Tannery industry fulfills a growing international appetite for leather and earns a large amount of foreign revenue. But the tanneries which are located at Hazarding are the major cause of Brigands river pollution. Tanneries of that area do not contain any treatment plant for treating their chemical effluents coming from tanneries processing. These tanneries discharge their liquid chemical and solid wastes into the river Brigands. As a result Brigands river pollution has reached to extreme level and its polluting rate is increasing rapidly. . 2 Wastes of Tanneries Tanneries of Hazarding produce a large quantity of solid and liquid wastes at the time of processing of hides and skins of animals. Table. 4. 1: Average amount of wastes produced by Dacha Hides and Skins Limited Waste Type Percentage (%) 19 91 100 I Waste Amount (ton) I Solid Liquid I I total 12 120 122 Source: Questionnaire Survey July, 201 2) It has been seen that, tanneries produces more liquid toxic waste than solid waste, which are mostly responsible for water pollution on Brigands.
Tanneries of Hazarding produce 25000 tons of solid waste and 40,000 tons Of toxic liquid waste everyday (Daniel 2010). Processing and production of leather and leather products are finished in three sectors, named a) Wet Blue ?? processing of raw hides. B) Crust – coloring of leathers. C) Finishing – producing leather products. [pick Figure 4. 1 : Percentages of waste from three sectors. Source: Questionnaire Survey. Date: July, 2012. Most of the wastes are produced at the primary stage of raw skin Processing. 4. 2. Solid waste 250 tanneries located at Hazarding produces 1 50 metric tons of solid waste everyday. These solid wastes are being produced at the initial and final stage of processing. Solid wastes produced from tanneries includes: Shaving Dust – while processing raw hides and skins. Scarp of hides and skins. These solid wastes are being reused and produce leather boards, Syllabic, Chicken feed, fertilizer, soap etc. 4. 2. 2 Liquid Chemical Waste Liquid chemical effluents are produced during tanning and dying.
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Different types of Chemicals are being in tanneries at the different stages of leather processing, including processing of raw hides and skins, chrome tanning turning a skin into bluish white colored leather. These chemicals includes:- Lime Sodium Sulfide Sulfuric acid Sodium hydrochloride Caustic Soda Arsenic Sulfide Calcium hydrochloride Chromium Chloride Dyes. 4. 3 Brigands River Pollution from Tanneries Water pollution of Brigands river is being affected and accelerated by 250 large and small tanneries located at Hazarding, at the bank of the Brigands.
These tanneries do not have any effective waste treatment facilities or any treatment plant [pick] Figure 4. 2: Status of treatment plant containment by tanneries. The diagram represents that nearly 99 percent of tanneries do not contain any treatment plant, less than 1 percent tanneries contain treatment plants. As these tanneries do not have any treatment plant, the tannery effluent with high organic and inorganic polluting loads is discharged on the Brigands river in the vicinity of the tannery area. Table 4. : Tannery Waste Disposal System. Disposal Place Brigands river (Liquid waste) Canal Road Open Space ( Solid waste) Others I Percentage (%) 80. 00 100. 00 | 00. 00 120. 00 From the table it is seen that most of the tannery wastes, which are liquid disposals are being disposed from Brigands river through drains. And some of that wastes which are solid disposals are being disposed on open space, on he low lands inside the Dacha flood protection embankment. Figure 4. 3: Drain carrying liquid chemical wastes from tannery to the river.
Source: Field Survey (June 2012) The wastewater carrying chemicals from the tanneries is discharged through open drains into a stagnant pond named ‘Initial Bell’ which is located between the Hazarding area and the flood protection embankment along the Brigands River. Ultimately, this wastewater is released through Arbitrary sluice gate into the river as every tannery is linked with Brigands river through drains 4. 3. 1 Location of Tanneries Most of the tanneries are located on the Brigands river bank and near the Dacha flood protection embankment.
Every tannery of Hazarding is linked with Brigands river through drains. Generally tanneries are being located besides river because of availability of sufficient amount of water to clean animal skins into the river. (Torque Islam, Leather technologist of Dacha Hides and Skins Limited) And all of these tanneries release their untreated effluents into Brigands river through these drains, as a result the magnitude of water pollution of Brigands river is severe. 4. 3. 2 Effluents Discharged to Brigands River Daily quantity of waste water produced by these tanneries varies from 0. 5 to 0. Cubic meter per meter square of hides and skin processed (Aimed M. A. Froze) According to DoE, the tanneries discharge 22000 cubic meters of untreated liquid toxic waste into the river daily. Tanneries of Hazarding generate 7. 70 million liter liquid waste and 88 metric ton solid waste everyday, which are discharge into the Brigands river and 80 % of the pollution of the river Brigands is caused from tannery wastes. 4. 3. 3 Polluting Loads Discharged to Brigands River Different kinds of chemicals are being used in tanneries at the time of recessing of animals skin to turn on leather and leather products.
