scholarly journals Risk for increased metal leakage due to ageing of landfills?

2019 ◽  
pp. 181-188
Author(s):  
Anna Mårtensson ◽  
Monica Östman ◽  
Cecilia Våg ◽  
Olle Wahlberg ◽  
Staffan Ågren

As landfill ages, oxygen will start to penetrate, We investigated whether aeration of a landfillaffected metal leaching, We found that aeration increased cation exchange capacity, butdecreased the buffering capacity and the metal-binding capacity. Leachates from an aeratedlandfill contained less than half the amount of aluminium and iron and more than double theamount of calcium, sulphur and zinc than leachates derived from an identical, but anaerobic,landfill. The leachate from the aerated landfill was capable of extracting metals from theoriginal landfill when recirculated. Leachate from the original landfill treated with leachatefrom the aerated landfill contained more than twice as much cadmium, copper, iron, sulphurand zinc than leachate from the identical anerobic landfill. We conclude that precautionsshould be taken considering the fate of deposited metals when extrapolating results derivedfrom studies on landfills at earlier degradation stages to landfills in more progressed phases.

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 510 ◽  
Author(s):  
Emmanuel Ayo ◽  
Athanasia Matemu ◽  
Germana Laswai ◽  
Martin Kimanya

Aflatoxins in feeds cause great health hazards to animals, and thus eventually to humans as well. The potential of clays from Arusha (AC), Kilimanjaro (KC), the Coast (CC), and Morogoro (MC), as well as volcanic ash (VA) and rice husk ash (RA), were evaluated for their capacity to adsorb aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1), and G2 (AFG2) relative to a commercial binder Mycobind® (R) using in vitro technique. On average, CC, VA, KC, MC, AC, RA, and R adsorbed 39.9%, 51.3%, 61.5%, 62.0%, 72.6%, 84.7%, and 98.1% of the total aflatoxins from solution, respectively. The capacity of AC and RA was statistically (p < 0.05) better in binding aflatoxins next to R. The adsorption capacity seemed to follow the trend of the cation exchange capacity (CEC) of these materials. The CEC (meq/100 g) of CC, MC, KC, VA, AC, RA, and R were 7.0, 15.4, 18.8, 25.4, 27.2, 27.2, and 38.9, respectively. On average 96.3%, 42.7%, 80.8%, and 32.1% of AFB1, AFB2, AFG1, and AFG2 were adsorbed, respectively. The binding capacity of the clays and ashes relative to Mycobind® was about 100% for AC and RA, 50% for KC, MC, and VA, and 33.3% for CC. The AC and RA seem to be promising resources in binding aflatoxins in solution.


HortScience ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 349-352 ◽  
Author(s):  
Janet F.M. Rippy ◽  
Paul V. Nelson

Variations in moss peat cation exchange capacity (CEC) and base saturation (BS) can result in inconsistent initial pH in moss peat-based substrates created using standard formulas for limestone additions and can lead to subsequent drift from the initial pH in those substrates. This study was conducted to determine the extent of such variation. CEC and BS were measured in three replications on 64 moss peat samples that were selected from three mires across Alberta, Canada, to represent maximum gradients in plant species composition within six degrees of decomposition acceptable for professional peat-based substrates. CEC ranged from 108 to 162 cmol·kg−1 (meq·100 g). Averaged overall samples, BS ranged from 15% to 71% of CEC and calcium accounted for 68%, magnesium for 25%, sodium for 5%, and potassium for 1.4% of BS. CEC was positively correlated to the amount of Sphagnum fuscum (Schimp.) Klingrr. in the sample (r = 0.22). BS was positively correlated to the amount of sedge (r = 0.28). Neither CEC nor BS was influenced by degree of decomposition (r = 0.002 and r = 0.08, respectively). Moss peats with high CEC have a greater buffering capacity than those with low CEC, resulting in less pH drift. Moss peats with high BS should have a low neutralization requirement to achieve a target pH. Understanding the species composition in peat-based substrates can alleviate problems of inconsistent initial pH and subsequent pH drift.


