Home Today's Paper Most Popular Video Gallery Photo Gallery
Subscription Blog Signin Register
Logo
Wednesday, June 19, 2019 08:02:43 PM
Follow Us On: Facebook Twitter Twitter Twitter Twitter

Hazardous Wastes

Modify Manufacturing Processes To Mend It

By
11th-Jun-2019       
Comments
Share your thought
Post a comment »
Read all () »

Shishir Reza :
Hazardous waste means a waste or combination of waste which because of the quantity concentration or physical, chemical characteristics may cause or contribute to increase in mortality or an increase in serious illness or potential health hazard or environmental degradation.
Setting the Scene
Hazardous waste is a waste with properties that make it potentially dangerous or harmful to human health or the environment. The universe of hazardous wastes is large and diverse. Hazardous wastes can be liquids, solids, or contained gases. They can be the by-products of manufacturing processes, discarded used materials, or discarded unused commercial products, such as cleaning fluids (solvents) or pesticides. In regulatory terms, a hazardous waste is a waste that appears four characteristics - ignitability, corrosivity, reactivity, or toxicity. However, materials can be hazardous wastes even if they are not specifically listed or don't exhibit any characteristic of a hazardous waste. For example, "used oil," products which contain materials on California's M-list, materials regulated pursuant to the mixture or derived-from rules, and contaminated soil generated from a "clean up" can also be hazardous wastes. There are mainly three types of hazardous waste; such as: (i) Radioactive wastes (ii) Medical wastes and (iii) Non radioactive industrial liquid waste.
Types and General Features
All nuclear reactors rely on uranium as fuel. The natural uranium contains 99% of U-238 and 1% of U-235. It can be used as such in heavy water reactors. For use in light reactors, it should be enriched about 3 to 3.6% with respect to U-235 content in an isotope enrichment plant. The enriched uranium is fabricated into fuel rods and is inserted in nuclear reactors. During operation of the reactor, the fuel rods become intensely radioactive due to the generation of fission products and Trans uranium elements such as plutonium americium and curium. After the fuel rods are removed from the reactor, they should be cooled in water-filled pools to remove the heat liberated due to radioactive decay. The fuel cycle is than completed by disposing of the fuel in an underground repository or separating the residual plutonium from uranium and fission products. The fission products are than immobilized by incorporating into ceramic or glass matrix and disposed off into an underground repository.
Biomedical waste originates from hospitals, clinics, research and testing laboratories and drug companies. These include pathological and surgical waste: experimental animals and cadavers, drug and chemical residues and their containers; discarded bandages, linens and infectious waste; disposable syringes, needles and surgical instruments, contaminated equipment, food and other waste materials. Chemical and chemotherapy waste, organic solvent waste and radioactive waste are not included in the biomedical waste because they are governed by different regulations. The normal practice of handling hospital waste is the on-site incineration of the combustible solids in a specially designed high temperature incinerator provided with after burners to heat the gases leaving the chamber to 700 degree Celsius for controlling odors. The ash thus produced is disposed in sanitary landfills.  
Modern civilisation has resulted in large scale manufacture of products such as TV sets, aerosol cans, pesticides, plastics, preservatives, automobiles. These industries generate a multitude of hazardous industrial waste, toxic substances such as heavy metals. Proper management of this hazardous industrial waste is mandatory from the point of view of public health and environmental protection; especially for the wastes that produce from industrial activities such as printing activities, mining activities and other industrial activities.
Impacts of Hazardous Waste
The particulate and electromagnetic radiation emanating from radioactive materials inflict deleterious effect on the living cells. These effects are classified as somatic and genetic. Somatic effects are caused on the exposed individuals and the cell damaged caused manifest in malignancies' such as leukemia or cancer. Genetic effects are transmitted to the descendants of the exposed individuals and thus can effect unexposed generation too. The radiation induced changes in the genes may manifest themselves in- Gene mutations, Chromosomal aeration and Changes in the number of chromosome.
