Introduction

It is the collection of technological processes which are used to conserve the natural environment and resources inspite of making full use of those resources. Sustainable technology requires the exploitation of the environment through creation and extraction of resources, and the exploitation of people through labor. Sustainable technology aims to make the environmental friendly.

Sustainable technologies use less energy, fever limited resources, do not deplete natural resources, do not directly or indirectly pollute the environment, and can be reused or recycled at the end of their useful life. There is a significant overlap with appropriate technology, which emphasizes the suitability of technology considering the needs of the people in developing countries. Sustainable technology may have high cost or maintenance requirements that make it unsuitable. In this modern era of industrialization and competition it is very difficult to have hand on sustainable technologies as everybody wants its work to get completed in just in a blink of eye. Sustainable technology includes all technological processes utilizing substrates from nanoparticles upto huge particles. It has been broadly classified into four main categories’.

1) Green technology2) Nonotechnology3) Appropriate technology4) Renewable technology

Sustainable technology

1) Green technology / clean technology:

Green technology or greentech or environment technology as envirotech or clean technology as cleantech is the application of the environmental science to conserve the natural environment and resources and to curb the negative impacts of human involvement. It works on 3R- reduce, reuse & recycle. Greentech involves all those technological processes which are beneficial for human beings taken in concern the environment. It includes following aspects:

a) Sustainable agriculture: It is the practice of farming using principles of ecology, the study of relationships between organisms and their environment. It has been defined as an integrated system of plants and animals production practices having a site specific application that will last over the long term of sustainable agriculture:-

Sustainable agriculture Approaches:

Satisfy human food and fiber needs. Make the most efficient use of nonrenewable resources and on farm resources and

integrate, where appropriate, natural biological cycles and controls. Sustain the economic viability of farm operations. Enhance the quality of life for farmers and society as a whole.

b) Organic farming : It is the form of agriculture that relies on techniques such as crop rotation, green manure, compost and biological pest control to maintain soil productivity and control pests on a farm. Organic farming excludes or strictly limits the use of manufactured fertilizers and pesticides, plant growth regulators such as hormones, livestock antibiotics, food additives and genetically modified organisms. Organic farming usually involves mechanical weed control rather than herbicidal weed. Organic agriculture is the production system that sustains the health of soils, ecosystems and people. It relies on ecological processes, biodiversity, and cycles adapted to local conditions. Use of genetically modified organisms is excluded in greentech but genetically modified crop for higher yield, resistant is included which do not have harmful effect as other organisms and environment.

c) Recycling: It is the worldwide phenomenon, which is a basic application towards greentech. It shows and encourages people to reuse items than can be reusable .Items like saving cans of food or drinks , paper etc. have been encouraged by the governing bodies around the world ,to be recycled so that it can be used in the future for several other purposes. It can thus protect the environment and cause less waste /pollution. Even glass bottles are recycled. Recycling includes mostly solid waste management programs. Solid waste management is the purification, consumption reuse, disposal and treatment of solid waste that is looked after by the government or the ruling bodies of the city / town. It further involves composting also in which the solid agricultural wastes are dumped on

big cans and then covered with soil. This leads to the degradation of that solid material, and thus the product formed is used as fertilizer.

Recycled tins used for decorative items

d) Water purification : is the whole idea of having germ /dirt/pollution free water flowing through the environment. Water pollution is the main enemy of this concept, and various campaigns and activists have been organized around the world to help purify water. According to the estimation of 2006, water born diseases are estimated to cause 1.1 billion people lack proper drinking water. Water generally needs treatment before use, depending on the source and the intended use. Greentech options in water treatment include both community scale and household scale point of use (POU) designs .The most reliable way to kill microbial pathogenic agents is to heat water to a rolling boil. Other techniques such as varying forms of filtration, chemical disinfection and exposure to ultraviolet radiation are also useful. The ability of POU options to reduce disease is a function of both their ability to remove microbial pathogen if properly applied and their ease of use. Specific examples of household or community scale POU include:-

Porous ceramic filtration: using either clay or diatomaceous earth, and oriented as either cylinder, pot, or disk, with gravity fed or siphon driven delivery systems. Silver is frequently added to provide antimicrobial enhancement.

Slow sand filtration: also known as biosand filtration. Chlorine disinfection: employing chlorine hypochlorite powder, sodium

hypochlorite solution. Chemical flocculation: using either commercially produced iron or aluminum salts or the crushed seeds of certain plants such as Moringa oleifea. Irrdition with UVlight: whether using electric powdered lamps or direct solar

exposure.

