HISTORICAL DEVELOPMENT IN FOOD CONFECTIONARY WASTE WATER TREATMENT PROCESS

For centuries, managing wastewater was a problem with no discernable solution. Dealing with waste-water  usually meant  moving it  somewhere  else,  dumping into  rivers  and  streams with Virtually no treatment, or other “out-of-sight-out-of-mind ”solutions ,which in many cases had negative residual effects on people’s health, public infrastructure or the environment. Even as recently as the 1960s and ‘70s, most wastewater was simply drained into lagoons or large ponds. Of course, while this may have provided a simple partial treatment solution to the problem of wastewater, this process also had significant negative impacts on local environments and ecosystems. Entire bodies of water became unusable and the land immediately adjacent could experience odor and other aesthetic issues.

The process of suspended biological growth was born on Friday, the 3rdof April 1914 when two English researchers, Edward Ardern and William Lockett, submitted a report to the Industrial Chemicals Society in London on their work under the title "Experiments on sewer water oxidation without the use of filters ".They observed that if sewage is exposed to air for a sufficient period of time, the organic contents are gradually oxidized with formation of deposits called “humus” and final production of nitrate from ammonium salts and nitrogenous organic matter. They conducted their experiments in 80 oz (2365 ml) and aeration was done by ordinary filter pumps. Their experiments concluded that it was possible to completely oxidize a fresh sample of crude sewage within 24 hrs. The deposited solids resulting from the complete oxidation of sewage was designated as “activated sludge”.

 The confectionery industry is one of the most widespread and important industries around the world. It manufactures sweets including chocolate confectionery and gum products which are characterized by significant amounts of sugar and sugar substitutes, cocoa, fats, emulsifiers, and flavors used in the production process (Edwards 2000; El-kalyoubi et al. 2011; García-Morales et al. 2018).

The confectionery industry, which manufactures different sweets including chocolate, chewing gum and gumdrops, is one of the most widespread and important industries worldwide. Sugar, water, and ingredients such as milk, flavouring materials, nuts, and cereals are the most important raw materials for confectionary production.

 Confectionery plants produce large amounts of waste- water characterized by high concentrations of readily biodegradable organic materials and low nutrient concentration. The discharge of confectionery wastewater into surface waters results in rapid dissolved oxygen depletion and aquatic ecosystem deterioration because of its high readily biodegradable organic matter content .Therefore, appropriate treatment technologies should be used.

 Suspended growth process is a secondary treatment process to remove the soluble and colloidal organic matter which remains after primary treatment. It is the wastewater treatment processes in which the microorganisms and bacteria treating the wastes are suspended in the waste water being treated. The wastes flow around and through the suspended growths. The various modes of the activated sludge process make use of suspended growth reactors. These reactors can be used for BOD (biochemical oxygen demand) removal, nitrification, and denitrification. 

Suspended growth processes maintain adequate biological mass in suspension within the liquid in the reactor, by employing either natural or mechanical mixing. The organic matter and other constituents of the wastewater are converted into gases and cell tissues.

 The suspended growth systems comprise aggregates of microorganisms generally growing as flocs in intimate contact with the wastewater being treated. The aggregates or flocs are responsible for the removal of polluting material and comprise a wide range of microbial species. The suspended growth treatment systems permit the exploitation of the full range of microbial metabolic capabilities. Waste stabilization ponds, aerated lagoons, and activated sludge are examples of the treatment options that rely on the actions of the microorganisms growing in a suspension of the waste water under treatment. A suspended growth waste water treatment process can be carried out in a biological reactor, which encourages the growth of specific types of microorganisms that are able to undertake the reactions necessary to achieve purification of the influent wastewater. Its successful design requires the provision of a reactor(or series of reactors)of sufficient capacity to retain the wastewater long enough for the microorganisms to undertake the biological inter conversions, facilities to ensure that the microorganisms are retained in the reactor long enough to grow and divide, and the correct redox environment to achieve the required biological reactions.

Anshuman Santra, 

Assistant Professor, Institute of Science & Technology.

Civil Engineering Department.

GOPSAI AVINANDAN SANGHA

Editor