Such changes can result in abnormalities in the offspring which may be mild or lethal. Hazardous and toxic wastes are waste materials that cause health problems, including birth defects, neurological disorder, reduced résistance to infections and cancer. Environmental costs of hazardous and toxic waste include contamination of water supplies, poisoning of soil and destruction of habitat.
How to Manage Hazardous Waste?
1. pollution should be prevented or reduced at the source whenever feasible; 2.pollution that cannot be prevented should be recycled in an environmentally safe manner whenever feasible; 3.pollution that cannot be prevented or recycled should be treated in an environmentally safe manner whenever feasible; and 4.disposal or other release into the environment should be employed only as a last resort and should be conducted in an environmentally safe manner.
Converting Less Hazardous Substance
Several processes are available to make hazardous materials less toxic. Physical treatment ties up or isolates substances. Charcoal or resin filters absorb toxins. Distillation separates hazardous components from aqueous solution. Precipitation and immobilization in ceramics, glass or cement isolate toxins from the environment; so that they become essentially non-hazardous. One of the few ways to dispose of metals and radioactive substances is to fuse them in silica at high temperature to make a stable, impermeable glass that is suitable for long term storage. Plant, bacteria and fungi can also concentrate or detoxify contaminants.
Incineration is applicable to mixtures of waste. A permanent solution to many problems, it is quick and relatively easy, but not necessarily cheap - nor always clean- unless done correctly. Wastes must be heated to over 1000 degree Celsius for a sufficient period of time to complete destruction. The as resulting from through incineration is reduced is volume up to 90% and often is safer to store in a landfill or another disposal site than the original site. Nevertheless, incineration remains highly controversial.
Chemical processing can transform materials so they become nontoxic. Included in this category are neutralisation, removal of metals or halogens and oxidation. The Sunohio Corporation in Ohio, for instance have developed a process called PCBx, in which chlorine in such molecules as PCBx is replace with other ions that render the compounds less toxic. A portable unit can be moved to the location of the hazardous waste, eliminating the need for shipping them.
 Storing Permanently
Secure landfill one of the one of the most popular solution for hazardous waste disposal has been land filling. Although as we saw earlier, many such landfills have been environmental disaster, newer technique make it possible to create safe, modern secure landfills that are acceptable for deposing of many hazardous waste. The first line of defense n a secure landfill is a thick bottom cushion of compacted clay that surrounds the pit like bathtub. Moist clay is flexible and resists cracking if the ground shifts. It is impermeable to ground water and will safely contain waste. A layer of gravel is spread over the clay liner and perforated drainpipes are laid in a grid to collect any seepage that escapes from the stored materials. A thick polyethylene liner, protected from punctures by soft padding materials, covers the gravel bed.
When the landfills has reached its maximum capacity, a cover much like the bottom sand witch of clay, plastic and soil-in that order - caps the site. Vegetation stabilizes the surface and improves its appearance. Sumps pumps collect any liquid filter through the land fill, either from the rain water or leaking drums. This leach ate is treated and purified before released. Monitoring wells check ground water around the site to ensure that no toxins have escaped.
Concluding Remarks
Global waste production is a critical issue in environmental quality. Every day a huge amount of hazardous and toxic waste discharge into our natural environment. These materials throw into the environment without any treatment, which are very harmful for organisms live in the environment. Incineration is the important method for waste disposal. Incineration can destroy the organic compounds and it can be used to produce energy. Recycling is another method to reduce the pollution, which is occurring by hazardous waste. Reusing, demanufacturing and reducing material consumption are important additional strategies for reducing the waste stream.
(Shishir Reza, Environmental Analyst and Associate Member, Bangladesh Economic Association)