Membrane filtration: employing ultrafilteration or reverse osmosis filter elements preceded by pretreatment.

Deep wells and shallow wells lined with walls and covers. Rain water harvesting systems. Fog collection: suitable for areas which experience fog even when there is little

rain. Airwell: a structure designed to promote the condensation of atmospheric

moisture. The hippo water roller allows more water to be carried with less effort and thus

could be good alternative in areas with low topographic relief.

Water filter outside purification of water

e) Air purification: for air purification the basic and common green plants can be grown indoors to keep air fresh because all plants remove CO2 and convert it into oxygen. The best examples are , Dypsis lutescens, Sanseveria trfasciata and Epipremmum aureum.

f) Sewage treatment: it is a compact somewhat closely to water purification. Sewage treatments are very important as it purifies water of its pollution. The more water is polluted, it’s not used for anything, and the least polluted water is supplied to places

where water is used affluently. It may lead to various other concepts of environmental protection, sustainability etc.

Sewage treatment plant

g) Environmental remediation: is the removal of pollutants or contaminants for the general protection of the environment. This is accomplished by various chemical, biological and bulk movement methods, in conjunction with environmental monitoring.

Pit airbrush used in environmental remediation

h) eGain forecasting: It is a method using forecasting technology to predict the future weathers impact on a building by adjusting the heat based on weather forecast, the

system eliminates redundant use of heat, thus reducing the energy consumption and the emission of greenhouse gases.

i) Energy conservation: It is the utilization of devices that require smaller amounts of energy in order to reduce the consumption of electricity. Reducing the use of electricity causes less fossil fuel to be burned to provide that electricity. Under greentech it involves:-

i) New solar technology.

ii) Trees power.

i) New solar technology: The new solar technology includes treated includes treated silicon solar cells. An untreated silicon solar cell only absorbs 67.4% of sunlight shone upon it meaning that nearly 1/3rd of that sunlight is reflected away and thus unharvestatible. After a silicon surface was treated with nanoengineered reflective coating, the material absorbed 96.2% of sunlight shone upon it meaning that only 3.7 % is reflected and harvested. The new anti-reflective coating is being hailed as a (game changer) for photovoltaic energy. The nanostructure coatings help panels absorbs nearly all the light that falls on them , including light at angles that normally bounces off. This technology could increase solar output by 20-30%.

New Anti Reflective Coating Increases Solar Power

ii) Tree power: It is defined about the trees that produce electricity. Researchers found that

plants generate a voltage of upto 200 mill volts when one electrode is placed in a plant and the other in the surrounding soil. A university of Washington team has run a custom circuit entirely of tree power .By hooking nails to trees and connecting a voltmeter , it was observed that big leaf maple generate a steady voltage of upto a few hundred mill volts.

Scientists working on trees producing electricity

2) NANOTECHNOLOGY

It is also known as nanotech and is the manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with structures sized between 1-100 nanometers in atleast one dimension, and involve developing materials or devices within that size. One nanometer (nm) is one billionth, or 10-9, of a matter. Carbon – carbon bond lengths, or the spacing between these atoms in a molecule are in the range 0.12-0.15nm, and a DNA: double helix has a diameter around 2nm. On the other hand, the smallest cellular life forms, the bacteria of the genus myoplasma, are around 200nm in length.

Nanotechnology is very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self assembly, from developing new materials with dimensions on the nanoscale to investigating whether we can directly control matter on the atomic scale.

Nanotechnology may be able to create many new materials and devices with vast range of application such as in medicine, electronics, biomaterials and energy production. On the other hand, nanotechnology raises many of the same issues as any new technology, including concerns about the toxicity and environmental impacts of nanomaterials, and their potential effects on global economics.

Nanotechnology has introduced areas like nanoelectronics, nanomechanisms ,nanophotonics and nanoionics.

i) Nanomaterials :-The properties of materials changes when its size decreases,eg) the quantum size effect , where the electronic properties of solids are altered with great

reductions in particle size. However quantum size effect becomes dominant in nanometer size range typically at distances of 100 nanometers or less, the so called quantum realm.