The polluting loads which are generated from tanneries are being discharged to Brigands river includes: Suspended Solids Chromium (Cry) Chloride (CIO Different types of acids such as Nitric acid (HON.), Sulfuric Acid (HOSTS), Formic Acid (HOOCH) Salt’s of sodium Chloride (Nasal) Lime (Calcium Hydroxide-Cash) sodium sulfate (Nassau) Hazardous dyes etc. Due to indiscriminate discharge of these polluting loads to Brigands. The quality of water of Brigands as degraded to a great extent.
The physical look ND smell of the water of Brigands is frightening intolerable and horrendous. 4. 4 Status of Brigands River Pollution at Hazarding 250 tanneries and their generated wastes cause huge pollution of Brigands river at Hazarding. To realize the level of pollution at Hazarding a few Water quality parameters pH, T DES, DO, BODY, COD and Cry are being analyzed by comparing with standard drinking water quality determined by DoE. PH is the indicator of acidic or alkaline condition of water status. The standard for any purpose in-terms of pH is 6. -8. 5; in that respect the value of Brigands River water are 7. 8 to 8. 9 in dry season. The overall result indicates alkaline water. From 1 983 to 1 993 the increasing rate of pH concentration was very high and in 201 1 it has slightly decreased. PH. Figure 4. 4: Concentration of pH on Brigands river at Hazarding (dry season). Source: DoE (June 2012). TTS. Figure 4. 5: Concentration of TTS on Brigands river at Hazarding (dry In case of TTS Bangladesh Standard in terms of inland surface water is 1 000 MGM/L. Figure 4. Shows that TTS concentrations in Brigands river in dry season was found to be 6583 MGM/L in 1983, 2475 MGM/L in 1 993 and 1 188 in 201 1, which indicates that TTS concentration is decreasing. Alkalinity. Figure 4. 6: Concentration of Alkalinity on Brigands river at Hazarding (dry Bangladesh standard Alkalinity concentration in drinking water is pumps. Figure 4. 5 reveals that in Brigands river water at Hazarding Alkalinity concentration was 1580 in 1983, 1220 in 1993 and 284 in 2011. Alkalinity concentration at Hazarding in Brigands river water is too high and this water is not suitable for drinking and sustaining aquatic life.
DO. [P[Pick]igure 4. 7: Concentration Of DO on Brigands river at Hazarding (dry source: DOE (June 2012). DO standard for sustaining aquatic life is 4 MGM/L, whereas for drinking purposes it is 6 MGM/L. Figure 4. 5 reveals that DO concentration at Hazarding in Brigands river water from 1983 to 2011 was O in dry season, which indicates that the water is not suitable for sustaining aquatic life BODY. Figure 4. 8: Concentration of BODY on Brigands river at Hazarding (dry In the case of BODY standard for drinking purpose is 0. OMG/L. Figure 4. Shows that BODY concentration at Hazarding in Brigands river water was MGM/L in 1983, 386 in 1993 and 42 in 201 1. Figure 4. 9: Concentration of COD on Brigands river at Hazarding (dry Source: DoE dune 2012). Chemical oxygen demand (COD) is other important parameter of water quality assessment. A standard for drinking purposes is 4 MGM/Lћ which are not acceptable in-terms of Brigands river water. From figure 4. 8 it is seen that concentration of COD at Hazarding in Brigands river water was 101 Omg/L in 1983 and MGM/L in 2011.
Chromium. Figure 4. 10: Concentration of Cry on Brigands river at Hazarding (dry source: WAS (June 2012). A standard for drinking purposes for Cry is 0. 5 MGM/L. But figure 4. 9 shows that concentration of COD at Hazarding in Brigands river water was 0. 104 MGM/ in 1983 and 0. 093 MGM/L in 1993 and 0. Mini 201 1. 4. 5 Affected Area The pollution of Brigands river from tanneries not only affect the environment and people of Hazarding, it also affects the downstream areas as well as some upstream areas of the river.
The tannery pollution exposed to the residents of Arbitrary, Agitated, Kernighan, southern part of Diamond and Saver. Map 4. 1 . Areas affected by Brigands river pollution. Bangladesh 2012. Source: The pollution is even bleaker in the villages along the river, in the upstream of the Brigands. Thousands of families living in Zanzibar, Kilogram, Cunningham, Charcoal, Matriarchy, Wasp, Basil and Altogether. These areas face severe water crisis for at least six months a year.