Tariff
Add Rate

News Archive

Inside The New Nation

Business & Economy »

MBL's award giving ceremony held


Economic Reporter :Mercantile Bank Ltd on Monday organised the 'Mercantile Bank Sommanona-2019' to award four eminent personalities and one institution for their outstanding contributions to the society. Bangladesh Bank Governor Fazle Kabir handed over the gold medals, crests and cheques to all the awardees at a graceful ceremony at Hotel ...

Entertainment »

Maera Mishra is excited about her upcoming projects!


Maera Mishra is an Indian actor and model. She is as in the 11th season of MTV Splitsvilla. Ever since she featured in Splitsvilla Maera has not looked back. Maera is also a budding actor and she could be seen in love on the run on MTV, Savdhan India, Fear ...

Entertainment »

Soundarya Sharma yet again strikes a humanitarian chord


It was just recently when she instead of attending an event chose to help an injured cyclist. Now we just learned that Actor Soundarya Sharma is sponsoring health care for an elderly couple for a year, she came across an article about how elderly are lacking proper health care, as ...

International »

Trump heads back to base for 2020 campaign kickoff


President Donald Trump will get a big crowd of his most loyal supporters at Tuesday's official 2020 reelection campaign kickoff in Florida but dismal early poll numbers show the larger-than-life Republican businessman is vulnerable.Organizers claim the Orlando rally has sold out a 20,000-seat arena, with many more to gather outside, ...

International »

China warns US against opening ME 'Pandora's box'


AFP, Beijing :China on Tuesday warned against opening a "Pandora's box" in the Middle East after the United States announced the deployment of 1,000 additional troops to the region amid escalating tensions with Iran.Foreign Minister Wang Yi also urged Tehran to not abandon the nuclear agreement "so easily" after Iran ...

Cricket »

Shakib Al Hasan: A man born to create milestone


Talismanic all-rounder Shakib Al Hasan now won two matches for Bangladesh in this World Cup, all by alone. When most of his teammates looked inconsistent, he did it by his own almost, albeit with little support from two different men in two different games.In Bangladesh's 21-run victory over South Africa, ...

Editorial »

No development projects destroying the Sundarbans


TRANSPARENCY International Bangladesh has called upon the government to immediately suspend all controversial projects, including the Rampal Power Plant near the Sundarbans. TIB also expressed deep concern following the UNESCO's recent proposal to put the Sundarbans on the list of "World Heritage in Danger" in the proposed agenda for its ...

Cricket »

Jason Roy to miss Afghanistan, Sri Lanka games with hamstring tear


England opening batsman Jason Roy, who left the field during the team's eight-wicket win over West Indies, has been ruled out of their next two matches, against Afghanistan and Sri Lanka, an England and Wales Cricket Board release announced on Monday, 17 June.Roy had left the field during the West ...

International »

"Khashoggi death painful, stop exploiting case": Saudi Crown Prince


 AFP, Riyadh :Saudi Crown Prince Mohammed bin Salman has warned against "exploiting" the murder of journalist Jamal Khashoggi for political gains, in what appeared to be a veiled attack on Turkey.Turkey's ties with Saudi Arabia have come under strain since the brutal murder last October of Khashoggi in the Saudi ...

Editorial »

No end to pain and miseries of slum dwellers


LOCAL Government Division Minister on Sunday informed the National Parliament that about 6.46 lakh people were living in 3,394 slums in the capital city Dhaka. Responding to a question from a lawmaker, he said there were 1,639 slums housing 4,99,011 people in the Dhaka North City Corporation area and 1,755 ...

Entertainment »

Taylor Swift releases new single You Need To Calm Down


Singer-songwriter Taylor Swift needs us to calm down but with the release of her latest single we just can’t! The 29-year-old singer dropped her new single titled You Need To Calm Down from her upcoming studio album Lover. The artist shared the lyrical video of the song on her official ...

Cricket »

No fracture found on Mushfiqur's forearm


Bangladesh heaved a huge sigh of relief after an X-ray report revealed that Mushfiqur Rahim had no fracture on his forearm.Mushfiqur, considered as the most dependable batsman of the country, got hit on his right forearm during a batting practice session while facing a bouncer from pace bowler Mustafizur Rahman.He ...

International »

Saudi Crown Prince lashes out at arch-rival Iran over tanker attacks


AFP, Riyadh :Saudi Crown Prince Mohammed bin Salman accused arch-rival Iran of attacks on oil tankers in a vital Gulf shipping channel, adding he "won't hesitate" to tackle any threats to the kingdom, according to an interview published on Sunday.Two tankers were struck by explosions on Thursday in the Gulf ...

Cricket »

More than just a game: India face Pakistan in World Cup battle royale


Virat Kohli will have history on his side when India take on arch-rivals Pakistan in a World Cup blockbuster on Sunday -- a clash that is always more than just a game of cricket.India cut off bilateral cricket ties with its neighbour after the 2008 Mumbai terror attacks, with authorities ...

Cricket »

Eoin Morgan downplays England's injury concerns


England captain Eoin Morgan said that his team is "not at panic stations", after he and Jason Roy left the field with discomfort during the game against West Indies in Southampton on Friday, 14 June.Both Roy and Morgan had left the field at different points during West Indies' innings and ...

 
Items that you save may be read at any time on your computer, iPad, iPhone or Android devices.
 
Are you new to our website? Do you have already an account at our website?
Create An Account Log in here
Email this news to a friend or like someone
Email:
Write a comment to this news