N.A. Nik Norulaini

Clinical solid waste management practices and its impact on human health and environment--A review.

The management of clinical solid waste (CSW) continues to be a major challenge, particularly, in most healthcare facilities of the developing world. Poor conduct and inappropriate disposal methods exercised during handling and disposal of CSW is increasing significant health hazards and environmental pollution due to the infectious nature of the waste. This article summarises a literature review into existing CSW management practices in the healthcare centers. The information gathered in this paper has been derived from the desk study of open literature survey. Numerous researches have been conducted on the management of CSW. Although, significant steps have been taken on matters related to safe handling and disposal of the clinical waste, but improper management practice is evident from the point of initial collection to the final disposal. In most cases, the main reasons of the mismanagement of CSW are the lack of appropriate legislation, lack of specialized clinical staffs, lack of awareness and effective control. Furthermore, most of the healthcare centers of the developing world have faced financial difficulties and therefore looking for cost effective disposal methods of clinical waste. This paper emphasizes to continue the recycle-reuse program of CSW materials after sterilization by using supercritical fluid carbon dioxide (SF-CO2) sterilization technology at the point of initial collection. Emphasis is on the priority to inactivate the infectious micro-organisms in CSW. In that case, waste would not pose any threat to healthcare workers. The recycling-reuse program would be carried out successfully with the non-specialized clinical staffs. Therefore, the adoption of SF-CO2 sterilization technology in management of clinical solid waste can reduce exposure to infectious waste, decrease labor, lower costs, and yield better compliance with regulatory. Thus healthcare facilities can both save money and provide a safe environment for patients, healthcare staffs and clinical staffs.

Functionalization of magnetic chitosan with graphene oxide for removal of cationic and anionic dyes from aqueous solution.

In the present study, we decorated chitosan (©) with Fe3O4 nanoparticles followed by cross-linking with GO to prepare Fe3O4 supported chitosan-graphene oxide composite (Fe3O4©-GO). Different properties of synthesized material were investigated by SEM, XRD, FTIR, TGA and EDX. Batch adsorption experiments were performed to remove toxic cationic and anionic dyes from industrial wastewater. To maximize removal efficiency of composite material, effect of pH (4-12), time (0-80min), Fe3O4©-GO dosage (2-10mg), initial dye concentration (2-30μgmL̄ (1)) and temperature (303, 313, and 323K) were studied. The uptake of dyes presented relatively fast adsorption kinetics with pseudo-second-order equation as the best fitting model. To understand the interaction of dye with adsorbent, Langmuir and Freundlich isotherm were applied. Thermodynamic studies were conducted to calculate the changes in free energy (ΔG(0)), enthalpy (ΔH(0)) and entropy (ΔS(0)). In view of practical application, the influence of ionic strength, recycling as well as investigations based on percent recoveries from spiked real water samples were also taken into account.

Hard cocoa butter replacers from mango seed fat and palm stearin

The blending effects of mango seed fat (MSF), extracted using supercritical fluid, and palm stearin (PS) to formulate hard cocoa butter replacers (CBRs), were investigated. The triglycerides (TG), thermal properties and solid fat content (SFC) of the formulated blends were determined using different chromatographic and thermal techniques. All the blends had three main TGs; namely, 1,3-dipalmitoyl-2-oleoylglycerol (POP) (8.6-17.7%), 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol (POS) (12.6-19.6%), and 1,3-distearoyl-2-oleoyl-glycerol (SOS) (37.2-31.4%), with SOS being the major component. The melting peak temperatures gradually increased and shifted towards higher temperatures with PS. The crystallization onset temperatures increased, while the offset decreased with PS. The SFC did not drop to 0% at 37.5°C, which was shifted to 0% at and above 40°C for some blends. The studies revealed that CBRs could be prepared by blending MSF and PS, and they could be utilised by chocolate manufacturers in tropical countries.

Risk Assessment of Metal Contamination in Soil and Groundwater in Asia: A Review of Recent Trends as well as Existing Environmental Laws and Regulations

Abstract Asia is experiencing a more rapid economic growth compared to any other regions. The contamination of soil and groundwater with metals can mainly be attributed to human activities; therefore, risk assessments to characterize the nature and magnitude of risks to humans and ecological receptors from contaminants are important. Risk assessments are often iterative processes, which involve identification and filling data gap. Experimental samplings, geostatistical and multivariate statistical methods as well as multimedia risk assessment modeling are the three major methodologies used in the assessment of metal contamination in soil and groundwater. This review highlights a number of measurements for improving risk calculation methods and expounds scientific approaches that involve the identification of the major source of contamination, exposure pathways and bioavailability of metals. In general, risk assessments of metals in soil and groundwater worldwide are mainly focused on the levels of contamination, identification of exposure pathways, and prediction of the probability of contamination. To date, very limited studies have reported the development of relevant environmental laws and policies in the regulation of soil and groundwater contamination in Asia. The development, variations and limitations in the regulations of soil and groundwater contamination among developed countries may provide helpful guidance for the developing countries in Asia.

STUDY OF RHEOLOGICAL PROFILE ANALYSIS RELATED TO TEXTURE FOR MIXTURES OF SAGO-WHEAT GEL

ABSTRACT Starch gels containing mixtures of sago+wheat of different protein content at different levels of sago substitutes were prepared as follows: sago+high protein wheat (HPW), sago+medium protein wheat (MPW) and sago+slow protein wheat (LPW). The rheological profile analysis (RPA) related to texture was carried out for sago-wheat mixtures at different percentages of sago substitutions of 10,15, 20, 30, 40 and 50% of sago. The hardnes for control sago gel increased gradually with the increment of concentration of gel and the value tends to be higher than control wheat gels at 20% concentration. The gel becomes too hard for control sago when the concentration exceeded 30%. In RPA study, gel did not exhibit any significant differences in hardness, cohesiveness and adhesiveness with sago portion in HPW, MPW and LPW flour mixtures at different percentages. In retrogradation study, the hardness was found to decrease in comparison to the values for fresh samples.

Stress Relaxation Test for Sago–Wheat Mixtures Gel

Abstract Viscoelastic properties of sago starch and wheat flour, and sago–wheat flour mixtures at different percentages of sago substitution were studied. Swelling characteristics of high protein wheat (HPW), medium protein wheat (MPW) and low protein wheat (LPW) flour, and sago starch were determined at various temperatures (55°–95°C). Both sago and wheat starch granules started to swell from 55°C and reached a maximum at 75°C. Flour gels containing mixture of sago + wheat of different protein content at different levels of sago substitutions were prepared as follows: sago + HPW, sago + MPW, and sago + LPW flours. Stress relaxation (SR) test for control sago and control wheat flours and sago–wheat mixtures were carried out at different percentages of sago substitutions from 10 to 50%. For control flours the value of asymptotic residue modulus, E A for HPW and MPW was rapidly increased with the increase of the gel concentration up to 30% but it decreased at 20%. For LPW it decreased at 20 and 25%, and increased at 30%. At higher percentage of sago in the mixture, E A value does not show uniform consistence pattern. It was found to increase rapidly at 50% of sago portion for all types of wheat flour.