Al-Gheethi A.A.S.,Yemeni Jordanian University |
Ismail N.,Universiti Sains Malaysia |
Efaq A.N.,Universiti Sains Malaysia |
Bala J.D.,Universiti Sains Malaysia |
Al-Amery R.M.A.,Yemeni Jordanian University
Journal of Water Reuse and Desalination | Year: 2015
Yemen is the least advanced country among Middle Eastern countries in sewage reuse and safety control. The current sewage effluent quality in Yemen is generally poor as none of the existing sewage treatment plants produces effluents that comply with the effluent quality regulations. There is no plan to build tertiary treatment systems. However, the oxidation and stabilization ponds are considered most appropriate for the warm climate conditions in the country. Sewage effluents and biosolids generated from these ponds are used extensively for agricultural purposes. This review discusses the potential use of solar disinfection (SODIS) and lime treatment for the reduction of pathogens in sewage effluents and biosolids before reuse. SODIS and lime treatment are natural processes, simple, easily implemented, produce non-toxic by-products and are low cost. The merits of these processes are enormous, and they are suitable for application in developing countries such as Yemen. © IWA Publishing 2015.
Al-Gheethi A.A.S.,Yemeni Jordanian University
International Journal of Recycling of Organic Waste in Agriculture | Year: 2015
Background: Cellulase is one of the enzymes commonly used in several agricultural, industrial and sewage sludge treatment processes. The present study aimed to investigate the potential use sludge generated from sewage treatment plants as a production medium for cellulase by B. megaterium strain that was isolated from a sewage treatment plant. The production of cellulase in the sludge medium was compared to different cellulosic materials: cotton, filter paper, bagasse and sawdust as well as to galactose, fructose, lactose, maltose, mannitol, mannose, ribose, sucrose and xylose. The production of cellulase was conducted at optimum conditions (0.4 mL of the bacterial inoculum, 45 °C, 72 h, pH 6.5 and citrate phosphate buffer) that were determined in this study. Results: The sludge medium has induced the cellulase production by B. megaterium strain compared to cotton, filter paper, bagasse and sawdust. However, B. megaterium produced high cellulase in the presence of carbohydrate compounds as carbon source. More cellulase was produced in the sludge medium containing low concentrations of Ni2+, Zn2+ and Cu2+ ions. Discussion: The ability of B. megaterium strain to produce cellulase in the sewage sludge medium was due to that the strain has acclimatized to resist heavy metals and produce the enzyme genetically. Moreover, B. megaterium has an important environmental role for reuse of sewage sludge as production medium for cellulase that could be used in many of applications, including production of animal feed, formulation of detergents, juice clarification, paper industry and wine production. © 2015, The Author(s).