Effect of season and landscape position on the aluminium geochemistry of tropical acid sulfate soil leachate

Soil Research ◽  
2009 ◽  
Vol 47 (2) ◽  
pp. 137 ◽  
Author(s):  
W. S. Hicks ◽  
G. M. Bowman ◽  
R. W. Fitzpatrick
Keyword(s):  
Process Model ◽  
Iron Oxidation ◽  
Oxidation Products ◽  
Wet Season ◽  
Soil Leachate ◽  
Acid Sulfate ◽  
Seasonal Factors ◽  
Water Ph ◽  
Drying Conditions ◽  
Sulfate Soils

Acid sulfate soils (ASS) occupy an estimated 5.8 × 106 ha of coastal Australia. In tropical Australia, the processes operating in these soils, and their environmental hazards, are poorly understood. Drainage of a tropical estuarine wetland containing extensive ASS deposits left the area in a highly degraded condition. Surface and soil water pH values from the site were consistently <5 and commonly <3.5. Aluminium activity was several orders of magnitude greater than the level set for the protection of aquatic ecosystems, with a seasonal variation of 3 orders of magnitude. Aluminium behaved conservatively at the discharge point to receiving waters. In drainage lines and soil solution, aluminium activity was limited by elevated sulfate activity. Aluminium was commonly supersaturated with respect to alunite and behaved as though an aluminium species with the stoichiometry Al:OH:SO4 regulated its activity, which was 2–5 orders of magnitude lower than if gibbsite or amorphous aluminium hydroxide solubility was the control. While jurbanite (AlOHSO4.5H2O) is no longer considered a potential mineral in ASS, these data again raise the question of a satisfactory explanation of aluminium activity. Sulfate activity was influenced by seasonal factors. Wet season conditions were reducing and favoured the dissolution of acid iron oxidation products. The dry season oxidising and drying conditions favoured their precipitation, resulting in seasonal cycling. Based on our findings we developed a landscape geochemical process model for the site.

Characteristics of the Acidity in Acid Sulfate Soil Drainage Waters, McLeods Creek, Northeastern NSW, Australia

2006 ◽  
Vol 3 (3) ◽  
pp. 225 ◽  
Author(s):  
Rosalind Green ◽  
T. David Waite ◽  
Michael D. Melville ◽  
Ben C. T. Macdonald
Keyword(s):  
Oxidation Products ◽  
Metal Species ◽  
Acid Sulfate Soils ◽  
Iron Sulfides ◽  
Dissolved Metals ◽  
Species Determination ◽  
Acid Sulfate ◽  
Direct Titration ◽  
Sulfate Soils ◽  
Drainage Waters

Environmental Context. Acid sulfate soils are found in many low-lying coastal areas, but they can also be encountered in inland areas of Australia and other parts of the world. These soils typically contain iron sulfides, primarily pyrite (FeS2) and mackinawite (FeS), and the products that result from oxidation of these iron minerals. Acidic and metal-rich waters can be produced when the pyrite in soil is oxidized by natural means or accelerated when the soil is drained, which typically occurs when it is developed for agriculture or urban use. In general, acid sulfate soils become a problem when oxidation products are transported from the soil profile into nearby streams and estuaries, which can severely affect the ecology, biodiversity, economic development, and the aesthetics of adjacent waterways. The key contributors to acidity in drainage waters from the site examined are Al3+, AlSO4– and, under particular circumstances, Mn2+ and Fe2+, but the principal species contributing to acidity are strongly time variant and would be expected to vary from site to site. Abstract. Catchments that contain acid sulfate soils can discharge large quantities of acid and dissolved metals into waterways. At McLeods Creek in far northern NSW, Australia, the acidity from the hydrolysis of dissolved metal species, particularly aluminium and iron, contributes to greater than 70% of the total acidity. Therefore, a poor relationship exists between both calculated and titrated acidity and pH because of the dominant influence of these hydrolyzable metal species. Determination of the so-called ‘cold acidity’ by direct titration with NaOH yields results that are difficult to replicate because of the buffering effects of suspended solids, carbon dioxide ingassing, and/or MnII and FeII oxidation in the sample as the titration end-point is approached. Samples that are pre-treated with sulfuric acid and hydrogen peroxide produce results (of ‘hot acidity’) that can be easily replicated and are similar to calculated acidities based on elemental analysis and speciation calculations. The cold acidity values for titrations of 105 water samples from the chosen field site are often higher than hot acidity values as a result of the loss of carbonate acidity during pre-treatment of samples for hot acidity analysis.

