Papers by Taher Alrajoula
Fibrous microplastics (FMPs) are ubiquitous worldwide, existing from lands to oceans and from sur... more Fibrous microplastics (FMPs) are ubiquitous worldwide, existing from lands to oceans and from surface waters to sediments. Ingestion and toxic effects of FMPs have been detected in organisms. FMPs released from synthetic textiles during laundering are thought to be a large source contributing to the current overall load of microplastics (MPs) in the environment. Given the fast growth of the synthetic textile market and the continuing emission of FMPs, this review aims to present measures to reduce FMP emissions to the environment. To achieve this aim, we summarise existing data and knowledge about FMPs to elucidate a) the definition of FMPs, b) FMP release during textile washing and influencing factors, and c) FMP retention in wastewater treatment plants (WWTPs) at different treatment stages and subsequent emission to the aquatic environment. Based on the existing data, we estimate that the annual release of FMPs from synthetic textile washing is in the range of 50.6 – 1180 kg per 1...
Water Science and Technology, 2009
Anaerobic filter (AF) was used for polishing effluent of UASB reactor treating strong sewage at a... more Anaerobic filter (AF) was used for polishing effluent of UASB reactor treating strong sewage at an average water temperature of 238C. The UASB-AF system was operated with sludge discharge taking place only from the AF reactor. It was hypothesized that better removal of suspended COD (COD ss) fraction from the system can be achieved by increasing sludge discharge frequency from the AF reactor. For this purpose, sludge discharge frequencies of once, twice and thrice per day from the AF reactor were investigated. Results showed that average total COD (COD tot) removal efficiency of the system increased from 62% when sludge was discharged once per day from the AF reactor up to 67% when sludge was discharged twice and thrice per day. However, the increase in COD tot removal was not due to increased removal of COD ss fraction; but mainly due to development of an active biomass on the filter media, which increased removal efficiency of soluble COD fraction. The AF reactor had also an evidence of pathogens reduction. The AF reactor achieved 1-2 log reduction in Fecal Coliform counts.
Hydrological, socio-economic and reservoir alterations of Er Roseires Dam in Sudan
Science of The Total Environment, 2016
Er Roseires Dam plays a key role in controlling the Blue Nile flow in Sudan. This study explores ... more Er Roseires Dam plays a key role in controlling the Blue Nile flow in Sudan. This study explores the influence of the dam on the hydrological regimes, which in turn have implications for the ecosystem. The Range of Variability Approach (RVA) - based on a set of 32 indicators - was applied over the period 1965 to 2014 to establish a safe range of river flow. Moreover, remotely-sensed data of the Normalized Difference Vegetation Index (NDVI) was used to analyse the spatio-temporal variation of the dam's reservoir area over the period 2000-2014. Significant influence on the dry-season hydrological indicators is expressed by high negative hydrological alteration of the range from -47% to -100%, but the dam contributes positively through flow regulation during the flood season. Impounding water procedure and fluctuation of water flow caused by the dam are found to induce significant alterations. Releasing less water during the dry season and more gradual impounding process, which are not expected to affect the power generation or irrigation practices, are recommended for better ecological restoration. The total surface area of the reservoir has changed post the implementation of the dam heightening project. Since 2012, the lake surface area has expanded by 250%. Relationships between the lake size and the head have been developed to help in the monitoring of the hydrological conditions and, accordingly, in managing the dam operation. A field survey showed that the dam plays a positive social role as the reservoir supports local activities, such as fishery, farming, and collection of wood and fruits. But increased humidity and health problems have also been noted. The Grand Ethiopian Renaissance Dam (GERD) would have a direct effect on Er Roseires Dam and the river flow downstream. High level of coordination among the riparian countries is recommended for better river water management.
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Papers by Taher Alrajoula