PHENOL removal in refinery wastewater using mixed oxides prepared by green synthesis

Mixed solid oxides are known for their excellent catalytic property and applications in environmental remediation. This study presents a green-synthesis route for magnesium oxide–titanium oxide, a mixed oxide here demonstrated to possess high performance of phenol removal from hydrocarbon refinery process wastewater. Mixed oxide (MgO-TiO2) was prepared by using the whole extract from leaves of Piliostigma Thonningii as reducing agent. A structural attribute of the mixed oxide was investigated using X-ray Diffractometer, High-Resolution Scanning Electronic Microscopy and Energy Dispersive X-ray. Petroleum refinery raw wastewater having phenol concentration of 19.961 mg/L was treated using the green-synthesized mixed oxide. Adsorptive phenols removal up to 99.5% was achieved with a dosage of 0.04 g/100 mL at temperature of 35 °C, and contact time of 1.167 h. By this, the treated water meets the standard acceptable phenol concentration (0.1 mg/L) in wastewater of hydrocarbon refinery.

Removal of cyanide from alumina smelter wastewater using precipitation and filtration technique

Aluminum is a metal that is used in many products because of its good conducting properties. However, in the production process, aluminum is not obtained easily but through a long process. In aluminum smelting process, wastewater that is produced indicates the existence of pollutants as determined by several indicators of water pollution, one of which is cyanide that will threaten human and environmental health if not treated properly. This study was conducted to determine the optimal dose of ferrous sulfate to remove cyanide, the precipitation and filtration process efficiency in reducing cyanide, and its effect on pH of wastewater. Data were collected from an aluminum smelting company, and experiments were conducted in the laboratory. Based on results, ferrous sulfate dose of 93 mg/l is the most optimal dose in removing cyanide with an efficiency of 58.74±0.51%, while filtration process provides an efficiency of 81.65±0.42%. Precipitation with ferrous sulfate makes pH value of wastewater decrease, but filtration process increases the value again. Throughout the whole process, cyanide can be reduced by a combination of precipitation and filtration process with the efficiency of 92.43±0.26% and an average final effluent concentration of 0.78 mg/L from an initial concentration of 10.3 mg/L.

Reducing Energy and Water Consumption in Textile Dyeing Industry with Cleaner Production by Inlet-Outlet Modification to Reuse Wastewater

Dyeing Finishing (DF) textile industries which consume a lot of energy, chemicals, water, etc., then produce a lot of wastewater which creates significant environmental problems, can be anticipated by applying Cleaner Production. This paper is presented to discuss the technical modification process of dyeing production machines, which reuse process wastewater to save water and energy consumption in the production process. For that reason, there are three steps taken. First, understand the process flow of the textile dyeing industry. Second, understand in detail the dyeing process of the Jet Dyeing (JD) machine. Third, implement steps on the floor, focusing on the JD machine, starting from the initial conditions until the third step. As a result, savings in water consumption per day for 10 JD machines were achieved by almost 50 %, with details; at the initial status 700 000 L, 600 000 L in the first step, 430 000 L in the second step, and finally 400 000 L in the third step. A similar action can be carried out in other processes, such as washing, de-sizing, or in other industries which also consume a lot of water and energy.

Anaerobic Degradation of Individual Components from 5-Hydroxymethylfurfural Process-Wastewater in Continuously Operated Fixed Bed Reactors

Production of bio-based materials in biorefineries is coupled with the generation of organic-rich process-wastewater that requires further management. Anaerobic technologies can be employed as a tool for the rectification of such hazardous by-products. Therefore, 5-hydroxymethylfurfural process-wastewater and its components were investigated for their biodegradability in a continuous anaerobic process. The test components included 5-hydroxymethylfurfural, furfural, levulinic acid, and the full process-wastewater. Each component was injected individually into a continuously operating anaerobic filter at a concentration of 0.5 gCOD. On the basis of large discrepancies within the replicates for each component, we classified their degradation into the categories of “delayed”, “retarded”, and “inhibitory”. Inhibitory represented the replicates for all the test components that hampered the process. For the retarded degradation, their mean methane yield per 0.5 gCOD was between 21.31 ± 13.04 mL and 28.98 ± 25.38 mL. Delayed digestion was considered adequate for further assessments in which the order of conversion to methane according to specific methane yield for each component from highest to lowest was as follows: levulinic acid > furfural > 5-hydroxymethylfurfural > process-wastewater. Disparities and inconsistencies in the degradation of process-wastewater and its components can compromise process stability as a whole. Hence, the provision of energy with such feedstock is questionable.

Removal of Turbidity and Sludge Production from Industrial Process Wastewater Treatment by a Rejection of Steel Rich in FeCl3 (SIWW)

The pollution of industrial wastewater in Morocco poses serious problems for the environment. These effluents must be treated before discharge into the receiving environment. In this work, industrial steel wastewater (SIWW), rich in FeCl3 30%, was used as a useful and profitable coagulant and as liquid waste to be recovered in the treatment of wastewater. The coagulation-flocculation process using ferric chloride was studied using the Jar Test technique. The results obtained using FeCl3 30% (SIWW) have shown that the pH has a very significant effect on reducing turbidity for three types of polluting loads: high load, medium load. The reduction of turbidity and sludge production by FeCl3 30% (SIWW) is a function of the pollutant load of the wastewater to be treated and the pH. The higher the pollution load, the higher the optimal concentration of FeCl3 30% (SIWW). The 30% FeCl3 made it possible to remove more than 95% of the turbidity at a high load. In conclusion, industrial rejection rich in FeCl3 could be used to reduce the turbidity of industrial refinery wastewater considerably.