Treatment Of Wastewater Discharged By Small Tanneries Biology Essay

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The study was focused on applicability and relevance of a Participatory GIS approach in the context of in-house treatment of wastewater discharged by small tanneries in Kasur. The research methodology incorporated participatory techniques with Geographic Information System. In present study psychological, social, technical and economic barriers related to in-house treatment of tanneries were identified. On the basis of collected data formulated a participatory action plan to provide effective solution for in-house wastewater treatment. Efficacy of selected treatment technology was tested in laboratory experiments and developed simplified methods of in-house treatment with participation of community to increase social acceptance of technology for in-house treatment purpose.

Study Area

The Kasur is situated about 55 km southeast of Lahore, in the province of Punjab, near the border with India, where the river Sutlej enters Pakistan. In Pakistan biggest cluster of tanneries are in Kasur. In Kasur tanning units are spread over wider area mainly Dingarh, Kot Molvi Abdul Qadir, Niaz Nagar and Younas Nagar where approximately more than 350 tanning industries are set up including large, medium and small tanning units.

3.1. Data Collection

In the perspective of participatory research approach understanding and communication with target community was very important aspect and useful to get the sense of both community's issues and willingness of community to take action on identified issue. In this study the target community was tannery owners, workers and local people and they were involved in the process of problem identification, data collection and participatory GIS mapping.

Primary data was collected through participatory GIS approach. Quantitative, qualitative and spatial data was collected through participation of local community. For collection of quantitative and qualitative data field surveys, direct observations, transects walks, focus group discussion and questionnaire surveys methods were used.

The relevant data was collected from field surveys. The major industrial units of leather tanning are situated in Kasur so the study area was Dingarh, Kot Molvi Abdul Qadir, Niaz Nagar and Younas Nagar. Various visits were arranged to get the detail information regarding sites. During field visits various methods and approaches were identified to communicate with local peoples and collect information regarding study.

3.1.1. Qualitative data

A wide variety of qualitative methods in terms of PAR, participatory approach, in-depth interviews and focus-group discussions were mainly used for this study. The participatory approach was chosen as a means of identifying problems, collection and analysis of relevant information, exploring perceptions about in-house treatment of wastewater and developed solutions regarding waste minimization.

In this study the target community was tannery owners, workers and local people. Focus group discussions and interviews with people provided a great exchange of knowledge and greater insight into people's perceptions. I arranged different meetings with President of small Tanneries Association to get in depth information about the study area, tanning practices and tanning waste management.

3.1.2. Quantitative data

Questionnaire surveys were also conducted to collect additional information. The questionnaire was based on collection of information about tanning process wastewater treatment, identification of barriers in technology adaption and perception about in-house treatment of wastewater. The questionnaire was carefully designed according to my target community and tested in surveys in order to ensure its effectiveness for collection of relevant data. The questionnaire is given in Appendix I. For questionnaire data collection tanneries were randomly selected in Dingarh, Kot Molvi Abdul Qadir, Niaz Nagar and Younas Nagar area.

3.2. Participatory GIS mapping

3.2.1. Spatial data collection

GIS maps of Kasur tanneries and wastewater channels were also prepared. The spatial data and attribute data was combined through Arc GIS software. Spatial data or coordinates of tanneries and channels were acquired through GPS (Garmin etrex SUMMIT HC) in study area. During the transect walks and field surveys, local people participated in identifying features and site mapping in addition to collection of questionnaire data. Major clusters of tanneries Dingarh, Kot Molvi Abdul Qadir, Niaz Nagar and Younas Nagar and wastewater channels discharged from industries were marked through participation of community.

3.2.2. Data Processing for Preparation of Maps

Way points or coordinate values and tracks were transferred from GPS to computer. All transferred data (waypoints and tracks) was saved as "gpx" format. The captured point was view on Google earth. The waypoints which were collected from the industrial area were overlapped on the satellite images taken from Google earth. Satellite images with captured point were saved in "dxf" format.

Arc GIS 9.0 was used for displaying and further processing of data. Tanneries clusters were digitized in polygon format and wastewater channels were digitized in line formats. Attribute data collected through participatory approach was prepared on Microsoft Excel which was linked to Arc GIS for preparation of GIS database. GIS maps of tanneries clusters and wastewater channels were displayed as "jpeg" format.

3.3. Selection of Technology for Tannery Wastewater Treatment

For tannery wastewater treatment purpose Effective Microorganisms or EM Technology was selected. EM solution was taken from Nature Farming Research and Development Foundation (NFRDR) Faisalabad trade name as BioAAB. BioAAB is the mother culture of lactic acid bacteria (Lactobacillus spp.), photosynthetic bacteria (Rhodopseudomonas spp.), Yeast (Saccharomyces spp.) and actinomycetes.

