Removal and Recovery are two keywords for effective and economical process. In the process of guiding the engineering students in their projects, the author has worked towards removal of some pollutants from wastewater by using low cost adsorbents. Also use of some waste materials was investigated with the help of graduate students. This book is an effort to publish some valuable work in book format. Galore Publication has very long standing working relation with author. First chapter is introduction to the book topic with authors’ aims and objectives. Second chapter carries in detail literature survery of the investigations on the related topics in recent past. Third chapter discusses use of low cost adsorbent for organic matter removal. Organic matter removal from waste water is principle purpose behind treatment operations. Organic matter, if present in wastewater, reduces dissolved oxygen and forces the waster contaminants to undergo anaerobic decomposition. The treatment for organic matter removal can be carried out by various physical, chemical and biological methods, in combination or separately. The most important methods in biological and physic-chemical category are activated sludge process and adsorption. The adsorption with low cost adsorbents is feasible and economical method. In current research, three adsorbents namely, commercial activated carbon(AC), leaf litter derived adsorbent(LLDA)and wood charcoal derived adsorbent(WCDA) are used for studying their ability to removal organic matter measured as chemical oxygen demand(COD) and biological oxygen demand( BOD) from wastewater. The studies were carried out for parameters such as contact time, adsorbent dose and pH. With adsorbent dose and contact time, the adsorption increased for initial increase and then remained constant. The pH value of 6 provided best results for all three adsorbents.
Fifth chapter deals with acetic acid adsorption on rice husk adsorbent. Low cost treatment of the wastewater is the need of the hour. Wastewater treatment can be carried out by various chemical, physical and biological methods. Water treatment technologies in the developing world typically focus on removing various types of impurities from waste water such as suspended solids, microbial pathogens, inorganic and organic components. Adsorption by using low cost adsorption is widely studies treatment method. Activated carbon has the capacity to remove these problematic chemicals from waste water. A simple, inexpensive and effective activated carbon production process use local agriculture waste. Acetic acid is present in the effluent from petroleum, fine chemical, pharmaceutical and textile industry. Sixth chapter deals with heavy metal removal. Heavy metal removal from wastewater can be carried out by various chemical, physical and biological methods. The presence of heavy metal can affect man and environment adversely. The heavy metal treatment by using adsorption can be carried out by using low cost adsorbents. In the research, the bagasse and groundnut shells are used as low cost starting materials for adsorbent preparation. Batch studies are carried out for studying removal of iron and chromium from synthetic wastewater for bagasse adsorbent (BA) and groundnut shell adsorbent(GSA). It was observed that optimum adsorbent dosage of 2.5 g/100 ml and 1.5 g/100 ml were sufficient for adsorption of almost 90% of the initial metal concentration for iron and chromium respectively. The amount of the metal removed at optimum pH increased with increase in adsorbent dosage. The optimum pH for the removal of chromium (VI) and iron (III) was in the range of 2 to 4 for both, BA and GSA. Seventh chapter deals with packed bed heavy metal treatment. Packed and fluidized beds can be used for removal of heavy metals from wastewater. In the current investigation, packed bed, 45 mm in diameter is used for adsorption of iron and chromium from synthetic effluent. The break through time was observed to be 40 to 45 minutes for removal of these heavy metals. Ideal adsorption time was 88 to 90 minutes.
Eighth chapter discusses the essential oil extraction from lemon grass. Distillation based recovery processes such as steam and vacuum distillation are preferred for the extraction of essential oils from plant materials. Other methods include solvent extraction, expression or enfleurage. In the present work, three methods are used for oil extraction namely solvent extraction, hydro distillation and enfleurage. By using solvent extraction, 2.9 grams of essential oil per 140 grams of dry lemongrass sample. This gives about 2.07% yield of essential oil. By enfleurage method, 2.74 grams of essential oil per 140 grams of dry lemongrass sample was obtained. This amounts to 1.957% oil yield. 1.325 grams oil per 140 grams of lemongrass sample was obtained by hydro distillation process, i.e. 0.946% yield of oil. 9th chapter deals with ethanol synthesis from maize. Ethanol synthesis by using raw feed stock is being widely explored. Production of ethanol from waste food grains, fruit wastes, vegetable wastes, and sugar industry byproducts is being carried out on experimental, pilot plant and in some cases industrial scale. Ethanol has huge potential as fuel and is main compound in alcoholic beverages. It is most often used as a motor fuel, mainly as a bio fuel additive for gasoline. Bio ethanol can be made from very common crops such as sugar cane, potato, manioc and corn. In current research sugar molasses is used for ethanol synthesis. Ethanol production from sugarcane molasses can serve as value addition to the sugar factory or the distillery. It minimizes the dumping problem of the sugar cane waste. The last chapter explores the use of sugar cane juice molasses as feed stock for ethanol production.