Detection of heavy metal residues in the muscle and skin of Tilapia.

A study of detect the presence of heavy metals, which are Lead (Pb), Copper (Cu) and Zinc (Zn) in Tilapia cought from 3 waterways in Universiti Putra Malaysia, Serdang, Selangor was conducted. Water samples from the study sites were also sampled and analysed. These locations were in the academic areas of Universiti Putra Malaysia, Serdang campus near the agricultural and housing areas. Results showed that the mean concentration of Cu, in the water was 0.04 µg/mL and Pb and Zn were 0.03 µg/mL. The concentration of the elements tested was found to be lower than the recommended limits set by FAO/WHO but the concentration of Pb almost breached the limit of 0.05 µg/mL. The mean concentration of Pb in the fish muscles (0.64 µg/g) did not exceed the permissible limits set by FAO/WHO (1.5 µg/g) and the Malaysian Food Regulation (1.0 µg/g). The concentration of Cu in the fish muscle was much lower (2.13 µg/g) than the permissible limits set by the WHO (10.0 µg/g) and the Malaysian Food Regulation (30.0 µg/g). The highest element that had accumulated in the fish muscle was Zn (8.28 µg/g). However. The concentration of Zn did not exceed the permissible limits set by FAO/WHO (150.0 µg/g) and the Malaysian Food Regulation (100.0 µg/g). In the fish skin, the concentration of Cu and Pb were quite high. The concentration for Pb in the skin (6.77 µg/g) exceeded both the permissible limits set by FAO/WHO (1.5 µg/g) and the Malaysian Food Regulation (2.0 µg/g) while the concentration of Cu in the skin only exceeded the permissible limits set by FAO/WHO (10.0 µg/g). Among the three elements studied, Zn concentration was highest in the fish skin (45.8 µg/g). However, the Zn levels did not exceed the permissible limits of FAO/WHO and the Malaysian Food Regulation. Therefore, it can be concluded that the Tilapia caught from the waterways were not suitable for animal animal and human consumption because the concentration Pb in the fish skin was too high. Cooper was also found to be present in the skin at concentration that can pose health hazard. However, these fishes can be said to be safe to be consumed if the skin were to be removed

Heavy Metal Concentration in Mangrove Soils under Sonneratia caseolaris Trees: The Case of Kampung Kuantan Fireflies Park

The local ecosystem potentiality is pressurized by the getting up heavy metal concentrations, especially in Kampung Kuantan Fireflies Park. This mangrove forest park, which is dominated by Sonneratia caseolaris, is a well-known place to visit for people who like nature in Kuala Selangor Peninsular Malaysia. However, the investigations on heavy metal concentration in mangrove soils under S. caseolaris are still limited.  This study aims to find out the concentration of heavy metal in mangrove soil under S. caseolaris.  The soil samples were taken from under S. caseolaris trees zone. Five plots were built up on mangrove soils through the Selangor River. Five sub-plots, each measuring 2 m ´ 2 m, were made for sample collection in each plot. The heavy metal contents and the geo-accumulation index (I-geo) were evaluated. As the results, the concentration of heavy metals on soils such as zinc (Zn), copper (Cu), lead (Pb), chromium (Cr), and cadmium (Cd) under the S. caseolaris trees of 240.24 mg/kg, 6.89 mg/kg, 25.46 mg/kg, 34.88 mg/kg, and 0.14 mg/kg, respectively.  The I-geo ratio indicated that the soils have low heavy metal deposits, with Cd having the lowest concentration and Zn having the highest. There is a significant difference between Zn and Cr concentrations on the soils in five plots, but there are no significant differences for Cu, Pb, and Cd. In general, the heavy metal contents throughout the sampling area were considered not polluted, since the amount of trace elements in the soil was relatively low compared to the average limit. Keywords: heavy metal, Kampung Kuantan Fireflies Park, Kuala Selangor, mangrove, Sonneratia caseolari

Adsorption and desorption of glufosinate ammonium in soils cultivated with oil palm in Malaysia

In Malaysia, glufosinate ammonium (GLUF) is a commonly used herbicide in oil palm plantations to control broad-leaved weeds and grasses. Adsorption and desorption of (GLUF) were studied using the batch equilibrium technique in four mineral soils, Inceptisols (Selangor), Oxisols (Munchong) and Ultisols (Serdang and Rengam) series and peat (Histosols) collected under oil palm cultivation from 0-15 cm and 15-30 cm depths. Adsorption coefficients of the herbicide were correlated with soil properties i.e. organic matter content, clay content, cation exchange capacity (CEC) and pH. The concentrations of GLUF used were (0, 0.25, 0.5, 1, 1.5, 3, 5 and 10 μg/mL). The adsorption and desorption isotherms were fitted using linear and Freundlich equations. Adsorption of GLUF was in the following order: Selangor > Rengam> Munchong> peat > Serdang. The results indicate that the adsorption of GLUF is positively correlated only with clay content. The high sorption of the Selangor soil could be explained by the high clay content in Selangor series soil compared to the other soil series. However, the order of GLUF desorption was in the following order: Serdang> peat> Munchong> Rengam> Selangor. Results indicate that adsorption of GLUF was mainly on the clay fraction of the soil and the binding strength of adsorbed GLUF was high as indicated by the order of GLUF desorption from the soils