scholarly journals Biochar Capacity to Mitigate Acidity and Adsorb Metals—Laboratory Tests for Acid Sulfate Soil Drainage Water

2021 ◽  
Vol 232 (11) ◽  
Author(s):  
Niko Kinnunen ◽  
Annamari Laurén ◽  
Jukka Pumpanen ◽  
Tiina M. Nieminen ◽  
Marjo Palviainen
Keyword(s):  
Surface Characteristics ◽  
Drainage Water ◽  
Water Protection ◽  
Acid Sulfate Soils ◽  
Acid Sulfate Soil ◽  
Soil Drainage ◽  
Acid Sulfate ◽  
Water Ph ◽  
Concentration Changes ◽  
Sulfate Soils

AbstractA 96-h laboratory experiment was conducted to assess the potential of biochar as a water protection tool for acid sulfate soil runoff. Acid sulfate soils pose a risk to water bodies due to acid, metal-rich runoff, especially in drained peatland forests. New water protection methods, such as adsorption with biochar, are needed. We investigated the capability of spruce and birch biochar to adsorb metals and reduce acidity in the water. Water from an acid sulfate site was stirred with biochar, biochar with lime, and biochar with ash. We determined water Al, S, Fe, Cu, Co, Cd, Ni, and Zn concentrations periodically, as well as pH and total organic carbon at the beginning and the end of the experiment. The studied substances are considered the most abundant and environmentally harmful elements in the acid sulfate soils in Finland. Biochar surface characteristics were analyzed with FTIR spectroscopy. Concentration changes were used to parametrize adsorption kinetics models. Biochar adsorbed metals and increased pH, but lime and ash additives did not always improve the adsorption. Spruce biochar and ash addition had generally higher adsorption than birch biochar and lime addition. The adsorption was dominated by Al and Fe at lower pH, while increasing pH improved the adsorption of Cd and Zn. The results show that biochar can increase the water pH, as well as adsorb Al, Fe, Co, Cd, Ni, and Zn. Further work could include an actual-scale biochar reactor in a laboratory and field conditions.

Climate-driven mobilisation of acid and metals from acid sulfate soils

2010 ◽  
Vol 61 (1) ◽  
pp. 129 ◽  
Author(s):  
Stuart L. Simpson ◽  
Rob W. Fitzpatrick ◽  
Paul Shand ◽  
Brad M. Angel ◽  
David A. Spadaro ◽  
...  
Keyword(s):  
Metal Release ◽  
Acid Sulfate Soils ◽  
Acid Sulfate ◽  
Metal Concentrations ◽  
Australian Water ◽  
Quality Guidelines ◽  
Eastern Australia ◽  
Water Ph ◽  
Co Precipitation ◽  
Sulfate Soils

The recent drought in south-eastern Australia has exposed to air, large areas of acid sulfate soils within the River Murray system. Oxidation of these soils has the potential to release acidity, nutrients and metals. The present study investigated the mobilisation of these substances following the rewetting of dried soils with River Murray water. Trace metal concentrations were at background levels in most soils. During 24-h mobilisation tests, the water pH was effectively buffered to the pH of the soil. The release of nutrients was low. Metal release was rapid and the dissolved concentrations of many metals exceeded the Australian water quality guidelines (WQGs) in most tests. The concentrations of dissolved Al, Cu and Zn were often greater than 100× the WQGs and strong relationships existed between dissolved metal release and soil pH. Attenuation of dissolved metal concentrations through co-precipitation and adsorption to Al and Fe precipitates was an important process during mixing of acidic, metal-rich waters with River Murray water. The study demonstrated that the rewetting of dried acid sulfate soils may release significant quantities of metals and a high level of land and water management is required to counter the effects of such climate change events.