2011 ◽  
Vol 6 (3) ◽  
Author(s):  
J. Zake ◽  
J. Y. Z. Kitungulu ◽  
H. Busurwa ◽  
F. Kyewaze

Wetlands are not wastelands but wealth lands, which are widely distributed throughout Uganda currently covering 11% of the total land area. They are accessible to a large proportion of the population. As the country's population grows, people increasingly convert wetlands for other land uses such as farming, settlement among others thus making it difficult to enforce legislation for their protection, sustainable management and utilization. Their profound importance to both humans and wildlife calls for a concerted effort to ensure their sustainable utilization and attempts should be made to promote sustainable development of such wetlands with adequate considerations being given to human and environmental requirements. This study was therefore carried out to determine the effect of drainage on organic matter levels and on soil chemical changes in wetland soils in eastern Uganda around the Lake Victoria basin. Secondly, to assess potential lime requirements for drained wetland soils in eastern Uganda around the Lake Victoria basin, this would reflect on wetland soil buffering capacity. In green house studies it was found that drainage of wetland soils led to a reduction of organic matter relative to soil structure and where sulfur and iron were present in large amounts, drainage caused decrease in soil pH to moderately acidic levels; but in cases where exchangeable bases were present in large amounts there was an increase in soil pH. Lime requirements were greater where the amount of clay, organic matter and cation exchange capacity were high. Consequently, such wetland soils had a high buffering capacity. It was concluded that wetland soils should be characterized in terms of potential of acidification, level of organic matter, nutrient content, cation exchange capacity, soil texture and levels of trace elements. Decisions to drain or not to drain should depend on these parameters and other socio-economic considerations for the area.


Author(s):  
Emmanuel Ayo ◽  
Athanasia Matemu ◽  
Germana Laswai ◽  
Martin Kimanya

Aflatoxins in feeds cause great health hazards to animals and in advance, to human. Potential of crude clays designated AC, KC, CC and MC and ashes VA and RA were evaluated for their capacity to adsorb aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) relative to a commercial binder MycobinderR (Evonik Industries AG) using in-vitro technique. On average, CC, VA, KC, MC, AC, RA and MycobindR adsorbed 39.9%, 51.3%, 61.5%, 62.0%, 72.6%, 84.7% and 98.1% of the total aflatoxins in buffered solution, respectively. The capacity of AC and RA was statistically (p&lt;0.05) better in binding aflatoxins next to MycobindR. Capacity of the TBM and MycobindR to bind aflatoxins, seemed to follow the trend of their cation exchange capacity (CEC). The CEC (meq/100g) of CC, MC, KC, VA, AC, RA and MycobindR were 7.0, 15.4, 18.8, 25.4, 27.2, 27.2 and 38.9, respectively. On average 96.3%, 42.7%, 80.8% and 32.1% of AFB1, AFB2, AFG1 and AFG2 were adsorbed, respectively. &nbsp;Binding capacity of the clays and ashes relative to MycobindR was about 100% for AC and RA, 50% for KC, MC and VA and 33.3% for CC.&nbsp; The AC and RA seem to be promising resources in binding aflatoxins in solution.


1983 ◽  
Vol 34 (9) ◽  
pp. 910-916 ◽  
Author(s):  
Michael I. McBurney ◽  
Peter J. van Soest ◽  
Larry E. Chase

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Mardi Wibowo

Since year 1977 until 2005, PT. ANTAM has been exploited nickel ore resources at Gebe Island – Center ofHalmahera District – North Maluku Province. Mining activity, beside give economically advantages also causedegradation of environment quality espicially land quality. Therefore, it need evaluation activity for change ofland quality at Gebe Island after mining activity.From chemical rehabilitation aspect, post mining land and rehabilitation land indacate very lack and lackfertility (base saturated 45,87 – 99,6%; cation exchange capacity 9,43 – 12,43%; Organic Carbon 1,12 –2,31%). From availability of nutrirnt element aspect, post mining land and rehabilitation land indicate verylack and lack fertility (nitrogen 0,1 – 1,19%). Base on that data, it can be concluded that land reclamationactivity not yet achieve standart condition of chemical land.Key words : land quality, post mining lan


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