Methods of disposing biomedical and hazardous waste

 Methods of disposing biomedical and hazardous waste

Introduction

Modern society produce large quantities of biomedical waste and hazardous waste generated By hospitals, chemical manufacturing companies, petroleum refineries, paper  mills, smelters and other industries. Biomedical waste comprises human and animal anatomical waste, treatment apparatus like needles, syringes and other materials used in health care facilities, treatment and research. This waste is generated during diagnosis, treatment or immunization in hospitals, nursing homes, pathological laboratories, blood bank etc..Because some waste can be contaminated with disease or dangerous pathogens. All biomedical waste is not disposed in same way so this demands scientific disposal of biomedical waste. Waste is classified as hazardous when it causes or  significantly contributes to an increase in mortality, an increase in serious irreversible or incapacitating reversible illness, and poses a substantial present or potential hazard to human health or the environment when inadequately treated, stored, transported. When is classified as hazardous if it exhibits any of the four primary characteristics based on the physical or chemical properties of toxicity , reactivity, ignitability or corrosivity.

Methods of disposing Bio-Medical waste

Autoclaving

The process of autoclaving involves steam sterilization. Instead of incineration, which can be expensive, autoclaving simply introduces very hot steam for a determined amount of time. At the end of the process, microorganisms have been completely destroyed. This process is particularly effective because it costs much less than other methods, and doesn’t present any personal health risks. While some biomedical waste isn’t able to be disposed of via autoclaving, around 90% of materials are sanitized this way before being sent on to a landfill.

Incineration

The major benefits of incineration are that it is quick, easy, and simple. It effectively removes the waste entirely, and safely removes any microorganisms. However, when burning hazardous materials, emissions can be particularly dangerous. Some states prefer for waste disposal to look towards incineration as their first choice, but materials must be reviewed and determined as safe to burn.

 

Chemical disinfection

 When it comes to liquid waste, a common biomedical waste disposal method can be chemical disinfection. Chlorine is a regular choice for this process, and is introduced to the liquid waste in order to kill microorganisms and pathogens. Chemical disposal can also be used for solid wastes, but it is recommended that they be grinded first to ensure maximum decontamination. Liquid waste, once decontaminated, is then disposed into the sewer system.

 

 Microwaving

During this process, waste is shredded, mixed with water, and then internally heated to kill microorganisms and other harmful elements. One of the main benefits of this process is the shredding aspect; it lowers the volume of biomedical waste, and it is reportedly more energy efficient to use this method than to incinerate. While it can’t be used for all biomedical wastes, it can be utilized for a good 90% of it, just like autoclaving.

 Land disposal

Land disposal is typically used for shredded, treated and decontaminated waste. In certain cases it can also be used for hazardous waste or other untreated waste that cannot be decontaminated by other means. Specialized sanitary landfill sites exit to reduce the risk of soil and water contamination and provide a safe space for medical waste disposal.

 

Biomedical waste management rules

The MoEF&CC released bio medical waste management rules 2016 to bring in wider and more comprehensive regime for bio waste management. Bio medical waste management rules 2016 rules have been amended bio medical waste management rules, 2018 to improve compliance and strengthen the implementation of environmentally sound management to biomedical waste in india.

Salient features of Bio-Medical Waste management rules

1. Bio-medical waste has been classified into 4 categories instead of 10 to improve the segregation of waste at source.
2. Phase-out the use of chlorinated plastic bags, gloves, and blood bags within two years.
3. The ambit of the rules has been expanded to include vaccination camps, blood donation camps, surgical camps, or any other healthcare activity.
4. Pre-treatment of the laboratory waste, microbiological waste, blood samples, and blood bags through disinfection or sterilization on-site in the manner as prescribed by WHO or NACO.
5. State Government to provide land for setting up common bio-medical waste treatment and disposal facilities.
6. No occupier shall establish an on-site treatment and disposal facility if a service of `common bio-medical waste treatment facility is available at a distance of seventy-five kilometer.
7. The new rules prescribe more stringent standards for an incinerator to reduce the emission of pollutants in the environment.
8. Inclusion of emissions limits for Dioxin and furans.

 

Methods of disposing Hazardous waste

Secure landfill

Much like sanitary landfill, it is designed to confine the waste to a particular location, control the draining of leachate from the waste, collect and treat the leachate from the landfill. No landfill could be completely secure, implying that some leakage always occurs from the landfill

Deep well injection

Waste disposal involving injection of waste into deep wells drilled into earth’s crust. The deep well must be completely isolated from the fresh water aquifers. For example oil industry uses deep well injection to dispose liquid wastes like oil field brine. Limited number of suitable sites for disposal is a limitation in widespread use of this method.

Bioremediation

Reduction in concentration or clean up of toxic wastes using microorganisms like bacteria and fungi and also by plants. Certain strains of bacteria and fungi can breakdown even highly dangerous chemicals like DDT, toxic nitrates , PCBs etc. through microbial breakdown to produce simpler, less toxic or non-toxic forms. The microorganisms may be naturally occurring in a contaminated area or may be brought from elsewhere to contaminated site. This method can be effective only where environmental condition permit microbial growth and activity. For example bioremediation is used to treat organic petroleum waste of marine oil spills.

Salient features of hazardous waste management rules

This rules were notified by MoEF&CC in 2016 to ensure resource recovery and disposal of hazardous waste in environmentally sound manner.

Ambit of rules

Ø  The rules have been expanded to include other wastes apart from hazardous wastes.

Waste management hierarchy

Ø  waste management will be done in sequence of prevention, minimization, reuse, recycling, recovery, co-processing and safe disposal

Single window clearance

Ø  procedure has been simplified to merge all the approvals as a single window clearance for setting up of hazardous waste disposal facility and import of other wastes

 

Responsibility of the state government

Ø  it has to prepare integrated plan for effective implementation of these provisions, and has to submit annual report to MoEF&CC

Ø  To allot industrial space or sheds for recycling , pre processing and other utilization of hazardous or other waste

Ø  To register the workers involved in recycling, pre-processing and other utilization activities.

Ø  To undertake industrial skill development activities and ensure safety and health of workers

Revision of list of waste regulated for import / export

Ø  Items prohibited for import waste edible fats and oil of animals or vegetable origin ; household waste, critical care medical equipment, tyres for direct re use purpose, solid plastic wastes including pet bottles, waste electrical and electronic assemblies scrap other chemical wastes especially in solvent form

Ø  Import of metal scrap, paper, waste and electrical and electronic equipment does not require the ministry’s permission

Responsibility of SPCBs

SPCB must prepare a report on the waste generated, recycled, recovered, utilized, co-processed, re-exported and disposed and submit it to the CPCB every year.