The efficacy of EM technology was tested through laboratory experimentation. Wastewater treatment experiments were performed in Water and Wastewater Analysis Laboratory of PCSIR (Pakistan Council for Scientific and Industrial Research). This lab work was comprised on sampling of tanning wastewater, application of different doses of EM culture and physic-chemical analysis of untreated and treated wastewater to check the efficacy of EM technology.

3.3.1. Sampling Sites

Samples of industrial wastewater were collected from different points located in tanning industrial area in Kasur. Five different samples were collected one from small leather tanning industry, second from outside channel of industry and third from collective drain where effluents of different industries are collected. Samples were collected from two different points of common effluent treatment plant. One sample was collected from influent point (tannery wastewaters enter into treatment plant) and second from effluent point (from where treated wastewater discharged to drain).

3.3.2. Sampling Procedure

Grab sample was collected from treatment plant, collective drain and outside channel of industry where wastewater was constantly flowing. The samples were not collected from the depth of drain and channel because of high content of sludge so the samples were taken from the center of drain and channel.

Composite sample was collected from small leather tanning industry; the samples from different tanning processes of industry were collected and mixed together vigorously to make it a composite sample.

3.3.3. Samples labeling and storage

The volume of sample was taken according to requirement of work. Samples were collected in clean cans of polyethylene and labeled. The samples were stored at 4 °C prior to pretreatment analysis.

3.4. Wastewater Treatment Experimentation

3.4.1. Activation of EM

The wastewater treatment experiment was performed during the month of July to August, 2010. EM is a liquid solution of fermented EM where the microorganisms are alive but in dormant stage. EM is activated prior to application. For the production of EM activated solution (EMAS) water and food was provided to activate the microorganisms. EM activation was done according to formula of 1: 1: 20 (1 part of EM, 1 part of molasses in 20 parts of water). The required amount of EMAS was prepared in plastic bottle and kept for fermentation at ambient room temperature. The lower pH after 5 day showed that fermentation was completed with a release of pleasant sweet vinegar smell and solution was ready for use.

3.4.2. Application of EM

Good laboratory practices specifically emphasize the cleaning of glassware otherwise the most carefully executed work may give an erroneous result if contaminated glassware is used. All glassware was washed properly rinsed with acids and finally with distilled water. Flasks used for wastewater treatment experiments oven dried before used to avoid any contamination.

EM activated solution was applied on samples collected from tannery, outside channel of tannery and collective drain wastewater. Efficacy of five different doses of EM activated solution was checked i.e. 1 ml, 2 ml, 3 ml, 4 ml and 5 ml for treatment of tannery wastewaters. EMAS was applied on samples in flasks containing 500 ml of sample and one was for control on which EMAS dose was not applied. All these experiments were performed at ambient room temperature and flasks were cotton plug (not air tight) for avoiding any contamination. The reaction time was given to microorganisms to treat wastewater pollutants. After intervals of day the treated samples were analysed to check the pollutants reduction in wastewater.

3.5. Physico-Chemical Analysis of Wastewater

The analysis of wastewater before and after treatment was made to find out the efficiency of the EM culture. Effect of EM treatment was tested on following wastewater parameters pH, Electrical Conductivity (EC), Dissolved oxygen (DO), Biological Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Total Dissolved Oxygen (TDS), Total Suspended Solids (TSS), Chloride, Sulphide, Sulfate and Chromium. Replicates readings were taken for accuracy work.

pH, Electrical Conductivity and Sulphide was analysed after 3rd, 5th and 13th day of treatment while remaining parameters were tested after 5th and 13th day of treatment on the availability of solutions and equipments. Samples collected from treatment plant were not selected for treatment purpose only physico-chemical analysis was performed for these samples.


pH determines the concentration of hydrogen ions and measure the acidity and basicity of sample. pH in laboratory was checked in laboratory by using Micro pH 2001 digital meter. Temperature was also taken from pH meter.

Electrical Conductivity (EC)

Electrical Conductivity is a measured of conducting an electric current in water or sample and it depends on the presence, concentration and mobility of ions. EC was determined by using JENWA 4010 conductivity meter.

Dissolved oxygen (DO)

Dissolved Oxygen was determined by using Microprocessor AutoCal Hl 9143DO meter. The DO meter electrode was rinsed in distilled water and was connected to DO meter. The dissolved oxygen measurement was running continuously, it become stable after a short while at a certain reading showed DO value in mg/L.

Determination of TDS and TSS

Total Dissolved Solids (TDS) comprise of inorganic salts and small amounts of organic matter that are dissolved in water while Total Suspended Solids (TSS) consist of solid particles of organic and inorganic matter that are suspended in wastewater and regarded as a type of pollutants.

