Environmental Impact Of Leather Tanning Industry

The global environment is gradually worsening as a result of the socio-economic activities of mankind. Leather tanning industry plays significant role in economy of a country through employment and export earnings; but resulting pollution from tanning process causing severe environmental degradation.

Tanning is the process by which hides or skins are converted into leather. After removal of flesh and fur from the hide it is treated with chemicals which cross linked the microscopic collagen fibers to form a stable and durable leather product. A schematic diagram of tanning is presented and this indicates the type of waste stream generated from tanning process (Fig.1.1) (Harrison, 2001).

Leather processing comprises of series of operations that can be classified as pre-tanning, in which hides or skins are cleaned; tanning process, which permanently stabilizes the hides and post-tanning or finishing operations, where final shape value is added for manufacturing of leather (Ramasami, Rao, Chandrababu, Parthasarathi, Rao, Gayathri and Sreeram, 1999). Production of leather from tanning of hides and skins has been an important activity since ancient times. For processing a ton of hide approximately 30-40 cubic meter (m3) of water is used (Suthanthararajan, Ravindranath, Chitra, Umamaheswari, Ramesh and Rajamani 2004).

Currently, about 6.5 millions tons of wet salted hides and skins are processed worldwide annually. About 3.5 millions of various chemicals are used for leather processing. A considerable part of this amount is discharged into the effluent (Ludvik, 1996). Tanning of hides and skins by the usual tanning process is wholly a wet process from which a large volume of liquid waste is almost continuously discharged throughout the working hours of an industry. Usually soak waste, liming wastes and spent vegetable tan liquors are discharged intermittently (Song, Williams and Edyvean, 2000).

It is approximated that 30-40 x 1010 liters of effluent is generated by worldwide annual processing of 9 x 109 kg hides and skins (Thanikaivelan, Jonnalagadda, Balachetran and Ramasami, 2004). Leather industry consumes a large amount of water so the availability of good quality water and the treatment of large amount of effluent are the two major issues. The tannery wastewater is a mixture of bio matter of hides and a large variety of organic and inorganic chemicals. Tanneries leave the wastewater usually contain organic and inorganic matter with high level of salinity, ammonia and organic nitrogenous pollutants and other toxic pollutants including sulphide and residues of chromium metal salt) (Ros and Gantar, 1998). Tannery effluents are characterized as highly colored, foul smelling with acidic and alkaline liquor (World Bank, 1998).

Poor processing practices and use of unrefined conventional leather processing further aggravate the pollution problem. In tannery effluents presence of chromium and hydrogen sulfide formed due to sulfide are highly toxic to many living beings. Indiscriminate discharge of effluents into water bodies or open land causing contamination of surface and ground water in addition to degradation of flora and fauna of soil have direct impacts on agricultural land (Khawaja, Rasool, Fiaz and Irshad, 1995; Ramasami, Sreeram and Gayatri, 1997).

The leather tanning industry significantly contributes to economy of a country. The major leather production centers in the world are found in Mexico, Brazil, Japan, South Korea, China, India and Pakistan. Leather tanneries generate three type of waste including wastewater, solid waste and air emissions. So far, wastewater is considered as the most important environmental challenge faced by Pakistan’s tanneries (Iqbal, 1998).

In Pakistan, tanneries are established both in formal and informal sector presently over 596 tanneries are established in the formal sector and equally large number of tanneries exists in the informal sector (ETPI, 2001). Increasing number of tanneries in Pakistan is to be considered as the major cause of environmental degradation because untreated effluents from tanneries are released into environment. Kasur district has more than 350 tanning and it has become the mean livelihood of most of residents.

The present study focuses on identification environmental problems related to tanneries wastewater in Kasur through participatory action and involve local communities for self managed collective actions for application of locally available and cost effective wastewater treatment technologies within their industry premises. In this process participants learn wastewater treatment technologies through social learning process which is based on the principle of “learning by doing”.

Participatory research allows researchers to gain a better understanding of problem. Participatory GIS approach is used for the purpose of involving community and development of GIS database. Participatory GIS is a spatial decision making tool designed to utilize GIS technology with participatory approach in the perspective of needs and capabilities of communities that are involved through and affected by development projects. Novel community mapping and modeling methods linked to GIS for implementing community-based planning, have been studied and developed since the 1990s (Dunn, Atkins and Townsend, 1997; Abbott, Chambers, Dunn, Harris, DeMerode, Porter, Townsend and Weiner,1998; Sieber, 2006) and began to spread into China through international development projects (Cai, Zhu and Dai, 2001; McConchie and McKinnon, 2002; Wang, 2003).

