EPM - Module 5
EPM - Module 5
MODULE 5
India is a vast country with an average of 700 pulp and paper mills. It is one of the highest polluting
industries in India and is highly water intensive. Relatively large wastewater discharges and
accompanied release of high pollution load into the environment is the sequel of high water
consumption and pollution generation in the process of pulp and paper manufacture. Steps are been
taken to preserve the resources, especially water which is an integral part of the pulp and paper
industrial functioning. The need of cleaner production programs has been felt in recent times by
the paper industry by way of a resource and waste minimization concept. In India efforts have
been going on for years to improve house keeping, optimize process parameters, increase recycles
and adopt improved technology. This paper aims at highlighting the process used during
manufacture, sources and types of waste generated and treatment options available for improving
the quality of waste to be discharged.
Sources of Waste Generation
In pulp and paper industry, considerable quantity of water is used in paper making processes.
The quantity of water consumption varies according to the quality and kind of paper to be
manufactured. In addition considerable amount of solid waste and gaseous emission occurs.
regularly pumped out at about 3% solid consistency. The sludge can be dewatered to spedable
consistency by drying on usual drying beds, vacuum bed filters, and solid bowl centrifuges.
Biological Treatment : Depending upon the conditions at site and degree of treatment required
for final disposal of effluents, biological treatment methods that can be adopted include; oxidation
pond, aeration lagoon, trickling filter with secondary clarifier and activated sludge process.
   ➢ These wastes affect the main elements of environment such as air, water and soil and
     the animal or plants living depending on these elements are harmed drastically.
   ➢ It was showed that the most harmful environmental effect was bad smell to the
     surrounding areas which caused environmental pollution
b) Process-wise, some of the waste minimisation measures to be adopted by the tannery units
include the following:
 i) Soaking: The waste minimisation measures for reducing water consumption inter-alia include:
 • Use of counter current system of washing to concentrate the salt and other soluble materials
such as dirt and blood.
• Reuse of the 2nd main soak for dirt soak: Soaking consists of dirt soak and main soak. The main
soak is retained and used for dirt soak for the following batch.
• Reuse of dirt soak: The dirt soak liquor may be collected and added polyelectrolyte toflocculate
and settle the suspended solids. Soak liquor thus treated and filtered can be reused partially in
liming, deliming washes and pickling.
• Drum soaking instead of pit soaking: This will not only reduce water consumption but will also
bring down the soaking time from 12 hrs to 3 hrs. This will enable the tanners to construct solar
evaporation pond in less area thereby using the open land for more productive use.
• Addition of soaking enzymes: Soaking enzymes are added to achieve uniform and thorough
soaking. Further, to improve the treatability of waste water, regular wetting agent should be
substituted with biodegradable wetting agents.
• Stop ''open washing systems‖ in drum washing. Use batch systems only. Batch washinginvolves
washing of hides and skins during processing by introducing the required quantity of clean water
into the processing vessel and using the action of the vessel to achieve the required agitation as
opposed to running water washes which use the inflow and outflow of large quantities of water.
 ii) Liming: The following measures shall be adopted to optimise chemical consumption in this
process step. These include:
• Substitution of paste lime by 85% pure calcium hydroxide [Ca(OH)!]: This will bring down the
quantity of consumption of powdered lime to one third ofits original quantity. lt will also reduce
the frequency of cleaning the primary settling tanks which consisted mainly of the lime sludge.
• Use of liming enzymes: Use of liming enzymes will reduce Sodium sulphide (NaS)
consumption by 40%. • Provision of a slight slope in the pasting area: By providing a slight slope
in the pasting area the excess liming paste can be effectively collected and used which is otherwise
washed away in the drain by lime yard workers.
 • Reuse of relime liquor: 50% of relime liquor can be retained and reused for liming of
subsequent batches. This will also reduce water consumption in liming. In addition to optimisation
of the chemical consumption in liming section, fleshings can be used to produce biogas, gelatine,
glue and also high-grade protein. This will solve the problem of solid waste disposal from the
liming section.
