The present disposal of plastics (Non PVC) is either by recycling land filling or by incineration. Land filling and incineration have negative impacts on the environment.

Thinner polythene/polypropylene carry bags are the most abundantly disposed of wastes, which may not be collected by ragpickers for onward recycling because of lower returns. These polythene/polypropylene bags are easily compatible with bitumen at specified conditions and a blend can be prepared and used for road laying.

Almost 90% of the polymeric materials are made up of either polyethylene or polypropylene or polystyrene, which being heated at around  130-140⁰c gets softened without releasing any gaseous products, while,        when PVC is incinerated (>700⁰c), it  may produce toxic gases like Dioxins.

Homopolymers, like high and low density polyethylene and polypropylene, as well as  random and block copolymers, like ethylene-vinyl acetate, ethylene/propylene, styrene-b-butadiene-b-styrene and styrene-b-ethyl-ene-co butylene-b-styrene, have been used as bitumen modifiers. Polymer blended bitumen has better properties regarding softening point, penetration point, ductility, stripping value and marshall stability value. Hence the blend can be used for laying flexible pavement.

In the process of the preparation of polymer-bitumen aggregate mix, the temperature used is only-170⁰C and no chlorine or copper is present in the system. The polymer materials used are polyethylene, polypropylene and polystyrene only and polyvinyl chloride is not used to avoid the possibility of presence of chlorine in the system because of which Dioxin does not form.

The whole process is very simple and economical and needs no new machinery.

The technology is also very simple and the waste plastics available in the surrounding area can be used then and there.

Crumb rubber requires a temperature of 180⁰C whereas 60/70 grade bitumen needs 160⁰C only. This accounts for fuel conservation.

Roads have been laid at different places at Tamil Nadu using different surface area and different composition are performing well.

A scheme for laying waste plastics-Tar road in rural area for 1000 km was launched on 16^th July, 2003 at Namakkal by the Honourable Chief Minister of Tamil Nadu Dr. J. Jayalalitha.

One or the economic and effective anaerobic treatment method is the UASB (Upflow Anerobic Sludge Blanket) process. In a UASB Reactor wastewater is fed from the bottom. As it flows upward through the reactor, organic matter in the waste is degraded anaerobically by micro organisms resident in the sludge blanket. Besides converting organics to cell mass, biogas rich in methane is produced as a by product. A Gas Liquid Solid separator(GLSS) provided near the top of the reactor, enables sludge to settle into the blanket, biogas to escape into the dome at the top of the reactor, and treated supernatant to flow out of the reactor. High sludge concentration in sludge blanket and low concentration of suspended solids in the reactor over flow are characteristic features of a good UASBR.

UASB Technology

The basic advantages of a UASBR over aerobic treatment units are :

* UASBR in a compact unit, ideal for economic space utilization.
* UASB treatment process requires no external input of energy. Even the required mixing is achieve by upflowing waste water and rising gas bubbles.
* Nutrient requirement (i.e. N&P) is muc less than (about half that needed ) for aerobic treatment.
* Residuals (i.e.sludge) generated by UASB treatmet are much less in amount and well digested, requiring reduced sludge hanldling and causing much less odour problems.

The UASBR comprises no mechanical or moving part involving wear and tear. Thus it is virtually maintenance free and involves few operational problems. When properly designed and made, a UASBR provides trouble-free service for many years.

* Biogas, rich in methane, is generated as a valuable by product. Methane produced is about 0.15 to 0.35 Nm3/kg COD destroyed.
* Owing to the compactness of UASBR , absence of mechanical/moving components, energy efficiency of the process, and reduced post- treatment and sludge handling requirements, both the capital cost and running cost of a UASBR based treatment plant are significantly less than for a fully aerobic teratment plant.
* Once a UASBR has been put in operation, acclimatised bacteria can survive without food in the reactor for long durations. This enables easy strartup of the UASBR after prolonged periods of being out of operation.
* UASBR is a noiseless, closed and covered unit that is aesthetically very satisfying.

UASBR APPLICATIONS:
UASB Technology has found applications worldwide, in treating various types of wastewater. Among industries, some popular applications are in the food processing and producing industries, dairies and milk-processing units, sugar mills, pulp and paper, breweries, distilleries, potato, vegetable and fruit processing plants, soft drink plants, tanneries and slaughterhouses. For complex industrial wastes or adverse environmental conditions, however, a pilot study or treatability assessment is desirable. For municipal waste waters (Sewage) BOD removal of 60% to 80% is normal under favourable conditions (influent BOD >=140 mg/l. BOD/COD => 0.4, temperature 15-42 ºC, etc.) Suspended solids may be also reduced in the process, but some post-treatment (aerated lagoon or stablization/polishing pond) is generally needed for BOD removal to the desired degree.

