Husnul Azan Tajarudin

Challenges, Future Outlook, and Opportunities

Nocturnal cooling technology has the characteristics of cleanness, pollution-free, energy savings and great development potential. Throughout the literature, it can be seen that the nocturnal cooling technology has become a research hotspot since 1960s. Early researches were mainly concentrated in optimising the structure of radiation cooling systems and improving the radiation cooling capacity. The last recent years have witnessed exceptional achievements in nocturnal cooling approach, with a huge body of literature consisting of more excellent performance studies related to hybrid systems; improvement and advancement on the technological aspects of existing and previous works as well as design and applications of the system within building envelope. Nocturnal cooling systems are directly affected by the atmospheric conditions. The performance studies of these systems are widely distributed and various climatic conditions and regions. However, most of the studies are conducted under laboratory scale and not many studies focus on the performance of the systems on real or existing buildings towards commercialisation. In this chapter, challenges, future outlook and opportunities are highlighted.

Renewable and Sustainable Materials for Various Green Technology Applications

In the recent years, the environmental issues in terms of pollution and energy consumption foment an increasing interest to focus on green technology. Pertaining this, this chapter is intended to recapitulate a review on renewable and sustainable materials produced either from single unit process or integrated approach through chemical or biological methods or combination of these methods for various green technology applications. This includes the recent development and potential of these materials for energy, building and environmental applications.

Renewable and Sustainable Materials from Chemical Approach

Despite the negative connotations associated with the word ‘chemistry’, in reality many chemical principles and processes are used to develop renewable and sustainable materials. In order to do so, a wide selection of organic materials is readily available. Application of these ranges from renewable energy to advanced materials. In the near future, it is expected that chemistry for sustainability would become the new mantra in the world of ever-limited resources. This chapter presents a detailed discussion on chemistry and chemical approach of these materials. It is hoped that in the near future, chemistry for sustainability would become the new mantra in the world of ever-limited resources.

Microbial Fuel Cell (MFC) Development from Anaerobic Digestion System

Alternative energy technologies become more attractive as the price of energy from fossil fuels becomes more expensive and the environmental concerns from their use amount. The microbial fuel cell (MFC) is an innovative renewable energy technology that also serves to treat wastewater through the bacteria-driven oxidation of organic substrates. The electrons from oxidizing organic substrates are shuttled from the anode to the cathode, producing a current. The only byproducts of this process are respiratory waste in the form of water and carbon dioxide. MFCs operated using mixed cultures currently achieve substantially greater power densities than those with pure cultures. Community analysis of the microorganism that exists in MFCs has so far revealed a great diversity in composition. MFCs are being constructed using a variety of materials and diversity of configurations. These systems are operated under a range of conditions that include differences in pH, electrode distance, moisture content and temperature. The MFCs are believed to be a promising technology which could be implemented as wastewater treatment, recover energy production method from biomass, environment sensor and product recovery method. There are several aspects need to be considered in order to have an efficient upscale MFC.

Removal of total suspended solid by natural coagulant derived from cassava peel waste

The present study was aimed to investigate the performance of starch derived from cassava peel waste as primary coagulant and coagulant aid. Comparable study was also conducted using commercially used aluminium sulfate (alum) as primary coagulant. A series of Jar tests were performed using raw water from Sembrong Barat water treatment plant. It was observed that coagulation test using cassava peel starch (CPS) alone had unappreciable removing ability. However, it was found that combination of alum-CPS successfully achieve up to 90.48% of total suspended solid (TSS) removal under optimized working conditions (pH 9, 7.5mg/L : 100 mg/L of alum : CPS dosage, rapid mixing of 200 rpm for 1 minute; 100 rpm for 2 minutes, slow mixing of 25 rpm for 30 minutes and 30 minutes settling time). This remarks the reduction in alum dosage up to 50% compared to coagulation test using alum alone. Therefore this finding suggesting that CPS can be considered as potential source of sustainable and effective coagulant aid for water treatment especially in developing countries.

Utilization of Metroxylan sagu Pith Waste as Biodegradable Filler for Natural Rubber (NR) Latex Films

Utilization of agricultural waste toward sustainability has increase a value-added product from a natural resources nowadays. Metroxylan sagu pith waste (MSPW) is a residue from starch extraction process. This research aim to investigate the potential of MSPW as a biodegradable fillers to replace sago starch in Natural Rubber (NR) latex films. The MSPW flour is characterized and compared with sago starch. Results shown MSPW has almost similar properties with sago starch with high content of starch (60%) and moisture (80%). Spectra of MSPW and Sago Starch (SS) are very closed to one another due to the similarity of functional groups. SS has granular shape while MSPW has irregular shape under SEM analysis. The addition of MSPW shown slightly lower tensile properties and tear strength as compared to SS but still within the acceptable value. Thus, MSPW has high potiential to replace SS as biodegradable fillers in NR latex films.

Optimization of HCO3- Production Reflect to CaСo3 Precipitation for Self-Healing by Bacillus sphaericus

Bacteria are able to perform metabolic activities which promote the precipitation of calcium carbonate in the form of calcite. Bacillus Sphaericus was used in this study, which is an ureolytic bacteria that can precipitate calcium carbonate in its environment by the decomposition of urea into ammonium and carbonate. The bacterial degradation of urea basically increases the pH and promotes the microbial deposition of carbonate as calcium carbonate. In this research, the capability of bacteria to influence the formation of HCO3- by the production of urease enzyme was investigated. Results of growth rate and characteristics of bacteria showed that 20g/L of urea concentration was able to provide a good environment for bacteria with sufficient amount of nutrient to survive. The formation of HCO3- was parallel with NH3 production where the formation of HCO3- increased slowly as the ammonia production decreased. Urea degradation with suitable concentration of urea by 20g/L may form high HCO3- compared to 25g/L urea concentration. The results from the experimental works indicated that the optimal urea concentration was 20g/L.