Satu kajian kualiti air yang melibatkan pengukuran parameter seperti oksigen terlarut (DO), pH, permintaan oksigen biokimia (BOD), permintaan oksigen kimia (COD), jumlah pepejal terampai (TSS) dan nutrien terlarut telah dijalankan di lembangan Sungai Marang bermula dari bulan Julai-September 2001. Lapan stesen pensampelan telah dipilih yang merangkumi sungai utama dan cabangannya. Hasil kajian menunjukkan julat nilai untuk DO, pH, BOD, COD dan TSS masing-masing ialah 3.5-7.5 mg/L, 5.9-8.2, 0.4-1.3 mg/L, 4.0-50.2 mg/L dan 0.3-20.4 mg/L. Kepekatan ortofosfat, jumlah fosfat terlarut, nitrit, nitrat, ammonia dan jumlah nitrogen terlarut masing-masing adalah dalam julat 27-62 μg P/L, 55-105 μg P/L, 0.5-4.1 μg N/L, 65-426 μg N/L, 16-161 μg N/L dan 128-787 μg N/L. Julat kepekatan klorofil-a pula ialah 4.06-7.75 μg/L. Kajian menunjukkan taburan nutrien dipengaruhi oleh kesan antropogenik. Berdasarkan kepada Piawai Interim Kualiti Air Kebangsaan, kebanyakan kepekatan nutrien boleh dikelaskan dalam Kelas I dan II. Mengikut indeks kualiti air Jabatan Alam Sekitar, Sungai Marang berada dalam Kelas I dengan status bersih.
PM2.5 mass concentration and associated water-soluble ionic species in a sub-urban coastal area of Kuala Terengganu, Malaysia were investigated intermittently from year 2006 to 2009. A total of 78 weekly PM2.5 samples were analyzed. The mass concentration of PM2.5 exhibited annual, seasonal and diurnal variations. Temporal distributions of rainfall, sporadic haze episodes and local air flow (sea breeze circulation) were factors controlling PM2.5 mass variations in the study area. Although the PM2.5 concentrations were increased during haze episodes in 2006 (August and October) and2007 (October), their concentrations however, were still within the international guidelines. The average concentration of individual ions was in decreasing trend; SO42-> NH4+> K+> Na+> NO3-> Cl-> Ca2+. The concentrations of SO42- and NH4+ accounted for > 70% of the water-soluble aerosol mass. More than 80% of ionic species associated with PM2.5 are from non-marine sources. Major processes affecting the ionic composition of PM2.5 are biomass burning, crustal loading and sea spray. Air quality mitigation strategies should focus on anthropogenic activities emitting SO2, which promotes aerosol SO42- formation.
Taburan parameter fizikal, jumlah pepejal terampai (TSS), klorofil-a dan nutrien berasaskan fosfat telah dikaji di muara Sungai Dungun. Pada umumnya, kesemua parameter yang diukur menunjukkan sifat tak konservatif daripada garis pencairan teori. Analisis terhadap nutrien berasaskan fosfat menunjukkan perubahan kepekatan ortofosfat dan total fosfat masing-masing dalam julat 6.3-23.3 µg/L P dan 5.5-133.9 µg/L P. Hasil kajian juga menunjukkan taburan nutrien berasaskan fosfat dipengaruhi oleh parameter fizikal, TSS dan klorofil-a. Faktor-faktor antropogenik juga menyumbang kepada tingginya kepekatan ortofosfat dan total fosfat yang didapati terutamanya di kawasan pertengahan muara sungai.
Suatu kajian mengenai Indeks Kualiti Air (IKA) telah dijalankan di lembangan Sungai Paka, Terengganu. Ianya melibatkan pengukuran oksigen terlarut, pH, permintaan oksigen biokimia, permintaan oksigen kimia, jumlah pepejal terampai dan ammonia di lapan buah stesen pensampelan. Hasil kajian menunjukkan semua stesen pensampelan berada dalam status bersih kecuali dua stesen tercemar yang terletak di Sungai Rengat dan Sungai Rasau. Walau bagaimanapun, secara keseluruhannya purata nilai IKA bagi lembangan Sungai Paka adalah 72.4% dan boleh diklasifikasikan sebagai kelas II dengan status sedikit tercemar. Hasil kajian juga menunjukkan kumbahan daripada kilang kelapa sawit merupakan penyumbang utama kepada kemerosotan nilai IKA di kawasan kajian.
A study was carried out to determine the distribution of nutrient, chlorophyll-a and the physical properties of water at Setiu Wetland from May-October 2001. Ten sampling stations were selected to represent various locations within the study area. The analyses of dissolved nutrients and chlorophyll-a were carried out based on colorimetric methods while the physical parameters were measured in situ. The results indicated that pH values between 5.15-8.03, dissolved oxygen 4.89-6.85 mg/L, biological oxygen demand 0.04-1.80 mg/L and total suspended solids 1.3-19.7 mg/L. The concentrations of orthophosphate, total dissolved phosphate, nitrate, ammonia, total dissolved nitrogen and chlorophyll-a were in the range of 0.19-2.85 μg P/L, 1.06-25.81 μg P/L, 1.48-89.66 μg N/L. 6.0-125.7 μg N/L. 122.50-432.34 μg N/L and 0.03Â4.32 mg/L, respectively. In addition, the results obtained also suggest possible linkage between land use practices and deteriorations of water quality in the wetland area.
