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.

Mango (Mangifera indica L.) by-products and their valuable components: a review.

The large amount of waste produced by the food industries causes serious environmental problems and also results in economic losses if not utilized effectively. Different research reports have revealed that food industry by-products can be good sources of potentially valuable bioactive compounds. As such, the mango juice industry uses only the edible portions of the mangoes, and a considerable amount of peels and seeds are discarded as industrial waste. These mango by-products come from the tropical or subtropical fruit processing industries. Mango by-products, especially seeds and peels, are considered to be cheap sources of valuable food and nutraceutical ingredients. The main uses of natural food ingredients derived from mango by-products are presented and discussed, and the mainstream sectors of application for these by-products, such as in the food, pharmaceutical, nutraceutical and cosmetic industries, are highlighted.

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.

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.

Increasing the fertilizer value of palm oil mill sludge: bioaugmentation in nitrification.

Malaysia is essentially an agricultural country and her major polluting effluents have been from agro-based industries of which palm oil and rubber industries together contribute about 80% of the industrial pollution. Palm oil sludge, commonly referred to, as palm oil mill effluent (POME) is brown slurry composed of 4-5% solids, mainly organic, 0.5-1% residual oil, and about 95% water. The effluent also contains high concentrations of organic nitrogen. The technique for the treatment of POME is basically biological, consisting of pond systems, where the organic nitrogen is converted to ammonia, which is subsequently transformed to nitrate, in a process called nitrification. A 15-month monitoring program of a pond system (combined anaerobic, facultative, and aerobic ponds in series) confirmed studies by other authors and POME operators that nitrification in a pond system demands relatively long hydraulic retention time (HRT), which is not easily achieved, due to high production capacity of most factories. Bioaugmentation of POME with mixed culture of nitrifiers (ammonia and nitrite oxidizers) has been identified as an effective tool not only for enhancing nitrification of POME but also for improving quality of POME as source of liquid nitrogen fertilizer for use in the agricultural sector, especially in oil palm plantations. Nitrate is readily absorbable by most plants, although some plants are able to absorb nitrogen in the form of ammoniun. In this study, up to 60% reduction in HRT (or up to 20% reduction in potential land requirement) was achieved when bioaugmentation of POME was carried out with the aim of achieving full nitrification.