« Comparison of Dry Matter and Nutrient Partitioning in Organically and Conventionally Grown Tea | Home | Novel microbes on biodegradation of water borne hepatotoxin, mcrocystins »
Natural and Waste Materials as adsorbents in Oil Pollution Management
By Admin | July 1, 2009
Contamination of water with oil substances is a major problem in many industries mainly oil based industries like petroleum refinery industries, soap manufacturing industries and service stations. Sri Lankan coastal zone especially in Southern and Western is susceptible to oil pollution due to oil tankers and other shipping coming to Colombo harbour and a major shipping land existing beyond the shores of Hambantota.
There is a need for technology in managing related risks. So efficient oil-water separation is of prime importance in Sri Lanka and in industrial waste treatment stages, it is often required for operating the wastewater treatment plant efficiently without inhibit the downstream process. Normally large oil globules in wastewater are floating and reduce the Oxygen dissolution thus upsetting the biological treatment processes within the treatment plant. As well as, it may clog the pipe lines in treatment plant and it may impede overall process going on. Many sophisticated technologies are used to treat this wastewater and sometimes it would be prohibitively costly for wastewater treatment. Adsorption is a liable technical option though costly. Hence, the necessity of exploiting low cost adsorbents arises. So natural derived adsorbent or adsorbent coming from waste material is an intensity option to study.
In this study, priority was given to hair disposed from salons, as much of oil adsorbed to hair could be recovered. Then other materials such as coir pith, rice husk, saw dust and tea waste would be used as second adsorption material for removing remaining oil in wastewater treated with hair. Thus the interest is in a two stage adsorption device in oil spill control. The technique will be applicable from oil spill management to more local pollution issues such as service centers and workstations. By optimizing many parameters, such as hair soaking time in oily water, the thickness of oil layer, mixing rate and hair amounts used as adsorbents, the adsorption efficiency would be able to maximize. According to the experiments which were done to optimize the oil layer thickness, adsorption was highly depend on the oil layer thickness. According to the analyzed data, hair adsorbed 96.87%(v/v) of initial oil from the oily water sample which had 6 mm oil layer thickness and 8%(v/v) oil to water ratio. Then 68.75% of initial oil was recovered from hair. hair adsorbed 60%(v/v) of initial oil from the oily water sample which had 2 mm oil layer thickness and 8%(v/v) oil to water ratio. Then 50% of initial oil was recovered from hair. So oil thickness is a function of oil recovery. For large scale usage, the belt type skimmer which is used hair as the adsorption material will be used to recovering oil from water. This skimmer can be operated by using a lever and it will include a mechanism for pressing the hair after adsorbing to recover the oil. The schematic in Fig.(1) gives overall objective of the project.
Oil Separation Steps:
W A J Anurangi, B M P K Amarasinghe, A A P de Alwis.
Department of Chemical & Process Engineering
University of Moratuwa.
Topics: symposium2008 | No Comments »