Gaseous nitrogen losses from tropical soils with liquid or granular urea fertilizer application

Gaseous loss of N leads to lower nitrogen use efficiency (NUE) of applied urea and N content of the soil. This laboratory study was conducted to compare the nitrogen losses from two tropical soil series (Bungor sandy clay loam and Selangor clay) incubated with either liquid urea (LU) or granular urea (GU) at 0, 300, 400, or 500 mg/kg of soil for thirty days. The NH3 volatilization, N2O emission, and N content in the soils were measured throughout the incubation period. For the same application rate, the total NH3 volatilization loss was higher in GU-treated soils than the LU-treated soils. NH3 volatilization loss continued up to the 15th day in the Selangor soil, while in the Bungor soil series it continued up to the 26th day. Higher amounts of N2O emissions were recorded in GU-treated soils than the LU-treated soils, and N2O emission increased with increasing rate of GU and LU applications in both soils. The N2O emission was higher only in the first few days and then tapered off at the seventh and eighth day in Bungor and Selangor soil series, respectively. The total N2O emission was higher in the Selangor soil series than that of Bungor soil series. The total N content that remained in the LU-treated soils after 30 days of incubation was higher than the GU-treated soils. The total N loss from applied urea was higher in the sandy clay loam Bungor soils than that of clayey Selangor soil series. The results suggest that the LU may be a better N fertilizer source than GU due to lower N loss from NH3 volatilization and N2O emission

Sorption and desorption of zinc by clinoptilolite and cinoptilolite-tridymite

Industrial wastes and mining related activity are main sources of zinc contamination in soils and groundwater. The quality of soil, crop and water will also be affected by high concentrations of heavy metals. The adsorption behaviour of clinoptilolite (natural Iranian zeolite) and clinoptilolite-tridymite (Chinese zeolite) at different pHs has been studied in order to find out its applicability in agriculture as soil amendment. To elucidate zinc adsorption, batch experiment at constant pH was used. The mineralogical composition, specific surface area and CEC, were investigated by X-ray diffraction (XRD), BET-N2 sorption analysis and Na-acetate method, respectively. The data indicate that Iranian and Chinese zeolites contained 93.21 %, 58.83 % Clinoptilolite-Na, respectively, but high amount of tridymite (28.04 %) was also present in the Chinese zeolite. The Zn sorption isotherm data for both Iranian zeolite and Chinese zeolite were fitted to the Langmuir and Freundlich models. The sorption results at different pH showed that sorption at constant pH=5 and 7 can best be fitted to the Langmuir equation. It was found that qmax of Iranian zeolite was higher than Chinese zeolite at both pHs. According to the findings, the binding strength of Zn adsorption in Chinese Zeolite was 0.01, 0.03 (L mg-1) at pH 5 and pH 7 whereas KL for the Iranian zeolite was 0.02 (L mg-1) at both pHs. It is revealed that the affinity of Chinese zeolite for zinc adsorption was higher at pH=7. The results indicate that the zinc desorption percent at highest loading rates for Iranian zeolite were 36.1%, 41.5%, while for Chinese zeolite were 45.81%, 36.3% at pH value 5 and 7, respectively

Characteristics and heating values of pellets made from raw and charred rice residues-rubber tree twigs mixture

In this study, the characteristics and heating values of raw pellet (RP) and charred pellet (CP) made from rice residues-rubber tree twigs mixture were compared. The carbonization process to produce the charred plant residues was conducted in a locally fabricated stainless steel kiln. Both the RP and CP were evaluated for their heating values, pellet durability, carbon and inorganic ash content. The CP had higher heating value and carbon content than the RP. However, the ash content of CP was higher. The results indicate that the pellet made from the charred rice residues-rubber tree twigs mixture could be a suitable source of renewable fuel

Response of potato to ash as an alternative source of potassic fertilizer

An experiment was carried out during rabi season of 2011-2012 in the experimental field of Soil Science, Bangladesh Agricultural University (BAU), Mymensingh. The objectives of present research work was to evaluate ash as an alternative source of potassic fertilizer for potato cultivation. The treatment combinations were i) Control (No K), ii) 100% K of recommended dose from muriate of potash (MoP), iii) 75% K from MoP+ 25% K from ash, iv) 50% K from MoP + 50% K from ash, v) 25% K from MoP + 75% K from ash, and vi) 100% K from ash. The result of the experiment indicated that various combinations of ash and MoP influenced the yield, yield contributing characters (length of the tubers, breadth of the tubers, number of tubers per hill, weight of tubers per hill, weight of ten tubers and gross yield of tubers per plot), K content of potato as well as weed infestation. Among the treatments the highest yield was obtained from 50% K from MoP + 50% from ash (T3) treated plot. The K content in the potato tuber and weed infestation was also highest for that plot. Considering the yield contributing parameters, yield and number of weeds the T3 (50% K from MoP + 50% K from ash) treatment was found more suitable than others

