TROPICAL REHABILITATION FOREST CONTROL ON WATER CHEMISTRY PATTERN IN BINTULU SARAWAK MALAYSIA

With rapid development in South East Asian countries, there is a risk of serious degradation of stream water quality in areas adjacent to developing city areas, where basic information on toxic heavy metals and acidic compounds (NO3- and SO42-) concentrations and spatiotemporal variation is still unknown in these areas. The concentrations of water quality parameters, major ions, and heavy metals were examined from selected stream in a rehabilitation forest near a developing city having petroleum refinery facility in Bintulu, Sarawak, Malaysia. The concentrations of water quality parameters, major ions, and heavy metals were examined from twelve stream locations in a rehabilitation forest near a developing city with a petroleum refinery facility. Analyses suggested that there is no clear tendency that is detected in heavy metals and basic water properties (EC, DO, BOD, COD, alkalinity and pH) except for turbidity, total suspended solids, and major ion which were high during rainy seasons. Annual means of SO42-, NO3- and NH₄⁺ concentrations were 6.34, 1.05 and 0.24 mg/L. The concentration in K+, Mg2+, Na+ and Ca2+ were 0.61, 1.21, 2.82 and 1.12 mg/L during hot and rainy season. The mean concentration in almost all heavy metals (Mn, Fe, Cu, Zn) were less than 0.01 mg/L. The concentrations of water quality variables in all samples collected across the seasons except for turbidity found within the permissible limit by the WHO and NWQS for Malaysia. Rehabilitation forest might give a positive impact in preserving water quality especially for COD and major ions except SO42-.

Recovery of cobalt and molybdenum from consumed catalyst using hydrochloric acid

Cobalt and molybdenum are valuable metals whose presence in nature is very limited. The consumed catalyst, which is abundantly available in the petroleum refinery industry, is a potential source of those metals. A hydrometallurgical process using acid as a leaching agent is usually used to extract and separate the metals more effectively. This method is considered capable of yielding recovery of a higher percentage of metal. In this study, hydrochloric acid solutions at various concentrations of 1.0, 1.5 and 2 M were used. The consumed catalyst was obtained from Pertamina Refinery Unit IV, Cilacap, Indonesia. Leaching experiment was carried out for 300 minutes and sampling was undertaken at 1, 3, 5, 15, 30, 90 and 300 minutes. The particle size and agitation speed were fixed at 200 mesh and 400 rpm. Samples of consumed catalyst were analyzed using EDXRF before the leaching process. Samples of solution were analyzed using ICP-EOS. Experimental results have shown that the recovery of cobalt and molybdenum increases with the increase of either concentration of hydrochloric acid or temperature. The highest recoveries in cobalt and molybdenum were 34.66% and 5.03%, respectively, obtained at a concentration of hydrochloric acid of 2 M and temperature 60°C.

Elimination of phenol from refineries effluents using electrocoagulation method

The crude oil industry is a major source of water pollution because of huge volumes of refining effluents discharged into the aquatic environment. This effluent consequently consists of substances that causes harm to the aquatic environment and depletes the aquatic population due to depleted oxygen. This study investigated the application of various treatment procedures and materials to reduce the effects of refining process effluent on water. The current study proposes to employ the electrocoagulation (EC) method in the removal of phenol contamination from refining effluent utilising aluminium electrodes. Continuous flow studies have been carried out in order to remove phenolic chemicals from refinery effluent effects of experimental factors such as electrical current density (ECD), distances between electrodes (DE), and treatment durations (TD) while phenols were eliminated were examined. The results show that the EC method reduced the phenol level in petroleum refinery discharge. The EC unit decreased the phenol level by 57% using aluminium as electrodes. The-optimal removal efficiency was found at 120 TD with an ECD of 6 mA/cm2 and a DE of 20 mm.