ENVIRONMENTAL PROTECTION MANAGEMENT (21CV753)                          By: Dhanashree N Nerlikar
iii) Deliming: Efforts should be made to reduce the water consumption in this section process by
implementing the following measures:
• Reduce the use of ammonium by the injection of carbon dioxide gas (mainly applicable for
large tanneries and /or the use of other substitutes deliming agents 10
 iv) Pickling: In this process, the following measures should be adopted to reduce salt
consumption: a. Use of drained float for next batch or go directly to tanning. b. Controlling
pickle liquor to 6° - 7° to optimise use of sodium chloride (NaCl).
 v) Chrome tanning: The following measures should be adopted to recover chrome fromchrome
tanning process, if it is applicable for the tannery. It may be restricted by the need to produce
leather properties which meat the customer requirement in particular related to dyeing (reduced
fastnesss and less brightness of colours) and fogging. a. Collection of spent chrome liquor after
basification and recovery of chrome from the same. The recovered chrome can be used along with
regular Basic Chrome Sulphate (BCS) for chrome tanning.
vi) Dyeing: The waste minimization measures under this process include the following: a. Use of
soft water for dyeing process to reduce the dye consumption as well as syntans consumption, in
case, the fresh water quantity is not good enough (hardness). b. Use of automated water dosing
systems.
 3.   Recirculation of water employed in SO gas coolers, massecuite cooling, and elsewhere with proper cooling
                                             2
 6.   Installation of condensate polishing unit (CPU) where high pressure boiler is used
ENVIRONMENTAL PROTECTION MANAGEMENT (21CV753)                           By: Dhanashree N Nerlikar
10. Colour coding of pipelines carrying recycled process water and fresh process water
14. Ensuring the analysis of effluent discharge parameters notified under Environment (Protection) Rules, 198
daily basis.
Pollution Control
      ➢ There is scope of recycling and reuse of water in sugar mills thereby minimising water
        consumption and ultimately effluent quantity.
      ➢ The recycling and reuse of hot condensate water can reduce the water consumption to as
        low as. 100-200 litres, as against 1,500-2,000 litres per tonne of cane crushed.
      ➢ Proper housekeeping, periodic checking and maintenance of pipe joints, valves andglands
        further reduces the water consumption and effluent quantity
      ➢ .The effluents from the sugar industry can be treated added. The preparation of milk of the
        lime by conventional biological treatment systems. general, anaerobic biological processes
        (oxidation ponds and biomethanation) several advantages over aerobic processes (aerated
        lagoons, activated sludge process).
      ➢ Anaerobic processes are easier to control and operate, produce a lower quantity of sludge
        and their costs are lower. Anaerobic processes decompose the organic compounds in an
        atmosphere free of oxygen and consequently require significantly less energy as compared
        to aerobic processes.
      ➢ Among the air pollution control of treated equipments; wet collectors and multi-cyclones,
        can reduce particulate matter in boiler emissions by 90% or more.
      ➢ These equipments can reduce ..the concentration of particulate matter to 450 mg/ Normal
        cubic metre. Double Sulphitation Process, already adopted by most of the sugar industries,
        reduces the quantity of lime sludge and press mud to a I great extent.
      ➢ The lime sludge is usually dumped in low lying areas, whereas press mud is sold to farmers
        as it can be used as manure.
      ➢ Bagasse is either used as fuel or sold to pulp and paper industry which use them as raw
        materials.. Molasses produced in sugar industry is raw materials for fermentation
        industries.
ELECTROPLATING INDUSTRY
ENVIRONMENTAL PROTECTION MANAGEMENT (21CV753)                           By: Dhanashree N Nerlikar
Pollution Prevention and Control Plating involves different combinations of a wide variety of
processes, and there are many opportunities to improve on traditional practices in the industry. The
improvements listed below should be implemented where possible.
1. Changes in Process
   ➢ Replace cadmium with high-quality, corrosion-resistant zinc plating. Use cyanide-free
     systems for zinc plating where appropriate. Where cadmium plating is necessary, use bright
     chloride, high-alkaline baths, or other alternatives. Note, however, that use of some
     alternatives to cyanides may lead to the release of heavy metals and cause problems in
     wastewater treatment
   ➢ Use trivalent chrome instead of hexavalent chrome; acceptance of the change in finish
     needs to be promoted.
   ➢ Give preference to water-based surface-cleaning agents, where feasible, instead of organic
     cleaning agents, some of which are considered toxic.
   ➢ Regenerate acids and other process ingredients whenever feasible.
   ➢ Minimize dragout through effective draining of bath solutions from the plated part, by,
     for example, making drain holes in bucket-type pieces, if necessary.
   ➢ Allow dripping time of at least 10 to 20 seconds before rinsing
   ➢ Use fog spraying of parts while dripping.
   ➢ Maintain the density, viscosity, and temperature of the baths to minimize dragout.
   ➢ Place recovery tanks before the rinse tanks (also yielding makeup for the process tanks).
     The recovery tank provides for static rinsing with high dragout recovery
Testing is required to determine the optimum method for any specific process, but proven
approaches include:
   ➢ Agitation of rinse water or work pieces to increase rinsing efficiency
   ➢ Multiple countercurrent rinses
   ➢ Spray rinses (especially for barrel loads)
   ➢ Recycle process baths after concentration and filtration. Spent bath solutions should be sent
     for recovery and regeneration of plating chemicals, not discharged into wastewater
     treatment units.
