Code No: TMS080 Price: Rs1650/- Category: Water

Application of biotechnology for water treatment

INTRODUCTION

Water treatment has assumed importance in recent years with the increasing demand on this limited resource and pollution parameters arising out of discharge from untreated/partially treated effluents. As such, R&D effects for improving the conventional system and evolving new technologies for waster treatment have necessarily received attention more than ever before. These have resulted in development of several modified and new products which are significant from the view point of pollution control, water conservation, energy generation, resource recovery and such other attendant benefits.

Water treatment technology is an area of vital importance in the Indian context.

OBJECTIVES OF THE STUDY

The objectives of the study are:

a) To study the current status of biotechnologies for water treatment in the world and the country.

b) Assessment of technology options available, their financial aspects and feasibilities leading to selection of preferred options.

c) Suggested action plan and identification of agencies/groups/individuals for implementation of the same.

SCOPE

The scope of the study has been designed to cover the following aspects:

a) Basic water treatment biotechnology.

b) Water quality criteria-national and international.

c) Raw water treatment biotechnologies/national and international.

d) Domestic wastewater-national and international

e) Industrial wastewater- national and international.

f) Technology gaps and options available.

g) Sources ad recommended technology options

h) Action plan and agencies involved in implementation

SIGNIFICANCE OF THE STUDY

The socio-cultural roots of our present environmental crisis lie in the paradigms of scientific materialism and economic determinism which fail to recognize the physical limits imposed by ecological systems on economic activity. The economies must expand within ecosystems which have limited regenerative capacities. Contrary to the neoclassical theory of continuous material growth, economic activities directly undermine the potential for development through the discharge of residuals. The entrenchment with quantitative growth as a major instrument of social policy is thus quite paradoxical.

Discernible positive movement towards the overall aspirational goal of sustainable development warrants pursuance of a n effective R&D programme in environmental science and technology to enable solutions to the backlog and future environmental problems emanating from developmental imperatives in various socio-economic sectors. Accordingly it is of utmost importance for the government to launch missions on environmental biotechnology, in order to meet the basic needs of safe drinking water and hygienic sanitation facilities for the people.

METHODOLOGY FOLLOWED

The present study ahs encompassed a cross section of public and private sector organizations, city & industrial water works, equipment suppliers and R&D institutions in India and abroad. Adequate care has been taken at various stages of the study to consult different experts in the field. The study has also briefly covered the terminology and basic principals of water treatment biotechnologies.

WATER QUALITY CRITERIA

Major contaminants in surface and ground water sources, harmful for human health are bacteria, guinea worm, faecal coliforms and excess dissolved solids apart from hardness and turbidity. It is helpful to understand the water quality standards laid down by ISI and as per Water Act 1974 and Environment Act 1986. Annexures III-VIII include these water quality standards for various uses.

Treatment biotechnology for raw water

Raw water drawn from various sources is not fit enough for human consumption directly without subjecting it to treatment. Certain gases, traces ofmineral water and other undesirable substances gets dissolved in the raw water as a result of various hydrological processes. During runoff on the earth surface, raw water picks up soil, garbage, sewage, pesticides and other physical, chemical and bacteriological agents including human and animal wates.

The following treatment method are generally applicable each suing different technologies:

a) Screening
b) Sedimentation
c) Filtration
d) Disinfection
e) Softening
f) Desalination
g) Demineralization

The technologies available in India for treatment of municipal water supplies, for industry or for large communities are the following:

a) Clarification
b) Filtration
c) Ultra-filtration
d) Flocculation
e) Reverse-osmosis
f) Electro dialysis
g) Water-softening
h) Fluoride Removal
i) Disinfection
j) Iron removal.

The brief details of various biotechnologies for treatment of raw water as available in out country and in come of the advanced countries is described in Chapter 3. the available technologies and equipment are suitable and adequate for rural sectors and at small communities level. R&D agencies such as NEERI Nagpur etc. have done considerable work in this field. The technology gap is in respect to more sophisticated techniques such a reverse osmosis and ultra filtration including membrane technology and surface water pollution.

TREATMENT TECHNOLOGY FOR WASTEWATER

The objective of wastewater treatment is to remove the impurities and hence reduce pollution in order to return the effluent to the environment without causing unacceptable damage to land, air or water bodies and similarly to stabilize and dispose off the treatment residue. Various pollution parameters such as BOD, COD, TSS, Nitrogen, Phosphorous, metals, toxic elements, oils and greases have to be taken care of.

TREATMENT SYSTEM AND PROCESSES

The treatment system discussed in the present report include the following:

a) Secondary biological treatment processes- Aerobic and Anaerobic
b) Low cost treatment systems- Aerated Lagoons, extended aeration, oxidation or stabilization ponds etc.

c) Organic waste treatment
d) Tertiary biological treatment systems.

The details of the above processes and the latest biotechnology have been discussed in Chapter 4 to 10. A few case studies have also been included in these Chapters for highlighting some of the foreign as well as indigenous biotechnology presently being utilized.

TECHNOLOGY GAPS

On the basis of the details presented in Chapters 3 to 10 the following gaps have been identified:

a) Raw water
i) High grade water for special industries
ii) Brackish water treatment
iii) Surface polluted water.

b) Domestic Waste Water Treatment
i) Nutrient removal
ii) Small community waste water treatment plants.

c) Industrial Waste Water Treatment
i) Use of microbes for digestion of organic wastes
ii) Complex waste water in industries using multiple processes.

d) Sludge Disposal Technologies – Landfill, Hydrolysis, incineration, pyrolysis.

ACTION PLAN AND AGENCIES INVOLVED

In order to bridge the technology gaps, an action plan has been drawn and presented in Chapter 13. this action plan also includes the role of various R&D organization, industry, and financial organization such as Asian Development Bank, Manila ands World Bank etc.

Annexure IX includes various directories of major water and wastewater treatment companies all over the world.

It is importance that these organizations play complementary roles for facilitating the adoption and adaptation of the technologies to the Indian environment.

The action plan and agencies involved are given in Chapter 13 of this report. Some of the major actions are summarized below:

a) The criteria for beneficial uses of water be studied by Bureau of Indian Standards. The necessity and time frame for modifying the same be assessed.

b) Evolve a strategy to overcome technology gaps mostly by indigenous development. In exceptional cases assistance of foreign consultants or even collaboration be considered.

c) Adequate technology for treatment of raw water is available at household/village/town level. It is essential that the participation of the community is complementary to the efforts of the State and Central Governments. For this purpose suitable measures such as financial support, tax benefits and education are necessary.

d) Pollution Control is a very important activity and needs to be taken up as a mission. ‘Stick and Carrot’ policy be adopted to ensure that the industry adheres to the laid down effluent discharge standards.

e) In view of the overall constraints of finances, the allocation for the sewage treatment is limited. The facilities of the World Bank, Asian Development Bank and IDBI be utilized to the maximum.

f) Water treatment technology cannot be viewed in isolation and has to be related to the overall activity of water management. An apex body be formed to deal with major areas such as R&D, financial allocations, Import policy, taxation policy, industrial policy and overall coordination/monitoring.

CONCLUSION

This study has raised some pertinent issues in areas such as relevance of quality criteria with respect to technology gaps and financial implication of implementing the technology options. It has also highlighted that several technology options are available in the country and they need to be exploited to the maximum possible extent so as to mitigate the increasing environmental hazards as a result of water pollution. Laying down of the priorities and allocation of funds are necessary because the basic infrastructure for implementation exist in our country.