Evaluation of the Cr(VI) and other toxic element contamination and their potential sources:The case of the Thiva basin(Greece)

An integrated approach was performed on the soil, plant-crops and groundwater system at the Thiva basin, to evaluate the extent and intensity of the heavy metal contamination, the percentage of metals transferred into plants/crops （bio-accumulation） and the potential sources of contamination. Heavy metal contents （230--310 Cr, 1200--2200 Ni, 50--80 Co, 880--1150 Mn and 44,500--66,200 Fe all in ppm ） in the Thiva soils are higher than those in the Assopos basin. An increasing trend in the heavy metal contents, from the Assopos to the Thiva basin （Mouriki）, indicates that the metal source is probably the Ni-laterites and ophiolites, located towards north. On the other hand, groundwater samples from domestic and irrigation wells throughout the Thiva basin exhibit relatively low （8--37 ppb） concentrations in Cr compared to the Assopos （up to 150 ppb）. The plots of Cr versus Mg/Ca, Mg/Na versus Ca/Na, B versus Si/（Si ＋ Na） and Mg/Si versus Ca/Si ratios revealed a low degree of salinization in the Thiva compared to that in the Assopos （Avlida） basin. The low Cr concentration （average 23 ppb, during dry period） in the Thiva wells may be related with their depth （〉120 m）, in contrast to shallow wells in the central Euboea （hundreds ppb Cr） and points to a solution of a crucial environmental problem in Euboea and Assopos basin by using the deep karst-type aquifer instead the shallow-Neogene one. The average Cr contents （dry weight） ranges from 1.7 to 4.6 ppm （average 2.2） in carrots, potatoes and onions. The percentage of soil metals Crto^i, Cr（Vl）, Ni, Mn and Fe ranges between 0.06 and 3.2 （average （/.53 ~ 0.4）, whilst that for Cu and Zn ranges from 16 to 81 （average 36 ~ 24）. The Cr transfer to plants is low, due to the high resistance of chromite （main host of Cr）, but the determined Cr contents in plant- crops in the Thiva basin are higher than normal or sufficient vahles. Although mininml uptake for growth and production for Cr, Ni, Zn and Cn is still lacking, fnrthermorc research is required in order to restrict heavy metal accumulation and enstlre sustainability.

The Effect of Indigenous Growth Media on Allanblackia parviflora A. Chev in Ghana

Allanblackia parviflora A. Chev. also called vegetable tallow tree provides a variety of non-timber forest products of great importance to rural households including shade, timber, medicine and seed oil but attempts have not been made to improve the tree species and increase its production. Consequently, the species is being threatened due to unsustainable exploitation and poor regeneration and cultivation appears as the only viable option. In order to cultivate the species at meaningful scale, it is necessary to establish the optimum range of environmental factors that influence its propagation and growth. This study was therefore designed to investigate Allanblackia growth parameters and bio-accumulation under different growth media in a greenhouse study. The media were: 1) TS = top soil alone, 2) AB soil = Allanblackia soil alone, 3) TS + H = Top soil alone + humus, 4) AB + TS = Allanblackia soil alone + Top soil alone and 5) SAB = Sterilized Allanblackia soil alone. Each treatment was replicated three times in a complete randomized design. The experiment lasted for 18 months. Results showed that Fe was the micronutrient that accumulated greatest in the plant tissue. Among the treatments, Allanblackia soil showed the highest accumulation of Zn in the plant tissue with the top soil showing the least (7.67 mg·kg-l). Humus contributed largely to the bio-accumulation of Cu in the plant tissue. Bio-accumulation of manganese in the plant tissue ranged from 13.30 mg·kg-l to 207 mg·kg-l suggesting difference in manganese absorption by Allanblackia as influenced by the treatments. The growth parameters of Allanblackia parviflory were impacted differently by the growth media. The result was however controversial since no differences were found between growth of seedlings in sterilized Allanblackia soil and Allanblackia soil.

Study of Heavy Metal Uptake by the Crops Grown by Using Urban Wastewater of Mysore City, India

In the 21st century the fresh water scarcity increased very rapidly due to the urbanization and industrialization process. In these conditions the urban wastewater plays an important role in the water usage criteria. In this aspect, in all the major cities, wastewater treatment plants have been constructed to treat the urban wastewater in view of decreasing the water scarcity. The presence of nutrients in the wastewater is considered as beneficial to agricultural practices. The contaminants present in the wastewater pose health risks directly to agricultural workers and indirectly to the consumers as the long term application of the wastewater may result in the accumulation of toxic elements in soil and in plants. In this way the heavy metals will circulate among the food chain and food web to cause adverse effects on human health as well as on soil health. In the present study an attempt has been made to study the characteristics of urban wastewater at wastewater treatment plant of Mysore city. And also heavy metal behavior was studied with the analysis of heavy metals in wastewater, Biosolid and receiving soil along with the plants which indicates the uptake of heavy metals.

Seaweeds as Biomonitoring System for Heavy Metal (HM) Accumulation and Contamination of Our Oceans

This research manuscript reports the heavy metal accumulation in four marine seaweeds sp. 1)?Caulerpa sertlatioides (Cuba);2) Caulerpa cf. brachypus;(Bali, Indonesia);3) Undaria pinnatifida (West-Donegal, Ireland);4) Ulva lactuca (Easters-Scheldt, the Netherlands). Mechanical pressure at 10 bar of fresh seaweed fronds casu quo biomass in the laboratory delivered seaweed moisture which was analyzed by Inductively Coupled Plasma Spectroscopy (ICP)-techniques for heavy-metals = [HM], (Al, As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb & Zn). Three important observations were made: 1) The [HM] in the seaweed moisture is higher than in the surrounding seawater which directs to mechanism(s) of bio-accumulation;2) The accumulation factor [AF] is varying per metallic-cation with an overall trend for our four seaweeds and sampling locations for [HM] are: As & Co & Cu: 5000 - 10,000 μg/l;Ni & Zn: 3000 - 5000 μg/l;Cd: 2000 - 3000 μg/l;Cr: 1000 - 2000 μg/l;Al: 200 - 1000 μg/l;Mo & Pb & Fe: 0 - 200 μg/l range. 3) Seaweed moisture detected that [HM]: Pb & Zn & Fe—which all three could not be detected in the seawater—supports the view that seaweeds have a preference in their bio-accumulation mechanism for these three HM. Major conclusion is in general that “overall” for the macro-elements Ca, Fe, K, Mg, Mn, Na, P & S in the moisture of the four seaweed species the concentration is lower in the seaweed species, or equals the concentration, in comparison to the surrounding sea water. For the HM (Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb & Zn) the opposite is the case species and is the concentration “overall” higher in the seaweed species in comparison to the surrounding sea water. Further topics addressed include strategies of irrigation of the Sahara desert with the moisture out of seaweeds under conditions of low anthropogenic influences.