   ➢ Recycle rinse waters (after filtration).
   ➢ Regularly analyze and regenerate process solutions to maximize useful life. • Clean racks
     between baths to minimize contamination.
   ➢ Cover degreasing baths containing chlorinated solvents when not in operation to reduce
     losses. Spent solvents should be sent to solvent recyclers and the residue from solvent
ENVIRONMENTAL PROTECTION MANAGEMENT (21CV753)                         By: Dhanashree N Nerlikar
       recovery properly managed (e.g., blended with fuel and burned in a combustion unit with
       proper controls for toxic metals).
ELCROPLATING INDUSTRY
The key production and control practices that will lead to compliance with emissions guidelines
can be summarized as follows:
          o   Use cyanide-free systems.
          o   Avoid cadmium plating.
          o   Use trivalent chrome instead of hexavalent chrome.
          o   Prefer water-based surface cleaning agents where feasible, instead of organic
              cleaning agents, some of which are considered toxic.
          o   Minimize dragout.
          o   Use countercurrent rinsing systems; recycle rinse waters to the process after
              treatment.
          o   Regenerate and recycle process baths and rinse waters after treatment.
          o   Recycle solvent collected from air pollution control systems.
          o   Send spent solvents for recovery.
          o   Do not use ozone-depleting substances.
          o   Manage sludges as hazardous waste. Reuse sludges to the extent feasible but
              without releasing toxics to the environment.
Hazardous-waste management,
   ➢ the collection, treatment, and disposal of waste material that, when improperly handled,
     can cause substantial harm to human health and safety or to the environment.
   ➢ Hazardous wastes can take the form of solids, liquids, sludges, or contained gases, and they
     are generated primarily by chemical production, manufacturing, and other industrial
     activities. They may cause damage during inadequate storage, transportation, treatment,
     or disposal operations.
   ➢ Improper hazardous-waste storage or disposal frequently contaminates surface waterand
     groundwater supplies as harmful water pollution and can also be a source of dangerous
     land pollution.
   ➢ People living in homes built near old and abandoned waste disposal sites may be in a
     particularly vulnerable position. In an effort to remedy existing problems and to prevent
     future harm from hazardous wastes, governments closely regulate the practice of
     hazardous-waste management
   Hazardous-waste characteristics
   ➢ Hazardous wastes are classified on the basis of their biological, chemical, and physical
     properties. These properties generate materials that are either toxic, reactive, ignitable,
     corrosive, infectious, or radioactive.
ENVIRONMENTAL PROTECTION MANAGEMENT (21CV753)                        By: Dhanashree N Nerlikar
   ➢ Toxic wastes are poisons, even in very small or trace amounts. They may have
     acute effects, causing death or violent illness, or they may have chronic effects, slowly
     causing irreparable harm. Some are carcinogenic, causing cancer after many years of
     exposure. Others are mutagenic, causing major biological changes in the offspring of
     exposed humans and wildlife.
   ➢ Reactive wastes are chemically unstable and react violently with air or water. They cause
     explosions or form toxic vapours. Ignitable wastes burn at relatively low temperatures
     and may cause an immediate fire hazard. Corrosive wastes include strong acidic oralkaline
     substances. They destroy solid material and living tissue upon contact,by chemical
     reaction.
   ➢ Infectious wastes include used bandages, hypodermic needles, and other materials from
     hospitals or biological research facilities.
   ➢ Radioactive wastes emit ionizing energy that can harm living organisms. Because some
     radioactive materials can persist in the environment for many thousands of years before
     fully decaying, there is much concern over the control of these wastes.
   ➢ However, the handling and disposal of radioactive material is not a responsibility of local
     municipal government. Because of the scope and complexity of the problem, the
     management of radioactive waste—particularly nuclear fission waste—is usually
     considered an engineering task separate from other forms of hazardous-waste management
   Treatment
   ➢ Hazardous waste can be treated by chemical, thermal, biological, and physical methods.
   ➢ Chemical methods include ion exchange, precipitation, oxidation and reduction, and
     neutralization.
   ➢ Among thermal methods is high-temperature incineration, which not only can detoxify
     certain organic wastes but also can destroy them.
   ➢ Special types of thermal equipment are used for burning waste in either solid, liquid, or
     sludge form. These include the fluidized-bed incinerator, multiple-hearth furnace, rotary
     kiln, and liquid-injection incinerator. One problem posed by hazardous-waste incineration
     is the potential for air pollution.