For determination of TSS and TDS shake the sample vigorously by keeping sample on magnetic stirrer to suspend sediment that settled on bottom. Using forceps placed the pre weighed filters on the funnel base. Then measured amount of sample was filtered and transferred the filtrate to a pre-rinsed, china dish. Then china dish with filtrate was placed in oven at 180°C liquid for evaporation of liquid. Before weighing kept the china dish in desiccators to cool and weighed the nearest 0.0001g (0.1 mg). For TSS determination, aluminum dishes with filters kept in oven at 105°C until the filter papers dried and died filter papers were kept in desiccators to cool before weighing. TDS and TSS were calculated from formulas given in Annex (APHA, 2005).

Calculations for TDS and TSS:

Total Dissolved Solids

TDS (mg/L) = post-weight of china dish (mg) - pre-weight of china dish (mg) Ã-1000 Sample volume (mL)

Total Suspended Solids

TSS (mg/L) = post-weight of filter paper (mg) - pre-weight of filter paper (mg) Ã-1000

Sample volume (mL)

Biological Oxygen Demand (BOD5)

BOD is an expression for the amount of oxygen consumed by the decomposition of organic matter in a biochemical process. Thermostatic Cabinet was used for BOD5 determination. Well shake sample was taken in BOD bottles of thermostatic cabinet and add 2-3 drops of Potassium hydroxide (KOH) and 5 drops of nitrifying inhibitor and kept bottles in Thermostatic Cabinet for 5 days at 20°C.

Chemical Oxygen Demand (COD)

COD was determined by COD Cell Test (Merck COD high range cell, 1.18753.0001). Samples containing more than 20000 mg/l chlorides were diluted with distilled water prior to determination. 2 ml of diluted sample was added in cell and heated the cell at 148 °C in the preheated thermoreactor for 120 min. Then removed the hot cell from the thermo reactor and allowed to cool. COD was measured by keeping cell in photometer.


Sulfate was determined on turbidity meter by the formation of barium sulphate in sample. The sample was taken in 250 ml of flask then added 20 ml of buffer solution. Put the sample flask on magnetic stirrer for mixing, while stirring added a pinch of barium chloride. Sample was stirred for a minute. The barium sulfate turbidity was determined on photometer. The sulfate concentration in sample was measured by comparing turbidity reading with a calibration curve (Appendix III) which was prepared by standard solution of sulfates (APHA, 2005).


For determination of sulphide first prepared the iodine solution (0.01N) and Sodium thiosulfate (0.01N) solution (Appendix IV). The sample was taken in flask and added 10 ml of iodine solution (0.01N) and 10 ml of concentrated HCl and titrate it against Sodium thiosulfate (0.01N). The color was dark brown to pale yellow again added 4-5 drops of starch solution the end color was dark blue to colorless. The value for blank was determined by the same procedure (APHA, 2005). The sulphide concentration was calculated by formula given below


mg/L of S¯ = 1000Ã-0.1704(ml of titrant used for blank- ml of titrant used for sample) Volume of sample


For determination of chloride potassium chromate indicator (5%) and silver nitrate (0.0141 N) was prepared (Appendix V) . 10 ml of sample was taken in 250 ml flask, 2-3 drops of potassium chromate indicator ( 5%) was add then titrate it against silver nitrate (0.0141 N). The end color was pink to brick red (APHA, 2005).


mg/L of Cl- = titrant used for sampleÃ- N of AgNO3 Ã- Equivalent wt of CI x 1000

Volume of sample


The concentration of Cr was determined by UV-Spectrophotometer (SPECORD 200). Diphenyl-carbazide method was used for determination of chromium. Acidic buffer combined with 1, 5- Diphenyl-carbazide when reacts to chromium solution give a purple color, which is proportional to the concentration of hexavalent chromium in sample.

In this method for the determination of total chromium content, all the chromium was converted to hexavalent state by oxidation. The sample was filtered through a 0.45 μm membrane filter and adjusted the pH to 8.0-8.5. The filtered sample or a smaller aliquot of the sample diluted to 50mL in 250mL flask. Then added 2.0 mL of Diphenylcarbazide solution to sample and swirl to mix. Immediately 5mL of phosphoric acid solution (1+1) was added to solution and swirl to mix. The solution was permit to stand for 15 minutes for full color development. Spectrophotometer was adjusted at wavelength of 540 nanometer (nm) and absorbance of blank solution was taken. Four standard solutions containing from 0 to 2.00 mg/L of chromium was prepared by diluting measured volumes of the standard chromium solution. Calibration curve by plotting concentration of chromium (mg/L) versus absorbance (nm) on linear graph paper was drawn (Appendix VI). Concentration of chromium was determined by taking the value of absorbance on spectrophotometer and comparing values with calibration curve.

3.6. Data analysis

The data collected from questionnaire survey was entered in MS Excel. The statistical analysis was done as percentages and the results were displayed in bar and pie charts.

The data of laboratory experiments was arranged in tables. Efficiency of EM treatment was calculated in terms of % reduction. Graphs were prepared on MS Excel.

% reduction = Concentration before treatment -Concentration after treatment Ã- 100

Concentration before treatment