Search Results

1 - 2 of 2 items

  • Author: S. Gea x
Clear All Modify Search


Heavy metal waste is very dangerous, which can change the condition of water into a solid substance that can be suspended in water and can reduce the cleanliness level of water consumed by living things. To date, heavy metals can be managed through several processes, namely physics, biology or chemistry. One of the ways to overcome heavy metal pollution is to use natural zeolite applying a co-precipitation method, as it is known that zeolite is a powerful natural material to be used for certain purposes. In order to justify the research results, several analyses have been performed, such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Surface Area Analyser (SAA), and Atomic Adsorption Spectrophotometric (AAS). From the XRD results, it has been found out that the size of each zeolite with variations in size of 150 mesh, 200 mesh, and 250 mesh is 29.274 nm, 38.665 nm and 43.863 nm, respectively. Moreover, the SEM-EDX has shown that the zeolite under consideration is a type of Na-Zeolite and that the co-precipitation method successfully removes impurity elements, namely, Fe, Ti, and Cl. The results of SAA testing have indicated that the total surface area for each variation of zeolite sizes is 63.23 m2/g, 45.14 m2/g and 59.76 m2/g. The results of the AAS test analysis have demonstrated that the optimal absorption of metal content is observed in a size of 150 mesh zeolite with adsorption power of 99.6 % for Pb metal, 98 % for Cu metal, and 96 % Zn metal.


Genetic gains in breast-height diameter were estimated using deterministic simulation. Simulations of gain from one generation of selection were undertaken in large Main and small Elite breeding populations for a range of heritabilities, with varying numbers of parents, families, seedlings/family, clones/family and ramets/ clone to aid revision of the New Zealand Pinus radiata breeding strategy. Cloned versus seedling populations of equal numbers of plants were simulated, derived from open pollination, polycrossing, and pair crossing. Balanced within-family selection was used for 200, 400 and 800-parent Main breeding populations and among- and within-family selection for 25-parent Elite populations of 25 up to 100 full-sib families. Predicted gains from within-family selection in the Main population were highest from cloned polycross families at all heritabilities and lowest for seedling fullsib families. Gains from cloned populations were higher than seedling equivalents at heritabilities ≤0.5, and their advantage in gain was greatest at lower heritabilities. Elite populations of 25 parents showed similar trends but intensive among- and within-family selection resulted in much higher gains than from the Main, highest from the cloned options. The increase in gain with increased number of families diminished with more than 2-3 times as many families as parents. A new strategy was proposed for P. radiata, based on the simulation results, involving an expanded Main breeding population of open-pollinated (OP) seedling families, together with pair-cross family seedlots already available, supported by parentage reconstruction using DNA markers. Forwards selection in small cloned Elite populations was proposed as the main source of seed orchard clones.