Nanomaterial structure

ii) Nanoionics :- where fast transfer of ions take place.

iii) Nanomechanisms:- Mechanical properties of nanosystems are of interest in the nanomechnics research. When materials are reduced to nanomaterials they show different physical properties compared to what they exhibit at macro scale .e.g.) opaque substances become transparent (copper); stable materials turn combustible (aluminum); insoluble materials become soluble gold. Gold which is inert at normal scale turns chemical catalyst at nanoscales.Approaches of nanotechnology :

i) Bottom –up approach.ii) Top-down approach.

i) Bottom-up approach :- This seek to arrange smaller components into more complex

components .

DNA nanotechnology utilizes the specificity of WATSON CRICK base pairing to construct well defined structures out of DNA and other nucleic acids.

Nanotechnology aims to design molecules with well defined shape. E.g.) bis –peptides.

It involves concepts of supramolecular chemistry and molecular recognition to arrange single molecular components into some useful conformation.

Atomic force microscope tips can be used as a nonoscale”write head” to deposit a chemical upon a surface in a desired pattern in a process called dip pen.

Nanolithography: - this technique fits into the larger subfield of nanolithography.

Image of DNA biochip

ii) Top down approaches: It leads to the creation of smaller devices using larger ones. Solid state silicon methods for fabricating microprocessors are now capable of

creating features smaller than 100nm. Giant mangetoresistance based hard drives are the examples of this. Solid state techniques can also be used to create devices known as

nanoelectromechanical systems or NEMS, which are related to microelectromechanical systems or MEMS.

In transmission electron microscopy focused ions beams can directly remove material, or even deposit material when suitable gases are applied at the same time.

Image of nanocrystalApplications:

I) Nanotechnology leads to the creation of nanocars, which are synthetic molecular motors. ii) Bionanotechnology involves the use of biomolecules for applications in nanotech including use of viruses. iii) Molecular nanotechnology involves manipulating single molecules in a finely controlled way. iv) Nanorobotics centers on self sufficient machines operating at the nanoscale. There are hopes for applying it in medicines. v) Nanotechnology has proved a significant role in industrial sector. vi) It is attaining a great demand in the field of medical science. vii) Nanomaterials have found their role in many daily use items of a common man like titanium dioxide in sunscreen and cosmetics , silver in food packaging clothing, disinfectants and household appliance zinc oxide in cosmetics surface coatings, paints and outdoor furniture varnishes. viii) One of the major applications of nanotech is in the area of electronics where nanowires~ 10nm in length are made.

Implications / Drawbacks :-

i) It can lead to the development of untraceable weapons of mass destruction.ii) Networked nanotech cameras will break the privacy.iii) Nanotoxicology research states the effect of improper use of nanomaterials on human health and the envirionment.

iv) Nanoparticles like silver nanoparticles used in socks only to prevent bad odour are being realesed afer wash and kill many usefull bacteria which are useful in waste water treatment plants.v) Nanoparticles in case of animals like rats get settled in their brain and lungs leading to stress and inflammation response.vi) Nanomaterials consumption cause cancer, heart disease, neurological disease and aging.

Regulation : Tighter regulation of nanotechnology related to human health and safety risks is needed. Some agencies have taken control over it. Some agencies have taken control over it .Some regulatory road map for administrations are necessary to oversight. The nanoparticles being released during disposal, destruction and recycling, and recommended to fall under responsibility regimes. It is our responsibility to play a meaningful role in the development of these standards.

3) APPROPRIATE TECHNOLOGY:

It is the technology that is designed with special considerations to the environment, ethical, cultural, social, political and economical aspects of the community. With environmental and ethical goals in mind, claims their methods require fewer resources, are easier to maintain, and have less of an impact on the environment compared to techniques from mainstream technology which they contend is wasteful and environmentally polluting.

Appropriate technology describes as simple technologies which are suitable for use in developing nations or less developed rural areas of industrialized nations. This form of appropriate technology usually prefers labor- intensive solutions although labor saving devices are also used. In other words it is the usage of simplest level of technology that can effectively achieve the purpose in a particular location. In industrialized nations, the term appropriate technology often refers to engineering that takes consideration of its social and environmental ramifications.

A nut sheller

Appropriate technology founders :- It is supposed to commence from Mahatma Gandhi who encouraged small, local, mostly village based technology to help India’s villages become self reliant and aid in the freedom struggle against British and wealthy Indians. E.F.Schumacher who was very strongly influenced by Ghandhiji,s philosophy took his village development at international level. Steward Brand popularized it and contributed ideas which inspired it, where he sometimes listed as a founder.