The process of sulfide oxidation in some acid sulfate soil materials

Soil Research ◽  
2004 ◽  
Vol 42 (4) ◽  
pp. 449 ◽  
Author(s):  
N. J. Ward ◽  
L. A. Sullivan ◽  
D. M. Fyfe ◽  
R.T. Bush ◽  
A. J. P. Ferguson
Keyword(s):  
Sulfide Oxidation ◽  
Water Soluble ◽  
Oxidation Products ◽  
Total Acid ◽  
Sulfur Species ◽  
Acid Sulfate ◽  
Incubation Experiments ◽  
O2 Concentration ◽  
Order Of Magnitude ◽  
Sulfate Soils

The process of sulfide oxidation in acid sulfate soils (ASS) is complex, involving the formation of numerous oxidation products. In this study the sulfide oxidation process was examined in 2 ASS materials over a period of 36 days using laboratory incubation experiments. Both ASS materials experienced substantial sulfide oxidation and acidification during incubation. The oxidation of pyrite was the primary cause of acidification in these ASS materials. Although a decrease in magnetic susceptibility (χ) over the initial 4 days of incubation suggested the rapid oxidation of ferromagnetic iron monosulfide greigite (Fe3S4), the total acid volatile sulfur (SAV) fraction increased in concentration by an order of magnitude over the initial 8 days of incubation. Oxygen (O2) concentration profiles indicated the presence of anoxic conditions in the centre of the incubating materials even after 16 days of exposure to the atmosphere enabling SAV formation to occur. The oxidation of the SAV fraction did not result in substantial acidification. A large proportion of the water-soluble iron released by sulfide oxidation was precipitated as iron oxides and hydroxides. Sulfate (SO42–) was the dominant sulfur species produced from sulfide oxidation in both ASS materials, although water-soluble SO42– was a poor indicator of the extent of sulfide oxidation. The sulfoxyanion intermediates, thiosulfate (S2O32–) and tetrathionate (S4O62–), were detected only in the early stages of incubation, with minimal amounts being detected after the initial 4 days. The relative abundance of these 2 intermediate sulfur species appeared to be dependent on the soil pH, with S4O62– dominating S2O32– in the more acidic ASS material (i.e. pH <6) as has been observed in previous studies. The diminishing presence of sulfoxyanion intermediates as oxidation progressed was indicative that ferric ion (Fe3+) and bacterial catalysis were driving the oxidation processes. While these sulfoxyanion intermediates only constituted a small percentage of the reduced inorganic sulfur (RIS) fraction, they accounted for up to 9.3% of the total soluble sulfur fraction. Elemental sulfur (S0) was not an important sulfide oxidation product in the ASS materials examined in this study.

scholarly journals EFFECT OF DIFFERENT REMEDIATION TECHNIQUES AND DOSAGES OF PHOSPHORUS FERTILIZER ON SOIL QUALITY AND KLEKAP PRODUCTION IN ACID SULFATE SOIL AFFECTED AQUACULTURE PONDS

2007 ◽  
Vol 2 (2) ◽  
pp. 141 ◽  
Author(s):  
Akhmad Mustafa ◽  
Jesmond Sammut
Keyword(s):  
Soil Improvement ◽  
Oxidation Products ◽  
Available P ◽  
Poor Growth ◽  
Acid Sulfate ◽  
Soil Variables ◽  
Aquaculture Ponds ◽  
Two Factors ◽  
Forced Oxidation ◽  
Sulfate Soils

<p>Acid sulfate soils (ASS) contain sufficient pyrite which, when oxidised following excavation for brackishwater aquaculture ponds, will generate acid and mobilise toxic metals. Production in affected ponds can be low due to poor growth of shrimp and fish, mass mortalities of stock and low plankton blooms. The resultant low soil pH can also cause poor klekap production due to the retention of phosphorus associated with elevated concentrations of Fe and Al in the pond soils. A series of experiments was conducted to determine the effects of different soil amelioration techniques and dosage of phosphorus (P) on soil and klekap production under laboratory conditions. The treatments consisted of two factors. The first factor tested was different techniques for ASS improvement (non-improvement, improvement through liming and improvement through remediation involving forced oxidation of pyrite, flooding and flushing of oxidation products). The second factor tested was phosphorus dosages, that is, with phosphorus and without phosphorus-based fertilizer. Each treatment had three replications. The experiment showed that liming and remediation had the same effect on several soil variables; they raised the soi pH (pHF, pHFOX, pHKCl) and decreased SPOS, Fe and Al. Remediation of ASS decreased retention of P and increased available-P of soil, whereas liming did not show a significant effect on retention of P and available-P in the doses used for this experiment. The interaction between the different soil improvement techniques and phosphorus fertilising showed a significant effect on klekap production with the highest klekap production of 23.21 mg/cm2 found in remediated soil and with a phosphorus fertiliser dosage of 75 kg/ha.</p>

PEUBAH KUALITAS AIR YANG MEMPENGARUHI PERTUMBUHAN RUMPUT LAUT (Gracilaria verrucosa) DI TAMBAK TANAH SULFAT MASAM KECAMATAN ANGKONA KABUPATEN LUWU TIMUR PROVINSI SULAWESI SELATAN

