The common type of fixed and variable capacitors under this subcategory include
paper dielectric, film dielectric, metalized dielectric, dual dielectric, tantalum dry
slug and wire, tantalum foil, tantalum wet slug, aluminum electrolytic, mica dielectric, ceramic and glass encapsulated capacitors. Other types of capacitors like the
oil-filled capacitors are classified under the SIC 3629 category. Some of the capacitors under the SIC 3675 have the same manufacturing processes, particularly, in
relation to the use of process water.
2.6.2 Description of Industrial Plant
A typical plant used for the production of capacitor is plant 09062. This one-process
line plant produces dry tantalum slug capacitors, and the water use in this plant is less
compared to those engaged for cooling tower and boiler, blowdown, and water
deionizer backwash. Table 4.31 shows the plant’s specific verification data.
2.6.3 Water Use
Large volume of water used in the manufacturing process of capacitors is employed
as process water. An estimate of 0.95 million L/day of process water usage has been
recorded for the entire capacitor industry and is discharged as wastewater. Product
type, production rate, location, and facility size are the factors that influence the flow
rate of water leaving a particular plant. About 40% of this water has been subjected
to treatment before being discharged into the environment.
2.6.4 Wastewater Characterization
Besides water use in the manufacturing process steps, which is relatively less, large
volume of wastewater is generated in some capacitor manufacturing ancillary
operations like cooling tower, blowdown, boiler blowdown, and water deionizer
backwash. Information on the specific raw wastewater data is not available; however, pollutants that were detected in raw waste that was verified in some plants in
the capacitor subcategory are presented in Table 4.32.
2.6.5 Wastewater Treatment Process
Wastewater treatment technologies applicable in the capacitor manufacturing facilities are subdivided into three steps. Step 1 treatment for capacitor manufacturing
facilities is primarily pH adjustment of the wastewater before discharge. The pH of
the ball mill discharge is also adjusted and then subjected to settling process before
discharge. Step 2 treatment systems include chemical precipitation and sedimentation to remove solids and other metals in the wastewater stream. Others are
4 Electrical and Electronic Wastes Treatment
161
paper dielectric, film dielectric, metalized dielectric, dual dielectric, tantalum dry
slug and wire, tantalum foil, tantalum wet slug, aluminum electrolytic, mica dielectric, ceramic and glass encapsulated capacitors. Other types of capacitors like the
oil-filled capacitors are classified under the SIC 3629 category. Some of the capacitors under the SIC 3675 have the same manufacturing processes, particularly, in
relation to the use of process water.
2.6.2 Description of Industrial Plant
A typical plant used for the production of capacitor is plant 09062. This one-process
line plant produces dry tantalum slug capacitors, and the water use in this plant is less
compared to those engaged for cooling tower and boiler, blowdown, and water
deionizer backwash. Table 4.31 shows the plant’s specific verification data.
2.6.3 Water Use
Large volume of water used in the manufacturing process of capacitors is employed
as process water. An estimate of 0.95 million L/day of process water usage has been
recorded for the entire capacitor industry and is discharged as wastewater. Product
type, production rate, location, and facility size are the factors that influence the flow
rate of water leaving a particular plant. About 40% of this water has been subjected
to treatment before being discharged into the environment.
2.6.4 Wastewater Characterization
Besides water use in the manufacturing process steps, which is relatively less, large
volume of wastewater is generated in some capacitor manufacturing ancillary
operations like cooling tower, blowdown, boiler blowdown, and water deionizer
backwash. Information on the specific raw wastewater data is not available; however, pollutants that were detected in raw waste that was verified in some plants in
the capacitor subcategory are presented in Table 4.32.
2.6.5 Wastewater Treatment Process
Wastewater treatment technologies applicable in the capacitor manufacturing facilities are subdivided into three steps. Step 1 treatment for capacitor manufacturing
facilities is primarily pH adjustment of the wastewater before discharge. The pH of
the ball mill discharge is also adjusted and then subjected to settling process before
discharge. Step 2 treatment systems include chemical precipitation and sedimentation to remove solids and other metals in the wastewater stream. Others are
4 Electrical and Electronic Wastes Treatment
161