11 Sludge Hygienisation—A Novel Technology for Urban Areas …
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The industrial wastewater (IWW) encompasses contaminated stormwater, washdown waters from mechanical plants and vehicles, cooling water from the energy
production industries and process waters from several plant units dedicated to food
processing, mineral processing, fertilizer production, textile processing, manufacturing chemicals, petrochemical works, etc. [28]. Several IWW streams contain both
heavy metals and the organic compounds as the pollutants [29], and studies indicate the emergence of IWW as a major source through which anthropogenic organic
chemicals (e.g. acrylonitrile, styrene, ethylbenzene, dimethyl-benzene, chlorinated
organics and other functional chemicals) enter the environment [30, 31]. In the
stormwater run-offs, the Pb load is largely attributed to the abrasion of paved surfaces
due to the friction between the vehicle tyre and the road, as well as, the wearing of the
brake lining [12]. Wearing of brake lining can also lead to the release of other metals,
such as Cd, Cu, Sb and Zn into the urban run-offs [32]. Additionally, Pb and Zn being
washed down from the roofing materials in the housing complexes serve as the localized sources of these elements in the stormwater [12], especially during the periods
of heavy monsoon. The organic load in IWW occurs in the form of various organic
substances [12], of which the non-polar organic compounds (NPOC) that are lighter
than water (e.g. phthalate esters, alkanes, polycyclic aromatic hydrocarbons (PAHs),
etc.) tend to form a prohibitive layer [33], essentially blocking the flow of oxygen into
the wastewater stream, whereas, a few polar substances [34, 35] (e.g. pharmaceuticals, viz.1 H-Benzotriazole, Clofibric acid, Sulfamethoxazole etc.) that are soluble
in water have been toxic to the aquatic fauna and have been found to even trigger the
eutrophication upon being discharged into the urban waterbodies, thereby disrupting
the equilibrium in the biotope [36]. From the viewpoint of treatment of IWW, a
critical problem arises due to the fact that the wastewater stream contains a combination of organics. It is comparatively easier to deal with the organic compounds
when a particular compound (e.g. Lindane, a common insecticide) is alone in the
IWW, using specialized disposal techniques such as high-temperature incineration.
However, for the wastewater containing different combinations of organic wastes,
no single treatment technique is found to be fully amenable.
The wastewater streams from the healthcare establishments or the medical
wastewater (MWW) usually exhibit a physico-chemical quality akin to urban
wastewater; however, the presence of various potentially hazardous components, viz.
high concentration of enteric pathogens (including bacteria, viruses and helminths),
hazardous chemicals used in cleaning and disinfection, pharmaceuticals (including
antibiotics and genotoxic drugs), radioactive isotopes from oncology departments,
make the MWW a high-risk flow stream [11]; and adherence to biomedical waste
guidelines is a must for ensuring safe discharge of healthcare waste in to the sewer.
Particularly, the healthcare waste contaminated with pathogens and infectious
particles poses serious concern for the people dealing with it at each stage starting
from the waste generation to ultimate disposal. The biomedical waste generated while
treating the patients in the care units is taken away by the hospital staffs and practitioners, and thereafter, it is handed over to the disposal staff. As the infected waste
passes through several hands, there is a finite chance that the infectious particles
would spread, which may at times assume the form of a pandemic if not intervened
267
The industrial wastewater (IWW) encompasses contaminated stormwater, washdown waters from mechanical plants and vehicles, cooling water from the energy
production industries and process waters from several plant units dedicated to food
processing, mineral processing, fertilizer production, textile processing, manufacturing chemicals, petrochemical works, etc. [28]. Several IWW streams contain both
heavy metals and the organic compounds as the pollutants [29], and studies indicate the emergence of IWW as a major source through which anthropogenic organic
chemicals (e.g. acrylonitrile, styrene, ethylbenzene, dimethyl-benzene, chlorinated
organics and other functional chemicals) enter the environment [30, 31]. In the
stormwater run-offs, the Pb load is largely attributed to the abrasion of paved surfaces
due to the friction between the vehicle tyre and the road, as well as, the wearing of the
brake lining [12]. Wearing of brake lining can also lead to the release of other metals,
such as Cd, Cu, Sb and Zn into the urban run-offs [32]. Additionally, Pb and Zn being
washed down from the roofing materials in the housing complexes serve as the localized sources of these elements in the stormwater [12], especially during the periods
of heavy monsoon. The organic load in IWW occurs in the form of various organic
substances [12], of which the non-polar organic compounds (NPOC) that are lighter
than water (e.g. phthalate esters, alkanes, polycyclic aromatic hydrocarbons (PAHs),
etc.) tend to form a prohibitive layer [33], essentially blocking the flow of oxygen into
the wastewater stream, whereas, a few polar substances [34, 35] (e.g. pharmaceuticals, viz.1 H-Benzotriazole, Clofibric acid, Sulfamethoxazole etc.) that are soluble
in water have been toxic to the aquatic fauna and have been found to even trigger the
eutrophication upon being discharged into the urban waterbodies, thereby disrupting
the equilibrium in the biotope [36]. From the viewpoint of treatment of IWW, a
critical problem arises due to the fact that the wastewater stream contains a combination of organics. It is comparatively easier to deal with the organic compounds
when a particular compound (e.g. Lindane, a common insecticide) is alone in the
IWW, using specialized disposal techniques such as high-temperature incineration.
However, for the wastewater containing different combinations of organic wastes,
no single treatment technique is found to be fully amenable.
The wastewater streams from the healthcare establishments or the medical
wastewater (MWW) usually exhibit a physico-chemical quality akin to urban
wastewater; however, the presence of various potentially hazardous components, viz.
high concentration of enteric pathogens (including bacteria, viruses and helminths),
hazardous chemicals used in cleaning and disinfection, pharmaceuticals (including
antibiotics and genotoxic drugs), radioactive isotopes from oncology departments,
make the MWW a high-risk flow stream [11]; and adherence to biomedical waste
guidelines is a must for ensuring safe discharge of healthcare waste in to the sewer.
Particularly, the healthcare waste contaminated with pathogens and infectious
particles poses serious concern for the people dealing with it at each stage starting
from the waste generation to ultimate disposal. The biomedical waste generated while
treating the patients in the care units is taken away by the hospital staffs and practitioners, and thereafter, it is handed over to the disposal staff. As the infected waste
passes through several hands, there is a finite chance that the infectious particles
would spread, which may at times assume the form of a pandemic if not intervened