Waste Management flows in a cycle: Monitoring, Collection, Transportation, Processing, Disposal / Recycle. Through these steps a company can effectively and responsibly manage waste output and their positive effect they have on the environment.

Monitoring is identifying the waste management needs, identifying recycling opportunities and ways to minimize waste output, and reviewing how waste minimization is progressing. Through keeping records of the different waste streams, a customer can see the results of their efforts in becoming more environmentally friendly, and a more efficient business.

Collection involves the logistical organization to guarantee that bin containers will not overfill and waste sit time does not become too long. The correct bin container size and service frequency is a must to prevent overspill or excessive smell. The correct bins for different wastes must be available with sticker and bin colour identification. Locks, chains, lids and bars prevent public access and non-trained personnel putting rubbish in the incorrect bins.

Cooperation between the waste company and customer is vital. Bins must be accessible to the truck driver at the agreed times. Access to work premises outside work hours will cause an issue if unaddressed. Bin wheels can allow customers to move bins from convenient areas to serviceable locations.

Transportation is the organizing of waste transport vehicles with the authorization and ability to transport the specified wastes from a customer’s work residence to landfill or processing plant. A waste must be transported by the vehicle designed for it. For example, general waste requires a vehicle with thicker compacter walls, to that of a cardboard and paper waste transporting vehicle. Therefore, a customer may require a series of vehicles to meet their waste management needs.

Vehicles, drivers, and companies need licenses and approval in certain Council Areas to transport waste. EPA standards need to be upheld as well as General Public Safety. Safety standards are vital to the transportation of clinical and hazardous wastes. Drivers must undergo training for emergency circumstances that may arise.

Processing involves the separation of recyclables for treatment, and then after treatment are packaged as raw materials. These raw materials are sent to factories for production. Non-recyclable wastes by-pass this step and are delivered straight to landfill. Liquid and hazardous wastes are delivered to treatment plants to become less hazardous to the public and environment.

Disposal / Recycling is the disposal of non recyclables into landfill. Landfill sites must be approved by legal authorities. Legal authorities guarantee that specific wastes are buried at the correct depth to avoid hazardous chemicals entering the soil, water tables, water systems, air, and pipe systems.

In this step the raw materials made from recyclables are produced and sold as products on the market. Companies can purchase such products to further sustain the environment and natural resources.

In conclusion, waste management is a science that addresses the logistics, environmental impact, social responsibility, and cost of an organization’s waste disposal. It is a detailed process that involves human resources, vehicles, government bodies, and natural resources.

Landfill

Landfills are basically the specific areas or sites where waste materials and garbage is disposed off on a regular basis. These special sites are constructed for the decomposition of different types of waste, be it industrial or household waste. This is one of the most ancient forms of waste disposal method that has been used for centuries all around the world. If the landfills are organized in the proper manner then they can be a very good source of waste disposal. The landfills are divided into internal as well as external sites where waste is disposed off accordingly.

These days waste management is becoming a very big problem in most of the countries across the world that is why it is very important for households and industries to recycle and manage their waste before disposing it off in the landfills. Some important information that you need to know about landfills is mentioned below.

1. Used for the waste management purposes

Most of the landfills are used for waste management purposes. They can be used as internal as well external source of waste disposal. The waste is collected regularly from household as well as industries. Once all the waste is accumulated in the same place it is weighed. Those waste materials that do not come under the safe category are separated and removed from the rest of the bulk. Once the separation is made, the waste is carried to the site on various trucks. The vehicles that carry the weight also have to undergo a cleaning process before they can leave the premises. The landfills are usually situated out of the city and in very remote areas so that the dirt and odour of waste does not disrupt the ordinary city life.

2. Temporary storage

Sometimes the landfills are also used as temporary storage sites. The waste is collected on these sites and then it is shifted to other areas. Usually the waste that can be re-used and recycled is dumped here for temporary storage. Industrial waste is also sometimes dumped here on a temporary basis and later on they are taken out for chemical treatment. During the temporary storage the authority needs to be very careful. They are accountable to ensure that the chemical or harmful waste materials are kept separate from the ordinary household waste.

3. Processing of waste material

In most of the cases waste material is also processed in the landfills. The different processes like recycling, treatment and sorting take place in the same landfills that are used for dumping the waste matter. Recycling is a very efficient process through which the household and industrial waste can be converted into completely new products which can be used for number of times. When the materials are dumped into the landfills, the ones that are in good condition are kept out for the recycling process. These days most of the households are also recycling their products before they even reach the dumping area.

