Wastewater

About: Wastewater is a research topic. Over the lifetime, 92512 publications have been published within this topic receiving 1256590 citations. The topic is also known as: waste water.

Produced water treatment by membranes: A review from a colloidal perspective.

Abstract: While the world faces an increased scarcity in fresh water supply, it is of great importance that water from industry and waste streams can be treated for re-use. One of the largest waste streams in the oil and gas industry is produced water. After the phase separation of oil and gas, the produced water is left. This mixture contains dissolved and dispersed hydrocarbons, surfactants, clay particles and salts. Before this water can be used for re-injection, irrigation or as industrial water, it has to be treated. Conventional filtration techniques such as multi media filters and cartridge filters, are able to remove the majority of the contaminants, but the smallest, stabilized oil droplets (<10 μm) remain present in the treated water. In recent years, research has focused on membranes to remove these small oil droplets, because this technology requires no frequent replacement of filters and the water quality after treatment is better. Membranes however suffer from fouling by the contaminants in produced water, leading to a lower clean water flux and increased energy costs. Current research on produced water treatment by membranes is mainly focused on improving existing processes and developing fouling-resistant membranes. Multiple investigations have determined the importance of different factors (such as emulsion properties and operating conditions) on the fouling process, but understanding the background of fouling is largely absent. In this review, we describe the interaction between the membrane and a produced water emulsion from a colloidal perspective, with the aim to create a clear framework that can lead to much more detailed understanding of membrane fouling in produced water treatment. Better understanding of the complex interactions at the produced water/membrane interface is essential to achieve more efficient applications.

The Quest for Active Carbon Adsorbent Substitutes: Inexpensive Adsorbents for Toxic Metal Ions Removal from Wastewater

Abstract: Due to overgrowth in population, industrialization and civilization, demands for water are increasing geometrically. Therefore, alternative sources of water are required and wastewater treatment and recycling may serve this purpose. Among various water treatment technologies, adsorption onto activated carbon is in the front line due to its universal nature. Activated carbon is the best adsorbent able to capture inorganic, as well as organic, pollutants that contaminate water resources. Inorganic pollutants, especially metal ions, are more dangerous due to their toxic and possibly carcinogenic natures. Also they are most often persistent and difficult to biodegrade. The present article describes the quest to find an economically viable substitute to active carbon adsorbent to remove toxic metal ions. A brief discussion of design of batch and column adsorption experiments, development of inexpensive adsorbents, and experimental conditions of metal ions removal by batch and column procedures is included. Eff...

Carbon Dioxide Fixation by Algal Cultivation Using Wastewater Nutrients

Abstract: Chlorella vulgaris was cultivated in wastewater discharged from a steel- making plant with the aim of developing an economically feasible system to remove ammonia from wastewater and from Nue gas simultaneously. Since CO 2 no phosphorus compounds existed in wastewater, external phosphate (15E3E 46E 0gm ~3) was added to the wastewater. After adaptation to 5% (v/v) the CO 2 , growth of C. vulgaris was signi-cantly improved at a typical concentration of in Nue gas of 15% (v/v). Growth of C. vulgaris in raw wastewater was better CO 2 than that in wastewater bu†ered with HEPES at 15% (v/v) -xation CO 2 .C O 2 and ammonia removal rates were estimated as 26E 0g m~3 h~1 and 0E92 g CO 2 m~3 h~1, respectively, when the alga was cultivated in wastewater supple- NH 3 mented with 46E 0g m~3 without pH control at 15% (v/v) PO 4 CO 2 .