Participatory GIS technique encourages community participation and involves community in the production of GIS (Cinderby, 1999). Participatory GIS generally resulted from the combination of participatory methods i.e. Participatory Learning and Action (PLA) and Participatory Rural Appraisal (PRA) with geo-spatial technologies (Rambaldi, Kyem, Mbile, McCall and Weiner, 2005). Within this broad range of approaches different techniques have been employed in specific locations and projects to investigate specific issues or encourage participation from particular groups or stakeholders. It has been a commonality of many participatory GIS that the process of participation (including the collection and collation of information) has often been emphasized in the process more than the technical utilization of GIS which requires access to specific expertise (McCall, 2004). Geographic information system (GIS) is a computer-based system for capturing, storing, manipulating, analyzing, and displaying geographic data for solving spatial complex resource planning and management problems (Densham, 1991). In GIS framework data is categorized into spatial data and attribute data. The data is stored in current GIS within two separate databases one for spatial data and one for attribute data. In most GIS representation of spatial data is in vector (points, lines, and polygons) and raster (pixels or grids) forms (Burrough, 1986). These conventional vector and raster representation of geographic features in GIS focus on database management including query and spatial analysis (Rhind, 1990).

In the development of a GIS database, different features are processed and stored in separate data layers representing geographic themes. All data layers in the same GIS database are required to be geocoded to a standard coordinate system such as State Plane coordinate system. Therefore, a GIS database can be conceptualized as “sandwiched” data layers containing different types of geographic features, registered to a common base map. GIS store, manage, and analyze geographically referenced data and devices that measure geographic location such as Global Positioning System (GPS) provides data on location in terms of latitude, longitude and altitude required for the GIS (Deichmann and Wood, 2001).

Participatory action research combines aspects of popular education, community based research, and social action. Participatory action research is collaborative processes in which researchers work with community to identify an area of concern and community take part to generate knowledge about the issue, formulate plan and carry out actions meant to address the issue in substantial way (Brydon, 2001).

Participatory research approach empowers community members to collaborate with researchers to better understand their own problems and to find effective and viable solutions. Participants in the research process can identify a problem, collect and analyze relevant information, and act upon it in order to develop solutions and to promote social and/or political transformation (Selener, 1997). Participatory research represents a distinct set of practices or approaches to generate knowledge, including a variety of quantitative and qualitative research methods (e.g., participant observation, personal interviews, focus groups, and participatory needs assessment surveys).

Treatment of tannery effluents has been searched for physical, chemical and biological methods. The biological treatment, especially the use of microorganisms to improve polluted water quality is effective and widespread due to environmentally and economically as compared to chemical treatment. Effective Microorganisms or EM Technology is selected for the treatment of tannery wastewater. The concept of EM Technology was developed by Professor Teruo Higa, University of the Ryukyus, Okinawa, Japan. EM consists of beneficial naturally occurring microorganisms that have a reviving action on humans, animals, and the natural environment. EM is a mixed culture of selected species of microorganisms including predominantly lactic acid bacteria, yeasts, photosynthetic bacteria, actinomycetes and other types of organisms which are mutually compatible and can coexist in liquid culture (Higa, 1991; Higa and Wididana, 1991).

The ultimate goal of this research is to break psychological, social, technical and economic barriers in technology adoption by tanneries owners and workers. So that tanneries owners and workers are enabled for self organized collective wastewater management within their working environment. Through this process community participation is anticipated in all stages of action research including problem identification, data collection, participatory GIS and application of wastewater treatment technology.

AIMS AND OBJECTIVES

The objectives of my study are as follows:

Preparation of GIS database of small tanneries through participation of stakeholders in Kasur.

Demarcation of small tanneries and wastewater channels discharging from tanneries through participatory GIS mapping.

Identification and selection of locally available and effective wastewater treatment technologies.

Laboratory experimentation to check the efficacy of selected wastewater treatment technology.

Develop simplified methods to increase social acceptance of waste minimization techniques through community participation.