4. Impacts of the landfill operations

Landfill operations are very dangerous and they might have a bad impact on human health, if proper instructions are not followed. Some of the adverse impacts of the different operations are pollution, damage to infrastructure, soil contamination and injuries to animals and birds. The authorities should be very careful and they should take all the necessary steps to minimize the loss caused by the landfill operations. Sometimes organic waste materials produce Methane gas that is known to cause the green house effect. Most of the landfills that you would find in the city are funded by commercial authorities whereas others are operated for profit.

I am sure the article would definitely help you to gather all the important information that you require about the landfills and different operations that are carried out in that area.

Typical Hospital Waste

Hospital waste is very different from the ordinary waste that is produced in our homes on a daily basis that is why we need to adopt certain different methods for disposing off the hospital waste materials. Various complex substances are involved when it comes to the hospital waste. Hospitals are usually very big organizations that involve a lot of different departments. Medical care is provided to the patients in every department and during this process a lot of different materials are used which are disposed off as hospital waste.

In order to manage the waste in the most efficient manner, every hospital should operate a special program, so that the waste gets disposed off without harming the health of the patients or the people who are working in the hospital. In this article, my main focus would be to provide you some critical information and special techniques for an efficient hospital waste management system.

1. Categorisation of hospital waste

The hospital waste is divided into various different categories according to which they are disposed off. Some of the different hospital waste materials are mentioned below.

• General waste basically consists of various waste materials that are also used in households all around the world. They are not at all hazardous for the human beings.
• Infectious waste has pathogens that can cause various diseases. It is very important to treat the infectious waste properly before deposing it off.
• Radioactive waste contains liquid and solid waste that is contaminated by radionucleides that are basically formed by the in-vitro breakdown of various body tissues and cells. This type of waste is extremely harmful for the human health.
• Pharmaceutical waste usually contains waste from drugs or medicines which have been contaminated or are no longer in use.

2. Division of the waste

Before the hospital waste is decomposed it is extremely important to treat it with certain chemicals. Different categories of waste materials are divided into diverse sections so that they can be treated accordingly. It is a very important step that should be carried out at the place where the waste is generated. This activity should be carried out at diagnostic services areas, labour rooms, operations theatres, activity areas. Hygiene should be maintained at all time while treating the waste materials.

3. Transportation of waste

Once the waste is divided into the various different categories the next category involves the transportation of the waste matter from the place of origin to the place of decomposition. Bio-medical waste that is obtained from the hospitals should be treated separately and should never be mixed with the general waste. This reduces the chances of any disease.

4. Treatment of the hospital waste

The first step involves disinfecting the waste matter so that it no longer remains harmful for the human health. After disinfecting the waste the volume of waste should be reduced with the help of an efficient trash compactor. The waste matter should also be made unrecognizable so that it can be decomposed without any difficulty. The waste that can be recycled should be treated for further use.

5. Safety measures

Certain important safety measures should always be adopted while treating the waste. Waste which is of infectious nature can be very harmful for the environment and human health that is why measures would be taken for the prevention of any type of disease. Written instructions should be provided to all the people who are handling the hospital waste at the different stages of disposal. The management should be very careful and strict guidelines should be followed at all times without any fail. Awards would also be provided to people who complete the task in the most efficient manner.

So above are some of the most recommended steps to get rid of hospital waste in a healthier manner. I am sure this article would certainly provide you all the information that you require about hospital waste management techniques.

Plastic recycling is a very beneficial technique not only for the humans but also for the natural stability of the earth. Recycling this material is very easy and the process can easily be carried out at home. So now let us discuss some efficient techniques of recycling the plastic products.

1. Dividing the plastic products

There are various different categories of the plastic materials therefore before you carry out the recycling process it is very important for you to divide them in different categories so that the procedure becomes easier for you. Once you have divided the materials and categorized them accordingly it would give you a better idea about the waste that should be decomposed and the ones that can be re-used for other purposes in your home.

2. Mechanical recycling

Mechanical recycling of the plastic products is a very efficient way through which you can recycle the products without any trouble. This method is gaining rapid popularity and most people use it for recycling their household plastic waste materials. This process involves the melting of plastic after which it is shredded and granulation is done for completing the process. Various trained personnel are employed for sorting out the different plastic matter in order to make the procedure easier. A variety of special high technology techniques are also being used these days with the help of which plastic can be sorted out in different categories. Some of the most frequently used techniques and methods are infrared spectroscopy, electrostatics, fluorescence and the X-ray process.