[Satu kajian telah dijalankan untuk menentukan taburan nutrien, klorofil-a dan sifat fizikal air di Tanah Bencah Setiu dari bulan Mei-Oktober 2001. Sepuluh stesen pensampelan telah dipilih untuk mewakili kawasan-kawasan yang berlainan di kawasan kajian. Analisis nutrien terlarut dan klorofil-a dijalankan berdasarkan kaedah kolorimetrik manakala parameter fizikal diukur secara in situ. Hasil kajian menunjukkan bahawa pH mempunyai nilai antara 5.15-8.03, oksigen terlarut 4.89-6.85 mg/L, permintaan oksigen biokimia 0.04-1.80 mg/L dan jumlah pepejal terampai 1.3-19.7 mg/L. Kepekatan ortofosfat, jumlah fosfat terlarut, nitrat, ammonia, jumlah nitrogen terlarut dan klorofil-a adalah masing-Âmasing dalam julat 0.19-2.85 μg P/L, 1.06-25.81 μg P/L, 1.48-89.66 μg N/L, 6.0-125.7 μg N/L, 122.50-432.34 μg N/L dan 0.03-4.32 mg/L. Disamping itu, keputusan yang didapati turut mencadangkan kemungkinan wujudnya hubungan antara kepelbagaian aktiviti guna tanah dan kemerosotan kualiti air di kawasan tanal: bencah].
This study investigates the spatial variation of water quality parameters in Sungai Setiu Basin at ten different locations from March 2010 to February 2011. The water quality was assessed using the Water Quality Index by Malaysian Department of Environment (DOE-WQI) and classified according to the Malaysia Interim National Water Quality Standard (INWQS). Six water quality parameters embedded in the DOE-WQI were dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), pH, ammoniacal nitrogen (AN) and total suspended solid (TSS). In addition, this study also examined the changes in water quality over the past 10 years by comparing the present water quality to the previous works. The overall mean WQI value obtained was 84.0 which indicate that the Sungai Setiu basin is in clean condition and all measured water quality parameters gave value within the permissible limits of the INWQS classification except for pH which fall in Class III. It can be concluded that water quality in Sungai Setiu does not varies greatly over a decade. Hence continuous monitoring is needed to improve the water quality and minimize water pollution.
A seasonal study of phosphorus (P)-based nutrients was carried out in Sungai Setiu basin which is located in the southern
region of the South China Sea (Malaysia) from July 2010 until June 2011. Parameters measured were dissolved inorganic
P (DIP), dissolved organic P (DOP) and total particulate P (TPP). In addition, DOP concentration was size fractionated
into high molecular weight (HMW, 0.7 µm-100 kDa), middle MW (MMW, 100-30 kDa) and low MW (LMW, <30 kDa). The
results show that the mean concentration of P-based nutrients ranged between 3.2-7.0 µg/L P for DIP, 5.6-12.1 µg/L P
for DOP and 9.2-119.4 µg/L P for TPP. Higher mean concentrations of P were recorded at urban and agricultural areas.
In addition, the distribution of P was affected by season as higher mean concentrations of P were observed during the
north-east monsoon due to the surface runoff of nutrients during this heavy raining season. The fractionation study of
DOP further revealed that HMW fraction was abundant in Sungai Setiu, making up approximately 60% of the total DOP.
This high percentage of HMW DOP was recorded at stations in the vicinity of agriculture area and towns suggesting
an important contribution from anthropogenic activities. The LMW DOP fraction was not significantly associated with
chlorophyll-a, suggesting that the phytoplankton might not be the predominant contributor for LMW fraction in this river.
We suggest that these organic nutrient inputs should be monitored as part of the management of the aquatic system.
The aim of this study was to assess spatial and seasonal variations of dissolved and particulate organic carbon (DOC and POC, respectively) in the Setiu Wetland, which is located in the southern region of the South China Sea coastal area. Surface water samples were collected monthly from October 2009-September 2010. In addition, the concentration of chlorophyll-a was determined. The DOC and POC mean concentration varied between 80-340 μM and 60-115 μM, respectively. The results showed that the concentrations of these parameters were mainly influenced by human activities and season. Higher concentrations of DOC (150-340 μM) and POC (75-115 μM) were found at stations near the populated area, aquaculture and palm oil plantation. In addition, higher concentrations of DOC (200-275 μM) and POC (105-150 μM) were also recorded during the monsoon season due to runoff from terrestrial sources and resuspension from bottom sediments. No significant correlation between the low molecular weight (LMW) fractions of DOC and chlorophyll-a (R2=0.0096, p>0.05) further supports the hypothesis that phytoplankton not playing key role in regulating the organic carbon distribution. Higher percentage of LMW DOC in monsoon season suggesting possible input of this fraction from land runoff to the wetland are
A study was carried out to determine the distribution and behaviour of nitrogen (N) compounds (nitrite, nitrate, ammonia,
dissolved and particulate organic nitrogen) in Sungai Terengganu estuary (TRE). Surface water samples were collected
during ebb neap and spring tides for the longitudinal survey along the salinity gradient. The results indicated that all N
compounds behave non-conservatively with addition during both tidal cycles, except for nitrate which exhibited removal
behaviour during spring tide. In general, higher concentration of N compounds was observed during spring tide compared
to neap tide. It is suggested that during spring tide, stronger water turbulence resulted in resuspension of nutrients in
bottom sediment and lead to the increase in N compounds concentrations in the surface water. The diurnal survey for the
freshwater station showed that the concentrations of N compounds follow the ebb and flood variations, whereas for the
coastal station the reverse trend was observed. Comparisons with a previous study under similar tidal conditions show
there was an increase in nitrite and ammonia concentrations in TRE, which was probably due to increase in discharge
from the rapid development activities around this area. In addition, the presence of a breakwater at the lower part of
the estuary may also contribute to the high nutrient content in the estuary due to restricted outflow of nutrients to the
coastal area. Overall, the results from this study highlighted the importance of monitoring the N compounds for future
protection of the estuary.