Appropriate technology is divided under further headings:-

a) Intermediate technology.b) Hard technology.c) Soft technology.

a) Intermediate technology:- This term was coined by E.F.Schumacher. It refers specifically to tools and technology that are significantly more effective and expensive

than traditional methods, but still an order of magnitude cheaper than developed world technology. Such articles can be easily purchased and used by poor people and can lead to great productivity which minimizing social dislocation. This intermediate technology is compatible with the laws of ecology gentle in its use and serves to human person instead of making him the servant of machines.

b) Hard technology: - is engineering techniques, physical structures and machinery that meet a need defined by a community, and utilize the material at hand or readily available. It can be built, operated and maintained by local people with very limited outside assistance. It is usually related to economic goal.

c) Soft technology: - It is the technology that deals with “the social structures, human interactive processes, and motivation techniques. It is the structure and process for social participation and action by individuals and groups in analyzing situations, making choice implementing behaviors that bring about change. The campaigns by political parties, celebrations with loud music are the best examples against this, as they cause noise as well as environmental pollution.

Appropriate technology covers following fields;-

a) City construction : - it includes building construction mainly. Green building materials could be considered appropriate earth building technology for much of the developing world, as they make use of materials which are widely available locally and thus relatively inexpensive. e.g.) mud brick may not be durable in a high rainfall area; cemented material can be used instead. The building structure may also be considered. Cost effectiveness is also considered. Public housing approach is the best approach; this lets everyone have their own sleeping / recreation space and mess halls, washrooms etc. In addition to decrease costs of operation (heating, cooling) techniques as earth sheltering, tombs walls are also incorporated.

City constructed according to appropriate technology

b) Energy: - Appropriate technology includes renewable energy sources and excludes non renewable energy sources.

Photovoltaic (pv) solar panels, and large concentrating solar power plants. Human powered hand wheel generators. Zero emission generation methods. Bioethanol, biodiesel and straight vegetable oil can be appropriate, direct

biofuels in areas where vegetable oil is readily available and cheaper than fossil fuels.

Anaerobic digestion power plants. Biogas is another potential energy source when there is abundant supply of waste

organic matter. Animal excreta can also be used to obtain certain types of organic materials.

Urine can also be used as a basis to generate hydrogen. Urine usage is 33% more energy efficient than waste usage.

c) Transportation:-

Megabus:- It is double decker that holds 79 persons in comfort. It gets about 6-7 miles/gallon so that works out to 474-553 passengers/gallon.

Megabus Human powered vehicles

Human powered vehicles include the bicycle which provides general purpose, human powered transportation at a lower cost of ownership than motorized vehicles. Animal powered vehicles /transport may also be another appropriate technology. Zero emissions vehicles/ compressed air cars, liquid nitrogen and hydrogen powered vehicles.

d) Sanitation:- Water born diseases are estimated to cause 1.8 million deaths each year, marking the importance of proper sanitation systems. Ecological sanitation is the major process dealing with human excreta. It works by incorporating following steps:-

i) Containments

ii) Sanitization

iii) Recycling

The objective is to protect human health and the environment while limiting the use of water in sanitation systems for hand washing only and recycling nutrients to help reduce the need for synthetic fertilizers in agriculture.

Composting toilets: they are the most environmental form of excrement disposal system. In fact toilet design follows the nutrients to be reused and is also cost effective.

Composting toilet

Treatment ponds and constructed wetlands: they can help to purify sewage and grey water. They consist mostly of plants and therefore require only little power. Certain other options as slow sand filters, UVfilters may also be employed.

e) Food production: urban gardening, indoor cultivation, forest gardening are the methods of food production under appropriate technology. Crop production tools are best kept simple techniques. Tools can include animal- pulled plows, dibbers wheeled augers, kirpis, hoes. Greenhouses are also sometimes included.

f) Cooking: fossil (nonrenewable) and biofuels (renewable) for cooking cause more pollution. Other old methods are more wasteful and less effluent.

Solar cookers are appropriate to something depending on climate and cooking style. They are emission less and low cost.

Hot plates are 100% electrical, fairly low coast and are mobile. Rocket stoves and certain other wood stoves improve fuel efficiency, and reduce

harmful indoor air pollution.

Solar cooker used to cook food

g) Refrigeration :

Solar and thermal mass refrigerators reduce the amount of electricity required. Also they donot use haloalkanes but use heat pumps or mirrors instead.

The pot-in-pot refrigerator is an African invention which keeps things cool without electricity. It provides a way to keep food fresh for longer time.