3. Chemical recycling

This is another very efficient way of recycling the plastic products. This method is generally used for disposing off the waste materials that are in bulk. This method is a little different from the mechanical recycling process. The chemical technique involves breaking down of the polymers of the plastic in constituent monomers which can be further used in factories and big industries for the production of certain chemicals and petrochemical. More chemical recycling methods are being explored so that more and more plastic products can be recycled without any difficulties. It is capital incentive process that really requires a large quantity of plastic to be processed.

4. Cleaning the plastic products

Cleaning and removing the dirt from the plastic products is another very efficient way through which you can make the plastic reusable. While you are carrying out this task, you must make sure that each and every product that has to be recycled is cleaned in the most efficient manner otherwise the recycling process would not be completed properly. Ensure that you have removed every contaminant that might be left on the surface.

5. Squeeze the plastic products carefully

Before the plastic products are taken to the recycling station they would be properly squeezed and squashed so that any material that is left behind in the bottles or the back can come out. This process also helps in compressing the plastic materials and compressed products are very easy to recycle than the normal ones.

So, if you also want to recycle plastic, above stated are some highly efficient and useful techniques that you must follow in order to get the desired results.

As of estimates made in 2002, India had more than 3000 tanneries with a total capacity of 700000 tonnes of hides and skins per year. The annual income from leather trade in India was about Rs 20000 crores. More than 90% of the tanneries were small or medium with a processing capacity of less then 2 to 3 tonnes of hides/skins per day. Most of the tanneries are located near river banks. The highest concentration of tanneries in India is on the banks of Ganga river (Kanpur, Unnao) in North India and the Palar river system in Tamilnadu.

Leather Production Technology and Pollution:

An animal skin consists of about 61% water, 34% fibrous proteins, 1% globular proteins, 2% lipids, 1% natural salts and some other ingredients including pigments. Out of three layers, the epidermis, dermis and the hypodermis it is the dermis which is later transformed into leather. The epidermis primarily composed of keratin has hair which is removed and the hypodermis has flesh and blood vessels which is also removed. In leather processing, the basic operations revolve round cleaning the skin of unwanted inter fibrillary material through a set of pre-tanning operations in the Beam House, processing the leather permanently by means of tanning and adding aesthetic value during the post tanning process. The starting material in most cases is raw hide or skin which has been preserved temporarily by the addition of common salt.

1. The Beam House process involves the removal of salt, dirt and hair  in the following processes:

(a)   Desalting and Soaking the hides to remove salt and other foreign material such as dirt and also to remove the moisture content.  This process uses a large amount of water about 20 m³ per ton of hide and generates conspicuous pollution. Soaking generates about 6-9 m³ per ton of effluents with a BOD from 1100 to 2500 mg/l, a COD of 3000-6000 mg/L, very high total solids and suspended solids, 15000 to 30000 mg/l of chlorides and 800-1500 mg/l of sulphates.

(b)   Unhairing and Liming – The process yields one of the most polluting effluent streams from tanneries. Liming opens up the collagen structure by removing interstitial material, fleshing removes excess tissue from the interior of the hide.  Unhairing is done by treating soaked hides in a bath containing sodium sulphide / Hydrogen sulphide and lime. About 3 to 5 m³ of effluent per tonne of hide/skin is expected to be discharged with a high pH of 10.0 to 12.8, a BOD of 5000 to 10000 mg/l and COD of 10000 – 25000 mg/l. The concentration of sulphides ranges from 200 to 500 mg/l, the total solids (24000 to 48000 mg/l) and sulphates (600-1200 mg/L) are also high.

(c)    Deliming and bating: A bath of ammonium salts and proteolytic enzymes is used to process the pelt. About 1.5 m³ of effluents are generated in the process at a pH of 7 to 9. The pollutants from the process include Calcium salts, Sulphide residues (30 to 60 mg/l), degraded proteins, residual proteolytic enzymatic agents, Chloride (1000 to 2000 mg/l), Sulphates (2000 to 4000 mg/l), BOD (1000 – 3000 mg/l) and COD (2500 to 7000 mg/l). Nitrogen based deliming agents are considered a long term environmental threat because of their impact on soil NOx values.

Sulphates are an important content of pretanning waste waters. They readily get reduced to sulphide under anaerobic conditions in waste water treatment plants like anaerobic lagoons, contact filters or up flow anaerobic sludge blanket reactors. A build up of sulphides makes the biomethanation of organic materials less effective apart from adding to the COD load. Ammonia is also given off as an air pollutant in the process.