Major Source Of Waste Research Articles

Acetone–Heptane as a Solvent System for Combining Chromatography on Silica Gel with Solvent Recycling

Solvents used in chromatographic purification of intermediates and products are a major source of waste and expense in synthetic research and synthetic processes. The ethyl acetate–hexane mixtures most commonly used for flash chromatography on silica gel are not readily separable by distillation due to their similar boiling points and azeotrope formation. Potential solvents for chromatography that are more amenable to separation and recovery by distillation were thus explored. Acetone–heptane mixtures were found to be convenient and sufficiently separable for routine use and recovery for organic separations. The greater eluotropic strength and especially the transparent short-wavelength UV window of acetone provide additional advantages over the commonly used ethyl acetate. The recycling of solvents from chromatography can greatly reduce the volume of waste generated by synthetic laboratories while also reducing operating costs.

Reduction in the environmental impact of waste discharged by fish farms through feed and feeding

AbstractThe discharge of waste from aquaculture operations can lead to eutrophication and destruction of natural ecosystem in receiving water body. A controlled waste production strategy is necessary to maintain sustainable aquaculture growth into the future. As feed is the major source of waste in aquaculture, the management of aquaculture waste should be approached through diet formulation or feeding strategies. Highly digestible diets have been introduced as a solution to reduce solid waste excretion. Further reductions in solid waste can be achieved through careful selection of feed ingredients and feed processing to improve nutrient availability. An increase in faeces consistency by diet manipulation can improve solid removal efficiency. This condition can reduce the proportion of solids in discharged water in the effluent and also improve farm water quality. A reduction in dissolved nitrogen waste can be achieved by ensuring a balance between protein and energy causing fish to use non‐protein sources as energy. Phosphorous waste can be decreased through careful ingredient selection and proper processing to improve digestibility. A proper feed ration and feeding method for each species should be adopted because feed waste constitutes a large part of waste production.

Effective scheduling of a large-scale paint production system

Due to the large variety of options offered to customers, batch production schemes are highly accepted in the paint industry implying that scheduling plays an important role in optimal allocation of plant resources among multiple products. Since in a batch process, the cleaning of equipment units is the major source of waste, waste minimization is also to be taken into account in determining the schedule. The formerly developed S-graph framework [Sanmartí E, Holczinger T, Puigjaner L, Friedler F. Combinatorial framework for effective scheduling of multipurpose batch plants. AIChE Journal 2002;48(11):2557–70.] proved to be highly effective in solving multipurpose batch scheduling; it has now been specialized for solving paint production scheduling problems including waste minimization. The efficacy of the new approach is illustrated with the solution of large-scale paint production scheduling problems.

Indium Tribromide/[bmim]PF6: A Novel and Recyclable Catalytic System for the Deprotection of 1,1‐Diacetates.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Auf dem Weg zu einer ökologischen Stoffwirtschaft Teil I: Die Rolle des Recyclings

In the last few years the environmental policy in Germany and other European countries has focused its attention more and more on waste and product policy. Used products are a major source of waste. The most recent action taken in Germany is the waste framework law (Kreislaufwirtschafts- und Abfallgesetz) which has passed the German Parliament last year and will become fully enforced by 1996. There are several ways to reduce waste, and within an ecological management of materials flow, all of them must be pursued. Firstly waste avoidance by applying clean technologies in industrial production, the development of easily recycable products, and cutting down on packaging. Secondly, use of new design and usage concepts for products to extend the time the products are used by the consumers. And thirdly, recycling of used products with recovery of raw materials for repeated use in production. The opportunities for recycling were demonstrated recently by an initiative of the former German Environment Minister, Klaus Töpfer. He launched the draft of Takeback Decree for electronic waste. In spite of the fact that this decree has not yet come into force, the initiative pushed the research and development of recycling technologies for electrical and electronic components enormously. A market of at least 3 billion DM for new services would arise with this decree in Germany. Recycling and environmental protection as a whole have become major factors within the national economies. Germany's exports of environmentally benign goods amount to 35 billion DM yearly. Between 1975 and 1991, 420 billion DM were spent on national efforts to protect the environment. On the other hand, not more than 2 per cent of the production costs in German industry are caused by environmental protection due to national policy in this field. There is no doubt that a cautious greening of national economies not only helps to safeguard the fundamentals of life for future generations, it should also be understood as an economic opportunity.

A Review of Waste Management from the Foodservice Perspective

Waste management is a growing concern for the foodservice industry. The consumers' perception is that much of the problem is due to the foodservice industry's use of paper and plastic products. Landfilling has been the most common way to deal with such waste, but landfills are becoming filled and are not being replaced. Other alternatives have been suggested, such as source reduction, reuse of materials, recycling. and waste-to-energy incineration. Source reduction, reuse of materials, and recycling are more practical for foodservices and have been called the three R's of waste management. The major source of waste in foodservices is paper. The second major source of waste is plastic. The most common suggestion to reduce waste has been to eliminate the use of disposables, but more than two-thirds of all foodservices currently use disposables and would find it difficult to eliminate their use completely. Most likely the solution to the waste management problem will be an integrated waste management approach that uses several alternatives. Foodservices need to carefully consider the alternatives because waste management is a sanitation concern with environmental, legal, and financial implications.