Adsorption study of 14C-paraquat in two Malaysian agricultural soils

The adsorption equilibrium time and effects of pH and concentration of ¹⁴C-labeled paraquat (1,1^??-dimethyl-4,4^??-bipyridylium dichloride) in two types of Malaysian soil were investigated. The soils used in the study were clay loam and clay soils from rice fields. Equilibrium studies of paraquat in a soil and pesticide solution were conducted. Adsorption equilibrium time was achieved within 2 h for both soil types. The amount of ¹⁴C-labeled paraquat adsorbed onto glass surfaces increased with increasing shaking time and remained constant after 10 h. It was found that paraquat adsorbed by the two soils was very similar: 51.73 (clay loam) and 51.59 ?? g g^???1 (clay) at 1 ?? g/ml. The adsorption of paraquat onto both types of soil was higher at high pH, and adsorption decreased with decreasing pH. At pH 11, the amounts of ¹⁴C-labeled paraquat adsorbed onto the clay loam and clay soil samples were 4.08 and 4.05 ?? g g^???1, respectively, whereas at pH 2, the amounts adsorbed were 3.72 and 3.57 ?? g g^???1, respectively. Results also suggested that paraquat sorption by soil is concentration dependent.     

Mangrove vulnerability modelling in parts of Western Niger Delta, Nigeria using satellite images, GIS techniques and Spatial Multi-Criteria Analysis (SMCA)

Mangroves are known for their global environmental and socioeconomic value. Despite their importance, mangrove like other ecosystems is now being threatened by natural and human-induced processes that damage them at alarming rates, thereby diminishing the limited number of existing mangrove vegetation. The development of a spatial vulnerability assessment model that takes into consideration environmental and socioeconomic criteria, in spatial and non-spatial formats has been attempted in this study. According to the model, 11 different input parameters are required in modelling mangrove vulnerability. These parameters and their effects on mangrove vulnerability were selected and weighted by experts in the related fields. Criteria identification and selection were mainly based on effects of environmental and socioeconomic changes associated with mangrove survival. The results obtained revealed the dominance of socioeconomic criteria such as population pressure and deforestation, with high vulnerability index of 0.75. The environmental criteria was broadly dispersed in the study area and represents vulnerability indices ranging from 0.00?C0.75. This category reflects the greater influence of pollutant input from oil wells and pipelines and minimal contribution from climatic factors. This project has integrated spatial management framework for mangrove vulnerability assessment that utilises information technology in conjunction with expert knowledge and multi-criteria analysis to aid planners and policy/ decision makers in the protection of this very fragile ecosystem.     

Prenatal diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency by steroid analysis in the amniotic fluid of mid-pregnancy: Comparison with HLA typing in 17 pregnancies at risk for CAH

Amniotic fluid (AF) levels of 17-hydroxyprogesterone (17OHP) and testosterone (T) were determined at 16–17 weeks in 17 pregnancies at risk for CAH and results compared to 75 normal controls. The fetus was predicted to be unaffected in 12 cases on the findings of normal AF levels of both 17OHP and T and the latter allowed a correct prediction of fetal sex in all instances. HLA typing confirmed normality in 12 cases revealing 5 carriers, 5 homozygous normal and 2 indeterminate. Steroid levels of the 2 groups were similar. Three fetuses were predicted to be CAH affected on unambiguously high levels of 17OHP and T (in female only). HLA typing was in agreement, and the diagnosis was confirmed in 2 abortuses and a female newborn by physical and hormonal studies. In the last 2 cases AF levels of OHP and T were normal but HLA (A/B/C) genotypes were identical to the CAH affected siblings. Normal physical and hormonal findings in the 2 aborted fetuses would exclude the possibility of an in utero virilizing form of CAH. The discrepancy could be explained on the basis that the fetuses had an allelic form of 21-hydroxylase deficiency or on the basis of recombination (not fully tested). It is concluded that a fully informative prenatal diagnosis of CAH should not rely entirely on HLA typing but on hormonal studies.     

Nutrient and enzymatic changes of hydrolysed tannery solid waste treated with epigeic earthworm Eudrilus eugeniae and phytotoxicity assessment on selected commercial crops

Animal fleshing (ANFL) is the predominant proteinaceous solid waste generated during processing of leather and it is confronting disposal problems. The aim of this study was to assess the potential of epigeic earthworm Eudrilus eugeniae to utilize and transform the fermented ANFL in the solid state (SSF) and submerged state (SmF) into a value added product along a low residence period (25 days). A total of six treatment units containing different waste mixture compositions were established. Fifty healthy and non-clitellated earthworms were introduced in three different treatment containers: control, SSF, and SmF (+worm). Another set of treatment mixtures (control, SSF, SmF) was established without earthworms (?worm) to compare the results. The products were characterized for physico-chemical, enzymatic analysis and seedling growth parameters to compare the differences in the process with and without earthworms. The changes observed in the analytical parameters were in the following order: SSF > SmF > control mixtures (p?<?0.05). The vermicompost showed a significant reduction in heavy metals, total organic carbon and an increase in total Kjeldhal nitrogen as compared to the product untreated by earthworms. The maximum enzymatic activities were observed after 21 days of vermicomposting. The relative seed germination of vermicompost extracts were in the order of tomato (Lycopersicon esculentum) > green gram (Vigna radiata) > cucumber (Cucumis sativus) > bottle gourd (Lagenaria siceraria (Mol.) Standl.) and showed no phytotoxicity effects. The results indicated that the combination of both ANFL hydrolysis through fermentation and vermicomposting is a good alternative to the management of this kind of waste.     

