogen removal.

This study aims to compare the performance of planted and unplanted constructed wetlands with gravel- and raw rice husk-based media for phenol and nitrogen removal. Four laboratory-scale horizontal subsurface-flow constructed wetland units, two of which planted with cattail (Typha latifolia) were operated outdoors. The units were operated at a nominal hydraulic retention time of 7 days and fed with domestic wastewater spiked with phenol concentration at 300 mg/L for 74 days and then at 500 mg/L for 198 days. The results show that planted wetland units performed better than the unplanted ones in the removal and mineralization of phenol. This was explained by the creation of more micro-aerobic zones in the root zone of the wetland plants which allow a faster rate of phenol biodegradation, and the phenol uptake by plants. The better performance of the rice husk-based planted wetland compared to that of the gravel-based planted wetland in phenol removal could be explained by the observation that more rhizomes were established in the rice husk-based wetland unit thus creating more micro-aerobic zones for phenol degradation. The role of rice husk as an adsorbent in phenol removal was considered not of importance.

THE COMPARISON PROPERTIES OF RECYCLE RUBBER POWDER, CARBON BLACK, AND CALCIUM CARBONATE FILLED NATURAL RUBBER COMPOUNDS

The effects of filler loading on the curing characteristics, swelling behavior, and mechanical properties of natural rubber compounds were studied using a conventional vulcanization system. Recycle rubber powder (RRP), carbon black (CB) (N550), and calcium carbonate (CaCO3) were used as fillers and the loading range was from 0 to 50 phr. Results show that the scorch time, t 2, and cure time, t 90, decrease with increase in filler loading. At a similar filler loading, RRP shows shortest t 2 and t 90 followed by CB and calcium carbonate. The tensile strength, tensile modulus, and hardness increase with increase in CB loading, whereas elongation at break, resilience, and swelling properties show opposite trend. For RRP and calcium carbonate filled natural rubber compounds, the tensile strength increases up to 10 phr and starts to deteriorate at higher filler loading. The other properties such as tensile modulus, hardness, elongation at break, resilience, and swelling percentage show a small change (increase or decrease) with increase in RRP and calcium carbonate loading in natural rubber compounds. Overall results indicate that RRP can be used as a cheapener to replace calcium carbonate in natural rubber compounds where improved mechanical properties are not critical.

The Effect of Filler Loading on Curing and Mechanical Properties of Natural Rubber/recycled Rubber Powder Blends

ABSTRACT Curing characteristics and mechanical properties of carbon black– and silica-filled natural rubber (NR)/recycled rubber powder (RRP) blends were studied. Results indicate that the minimum torque and maximum torque increase with increasing filler loading in the compounds, whereas scorch time shows a decreasing trend. Cure time of carbon black–filled NR/RRP blends decreases with increasing filler loading whereas silca-filled NR/RRP blends show an opposite trend. Incorporation of filler loading has improved the tensile modulus, hardness, tear strength, and resistances toward swelling. However, elongation at break and resilience exhibit a different trend. For tensile strength, optimum values were obtained at 15 phr of both fillers. Overall results show that carbon black (N550) is more suitable to be used as a filler in natural rubber/recycle rubber powder blends compared to silica (Vulcasil S).

Application of Vegetated Constructed Wetland with Different Filter Media for Removal of Ammoniacal Nitrogen and Total Phosphorus in Landfill Leachate

Performance of vegetated horizontal subsurface-flow constructed wetland was evaluated for the removal of ammoniacal nitrogen (AN), total reactive phosphorus (TRP), and soluble reactive phosphorus (SRP) from landfill leachate. Four reactors were used, namely RI (granite without vegetation), RII, and RIII which consists of granite and gravel with different sizes respectively and RIV contained sand and 67.5 L of charcoal. RII, RIII, and RIV were planted with cattails. The leachate obtained from the site of Pulau Burung Sanitary Landfill, Penang was introduced into RI at flow rate of 18 mL/min which was continuous to flow through another three reactors. The leachate was analyzed for AN, TRP, and SRP before and after the treatment in each reactor by standard methods. The overall average removal efficiency of AN, TRP, and SRP were 86.7, 86.2, and 90.0%, respectively. Reactor IV performed the best for removal of all the parameter studies.

Influences and Properties of Various Activated Carbon and Carbon Black Filled in Epoxy Composite

This paper reports the investigation on the flexural properties of activated carbon filled epoxy composites. The Comparison of the properties between different sources of activated carbon, are illustrated. It has to be disposed safely or used for recovery of valuable materials as agricultural wastes like bamboo stem, coconut shell and Empty Fruit Bunch (EFB). Therefore these wastes have been explored for the preparation of activated carbon and carbon black employing chemical activation by H3PO4 and physical activation, respectively. The effect of pyrolysis and chemical activation on the activated carbon filled epoxy composite properties including mechanical (flexural strength), 5 % percent of carbon filler and Scan Electron Microscope SEM micrograph were analyzed. These determined the interaction between activated carbon filled epoxy composite. This study is to compare the effect of the nature of the different types of fillers on the epoxy composites material properties. The microstructures of the farcture surface was examined using a scanning electron microscope (SEM) were formed during the different preparation stages.

Removal of ammoniacal nitrogen and oxidised nitrogen in landfill leachate using vegetated constructed wetland with continuous flow through different filter media

Performance of the vegetated horizontal subsurface-flow constructed wetland was evaluated for the removal of ammoniacal nitrogen (AN), total oxidized nitrogen (TNOx-N) and nitrite nitrogen (NO2-N) from landfill leachate. Four reactors were used, RI (granite without vegetation), RII and RIII which consists of granite and gravel with different sizes respectively and RIV contained sand and 67.5 L of charcoal. RII, RIII and RIV were planted with cattails. The leachate obtained from the site of Pulau Burung Sanitary Landfill, Penang was introduced into RI at flow rate of 18 mL/min which was continuous to flow through another three reactors. The leachate was analyzed for AN, TNOx-N and NO2-N before and after the treatment in each reactor by standard methods. The overall average removal efficiency of AN and NO2-N were 86.7 % and 19.5 % respectively but negative effect to TNOx-N which was −16.3 %. The negative result shows the increased in the concentration of TNOx-N. Reactor IV performed the best for removal of AN and NO2-N which is 60.9 % and 66.2 % respectively, whereas, RII had highest performance for removal of TNOx-N of 24.1 %.

THE EFFICIENCY OF CHARCOAL AS A FILTER MEDIA IN NON-VEGETATION CONSTRUCTED WETLAND SUBSURFACE-FLOW SYSTEM (SF) FOR AMMONIA, CHEMICAL OXYGEN DEMAND, AND IRON TREATMENT OF LANDFILL LEACHATES

The thermal Charcoal for domestic used was crushed into powder and mixed with gravel. Four reactors of different proportion and size of charcoal and gravel were set up without vegetation. Sample of landfill leachates obtained from site of Pulau Burung Landfill, Penang, was introduced into the reactors. Ammonia, chemical oxygen demand (COD), and iron of inlet and outlet from four reactors were analyzed by standard methods. Result shows that overall performance of removing ammonia and iron were much better than COD.