Risks of ezo dyes on environment

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Environment means anything those surroundings human beings on earth like soil, water and air. A healthy environment is needed for human beings to live it shall be free from all kinds of pollution that may damage this remarkable gift of God to humans. Unfortunately, in this fast moving era of technology advancement we ourselves are destroying this precious gift. Pollution has different kinds that are affecting environment differently such as air pollution, water pollution and soil pollution. The causes of these pollutions are from different pollutants from different sources like soil is polluted by unchecked use of pesticides and other agricultural based chemicals and by use of polluted water coming from nearby industries. Air is polluted by effluents of vehicles whose number is increasing day by day on roads and other gases. Third and most important component of environment is water.


Pollutants involved in water pollution are mainly coming from industry specially textile industry. The diversity in composition of chemical reagents used in textile industries contributes is too much of the water pollution. Waste water generated by different production steps of a textile mills have high pH, temperature, detergents, suspended and dissolved solids, leveling agents, toxic colors and alkalinity. At present water pollution control is one of the major areas of scientific activity. Textile industry is the large consumer of water as well as producer of waste water. With the increasing demand for textile products, the textile industry and its waste water have been increasing proportionally, making it one of the main sources of severe water pollution worldwide. In Pakistan, unfortunately this problem is more than many other progressing countries of world. The reasons behind this major pollution have many causes and the important factor is the miserable role of responsible ministries such as environment and sanitation ministries of Pakistan. Major pollutants in textile industry are mainly recalcitrant organics, toxic colours, toxicants, surfactants and chlorinated compounds (AOX). These pollutants released into air, soil and water have harmful effects on the health of humans, animals and plants. In humans, many diseases caused by air and water pollution like lungs cancer, hepatitis and number of respiratory diseases like asthma.


As from previous two decades a major problem caused by water pollution is hepatitis. It is proliferating in the country unchecked and according to the latest research on hepatitis it is revealed that every third individual is convicted by this fatal disease. Most alarmingly this problem is more in industrial areas of Pakistan especially in Faisalabad which is considered as a hub of textile industry. Toxic colours (Azo dyes) are widely used in textile industry to impart colours to different materials. The dyes using in textile industry are toxic which are released from industry contaminate surface and underground water is hazardous for humans and their animals. Contamination of environment (soil and water) by textile dyes which are draining in over canals and rivers at the end reach our soils and ultimately in humans is one of the major environmental challenges in our country. These dyes not only destroy the quality of water but they also cause harmful effects on human. In present time especially in Pakistan the major problem is the use of untreated water for crops coming from industries and sewage system. Untreated water is directly used in agriculture especially in vegetable production in peri-urban areas containing dyeing effluents and toxic agent that have serious impacts on human health. Many reports proved that textile dyes and effluents have toxic effect on the biomass and germination rates of several plant species. Industrial effluents containing synthetic dyes when released into canals and rivers destroy the water quality and the chemical present in that water destroys the whole aquatic life of fresh water including fishes and other useful flora by reducing light penetration in water as a result this photosynthesis rate reduces that badly affects the food sources of aquatic organisms and destroy the aquatic food chain. It can be controlled by stopping the mixing of water from industry to our canal water. The dyes used in textile industry are synthetic compounds which are coloured matters that colour fibers permanently, so that they will not lose this colour when exposed to sweat, light, water and many chemical substances including oxidizing agents and also to microbial attacks.


Approximately 109 kg of dye stuffs estimated to be manufactured annually throughout the world. The two groups of dyes which are widely used in the textile industry are the azo and anthraquin one groups. Removal of dyes from textile effluents is a serious environmental issue. There are several methods used for the reducing of toxic colouring agents from the water. The applicability, reliability, effectiveness and cost of these different methods are different. These included physiochemical methods such as filtration, specific coagulation, adsorption, electrolysis and use of activated carbon, chemical flocculation. These are less efficient, costly, limited applicability, and produce wastes, which are difficult to dispose of. On the other hand via reverse Osmosis, Nano filtration, Multiple effect evaporator are found to be effective but quite expensive.


While the biological processes provide a low-cost, environmentally benign, and efficient alternative for the treatment of dye wastewater, wany species of bacteria, fungi, yeasts, microorganisms and algae are able to decolorize various kinds of textile dyes under certain environmental conditions. Microbial degradation of azo dyes occurs both under anaerobic and aerobic conditions. However, sequential anaerobic-aerobic treatment is better for complete removal of azo dyes from textile wastewater. While, azo re-educates and lactases seem to be the most promising enzymes for enzymatic remediation of azo dyes. There is need for both short-term and long-term measures to taken. In short term measures, there is a need to create awareness among people especially farmers who using industrial water unabatedly.


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Published in: Volume 05 Issue 08

Short Link: http://www.technologytimes.pk/?p=11229