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Soo Ching Lee Romano Ngui Tiong Kai Tan Muhammad Aidil Roslan Init Ithoi Yvonne AL Lim 《Environmental science and pollution research international》2014,21(1):445-453
An aquatic biomonitoring of Giardia cysts and Cryptosporidium oocysts in river water corresponding to five villages situated in three states in peninsular Malaysia was determined. There were 51.3 % (20/39) and 23.1 % (9/39) samples positive for Giardia and Cryptosporidium (oo)cysts, respectively. Overall mean concentration between villages for Giardia cysts ranged from 0.10 to 25.80 cysts/l whilst Cryptosporidium oocysts ranged from 0.10 to 0.90 oocysts/l. Detailed results of the river samples from five villages indicated that Kuala Pangsun 100 % (9/9), Kemensah 77.8 % (7/9), Pos Piah 33.3 % (3/9) and Paya Lebar 33.3 % (1/3) were contaminated with Giardia cysts whilst Cryptosporidium (oo)cysts were only detected in Kemensah (100 %; 9/9) and Kuala Pangsun (66.6 %; 6/9). However, the water samples from Bentong were all negative for these waterborne parasites. Samples were collected from lower point, midpoint and upper point. Midpoint refers to the section of the river where the studied communities are highly populated. Meanwhile, the position of the lower point is at least 2 km southward of the midpoint and upper point is at least 2 km northward of the midpoint. The highest mean concentration for (oo)cysts was found at the lower points [3.15?±?6.09 (oo)cysts/l], followed by midpoints [0.66?±?1.10 (oo)cysts/l] and upper points [0.66?±?0.92 (oo)cysts/l]. The mean concentration of Giardia cysts was highest at Kuala Pangsun (i.e. 5.97?±?7.0 cysts/l), followed by Kemensah (0.83?±?0.81 cysts/l), Pos Piah (0.20?±?0.35 cysts/l) and Paya Lebar (0.10?±?0.19 cysts/l). On the other hand, the mean concentration of Cryptosporidium oocysts was higher at Kemensah (0.31?±?0.19 cysts/l) compared to Kuala Pangsun (0.03?±?0.03cysts/l). All the physical and chemical parameters did not show significant correlation with both protozoa. In future, viability status and molecular characterisation of Giardia and Cryptosporidium should be applied to identify species and genotypes/subgenotypes for better understanding of the epidemiology of these waterborne parasites. 相似文献
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Tajul Baharuddin MF Taib S Hashim R Zainal Abidin MH Ishak MF 《Environmental monitoring and assessment》2011,180(1-4):345-369
Time-lapse resistivity measurements and groundwater geochemistry were used to study salinity effect on groundwater aquifer at the ex-promontory-land of Carey Island in Malaysia. Resistivity was measured by ABEM Terrameter SAS4000 and ES10-64 electrode selector. Relationship between earth resistivity and total dissolved solids (TDS) was derived, and with resistivity images, used to identify water types: fresh (ρ ( e ) > 6.5 Ω m), brackish (3 Ω m < ρ ( e ) < 6.5 Ω m), or saline (ρ ( e ) < 3 Ω m). Long-term monitoring of the studied area's groundwater quality via measurements of its time-lapse resistivity showed salinity changes in the island's groundwater aquifers not conforming to seawater-freshwater hydraulic gradient. In some aquifers far from the coast, saline water was dominant, while in some others, freshwater 30 m thick showed groundwater potential. Land transformation is believed to have changed the island's hydrogeology, which receives saltwater pressure all the time, limiting freshwater recharge to the groundwater system. The time-lapse resistivity measurements showed active salinity changes at resistivity-image bottom moving up the image for two seasons' (wet and dry) conditions. The salinity changes are believed to have been caused by incremental tide passing through highly porous material in the active-salinity-change area. The study's results were used to plan a strategy for sustainable groundwater exploration of the island. 相似文献
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Bahari M. B. Mamat C. R. Jalil Aishah Abdul Siang T. J. Hassan N. S. Khusnun N. F. Nabgan W. Roslan N. A. Abidin S. Z. Setiabudi H. D. Vo D.-V. N. 《Environmental Chemistry Letters》2022,20(4):2361-2384
Environmental Chemistry Letters - Rising energy needs and the exhaustion of fossil fuels are calling for renewable fuels such as dihydrogen (H2), commonly named 'hydrogen.' Biomass... 相似文献
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Roslan Noorain Tomonori Kindaichi Noriatsu Ozaki Yoshiteru Aoi Akiyoshi Ohashi 《环境科学学报(英文版)》2019,31(9):110-122
Biogas purification via water scrubbing produces effluent containing dissolved CH4, H2S, and CO2, which should be removed to reduce greenhouse gas emissions and increase its potential for water regeneration. In this study, a reactor built with air supplies at the top and bottom was utilized for the treatment of biogas purification effluent through biological oxidation and physical stripping processes. Up to 98% of CH4 was removed through biological treatment at a hydraulic retention time of 2 hr and an upper airflow rate of 2.02?L/day. Additionally, a minimum CH4 concentration of 0.04% with no trace of H2S gas was detected in the off gas. Meanwhile, a white precipitate was captured on the carrier showing the formation of sulfur. According to the developed mathematical model, an upper airflow rate of greater than 2.02?L/day showed a small deterioration in CH4 removal performance after reaching the maximum value, whereas a 50?L/day bottom airflow rate was required to strip the CO2 efficiently and raise the effluent pH from 5.64 to 7.3. Microbiological analysis confirmed the presence of type 1 methanotroph communities dominated by Methylobacter and Methylocaldum. However, bacterial communities promoting sulfide oxidation were dominated by Hyphomicrobium. 相似文献
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Latif MT Wanfi L Hanif NM Roslan RN Ali MM Mushrifah I 《Environmental monitoring and assessment》2012,184(3):1325-1334
This study aims to determine the composition of surfactants in the lake surface microlayer, rainwater, and atmospheric aerosols
in the area surrounding Lake Chini, Pahang. Surfactants in the lake surface microlayer were taken from seven different stations
around the lake, while samples of rainwater were taken from five different sampling stations. The samples of atmospheric aerosols
were collected from the Lake Chini Research Centre which is in close proximity to the lake. The colorimetric analysis method
was used to determine the composition and concentration of anionic surfactants as methylene blue active substances (MBAS)
and cationic surfactants as disulphine blue active substances (DBAS). The concentration of anionic surfactants, as MBAS, in
the surface microlayer ranged between 0.08 to 0.23 μmol L − 1, while the range of concentration of cationic surfactants as DBAS ranged from 0.09 to 0.11 μmol L − 1. The concentration of MBAS was higher in rainwater when compared to surfactants in the lake surface microlayer. The high
concentration of surfactants in the fine mode of atmospheric aerosols suggests that natural and anthropogenic sources of surfactants
contribute to the atmospheric surfactants. 相似文献
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Ahmad Farid Mohammed Abdillah Hassan Mohd Ali Roslan Ahmad Muhaimin Ariffin Hidayah Norrrahim Mohd Nor Faiz Othman Mohd Ridzuan Yoshihito Shirai 《Environmental science and pollution research international》2021,28(22):27976-27987
Environmental Science and Pollution Research - This study provides insight into the decolorization strategy for crude glycerol obtained from biodiesel production using waste cooking oil as raw... 相似文献
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