   ➢ Biological treatment of certain organic wastes, such as those from the petroleum industry,
     is also an option. One method used to treat hazardous waste biologically iscalled
     landfarming. In this technique the waste is carefully mixed with surface soil on a suitable
     tract of land.
   ➢ Microbes that can metabolize the waste may be added, along with nutrients. In some
     cases a genetically engineered species of bacteria is used. Food crops are not grown on the
     same site. Microbes can also be used for stabilizing hazardous wastes on previously
     contaminated sites; in that case the process is called bioremediation.
ENVIRONMENTAL PROTECTION MANAGEMENT (21CV753)                          By: Dhanashree N Nerlikar
   ➢ The chemical, thermal, and biological treatment methods outlined above change the
     molecular form of the waste material.
   ➢ Physical treatment, on the other hand, concentrates, solidifies, or reduces the volume of the
     waste. Physical processes include evaporation, sedimentation, flotation, and filtration.Yet
     another process is solidification, which is achieved by encapsulating the waste in concrete,
     asphalt, or plastic.
   ➢ Encapsulation produces a solid mass of material that is resistant to leaching. Waste can
     also be mixed with lime, fly ash, and water to form a solid, cementlike product
   Disposal methods
   1: Underground disposal
   ➢ The only way this method is compliant is when the hazardous waste is brought to mines
     that are either inactive or partially active (along with meeting additional geological and
     technical specifications).
   ➢ Many companies need to dispose of radioactive waste, whether from medical treatments,
     laboratory experiments, nuclear fuel production, or radioactive ore mining. For those cases,
     this method is considered a strong, cost-effective option.
   ➢ These hazardous waste facilities will vary in their sustainability, per the EPA. The agency
     is responsible for protecting people and the natural world by verifying that these units’
     design, operation, and maintenance adhere to its standards.
   2: Landfill disposal
   ➢ Dumpsites and landfills are the most commonly used and oldest method of waste disposal.
     Hazardous waste landfills are specially built and are NOT intended for liquid wastes. They
     are engineered and excavated so that they are within the ground rather than piling upward.
   ➢ These landfills are lined with clay, HDPE, or other non-porous materials to prevent the
     waste from leaching into the ground. Wind dispersal controls, leak protection systems, and
     a double liner are additional protections so that humans and the environment come into
     contact with as little of the waste as possible.
   ➢ Human health is generally not impacted by hazardous waste landfills. However, it is
     possible for people near the landfill to be harmed if there is a leak.
   Transboundary movement
   ➢ Any movement of hazardous wastes or other wastes from an area under the national
     jurisdiction of one State to or through an area under the national jurisdiction of another
     State or to or through an area not under the national jurisdiction of any State, provided at
     least two States are involved in the movement
   ➢ Controlling transboundary movements of hazardous and other wastes is a corner stone of
     the Basel Convention.
   ➢ Parties to the Basel Convention have the overall obligation to ensure that transboundary
     movements of hazardous and other wastes are minimized and that any such movement is
     conducted in a manner which will protect human health and the environment.
   ➢ In addition to these general obligations, the Convention provides that transboundary
     movements can only take place if certain conditions are met and if they are in accordance
     with certain procedures.
   ➢ Parties are under an obligation to take the appropriate measures to ensure that
     transboundary movements of hazardous wastes and other wastes are only allowed if one
     of the three following conditions is met:
   ➢ the State of export does not have the technical capacity and the necessary facilities,
     capacity or suitable disposal sites in order to dispose of the wastes in question in an
     ―environmentally sound manner‖; or
   ➢ the wastes in question are required as raw material for recycling or recovery industries in
     the State of import; or
   ➢ the transboundary movement in question is in accordance with other criteria decided by
     the Parties (such criteria will normally be found in the decisions adopted by the
     Conference of the Parties)
   ➢ In all cases, the Convention requires that the standard of environmentally sound
     management of hazardous wastes or other wastes is met. Environmentally sound
     management means taking all practicable steps to ensure that hazardous wastes or other
ENVIRONMENTAL PROTECTION MANAGEMENT (21CV753)                        By: Dhanashree N Nerlikar
     wastes are managed in a manner which will protect human health and the environment
     against the adverse effects which may result from such wastes.
   ➢ In addition to these conditions, the Basel Convention specifies instances in which Parties
     may restrict transboundary movements and instances in which Parties must restrict
     transboundary movements.
   ➢ Finally, the Basel Convention requires that only persons authorized or allowed to
     transport or dispose of wastes undertake such operations and that wastes subject to a
     transboundary movement be packaged, labelled and transported in conformity with
     generally accepted and recognized international rules and standards.