2009 ◽  
Vol 4 (1) ◽  
pp. 125
Author(s):  
Akhmad Mustafa ◽  
Rachmansyah Rachmansyah ◽  
Dody Dharmawan Trijuno ◽  
Ruslaini Ruslaini
Keyword(s):  
Water Quality ◽  
Growth Rate ◽  
Ammonium Phosphate ◽  
Gracilaria Verrucosa ◽  
Acid Sulfate Soils ◽  
Acid Sulfate Soil ◽  
Acid Sulfate ◽  
Independent Variables ◽  
Water Quality Variables ◽  
Sulfate Soils

Rumput laut (Gracilaria verrucosa) telah dibudidayakan di tambak tanah sulfat masam dengan kualitas dan kuantitas produksi yang relatif tinggi. Oleh karena itu, dilakukan penelitian yang bertujuan untuk mengetahui peubah kualitas air yang mempengaruhi laju pertumbuhan rumput laut di tambak tanah sulfat masam Kecamatan Angkona Kabupaten Luwu Timur Provinsi Sulawesi Selatan. Pemeliharaan rumput laut dilakukan di 30 petak tambak  terpilih selama 6 minggu. Bibit rumput laut dengan bobot 100 g basah ditebar dalam hapa berukuran 1,0 m x 1,0 m x 1,2 m. Peubah tidak bebas yang diamati adalah laju pertumbuhan relatif, sedangkan peubah bebas adalah peubah kualitas air yang meliputi: intensitas cahaya, salinitas, suhu, pH, karbondioksida, nitrat, amonium, fosfat, dan besi. Analisis regresi berganda digunakan untuk menentukan peubah bebas yang dapat digunakan untuk memprediksi peubah tidak bebas. Hasil penelitian menunjukkan bahwa laju pertumbuhan relatif rumput laut di tambak tanah sulfat masam berkisar antara 1,52% dan 3,63%/hari dengan rata-rata 2,88% ± 0,56%/hari. Di antara 9 peubah kualitas air yang diamati ternyata hanya 5 peubah kualitas air yaitu: nitrat, salinitas, amonium, besi, dan fosfat yang mempengaruhi pertumbuhan rumput laut secara nyata. Untuk meningkatkan pertumbuhan rumput laut di tambak tanah sulfat masam Kecamatan Angkona Kabupaten Luwu Timur dapat dilakukan dengan pemberian pupuk yang mengandung nitrogen untuk meningkatkan kandungan amonium dan nitrat serta pemberian pupuk yang mengandung fosfor untuk meningkatkan kandungan fosfat sampai pada nilai tertentu, melakukan remediasi untuk menurunkan kandungan besi serta memelihara rumput laut pada salinitas air yang lebih tinggi, tetapi tidak melebihi 30 ppt.Seaweed (Gracilaria verrucosa) has been cultivated in acid sulfate soil-affected ponds with relatively high quality and quantity of seaweed production. A research has been conducted to study water quality variables that influence the growth of seaweed in acid sulfate soil-affected ponds of Angkona Sub-district East Luwu Regency South Sulawesi Province. Cultivation of seaweed was done for six weeks in 30 selected brackishwater ponds. Seeds of seaweed with weight of 100 g were stocked in hapa sized 1.0 m x 1.0 m x 1.2 m. Dependent variable that was observed was specific growth rate, whereas independent variables were water quality variables including light intensity, salinity, temperature, pH, carbondioxide, nitrate, ammonium, phosphate, and iron. Analyses of multiple regressions were used to determine the independent variables which could be used to predict the dependent variable. Research result indicated that relative growth rate of seaweed in acid sulfate soils-affected brackishwater ponds ranged from 1.52% to 3.63%/day with 2.88% ± 0.56%/day in average. Among nine observed water quality variables, only five variables namely: nitrate, salinity, ammonium, phosphate and iron influence significantly on the growth of seaweed in acid sulfate soils-affected brackishwater ponds. The growth of seaweed in acid sulfate soils-affected brackishwater ponds of Angkona District East Luwu Regency, can be improved by using nitrogen-based fertilizers to increase ammonium and nitrate contents and also fertilizers which contain phosphorus to improve phosphate content to a certain level. Pond remediation to decrease iron content and also rearing seaweed at higher salinity (but less than 30 ppt) can also be alternatives to increase the growth of seaweed.

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