Characterization of Nitrogen Uptake Pattern in Malaysian Rice MR219 at Different Growth Stages Using 15N Isotope

Nitrogen (N) use efficiency is usually less than 50%, and it remains a major problem in rice cultivation. Controlled release fertilizer (CRF) technology is one of the well-known efforts to overcome this problem. The efficiency of CRF, however, is very much dependent on the timing of nutrient release. This study was conducted to determine the precise time of N uptake by rice as a guideline to develop efficient CRF. Fertilizer N uptake by rice at different growth stages was investigated by using 15N isotopic technique. Rice was planted in pots, with 15N urea as N source at the rate of 120 kg/hm2. Potassium and phosphorus were applied at the same rate of 50 kg/hm2. Standard agronomic practices were employed throughout the growing periods. Rice plants were harvested every two weeks until maturation at the 14th week and analyzed for total N and 15N content. Nitrogen derived from fertilizer was calculated. Total N uptake in plants consistently increased until the 11th week. After that, it started to plateau and finally declined. Moreover, N utilization by rice plants peaked at 50%, which occurred during the 11th week after transplanting. N derived from fertilizer in rice plants were in the range of 18.7% to 40.0% in all plant tissues. The remaining N was derived from soil. Based on this study, N release from CRF should complete by the 11th week after planting to ensure the maximum fertilizer N uptake by rice plants. Efficient CRF should contribute to higher N derived from fertilizer which also resultedin a higher total N uptake by rice plants, increasing the potential of rice to produce higher yield while at the same time of reducing loss

Phosphorous and lime-induced zinc fractions transformations in Zn deficit tropical paddy soils

The soil geochemical Zn controlling factors in soil solid- solution equilibrium influence the phyto-available forms of Zn in soil Zinc fraction pools. A laboratory incubation experiment was conducted on two highly weathered tropical soil orders (Ultisols and Entisols) to investigate the effects of some of the most important of these factors (various levels of Phosphorus (P), lime, and Zn) on Zn fractions in six tropical paddy soils. The sequential fractionation procedure was used to determine soils Zn fractions after 30 days of submerged incubation threaten by the aforementioned factors. The non- residual and available fractions (water-soluble plus exchangeable (WE) and organic complexes (Org)) increased by Zn treatments about 1.29 to 2.65 times, and 1.7 to 4 times, respectively and decreased with increasing lime application levels about 9 to 30%, and 3 to 37%, respectively, whereas the non-residual and non-available (amorphous (Amor) and manganese oxides (MN)) and the residual fractions increased with the increasing level of applied P and lime. The effects of P, lime, and Zn applications on Zn fractions were similar for all soils. The application of P plus lime was more effective in reducing available Zn fractions and increasing non-available fractions than the separate application of P or lime between 30 to 70%. It can be concluded that at the studied soil conditions and to avoid Zn deficiency in rice paddy fields due to P and lime application, Zn fertilizer should be applied more than rice nutrition requirements to overcome converted Zn to the unavailable fractions

Lime and Zn interactions effects on yield, yield component, and quality of rice in Zn deficit tropical paddy soil

A glasshouse experiment was conducted to investigate the lime and Zn application and interactions on rice, yield and yield components, and rice quality in various Zn deficit tropical paddy soil types. The tiller number, plant height and straw dry matter at maximum tillering and flowering stages significantly increased by the application of lime and both at 5 and 10 kg ha-1 Zn levels in Kundur (KUR) (pH= 5.2) and Telemong (TLM) (pH=7) soil series, whereas in Tepus (TEP) acid sulphate soil (pH=4), they increased in 5 kg ha-1 Zn and decrease at 10 kg ha-1. The grain per panicle(GPP), grain yield(GY), 1000grain weight(1000GW) and straw dry matter(SDW) significantly increased by application of Zn and increasing its levels. The highest increasing pattern were showed in Kundur (pH= 5.2) and Telemong (pH=7) soil series were recorded at 10 kg ha-1, whereas the highest and lowest values were obtained at 5 kg ha-1 and at 10 kg ha-1 in Tepus acid sulphate soil (pH=4). The highest grain and straw yield were obtained in TEP at 5 kg ha-1Zn level, which were 56 and 23% more than untreated Zn pots. The highest crude protein (CP) and grain Zn (GZn) were observed by 10 kg ha-1 applied Zn, 44% and 60% more than control, respectively. However, by lime addition CP and GZn decreased about 16 and 22% over the non-treated plots. The agronomic biofortification strategies such as Zn fertilization application and soil amendment addition improved rice MR219grain productivity and biofortification an average of 60%