4 Main Applications of Refractory Pollutants

The following points highlight the four main applications of refractory pollutants. The applications are: 1. Cyanide Removal 2. Distillery Spent Wash 3. Radionuclides 4. Heavy Metals.

Refractory Pollutants: Application # 1.

Cyanide Removal:

Effluents containing cyanide from various in­dustries must be treated before discharging into the environment. The conventional physicochemical processes for removal of cya­nides from waste water proved to present ad­vantages, but also disadvantages burdened with high reagent and liability costs.

Bio-removal was seen as an environment friendly alternative treatment process able to achieve high degradation efficiency at low costs.In biological treatment of cyanide, bac­teria convert free and metal-complex cyanides to bicarbonate and ammonia.

The free metals are further adsorbed or precipitated from solution.The microorganisms responsible for cyanide degradation could be bacteria or fungi, which use cyanide as a source of nitrogen and carbon.

Refractory Pollutants: Application # 2.

Distillery Spent Wash:

This is a liquid waste generated during alco­hol production,which confers unpleasant odours for waste water, posing a serious threat to water quality. Disposal of distillery spent wash on land is moreover hazardous to the veg­etation, since it reduces soil alkalinity and manganese availability, thus inhibiting seed regeneration.

A number of clean-up technolo­gies are used to process this effluent efficiently and economically and novel bioremediation ap­proaches for treatment of distillery spent wash are being worked out.

Refractory Pollutants: Application # 3.

Radionuclides:

Radionuclide like uranium or thorium are of particular concern in environmental impact and remediation researches due to their high toxicity and long half-lives, thus they are con­sidered severe ecological and public health hazards. Biosorptive accumulation of uranium and other radionuclides is of great interest for the development of microbe based bioremedia­tion strategies.

Refractory Pollutants: Application # 4.

Heavy Metals:

The application of biotechnological processes for the effective removal of heavy metals from contaminated waste waters has emerged as an alternative to conventional remediation tech­niques. Heavy metal pollution is usually gene­rated from electroplating, plastics manufactur­ing, fertilizers, pigments, mining, and metal­lurgical processes.

The application of conven­tional treatments is sometimes restricted due to technological and economical constraints. Metal accumulation on biomass can be passive (biosorptive), when non-living biomass is used as bio sorbent, or bio accumulative, by apply­ing living cells.