Refrigerator based on appropriate technology

h) Healthcare: according to Global Health Council the use of professionally schooled doctors, the training of villagers to remedy in towns in developing world is encouraged. Trained villagers are able to eliminate80% of the health problems. Herbalist medicines are appropriate medicines, as they can be freely made at home and are almost as effective as their chemical counter parts.

4) RENEWABLE ENERGY TECHNOLOGY:

It is that energy which can be replenished easily. For years using sources like wood, sun, water, etc, for means for producing energy. Energy that can be produced by natural objects like wood, sun, wind, etc. is considered to be renewable.

Renewable energy is critical to our fight against climate change. We simply must shift our world to a low- carbon economy and away from oil and coal. Experts suggest that there is a need renewable energy to replace fossil fuels now. Renewable energy technology tends to be located outside crowded urban areas, helping smaller, local economics which reducing reliance on fossil and foreign energy resources. Renewable energy carbon offset projects met the toughest industry standards and are third party verified to ensure the highest quality.

a) Bajaj Finserv Wind Project

Location: Maharastra, India Project type: Wind Energy Standard: Chicago Climate Exchange

Carbonfund.org supports the Bajaj Finserv Wind Project because it provides renewable electricity, supports local businesses and is a prime example of how wind projects can significantly contribute to a nation’s energy portfolio.

Bajaj Finserv Wind Project

b) Chino Basin Dairy Farm Biodigester

Location: Chino Basin, CaliforniaProject type: Waste-to-Energy BiodigesterThe Chino Basin Dairy Farm Biodigester Project generates clean electricity from local manure. Carbonfund.org helps this renewable energy project successfully reduce more than 8,000 tons of carbon dioxide each year and support local dairy farms.

Chino Basin Dairy Farm Biodigester

c )Freund’s Farm Dairy Methane Project

Location: East Cannan, Connecticut

Project type: Waste-to-Energy Biodigester

Carbonfund.org supports the Freund’s Farm Dairy Methane Project because it helps to reduce heat-trapping methane emissions which in turn, lessen the impact of global climate change. Freund’s Farm installed a 62-foot anaerobic biodigester that receives approx 3,600 gallons of manure each day from 240 cows and reduces up to 1,200 tonnes of carbon dioxide equivalent emissions each year. Biodigesters capture methane generated by manure and transform it into a clean, renewable energy source.

Freund’s Farm Dairy Methane Project

d) Fujian Nanridao Wind Project of China

Location: Nanri Island of Putian City, Fujian Province of ChinaProject type: Wind Energy

The nineteen turbines that make up this wind project have a total generation capacity of approximately 16.15 megawatts. In addition, this project promotes sustainable development by expanding local employment opportunities.

Fujian Nanridao Wind Project of China

e) Gardner Sanitary Landfill Methane Project

Location: Gardner, MassachusettsProject type: Methane Destruction

As landfills harbor methane from trash, the project destroys the landfill methane, which is approximately 23 times more potent as a greenhouse gas than carbon dioxide.

Gardner Sanitary Landfill Methane Project

f) Gujarat Wind Projects

Location: Gujarat, IndiaProject type: Wind EnergyThe Aggregated Wind Projects of Gujarat have made it possible for 52 owners to combine their 65 wind turbines into a single project. Each of the turbines has a capacity between 0.35 megawatts and 1.5 megawatts and collectively, they produce 59 megawatts of renewable electricity.

Gujarat Wind Projects

g) Kalani Wind Farm

Location: Rajasthan, IndiaProject type: Wind EnergyThe Kalani Wind Farm was the first private wind turbine project to be constructed in the state of Rajasthan. This project consists of 12 turbines, each with a capacity of 0.23 megawatts, for a total output of 2.76 megawatts.

 

Kalani Wind Farm

h) Neria Small Hydroelectric Project

Location: Karnataka State of IndiaProject type: Hydroelectric EnergyAs a run-of-river hydroelectric project, this project provides a sustainable source of renewable energy that does not require the displacement of people nor a dam. The project is located near the famous Dharmasthala temple village on the River Neria.

Neria Small Hydroelectric Project

i) New Hope View Dairy Methane Project

Location: Homer, New YorkProject type: Methane Destruction

Carbonfund.org supports the New Hope View Dairy Methane Project because it helps to reduce heat-trapping methane emissions which in turn, lessen the impact of global climate change. Biodigesters essentially capture methane generated by manure and transform it into a clean, renewable energy source.

New Hope View Dairy Methane Project