The status of heavy metal levels in a Ramsar site,Kuala Gula bird sanctuary: the impact of the anthropogenic inputs

Distributions of Cd, Cu, Pb, and Zn in the surface sediments from two sites of the Kuala Gula Bird Sanctuary, Malaysia were monitored for a period of 6 months from October 2006 to March 2007. In December 2006, the concentration of Zn in one location was significantly (p??1) than the other metals at both sites, but in the oxidizable organic fraction it was highest at both sites during October; with mean concentrations of 18?mg?kg^?1 at both locations. In the acid-reducible fraction, high concentrations of Pb (2.3?mg?kg^?1) were detected at station 2 in February 2007, being highest among all four metals at both stations. The acid-reducible fraction found in Pb ranged from 0.10% to 3.1% in both stations. Percentages ranging from 51% to 96% were observed for all four metals in the resistant fraction throughout the sampling period. These results indicate low contributions from anthropogenic sources. The findings constitute a baseline data archive for future reference.     

Photocatalytic degradation of ciprofloxacin in aqueous media: a short review

The frequent detection of antibiotics such as ciprofloxacin in surface and drinking waters around the world has attracted concern from various researchers. Such presence is an indication that the decontamination of water polluted by antibiotics is beyond the conventional treatment methods. However, among the different treatment methods that have been developed in the area of water purification, heterogeneous photocatalysis using semiconductor as a mediator has been rated as an efficient and a green wastewater treatment method. This is because, the process is effective in degrading and mineralizing organic pollutants, using UV or visible light. The present review paper covers a brief survey over a range of publications in the last decade, involving photocatalytic materials that have been employed in the purification of water contaminated by ciprofloxacin.     

Bioactivity,adsorption and persistence of pretilachlor in paddy field soils

The effects of environmental factors on bioactivity, adsorption and persistence of pretilachlor were studied in the laboratory and greenhouse using cucumber (Cucumis sativus L.) as the bioassay species. The three soils studied viz. Bernam, Selangor and Sabrang series were chosen for their different characteristics. The half‐life of pretilachlor decreased from 10.24 to 4.90 days as temperature increased from 25°C to 35°C in the Selangor Series soil and from 10.86 to 7.63 days in the Bernam Series soil at 60% field capacity. At the same moisture level, an increase of temperature from 25°C to 35°C also reduced the half‐life of pretilachlor in Sabrang soil from 8.87 to 2.59 days. The half‐life of pretilachlor also decreased with increasing moisture levels in Selangor and Sabrang series but not in Bernam series soils. The greatest adsorption of pretilachlor was observed in Bernam series, followed by Selangor and Sabrang series. No phytotoxic residue of pretilachlor was detected in the supernatant after 10 h incubation. Since the residue was strongly adsorbed in Bernam series, its biological activity was less than in the other soils studied.     

Removal of Remazol Brilliant Violet-5R dye using periwinkle shells

The purpose of this research is to obtain optimal processing conditions for the adsorption of Remazol Brilliant Violet-5R (RBV-5R) dye onto activated carbon prepared from periwinkle shells (PSAC) by chemical activation with KOH using response surface methodology. Central composite design (CCD) was used to determine the effects of three preparation variables; CO₂ activation temperature, CO₂ activation time and KOH:char impregnation ratio (IR) on two responses; percentage RBV-5R dye removal and PSAC yield. Based on the CCD, two quadratic models were developed for percentage RBV-5R dye removal and PSAC yield, respectively. The most influential factor on each experimental design response was identified from the analysis of variance (ANOVA). The optimum conditions for the adsorption of RBV-5R dye onto PSAC were CO₂ activation temperature of 811 °C, CO₂ activation time of 1.70 h and IR of 3.0, resulting in 81.28% RBV-5R dye removal and 28.18% PSAC yield. PSAC prepared under optimum conditions was mesoporous with a Brunauer–Emmett–Teller surface area of 1894 m²·g^?1, total pore volume of 1.107 cm³·g^?1 and average pore diameter of 2.32 nm. The surface morphology and functional groups of the activated carbon were respectively determined from the scanning electron microscopy and Fourier transform infrared analysis.     

Free radical-assisted electrocoagulation processes for wastewater treatment

The combination of electrocoagulation with another process is a promising approach to enhance the removal efficiency of water pollutants. For instance, free radical-assisted electrocoagulation is a new combination showing higher performance. There are different combinations depending on the free radical source. This article reviews free radical-assisted electrocoagulation processes. We discuss electrocoagulation mechanisms; ozone-assisted electrocoagulation processes; advanced oxidation-assisted electrocoagulation processes; and ultrasound-assisted electrocoagulation. We present kinetic models used in free radical-assisted electrocoagulation, scale-up of free radical-assisted electrocoagulation and cost estimation. The major points are: most of the available studies have been done at laboratory scale with synthetic wastewater, and lack holistic and systematic approaches to consider the process complexity. The performance of the combined process is improved, and the removal efficiency is increased especially with ozone-assisted electrocoagulation, which gives a removal efficiency of more than 95%. The use of ultrasound energy with electrocoagulation is advantageous in reducing the problem of electrode passivation.     

