Lecture 1 Introduction to Environmental Engineering
MAIN OBJECTIVES OF THE COURSE
To develop interest among Chemical Engineers regarding environment and its protection.
- To provide basic understanding of environmental engineering so that the Chemical Engineers may meet the expectation of the Industries for pollution control in their premises so as to comply with newer and tougher laws and acts that are being enforced in India and globally.
- To introduce the principles and methods to control air, water and soil pollution to the undergraduate students of chemical engineering.
- To develop basic understanding of following topics:
- sources of water, air and land pollution
- recycle and reuse of waste, energy recovery and waste utilization o air pollution and its measurement
- design of pollution abatement systems for particulate matter and gaseous constituents
- design of waste-water and industrial effluent treatment
- hazardous waste treatment and disposal
- solid-waste disposal and recovery of useful products.
- According to Peavy it is that branch of engineering that is concerned with protecting the environment from the potentially deleterious effects of human activity, protecting human populations from the effects of adverse environmental actors and improving environmental quality for human health and well being .
- Environmental engineering is still an evolving branch of engineering that is closely related to Chemical and Civil engineering.
- It is closely associated with chemistry, physics and biology; and has elements of hydrology, meteorology, atmospheric sciences, environmental chemistry, microbiology and ecology
ENVIRONMENTAL ETHICS AND EIA
- Traditionally, industries and its basic components were designed based upon technical and economic considerations only. Now-a-days, it is essential to consider environment, health and safety as factors during design .
- Environmental ethics is related to attitude of people towards other living beings and environment .
- During any project, though it is essential that ‘economic sustainability’ is attained; however, it is also essential that ‘ecological sustainability’ and ‘social sustainability’ are also attained.
- Impact assessment is a handy tool to assess the environmental compatibility of the projects in terms of their location, suitability of technology, efficiency in resources utilization and recycling, etc.
- Environmental Impact Assessment (EIA) has now been made a prerequisite for the settling up of new projects and renewal of licenses of old and existing plants.
- EIA is a major instrument in decision making and for measurement of sustainability in the context of the regional carrying capacity. It provides the conceptual framework for extending the cumulative assessment of development policies, plans and projects on a regional basis.
- Sustainable development of chemical process industries is a process in which the exploitation of resources and the direction of the investments are all made consistent with future as well as present heads.
POLLUTION DUE TO CHEMICAL PROCESS INDUSTRIES
The primary causes of industrial pollution are :
- Use of outdated and inefficient technologies for product manufacturing, pollution abatement and various other operation in industries which generate a large amount of wastes
- Development of unplanned industrial conglomerations without foreseeing the effect on environment
- The existence of large number of small scale industries without defining land use patterns and environmental regulations for them
- Poor enforcement of pollution control laws for big and small industries
Major polluting industrial sectors
1) Cement 2) Thermal power plants 3) Iron & Steel 4) Fertilizer 5) Zinc Smelters 6) Copper Smelters 7) Aluminum Smelters 8) Oil Refineries 9) Distilleries 10) Pulp & Paper 11) Dyes and Dye Intermediates 12) Pesticides 13) Petro Chemicals 14) Petroleum refining 15) Sugar 16) Tanneries 17) Basic Drugs
Major Concerns of Industrial Pollution
- Water and air pollution from chemical process industries need immediate attention.
- Industrial wastewaters vary widely in their composition and treatment methods, which have to take in to consideration the specific characteristic of the wastes.
- Many treatment practices have followed the approach of mixing the liquid sewage waste with industrial waste and treating the mixture by conventional methods.
- Treatment methods such as lagoon (aerobic & anaerobic), oxidation ditches and aerated lagoons have also been tried with varying degree of success. The majority of treatment plants have, however, failed to succeed. The chief reasons for this have been the omission of some of the key parameters that govern biological oxidation when industrial wastes are treated.
- Physico-chemical methods are necessary to remove or recover the chemical ingredients present in liquid effluents discharged from electroplating, chlor-alkali, pesticides, fertilizers, dyes and pigments, metallurgical, paper and pulp, etc. and other such process industries.
- The reuse of water in processes where the water quality standards are not stringent is worth considering. A considerable quantity of water is presently being reused in process industries in India but a lot more needs to be done in this area.
MAJOR DEFINITIONS AS PER INDIAN ENVIRONMENTAL ACTS
- “Environment” includes water, air and land and the inter-relationship which exists among and between water, air and land and human beings, other living creatures, plants, micro-organism and property.
- “Environmental pollutant” means any solid, liquid or gaseous substance present in such concentration and may be, or tend to be, injurious to environment.
- “Air pollutants” means any solid, liquid or gaseous substance (including noise) present in the atmosphere in such concentration as may be or tend to be injurious to human being or other living creatures or plants or property or environment.
- “Air pollution” means the presence in the atmosphere of any air pollutant
- “Ambient air” means that portion of the atmosphere, external to buildings, to which the general public has access.