scholarly journals Research on the Treatment of Soil Leachate by Using Microalgae

2020 ◽  
Vol 615 ◽  
pp. 012113
Author(s):  
Yaqing Zhao ◽  
Tiane Wu ◽  
Wei Wang ◽  
Lei Zhao ◽  
Jiangang Liu ◽  
...  
Keyword(s):  
Soil Leachate

CHEMICAL CHARACTERISTICS OF A NATURAL SOIL LEACHATE FROM A HUMIC PODZOL

1969 ◽  
Vol 49 (1) ◽  
pp. 151-158 ◽  
Author(s):  
M. Schnitzer ◽  
J. G. Desjardins
Keyword(s):  
Organic Matter ◽  
Fulvic Acid ◽  
Water Solubility ◽  
Structural Features ◽  
Natural Soil ◽  
Complexing Agent ◽  
Soil Leachate ◽  
Nitrogenous Compounds ◽  
Free Weight ◽  
Metal Organic

A leachate, collected in the field in a lysimeter placed between the Ae and Bhf horizon of a Humic Podzol in Newfoundland, was analyzed by chemical and spectroscopic methods.About 87% of the dry, ash-free weight of the leachate was fulvic acid, the remainder consisting mainly of polysaccharides and nitrogenous compounds. A comparison of the analytical characteristics of the purified leachate with those of extracted and purified Podzol Bh fulvic acid showed that the main structural features of the two materials were very similar. Judging from its high contents of oxygen-containing functional groups and from its water solubility, the organic matter in the leachate had all the characteristics of an efficient metal–complexing agent, capable of playing a significant role in metal–organic matter interactions in soils.An organic matter–silica sediment was isolated from the leachate, consisting of 47.6% organic matter and of 52.4% of almost pure SiO2∙nH2O. The organic matter in the sediment accounted for about 10% of the organic matter in the leachate. The isolation of the sediment suggests that investigations on interactions between compounds of silicon and humic substances deserve greater attention than they have so far received.

Macrostructural and Microstructural Properties of Residual Soils as Engineered Landfill Liner Materials

2021 ◽  
Author(s):  
Lee Li Yong ◽  
Vivi Anggraini ◽  
Mavinakere Eshwaraiah Raghunandan ◽  
Mohd. Raihan Taha
Keyword(s):  
Tap Water ◽  
Chemical Precipitation ◽  
Soil Samples ◽  
Residual Soil ◽  
Diffuse Double Layer ◽  
Microstructural Properties ◽  
Residual Soils ◽  
Soil Leachate ◽  
Landfill Liner ◽  
X Ray

ABSTRACT This study assessed the performance of residual soils with regard to their macrostructural and microstructural properties and compatibility with leachate in pursuit of exploring alternative cost-effective and efficient landfill liner materials. A series of laboratory investigations was conducted on three residual soil samples by using tap water and leachate as permeation fluid to achieve the objectives of the study. The zeta potential measurements revealed that the presence of multivalent cations in the leachate decreased the diffuse double layer (DDL) thickness around the soil particles. The reduced DDL thickness caused a decrease in Atterberg limits of soil-leachate samples and changes in the classification of fine fractions. Additionally, the effects of pore clogging attributed to chemical precipitation and bioclogging were responsible for the reduction in measured hydraulic conductivities of soil-leachate samples. These effects can be clearly observed from the field-emission scanning electron microscopy images of soil-leachate samples with the appearance of less visible voids that led to a more compact and dense structure. The formation of new non-clay minerals and associated changes in the Al and Si ratio as reflected in the x-ray diffraction diffractograms and energy-dispersive x-ray analyses, respectively, were attributed to the effects of chemical precipitation. This study concluded that S1 and S2 residual soil samples are potential landfill liner materials because they possess adequate grading characteristics, adequate unconfined compressive strength, low hydraulic conductivity, and good compatibility with leachate. In contrast, the S3 sample requires further treatment to enhance its properties in order to comply with the requirements of landfill liner materials.

