PHYCOREMEDIATION TECHNOLOGY APPLIED TO EFFLUENT TREATMENT
Phycoremediation may be defined in a broad sense as the use of macro algae or micro algae for the removal or biotransformation of pollutants, including nutrients and xenobiotics from wastewater and CO2 from waste air (Olguín, 2003). Microalgae play an important role during the tertiary treatment of domestic wastewater in maturation ponds or the treatment of small–middle-scale municipal wastewater in facultative or aerobic ponds (Aziz and Ng, 1993; Abeliovich, 1986; Mara and Pearson, 1986; Oswald, 1988, 1995). Micro algae enhance the removal of nutrients, heavy metals and pathogens and furnish O2 to heterotrophic aerobic bacteria to mineralize organic pollutants, using in turn the CO2 released from bacterial respiration . Photosynthetic aeration is therefore especially interesting to reduce operation costs and limit the risks for pollutant volatilization under mechanical aeration and recent studies have shown that microalgae can indeed support the aerobic degradation of various hazardous contaminants (Mun˜ oz et al., 2004). Hazardous pollutants include a wide range of toxic and/or persistent substances that can be found in all environmental compartments. The present thesis deals with the application of algal-based processes for the detoxification of industrial effluents under aerobic conditions (biodegradation of recalcitrant and toxic contaminants).
Phycoremediation potentials of micro algae:
The mechanisms involved in micro algal nutrient removal from industrial wastewater are similar than that from domestic wastewater treatment. Algae-based treatment is especially interesting in the case of N-containing contaminants whose biodegradation normally leads to NH4+ or NO3 _ release. (Mun˜ oz et al., 2005a, b).
Heavy metals represent an important group of hazardous contaminants often found in industrial wastewater (Kratochvil and Volesky, 1998). Microalgae can be efficiently used to remove these (Can˜ izares- Villanueva, 2000). Microalgae can biodegrade hazardous organic pollutants. Micro algal species have been successfully used for the treatment of olive oil mill wastewater and paper industry wastewater (Abeliovich and Weisman, 1978; Narro, 1987). Lima et al. (2003) reported -nitrophenol removal by a consortium of micro algae.
Phycoremediation of industrial effluents:
Proper management is industrial effluent is very essential for saving the environment. Careless and indiscriminate disposal of effluents have already caused major environmental and health problems. Technology should be developed not only to prevent further pollution but also remediate already polluted areas and make them habitable. Bioremediation can help manage effluents very effectively than the conventional methods.
Conventional methods vs Algal technology
Industrial effluents are conventionally treated using a variety of hazardous chemicals for pH correction, sludge removal, colour removal and odour removal. Extensive use of chemicals for effluent treatment results in huge amount of sludge which forms the so called hazardous solid waste generated by the industry and finally disposed by depositing them in landfills. Algal technology avoids use of chemicals and the whole process of effluent treatment is simplified. There is considerable reduction in sludge formation. Algal technology is highly economical and eco-friendly.
Sewage into energy
Phyco Spectrum is exploring the possibilities of growing micro algae in domestic sewage to produce valuable algal biomass which could be converted in to biofuel. Sewage is an excellent source of nutrients for algae. Algal technology treats sewage effectively to produce valuable biomass and remove CO2 from air thereby helping in reducing global warming. For more information click here
R/O REJECT and REJECT FROM DESALINATION PLANTS
Rejects from desalination plants and R/O plants are evaporated using SEPs and this generates huge amounts of sludge causiing enviornmental problems while disposal. Algal technology has been developed to effeciently treat R/O rejects with high TDS with a significant reduction in sludge. Micro algal species have been identified and developed by PHYCO SPECTRUM for this purpose and tested in field conditions.
Advantages of Phycoremediation
- pH correction without chemicals
- Sludge reduction by utilization of salts
- This technology does not involve any costly chemicals or equipments so very economical
- Effective reduction of BOD and COD and oxygenation of environment
- Removal waste CO2 due to photosynthetic fixation ( carbon credits)
- Useful bio-chemicals ( nutraceutical, pharmaceutical, bio-fertilizer and bio-fuel) from the algal biomass
- Accepted by PCB
- Not only the industry can save a lot of money but the environment is also saved
Industries employing this technology
Phycoremediation technology is being employed in the following industries:
- alginate industry
- leather processing chemicals industry
- detergent manufacturing industry
- confectionary industry
- electroplating industry
- soft drink industry
- textile dyeing industry
- pharmaceutical industry
- oil drilling sludge and distilleries
Implementation is carried out in three stages:
1. Laboratory level feasibility studies
2. Field level pilot scale studies
3. Scaling up to meet the industry’s requirement