Waste lactic acid

There has been recent interest in lactic acid polymers and copolymers. These materials are environmentally attractive in that renewal and cheap source materials such as potato waste and cheese whey may be used. Such materials have been used for some time in degradable and resorbable surgical sutures but recent efforts have been directed at food packaging applications. There is... 

Pedaling at the rate shown to be most efficient uses up blood glucose the fastest. This leaves the rider more susceptible to that sudden loss of energy known as the bonk, and it also tends to leave more lactic acid and other waste products in the muscles, increasing discomfort and extending recoveiy time. 

In metabolic terms there are three dearly distinguishable types of compound to deal with. Firstly, compounds which are obviously waste products - end products of one or more pathways which would normally be excreted from the cell (for example lactic acid). Secondly, compounds which are end products of pathways but which are not waste products and whose synthesis is normally very carefully controlled (for example amino adds). Thirdly, compounds which are intermediates of pathways and hence not normally considered as end products or wastes at all (for example ritric add). 

The solution to this problem has been to isolate the lactide and to polymerize this directly using a tin(ii) 2-(ethyl)hexanoate catalyst at temperatures between 140 and 160 °C. By controlling the amounts of water and lactic acid in the polymerization reactor the molecular weight of the polymer can be controlled. Since lactic acid exists as d and L-optical isomers, three lactides are produced, d, l and meso (Scheme 6.11). The properties of the final polymer do not depend simply on the molecular weight but vary significantly with the optical ratios of the lactides used. In order to get specific polymers for medical use the crude lactide mix is extensively recrystallized, to remove the meso isomer leaving the required D, L mix. This recrystallization process results in considerable waste, with only a small fraction of the lactide produced being used in the final polymerization step. Hence PLA has been too costly to use as a commodity polymer. 

Effect of Na-alginate and bead diameter on lactic acid production from pineapple waste using immobilized Lactobacillus delbrueckii ATCC 9646... 

Lactic acid bacteria were immobilized in Ca-alginate beads prepared from different concentration of Na-alginate (1.0%, 2.0%, 4.0%, 6.0% and 8.0% w/v) and their fermentation efficiencies were investigated in liquid pineapple waste containing 31.3 gL of glucose... 

The principal function of the circulatory system is to supply oxygen and vital metabolic substrates to cells throughout the body, as well as removal of metabolic waste products. Circulatory shock is a life-threatening condition whereby this principal function is compromised. When circulatory shock is caused by a severe loss of blood volume or body water it is called hypovolemic shock, the focus of this chapter. Regardless of etiology, the most distinctive manifestations of hypovolemic shock are arterial hypotension and metabolic acidosis. Metabolic acidosis is a consequence of an accumulation of lactic acid resulting from tissue hypoxia and anaerobic... 

Sometimes, scientists just get it wrong. That certainly seems to be the case with lactic acid and exercise. For more than a century, lactic acid was seen as the "bad boy" of exercise. People believed that intense, unaccustomed exercise made lactic acid build up in muscles and made them burn and eventually tire and give out. Some athletes even went as far as to have the lactic acid level in their blood tested. Everyone considered lactic acid a toxic waste product. As it turns out, that is not true. 

The circulatory system carries out many important functions that contribute to homeostasis. It obtains oxygen from the lungs nutrients from the gastrointestinal tract and hormones from the endocrine glands and it delivers these substances to the tissues that need them. Furthermore, it removes metabolic waste products, such as carbon dioxide, lactic acid, and urea, from the tissues. Finally, it contributes to the actions of the immune system by transporting antibodies and leukocytes to areas of infection. Overall, the circulatory system plays a vital role in maintenance of optimal conditions for cell and tissue function. 

The additional interesting part of Fig. 1.12 is the biorefinery, which uses biomass and waste, produces waste products C02 and ash, both to be recycled for the production of biofuels, heat and electricity and biomaterials. These biomaterials are highly oxygen functionalized for products such as alcohols, carboxylic acids and esters. A currently produced bioplastic is poly(lactic acid). A main cost factor is separation. 

Early routes to AA were complex and expensive. In 1927 the ethylene chlorohydrin process was introduced, but it was also still expensive, and not much commercial interest was stimulated in AA. In 1940 a process came literally right off the farm—pyrolysis of lactic acid, a waste product of the dairy industry found in sour milk. 

Figure 3.4 — (A) FIA manifold for the determination of L-lactic acid in milk products P peristaltic pump C carrier S sample V injection valve AD air damper FTC flow-through cell W waste BFB bifurcated fibre LS light source PMT photomultiplier tube R recorder. (B) Cross-section of lactic acid optrode. (Reproduced from [39] with permission of VCH Publishers).

Jin, B., Huang, L. R, Lant, R. (2003). Rhizopus arrhizus - a producer for simultaneous saccharification and fermentation of starch waste materials to L(+)-lactic acid. Biotechnol. Lett., 25, 1983-1987. 

Jin, B., Yin, R, Ma, Y, Zhao, L. (2005). Rroduction of lactic acid and fungal biomass by Rhizopus fungi from food processing waste streams. J. Ind. Microbiol. Biotechnol., 32, 678-686. 

Zhang, Z. Y, Jin, B., Kelly, J. M. (2007). Production of lactic acid and byproducts from waste potato starch by Rhizopus arrhizus role of nitrogen sources. World J. Microbiol. BiotechnoL, 23,229-236. 

Waste Acid Recovery via Purification Lactic Acid Production Recovery of Na-CO, from Trona... 

The human body is about 70 percent water. Water is involved in nearly every body process, including digestion, absorption, circulation, and excretion. Blood is about 90 percent water it transports nutrients to the cells and washes out lactic acid and other waste products. 

Separation of citric acid from fermentation broth Separation of lactic acid from fermentation broth Production of acetone, butanol, and ethanol (ABE) from potato wastes Separation of long-chain unsaturated fatty acids... 

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