Waste management is a nuisance in developing countries. All kinds of waste, including hazardous industrial, commercial and municipal waste, are dumped without segregation at designated dumping sites. Dumping sites in the developing world are far more different from properly-designed landfill sites. The landfills are usually built at a distance from residential areas so the smell of rotten waste and vector-borne diseases do not trouble people. Moreover, properly-designed landfills have designated sections lined with geoliners (plastic sheets spread at the bottom of landfills) to dump waste with all precautionary measures and covering them with soil layers. In Pakistan, different dumping sites are currently active prior to unsegregated dumping and proper disposal.
Improper dumping and disposal of wastes produce a serious environmental hazard called “leachate”. This is the fluid produced by the moisture content in the waste, leaching down all the characteristic qualities of the waste. The rain accelerates its generation, especially during the Monsoon season. Thanks to the mutual dumping of waste, leachate can be considered the king of wastewater as it has the highest quantities of toxicants, metals, hormonal disrupters, bacterial infections and all emerging pollutants. High composition of degradable waste is generated from municipal sector along with acids, surfactants and bleaches, while most of the polythene and paper waste is generated from the commercial sector. The industrial and hospital waste is most concerning. Industries, including the pharmaceutical, chemical, paint, plastic, textile, leather industry produce extremely toxic waste, whereas used syringes, blood bags, expired medicines, and other utensils of patients are thrown unattended at open waste dump sites.
Leachate is highly variable and heterogeneous. Generally, leachate produced in freshly-dumped waste is characterised by the presence of substantial amounts of volatile acids, as a result of the acid phase of fermentation. In mature dumping sites, the greater portion of organics in leachate are humic and fulvic compounds. The leachate contains organic hazardous substances such as aromatic compounds, chlorinated aliphatic compounds, phenols, phthalates and pesticides. However, biodegradable waste like organic matter including kitchen waste, dairy waste from dairy industries, sewage sludge, and breakdown starting with aerobic degradation, followed by anaerobic phase and ending up with the humic phase.
Introducing air to the waste tip encourages aerobic transformation of wastes which is expected to increase the degradation rate, enhance ammonium nitrogen removal and shorten the waste stabilization period. This suggestion is for newly designed landfills. However, the main problem with un-engineered landfill or dumping sites is that they have do not have geoliners to prevent the percolation of leachate in ground water aquifers, and resulting in contamination. It may also be released to nearby water bodies and causing potential hazards to the ecosystem and to human health.
The concentration of toxicants depends on the age of the dumping site and it metastasizes diseases. Metals and other toxicants in the leachate may transform physically and chemically, and can possibly be carcinogenic, while also causing impairments to the ecosystem. Unfortunately, there is barely any awareness about waste handling and dumping, and leachate generation in Pakistan as tons of waste is dumped on empty lands in residential or commercial zones. Waste management is very crucial for any society as its absence may lead to many problems including leachate generation and contamination. We are blindly running behind the cure for diseases without paying attention to the cause and source of the problem. Meanwhile, tackling this one problem can save many lives and reduce national health costs All of our hospital, commercial, and industrial waste should be checked and regulated by implementing the existing laws strictly, and the government should provide subsidized waste collection and healthy waste disposal with leachate collection and treatment facilities for the betterment of Pakistan’s health.
Published in The Express Tribune, August 2nd, 2019.