Composition, concentration and distribution of linear alkylbenzenes in surface sediments from selected locations in Malaysia

Linear alkylbenzenes (LABs) are a group of organic chemical markers that primarily constitute raw materials of linear alkylbenzene sulfonates (LAS) type detergents. LABs are ubiquitous compounds and of high concern due to their intensive usage in detergents around the world. The objective of this study is to investigate the composition, concentration and distribution of LABs in surface sediment samples from selected locations in Malaysia and to identify possible sources and biodegradation of LABs in the sediment samples of the studied areas using the ratio of internal (I) and external (E) isomers of LABs (I/E ratios). The correlation between LABs concentration and total organic carbon (TOC) is also investigated. Thirty two surface sediments were collected from developed and less developed areas around Peninsular Malaysia, that is at Port Dickson, Muar River, Pulau Merambong, the Johor Bahru coast, the Kim Kim River as well as Brunei Bay in Sabah and Brunei waters. The sediment samples were analyzed using gas chromatography-mass spectrometry (GC-MS). The compositional profiles of LABs showed that the long chain alkylbenzenes (C13+C14) were higher than short chain alkylbenzenes (C11+C10). The C13 homolog was the most abundant type of LAB found in sediments of the studied areas.The concentrations of LABs found ranged from 7.1 to 255.8 (ng.g-1 dw), representing low to moderate levels. The results showed higher levels of LABs in the Muar River and Kim Kim estuary than those investigated in 2004 at the same areas. LABs found in this study are lower than those detected in other places of Southeast Asia such as at Kolkata, India and Jakarta, Indonesia, whereas they are consistent with the levels found in other parts of the world such as Humber, UK, and Santos Bay, Brazil. The results also showed that LABs were strongly correlated with TOC in Port Dickson, Muar River, Merambong and Brunei Bay in Sabah and Brunei waters and weakly correlated in Johor Bahru coast and the Kim Kim River. The I/E ratio of LABs was used as an indicator of LABs biodegradation in the aquatic environment. The results from I/E ratios were from 0.6 to 4.1 and indicate that the LABs come from a range of raw, primary to secondary treated effluents. Based on the results from the LABs concentrations, it is recommended that different sites of Malaysia should be monitored and managed to reduce the levels of LABs entering the marine environment

Assessment of Sewage Molecular Markers in Port Dickson Coast and Kim Kim River with Sediment Linear Alkylbenzenes

The present study aimed to determine linear alkylbenzenes (LABs) concentrations as organic molecular marker for sewage pollution in the sediment samples collected from Coast of Port Dickson and Kim Kim River, Peninsular Malaysia. The adverse effects of anthropogenic inputs into the rivers and coastal environment could be detected by molecular organic markers such as LABs. The sediments were processed; their sources were identified and tested by gas chromatography-mass spectrometry (GC-MS). The significance of the differences among sampling stations for LAB concentrations and distribution at p < 0.05 was performed by analysis of variance and Post Hoc Tests, LSD procedures (ANOVA) and Pearson correlation coefficient. LABs indices which include internal to external (I/E) congeners, long to short chains L/S and homologs C13/C12 were used to identify the sewage treatment and degradation levels. Results of this study are statistically uncovered that the range of RLABs concentration in the investigated locations was between 112.0; 88.3 and 256.0; 119.0 ng�g1 dw, respectively. There was significant difference (p < 0.05) of LAB homologs with high percentage of C13-LAB homologs along sampling locations. The calculated LAB ratios (I/E) were within the range between 2.0; 1.7 and 4.1, 2.0, demonstrated that, the treated effluents from primary and secondary sources were discharged to the study areas. The degradation of LABs was 40–64% and 34–38% in the studied locations. The findings of this study suggested the powerfully indicators of LABs in tracing anthropogenic sewage contamination and the necessity of continuing wastewater treatment system improvemen

Unlocking the Secrets of River Pollution: Analyzing Organic Pollutants in Sediments—Experimental Study

Untreated wastewater released into rivers can result in water pollution, the spread of waterborne diseases, harm to ecosystems, contamination of soil and groundwater, as well as air pollution and respiratory problems for nearby humans and animals due to the release of greenhouse gases. The current study aims to investigate the recent input of anthropogenic loads into the rivers using linear alkylbenzene (LAB), which is one of the molecular chemical markers with application of sophisticated model statistical analyses. In order to determine the compositions of LABs, which act as wastewater pollution molecular indicators, surface sediment samples from the Muar and Kim Kim rivers were collected. Gas chromatography-mass spectrometry (GC-MS) was utilized to identify LABs and investigate their sources and degradation. ANOVA and the Pearson correlation coefficient were employed to determine the significance of differences between sampling locations, with a threshold of p 13/C12 homolog, and internal to external (I/E) congeners. The results indicated that LAB concentrations in the studied areas of the Muar River ranged from 87.4 to 188.1 ng g−1dw. There were significant differences in LAB homology at p 13-LAB homology. Based on the LAB ratios (I/E) determined, which ranged from 1.7 to 2.2 in the studied areas, it was concluded that effluents from primary and secondary sources are being discharged into the marine ecosystem in those areas. The degradation of LABs was up to 43% in the interrogated locations. It can be inferred that there is a requirement for enhancing the WWTPs, while also acknowledging the efficacy of LAB molecular markers in identifying anthropogenic wastewater contamination