Effect of car exhausts on lead contamination in vegetables grown adjacent to Kuala Lumpur - Ceras Highway

It has already been established from studies over a wide area of Kuala Lumpur that lead contamination in grass adjacent to heavy-traffic roads is hazardous to grazing cattle if local forage grass is the only source of food (Low, Lee and Arshad, 1979). In Kuala Lumpur, a number of vegetable farms are located near heavy-traffic roads and contamination of lead caused by car exhausts on these vegetables has not been reported. This paper reports the levels of lead in leafy vegetables and their supporting soils in two locations. The first was a commercial vegetable farm some 50 m from the Kuala Lumpur - Ceras Highway with heavy tra/fic density. The second was a domestic garden located on the Universiti Pertanian Malaysia campus where the flow of vehicles is generally low. In these areas deposition oflead, if any, on vegetables comes almost exclusively from automobile exhausts. There is no other known source of lead contamination in these areas

A study of wastewater discharge from electroplating factories

There are some fifteen electroplating factories lIT Kuala Lumpur and Klang area, specializing in various forms of plating, namely chromium, zinc, silver and occasionally, cadmium, Almost all of these electroplating factories do not have any facilities for wastewater treatment. Wastewater containing cyanide and metallic ions like copper, nickel, chromium, lead, zinc, silver and others is discharged directly into drains. The presence of these pollutants can pose a health hazard to the environment if their levels exceed certain allowable limits. The present study is an attempt to determine the extent of cyanide and metal pollution in the wastewater of a typical electroplating factory without wastewater treatment and to compare the quality of its wastewater with another with treatment facilitie

Non-living Biomass of Water Hyacinth Roots as a Sorbent for Chromium (III) in Aqueous Solution

The ability of the non-living biomass of water hyacinth roots, Eichhomia crassipes, to remove Cr(III) has been studied at different concentrations, pH levels and in the presence of Na and Ca ions in an attempt to simulate the real conditions of tannery waste. Ca ions exhibited a greater inhibitory effect on the Cr(III) sorption than the Na ions. Kinetic studies showed that more than one mode of sorption was operating in the uptake of Cr(III) by water hyacinth roots. The equilibrium data obeyed Langmuir isotherm for the Cr(III)-water hyacinth root system, implying mono-layer coverage of the sorbent material

An Investigation of the Chemical Composition of Precipitation in and around Kuala Lumpur

Individual rain event samples were collected at three sites in and around Kuala Lumpur from May, 1.982 to May 1983. The samples were analysed for pH, anions (sulphate, nitrate, chloride and fluoride) and cations (calcium, magnesium, sodium and potassium). Correlation and regression analyses indicated that the major anions appeared to be more closely associated with the cattons than the hydrogen ion. Pollutants from both natural and anthropogenic sources appeared to have contributed to the chemical composition of precipitation

Removal of Arsenic from Solution by Water Hyacinth (Eichhornia crassipes (Mart) Solms).

The potential of water hyacinth (Eichhornia crassipes (Mart) Solms) as a bioacummulatorl bioindicator of arsenic in dilute solution was investigated. Results show that in the absence of a high level of phosphate, it can remove arsenic effectively. However, in high phosphate concentration, arsenic uptake was inhibited. A arsenic could also be leached out from the plant. Hence caution must be exercised in interpreting the arsenic status of the aquatic environment as seen through water hyarcinth

Non-living Biomass of Water Hyacinth Roots as a Sorbent for Chromium (ITI) in Aqueous Solution

The ability of the non-living biomass of water hyacinth roots, Eichhomia crassipes, to remove Cr(lll) has been studied at different concentrations, pH levels and in the presence of Na and Ca ions in an attempt to simulate the real conditions of tannery waste. Ca ions exhibited a greater inhibitory effect on the Cr(lll) sorption than the Na ions. Kinetic studies showed that more than one mode of sorption was operating in the uptake of Cr(lll) by water hyacinth roots. The equilibrium data obeyed Langmuir isotherm for the Cr(III)-water hyacinth root system, implying mono-layer coverage of the sorben t material

The Removal of Cationic Dyes Using Coconut Husk as an Adsorbent

The ability of coconut husk to remove methylene blue from solution was investigated. Factors such as initial dye concentration, contact time, adsorbent dosage and pH of solution were studied. Results show that Langmuir isotherm can be successfully applied to the methylede blue - coconut husk system and that coconut husk is a suitable adsorbent for such a dye. Maximum adsorption capacity is 99 mg gl moss as derived from Langmuir isotherm. A series of fixed bed experiments was carried out and the results were applied to a bed-depth/service time model for column adsorption. The validity of such a model is discussed

EDTA Extractable Arsenic in Relation to Available Forms in Soil

Ten soil smaples from cocoa estates were extracted with 10 m MEDTA solution at a soil/solution weight ratio of 1/25. Arsenic in the extract was determined by hydride generation inductively coupled plasma atomic emission spectrometry. EDTA extractable arsenic showed significant positive correlation with Al-As, Fe-As, and arsenic extracted by the methods of Mehlich I and III, Bray PI and Olsen

The Influence of Metallicity on Star Formation in Protogalaxies

In cold dark matter cosmological models, the first stars to form are believed to do so within small protogalaxies. We wish to understand how the evolution of these early protogalaxies changes once the gas forming them has been enriched with small quantities of heavy elements, which are produced and dispersed into the intergalactic medium by the first supernovae. Our initial conditions represent protogalaxies forming within a fossil H II region, a previously ionized region that has not yet had time to cool and recombine. We study the influence of low levels of metal enrichment on the cooling and collapse of ionized gas in small protogalactic halos using three-dimensional, smoothed particle hydrodynamics (SPH) simulations that incorporate the effects of the appropriate chemical and thermal processes. Our previous simulations demonstrated that for metallicities Z < 0.001 Z_sun, metal line cooling alters the density and temperature evolution of the gas by less than 1% compared to the metal-free case at densities below 1 cm-3) and temperatures above 2000 K. Here, we present the results of high-resolution simulations using particle splitting to improve resolution in regions of interest. These simulations allow us to address the question of whether there is a critical metallicity above which fine structure cooling from metals allows efficient fragmentation to occur, producing an initial mass function (IMF) resembling the local Salpeter IMF, rather than only high-mass stars.Comment: 3 pages, 2 figures, First Stars III conference proceeding