Seedling growth and nutrient relationships in a New Jersey Pine Barrens soil treated with "acid rain"

1986 ◽  
Vol 16 (1) ◽  
pp. 136-142 ◽  
Author(s):  
George A. Schier
Keyword(s):  
New Jersey ◽  
Acid Rain ◽  
Seedling Growth ◽  
Dry Weight ◽  
Growth Stimulation ◽  
Pine Barrens ◽  
Soil Cores ◽  
Soil Leachate ◽  
Undisturbed Soil ◽  
Nutrient Contents

The effects of simulated acid rain solutions on growth of pitch pine (Pinusrigida Mill.) seedlings in undisturbed soil cores from the New Jersey Pine Barrens were examined. Solutions of pH 5.6, 4.0, and 3.0 (SO42−–Cl−–NO3−, 4:2:1), totaling 1.4 times annual ambient precipitation, were applied directly to soil cores from the A horizon during a 1-year period. By varying photoperiod and diurnal temperature, two growing "seasons" with an intervening dormant period were simulated. Soil chemistry, soil leachate chemistry, seedling nutrition, and seedling growth were monitored. Seedling dry weight was significantly greater at pH 3.0 than at the less acid treatments. Foliar nutrient contents indicated that growth stimulation at pH 3.0 probably resulted because of increased availability of nitrogen and input of nutrient cations from acid-induced weathering of soil minerals. There were sharp increases in Ca and Mg leaching when the pH of the irrigating solution was lowered, but solution acidity had little effect on depletion of K. Declines in nutrient leaching during the experiment indicated that weatherable cations were becoming depleted. Although Al mobility was greatly accelerated by an increase in acid inputs, Al toxicity symptoms were not observed.

scholarly journals Biodegradability of dissolved organic carbon in permafrost soils and aquatic systems: a meta-analysis

2015 ◽  
Vol 12 (23) ◽  
pp. 6915-6930 ◽  
Author(s):  
J. E. Vonk ◽  
S. E. Tank ◽  
P. J. Mann ◽  
R. G. M. Spencer ◽  
C. C. Treat ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Aquatic Systems ◽  
The Arctic ◽  
Permafrost Region ◽  
Soil Leachate ◽  
Discontinuous Permafrost ◽  
Spatial Coverage ◽  
Continuous Permafrost ◽  
Permafrost Regions

Abstract. As Arctic regions warm and frozen soils thaw, the large organic carbon pool stored in permafrost becomes increasingly vulnerable to decomposition or transport. The transfer of newly mobilized carbon to the atmosphere and its potential influence upon climate change will largely depend on the degradability of carbon delivered to aquatic ecosystems. Dissolved organic carbon (DOC) is a key regulator of aquatic metabolism, yet knowledge of the mechanistic controls on DOC biodegradability is currently poor due to a scarcity of long-term data sets, limited spatial coverage of available data, and methodological diversity. Here, we performed parallel biodegradable DOC (BDOC) experiments at six Arctic sites (16 experiments) using a standardized incubation protocol to examine the effect of methodological differences commonly used in the literature. We also synthesized results from 14 aquatic and soil leachate BDOC studies from across the circum-arctic permafrost region to examine pan-arctic trends in BDOC. An increasing extent of permafrost across the landscape resulted in higher DOC losses in both soil and aquatic systems. We hypothesize that the unique composition of (yedoma) permafrost-derived DOC combined with limited prior microbial processing due to low soil temperature and relatively short flow path lengths and transport times, contributed to a higher overall terrestrial and freshwater DOC loss. Additionally, we found that the fraction of BDOC decreased moving down the fluvial network in continuous permafrost regions, i.e. from streams to large rivers, suggesting that highly biodegradable DOC is lost in headwater streams. We also observed a seasonal (January–December) decrease in BDOC in large streams and rivers, but saw no apparent change in smaller streams or soil leachates. We attribute this seasonal change to a combination of factors including shifts in carbon source, changing DOC residence time related to increasing thaw-depth, increasing water temperatures later in the summer, as well as decreasing hydrologic connectivity between soils and surface water as the thaw season progresses. Our results suggest that future climate warming-induced shifts of continuous permafrost into discontinuous permafrost regions could affect the degradation potential of thaw-released DOC, the amount of BDOC, as well as its variability throughout the Arctic summer. We lastly recommend a standardized BDOC protocol to facilitate the comparison of future work and improve our knowledge of processing and transport of DOC in a changing Arctic.

