Noise Pollution in Metalwork and Woodwork Industries in the Kingdom of Saudi Arabia

This study was conducted in metalwork and woodwork industries in Jeddah Industrial Estate. The purpose of this study was to assess the magnitude of industrial noise exposure and to propose remedial actions. Noise was measured at different times of a day in 28 randomly selected factories and workshops. Results indicated that noise levels varied according to the type and size of a factory, and the type and number of machines used. Mean noise levels in metalwork factories were higher than those in woodwork factories. The highest noise levels were observed while manufacturing cans and forming steel reinforcement for concrete, where noise levels exceed 90 dB(A). All mean noise levels in all studied metalwork factories and in 50% of studied woodwork industries were higher than the standard level of 85 dB(A)

Biological treatment of hydrogen sulfide in an airlift bioreactor with direct gas injection

Bioconversion of H2S into elemental sulfur has been investigated using an airlift bioreactor with direct injection of the gas into the bioreactor. Almost complete removal of H2S has been achieved at its inlet concentrations lower than 25 000 ppm. Maximum bioconversion capacity of ca 111.3 g/(m3·h) and up to 93.5% conversion of the inlet sulfide to elemental sulfur was obtained. To further improve the bioreactor performance, factors influencing mass transfer and biological activity should be investigated in future studies