Volume 7 Number 3 July 2021

Prospects and Challenges of Chrome Tanning:  Approach a Greener Technology in Leather Industry

Authors: MD. Dipu Ahmed ; Kazi Madina Maraz ; Ruhul Amin Khan
Pages: 42-49
The leather industry is one of the heavy-polluting and hazardous industries that is creating toxic and harmful effects on the environment and human health by producing waste chemicals, tannery effluents, and various pollutants. Moreover, Tanning is the required stage to convert raw skin to durable and sustainable skin but most of the chemicals, salts, organic and inorganic toxic pollutants are produced. In commercial practices, Chrome tanning is the highly employed approach that uses a large number of basic chromium salts that becomes the major source of chromium pollutant in the environment. Chromium salt is not only harmful to the environment and ecology but also harms the human body such as causing respiratory problems, infertility and birth defects, skin and lung cancer of the workers. This article has presented two alternatives eco-friendly greener approaches of chrome tanning and waste management technique to reduce the toxic effect on the environment and human health. Firstly, to get rid of these harmful effects, the possible remedy of environmental and human health problems may be considered the vegetable tanning process. Vegetable tanning uses tannins (a class of polyphenol astringent chemicals), which occur naturally in the bark and leaves of many plants. Secondly, chrome tanning associate with ultrasound having a frequency range of 20–100 kHz is commonly employed for enhancing the physical processes and for performing chemical reactions. The basic principle associated with the process is an ultrasonic cavitation in dissolved media. Ultrasound decreases the consumption of conventional water and chemicals because it can also function as a physical activator resulting reduction in environmental pollution which is a prime concern nowadays to approach greener leather technology and eco-friendly leather processing. Furthermore, the possible waste management technique of chrome tanning helps to prevent pollution and ensure eco-friendly green technology of leather processing. Therefore, vegetable tanning and chrome tanning associated with ultrasound having proper waste management will be the viable and sustainable options for the tanners in the forthcoming future.

Surface and Ground Water Pollution: Causes and Effects of Urbanization and Industrialization in South Asia

Authors: Bijoyee Sarker ; Kamrun N. Keya ; Fatin I. Mahir ; Khandakar M. Nahiun ; Shahirin Shahida ; Ruhul A. Khan
Pages: 32-41
Water pollution in South Asia is an alarming issue that has immersed recently. Developing countries, particularly those in South Asia, are fast adopting industrial pollution control standards similar to those in developed countries.  So both surface and groundwater are already scarce however, individuals and industries continue to pollute the already limited supply of water. On the other hand, the pollution of rivers is more severe and critical near urban stretches due to huge amounts of pollution load discharged by urban activities. Unplanned urbanization and industrialization occurring in these countries like Bangladesh, India, Nepal and Sri Lanka, etc. may be largely responsible for this grave situation. Therefore these human activities including industrialization and urbanization contributed immensely in no small measure to the degradation and pollution of the environment which adversely has an effect on the water resources such as surface and groundwater that is a necessity for life. This paper tries to discuss basically the causes and effects of urbanization and industrialization in surface and groundwater pollution and equally to address the controlling issues and challenges in South Asia.

A Review on the Methods of Industrial Waste Water Treatment

Authors: Khandakar M. Nahiun ; Bijoyee Sarker ; Kamrun N. Keya ; Fatin I. Mahir ; Shahirin Shahida ; Ruhul A. Khan
Pages: 20-31
Nowadays environmental pollution is a great threat to us. Water resources are mostly polluted by industrial wastes. Among all other pollutions, water pollution is one of the most vital pollution caused by different sources like industrial, domestic, sewage, hazardous waste, municipal waste, medical waste, manufacturing waste, etc. Public concern over the impact of wastewater has increased. There are several methods for the treatment of wastewater. Among them, techniques like coagulation, adsorption, activated sludge are prominent. The use of aerobic wastewater treatment as a reductive medium is receiving attention for its low cost of operation and low cost of maintenance. The uses of low-cost adsorbents are also effective in wastewater treatment. The aerobic wastewater is effective in degrading the contaminants. There are different electrolytic techniques as well for wastewater treatment. This paper reviews the possible techniques available for the treatment of wastewater to remove contaminants such as halogenated hydrocarbon compounds, heavy metals, dyes, pigments etc. from the wastewater.