scholarly journals A Novel Bismuth-Chitosan Nanocomposite Sensor for Simultaneous Detection of Pb(II), Cd(II) and Zn(II) in Wastewater

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 511 ◽  
Author(s):  
Hwang ◽  
Pathak ◽  
Wang ◽  
Rodriguez ◽  
Cho ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Detection Limit ◽  
Simultaneous Detection ◽  
Soil Leachate ◽  
Limit Values ◽  
Relative Standard ◽  
Real Wastewater ◽  
Stock Solutions ◽  
Multiple Heavy Metals ◽  
Nanocomposite Sensor

A novel bismuth (Bi)-biopolymer (chitosan) nanocomposite screen-printed carbon electrode was developed using a Bi and chitosan co-electrodepositing technique for detecting multiple heavy metal ions. The developed sensor was fabricated with environmentally benign materials and processes. In real wastewater, heavy metal detection was evaluated by the developed sensor using square wave anodic stripping voltammetry (SWASV). The nanocomposite sensor showed the detection limit of 0.1 ppb Zn2+, 0.1 ppb Cd2+ and 0.2 ppb Pb2+ in stock solutions. The improved sensitivity of the Bi-chitosan nanocomposite sensor over previously reported Bi nanocomposite sensors was attributed to the role of chitosan. When used for real wastewater samples collected from a mining site and soil leachate, similar detection limit values with 0.4 ppb Cd2+ and 0.3 ppb Pb2+ were obtained with relative standard deviations (RSD) ranging from 1.3% to 5.6% (n = 8). Temperature changes (4 and 23 °C) showed no significant impact on sensor performance. Although Zn2+ in stock solutions was well measured by the sensor, the interference observed while detecting Zn2+ in the presence of Cu2+ was possibly due to the presence of Cu-Zn intermetallic species in mining wastewater. Overall, the developed sensor has the capability of monitoring multiple heavy metals in contaminated water samples without the need for complicated sample preparation or transportation of samples to a laboratory.

Leaching and persistence of herbicides for kudzu (Pueraria montana) control on pine regeneration sites

Weed Science ◽  
2006 ◽  
Vol 54 (02) ◽  
pp. 391-400 ◽  
Author(s):  
Yvette C. Berisford ◽  
Parshall B. Bush ◽  
John W. Taylor
Keyword(s):  
Loblolly Pine ◽  
Forest Regeneration ◽  
Shallow Groundwater ◽  
Pine Forest ◽  
Soil Leachate ◽  
Initial Application ◽  
Pine Regeneration ◽  
Residue Levels ◽  
Pueraria Montana

Clopyralid, picloram, triclopyr, metsulfuron, and tebuthiuron were applied to control kudzu on four loblolly pine forest regeneration sites during July 1997. Spot treatments were applied to recovering kudzu in June 1998 and June 1999. Soil leachate was monitored for these five herbicides from July 1997 to December 2000. All herbicides were detected in shallow (51–58 cm deep) and deep lysimeters (84–109 cm deep). Clopyralid was not persistent and limited leaching occurred, with residue levels of 0.4 to 2.8 μg L−1in 12 of 102 deep lysimeter samples. Picloram was mobile and persisted at 0.6 to 2.5 μg L−1in shallow and deep lysimeters for at least 10 mo after the initial application. Triclopyr residues were not persistent in shallow lysimeters and remained < 6 μg L−1during the study. Metsulfuron persisted at < 0.1 μg L−1for 182 to 353 d in shallow lysimeters and at < 0.07 μg L−1for 182 to 300 d in the deep lysimeters in various plots. Tebuthiuron peaks in the deep lysimeters ranged from 69 to 734 μg L−134 to 77 d after the first spot treatment. In the soil that was essentially a fill area, tebuthiuron residues remained > 400 μg L−1(402–1,660 μg L−1) in the shallow lysimeter samples and > 180 μg L−1(181–734 μg L−1) in the deep lysimeters throughout a 354-d period that followed the first spot application. When used as part of a forest regeneration program, the relative potentials of the herbicides to move into shallow groundwater were: tebuthiuron > picloram > metsulfuron > clopyralid > triclopyr.

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