Potential use of Caulerpa fastigiata biomass for removal of lead: kinetics, isotherms, thermodynamic, and characterization studies

The present study attempts to analyze the biosorption trend of biosorbent Caulerpa fastigiata (macroalgae) biomass for removal of toxic heavy metal ion Pb (II) from solution as a function of initial metal ion concentration, pH, temperature, sorbent dosage, and biomass particle size. The sorption data fitted with various isotherm models and Freundlich model was the best one with correlation coefficient of 0.999. Kinetic study results revealed that the sorption data on Pb (II) with correlation coefficient of 0.999 can best be represented by pseudo-second-order. The biosorption capacity (q _e ) of Pb (II) is 16.11?±?0.32 mg g^?1 on C. fastigiata biomass. Thermodynamic studies showed that the process is exothermic (ΔH° negative). Free energy change (ΔG°) with negative sign reflected the feasibility and spontaneous nature of the process. The SEM studies showed Pb (II) biosorption on selective grains of the biosorbent. The FTIR spectra indicated bands corresponding to –OH, COO^?, –CH, C?=?C, C?=?S, and –C–C– groups were involved in the biosorption process. The XRD pattern of the C. fastigiata was found to be mostly amorphous in nature.     

Marine organisms as heavy metal bioindicators in the Persian Gulf and the Gulf of Oman

In the present study, cadmium and lead concentrations were compared in barnacles, ghost shrimps, polychaetes, bivalves, and sediment from ten different locations along the intertidal zone of the Persian Gulf and the Gulf of Oman. The results revealed significant differences in the heavy metal concentrations between the organisms with barnacles showing, by far, the highest metal concentrations. The bioaccumulation factor of Cd in different animals follows this pattern with barnacles?>?bivalves?>?polychaetes?>?ghost shrimps, while the pattern for Pb was barnacles?>?polychaetes?>?bivalves?>?ghost shrimps. In most of the stations, sediments showed the lowest lead and cadmium concentrations. Therefore, it is concluded that barnacles with Pb concentrations between 0.17 and 2,016.1 μg/g and Cd concentrations ranging from 0.4 to 147.1 μg/g are the best organisms to be employed in monitoring programs designed to assess pollution with bioavailable metals in the Persian Gulf and the Gulf of Oman.     

Bioremediation assessment of diesel–biodiesel-contaminated soil using an alternative bioaugmentation strategy

This study investigated the effectiveness of successive bioaugmentation, conventional bioaugmentation, and biostimulation of biodegradation of B10 in soil. In addition, the structure of the soil microbial community was assessed by polymerase chain reaction-denaturing gradient gel electrophoresis. The consortium was inoculated on the initial and the 11th day of incubation for successive bioaugmentation and only on the initial day for bioaugmentation and conventional bioaugmentation. The experiment was conducted for 32 days. The microbial consortium was identified based on sequencing of 16S rRNA gene and consisted as Pseudomonas aeruginosa, Achromobacter xylosoxidans, and Ochrobactrum intermedium. Nutrient introduction (biostimulation) promoted a positive effect on microbial populations. The results indicate that the edaphic community structure and dynamics were different according to the treatments employed. CO₂ evolution demonstrated no significant difference in soil microbial activity between biostimulation and bioaugmentation treatments. The total petroleum hydrocarbon (TPH) analysis indicated a biodegradation level of 35.7 and 32.2 % for the biostimulation and successive bioaugmentation treatments, respectively. Successive bioaugmentation displayed positive effects on biodegradation, with a substantial reduction in TPH levels.     

From Valuation to Governance: Using Choice Experiment to Value Street Trees

This paper reports a choice experiment used to estimate the value of street trees in the city center of Lodz, Poland, and the broader context of how valuation results helped to improve governance of urban ecosystem services in this city. Based on a simplified inventory of trees, we prepared a set of hypothetical programs which put varying emphasis on the different ways to increase the numbers of trees, along with different levels of a hypothetical tax that would have to be paid by respondents to implement a given program. Our study indicated that the 351 surveyed Lodz residents were willing to pay the highest price for greening those streets where currently there are few or no trees and confirmed the general importance of planting trees. The results provided an argument in the debate on the new development strategy for the city and helped to promote the concept of ecosystem services.