Inherent risk assessment methodology in preliminary design stage: A case study for toxic release

At preliminary design stage, process designers normally lack of information on the risk level from process plant. An inherently safer process plant could be designed if the information of risk levels could be known earlier at the preliminary design stage. If the risk level could be determined, there is a possibility to eliminate or reduce the risk by applying the well-known concept: inherent safety principle. This paper presents a technique to determine the risk levels at preliminary process design stage using a 2-region risk matrix concept. A model to calculate the severity and likelihood of a toxic release accident was developed in Microsoft Excel spreadsheet. This model is integrated with process design simulator, iCON to allow for data transfer during preliminary design stage. 2-region risk matrix is proposed and used to evaluate the acceptability of the inherent risk based on the severity and likelihood rating. If the inherent risk level is unacceptable, modification for improvement can be done using the inherent safety principles. A case study has been carried out to illustrate the benefit of applying this newly developed technique. It was successfully shown that an inherently safer plant could easily be designed by applying this technique.     

Relative salinity tolerance of warm season turfgrass species

Fresh water, coupled with soil salinization in many areas has resulted in an increased need forscreening of salt tolerant turf grasses. Relative salinity tolerance of eightwarm season turfgrass species were examined in this study in sand culture. Grasses were grown in a glasshouse, irrigated with either distilled water or saline sea water adjusted to 24, 48 or 72 dSm-1. Salt tolerances of the grasses were assessed on the basis of their shoot and root growth, leaf firing and turf quality. Regression analysis indicated that Zoysiajaponica (Japanese lawn grass) (JG), Stenotaphrum secundatum (St. Augustine) (SA), Cynodon dactylon (satiri) (BS), Zoysia teneuifolia (Korean grass) (KG), Digitaria didactyla (Serangoon grass) (SG), Cynodon dactylon (Tifdwarf) (TD), Paspalum notatum (Bahia grass) (BG) and Axonopus compressus(Pearl blue) (PB) suffered a 50% shoot growth reduction at 36.0, 31.8, 30.9, 28.4, 26.4, 25.7, 20.0 and 18.6 dSm1 of salinity, respectively and a root growth reduction at44.9, 43.7, 33.4, 31.0, 29.5 27.5, 21.5 and 21.4 dSm- of salinity, respectively. Leaf firing and turf quality of the selected species, as a whole, were also found to be affected harmoniously with the change in root and shoot growth. On the basis of the experimental results the selected species were ranked for salinity tolerance as JG>SA>BS>KG>SG >TD>BG>PB.     

Studies on oxidative stress induced nerve conduction deficits in cigarette smokers

An important role of oxidative stress for the development of vascular and neurological complications has encouraged us to undertake a study to assess the oxidative stress induced nerve conduction deficits among cigarette smokers. Eighteen regular male cigarette smokers and twenty nine male non-smokers were diagnosed for clinical neuro-physiological tests viz., motor and sensory nerve conduction velocity (MNCV and SNCV) and redox status. Significant depletion of reduced glutathione (GSH) level (p < 0.05) and significant increase in malondialdehyde (MDA) level (p < 0.01) was found in smokers compared to non-smokers. Motor and sensory nerve conduction velocity showed no significant difference among smokers compared to non-smokers. The present study shows that smoking can induce oxidative stress among smokers but could not exacerbate to nerve conduction deficits.     

Time-lapse resistivity investigation of salinity changes at an ex-promontory land: a case study of Carey Island, Selangor, Malaysia

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.     

Turner syndrome-omphalocele association: Incidence,karyotype, phenotype and fetal outcome

Objective

Omphalocele is known to be associated with genetic anomalies like trisomy 13, 18 and Beckwith–Wiedemann syndrome, but not with Turner syndrome (TS). Our aim was to assess the incidence of omphalocele in fetuses with TS, the phenotype of this association with other anomalies, their karyotype, and the fetal outcomes.

Method

Retrospective multicenter study of fetuses with confirmed diagnosis of TS. Data were extracted from a detailed questionnaire sent to specialists in prenatal ultrasound.

Results

680 fetuses with TS were included in this analysis. Incidence of small omphalocele in fetuses diagnosed ≥12 weeks was 3.1%. Including fetuses diagnosed before 12 weeks, it was 5.1%. 97.1% (34/35) of the affected fetuses had one or more associated anomalies including increased nuchal translucency (≥3 mm) and/or cystic hygroma (94.3%), hydrops/skin edema (71.1%), and cardiac anomalies (40%). The karyotype was 45,X in all fetuses. Fetal outcomes were poor with only 1 fetus born alive.

Conclusion

TS with 45,X karyotype but not with X chromosome variants is associated with small omphalocele. Most of these fetuses have associated anomalies and a poor prognosis. Our data suggest an association of TS with omphalocele, which is evident from the first trimester.