Geochemical and physical properties of oils collected from several wells in the Shabwah depression, Yemen: implications of their characteristic organic matter input and maturity

2021 ◽  
Vol 14 (23) ◽  
Author(s):  
Mohammed Hail Hakimi ◽  
Aref A. Lashin ◽  
Mikhail A. Varfolomeev ◽  
Nor Syazwani Zainal Abidin ◽  
Shadi A. Saeed ◽  
...  
2021 ◽  
Author(s):  
Océane Gilibert ◽  
Dan Tam Costa ◽  
Sabine Sauvage ◽  
Didier Orange ◽  
Yvan Capowiez ◽  
...  

<p>Wetlands are known for their natural service of water quality regulation. The hyporheic zones of the rivers filter and purify the surface water from the stream and infiltrated waters in soil nearby through the riparian zone. This purification service occurs because of a synergy between the substrate and its biodiversity (including plants, bacteria and other invertebrates). Our study deals with constructed wetlands (CW) as a nature-based solution mimicking wetlands water purification process, to purify wastewaters. The REUSE technology of CW is based on the use of specific layers of gravels and sands inside a close concrete structure, planted with specific sub-aquatic plants, where wastewaters or runoff of stormwaters are introduced to be filtered. The technology of Vertical Flow Constructed Wetlands (VFCW) reproduces the water flux observed in the riparian zone with a gravity flow of water. It is composed of reeds planted on a sandy layer (Ø 0-4 mm) and succession of gravel layers. This substrate can be saturated or unsaturated to reproduce the functioning of the hyporheic zone or the riparian zone respectively. By the time, the substrate is colonized by a community of bacteria producing biofilms which capture the residual organic matter from wastewaters to mineralize them. However, the VFCW substrates tend to clog over time due to the accumulation of organic matter and biofilms. Many studies consider earthworms as one of the solutions to alleviate this clogging, thanks to their burrows recreating macropores and preferential channels which help to improve the dispersion of water into the deep soil. The main goal of this study is to assess the impact of earthworm activities on the hydraulic conductivity of columns composed with the same substrate used in the VFCW. Different densities of earthworms (Eisenia fetida) were introduced (0, 100, 500, 1000 g of earthworms/m²) in these columns to be monitored for 37 days. The hydraulic conductivity was measured every 7 days, aside from day 23 with the addition of 40 g of peat bedding on column surfaces to simulate a high organic matter input. Columns with earthworm density superior to 500 g/m² shows an amelioration of their hydraulic conductivity after 21 days. These densities are also able to restore the hydraulic conductivity of the column in less than 7 days after the setting of clogged condition due to the organic matter input (peat bedding) at the sediment surface. This study showed that the burrowing activity of E. fetida improves the hydraulic flux of a sandy substrate and this impact is dependent on the earthworm density introduced. So, the addition of earthworms in the VFCW could serve as a prevention against clogging.</p>


1987 ◽  
Vol 67 (4) ◽  
pp. 747-763 ◽  
Author(s):  
M. A. NAETH ◽  
A. W. BAILEY ◽  
W. B. McGILL

A study was conducted in Solonetzic mixed prairie of southern Alberta to evaluate and determine the longevity of selected ecosystem responses to pipeline installation. Five adjacent natural gas pipelines on a series of rights-of-way (ROW) were studied at three sites. The lines, which were installed in 1957, 1963, 1968, 1972 and 1981, had diameters of 86, 86, 91, 107 and 107 cm, respectively. Soils were analyzed for particle size distribution, bulk density, pH, electrical conductivity, ion composition, and organic matter content. It was concluded that pipeline construction in Solonetzic mixed prairie range-land initially tended to improve surface soil chemical and physical properties compared to blowouts, but reduced soil quality in vegetated native prairie. Surface bulk density increased to 1.3–1.6 Mg m−3 from an undisturbed density of 0.9–1.0 Mg m−3. Increased densities were evident to 55 cm in all 1981 transects except the trench where subsurface densities were reduced. Chemical changes were associated with reduced organic matter and increased salts at the surface. On the basis of differences between the various ages of pipelines (1981, youngest; 1957, oldest) there was evidence for greater amelioration of chemical changes than of physical disturbances over time. The time needed to restore half the lost organic matter was estimated to be approximately 50 y. Key words: Pipeline, Solonetzic soil, rangeland (native), soil chemistry, bulk density, reclamation


2014 ◽  
Vol 86 (7) ◽  
pp. 1129-1140 ◽  
Author(s):  
Setare Tahmasebi Nick ◽  
Ali Bolandi ◽  
Tova A. Samuels ◽  
Sherine O. Obare

AbstractEngineered nanoparticles (ENPs) are known to possess unique size and shape dependent chemical and physical properties. As a result of their properties, ENPs have been effective in several important applications including catalysis, sensor design, photonics, electronics, medicine, and the environmental remediation of toxic pollutants. Such properties and applications have led to an increase in the manufacture of ENPs and a rise in their presence in consumer products. The increase of ENPs in consumer products presents several opportunities and challenges, and necessitates a proactive study of their health and safety. This article highlights some recent work in which we have studied the effect of exposure of well-defined ENPs to pesticides and the effect of pH and dissolved organic matter. We also summarize our work and that of others who have studied the toxicity of ENPs with microorganisms. The results provide insights on the need for green manufacturing strategies of ENPs, their use and safe disposal practices.


2015 ◽  
Vol 7 (1) ◽  
pp. 1007-1024
Author(s):  
B. Turgut

Abstract. The aim of this study was to compare the soils of the wheat cultivation area (WCA) and the safflower cultivation area (SCA) within semi-arid climate zones in terms of their total carbon, nitrogen, sulphur contents, particle size distribution, aggregate stability, organic matter content, and pH values. This study presents the results from the analyses of 140 soil samples taken at two soil layers (0–10 and 10–20 cm) in the cultivation areas. At the end of the study, it has been established that there were significant differences between the cultivation areas in terms of soil physical properties such as total carbon (TC), total nitrogen (TN), total sulphur (TS) contents and pH, while only the TN content resulted in significantly different between the two soil layers. Moreover significant differences were identified in the cultivation areas in terms of soil physical properties including clay and sand contents, aggregate stability and organic matter content, whereas the only significant difference found among the soil layers was that of their silt content. Since safflower contains higher amounts of biomass than wheat, we found higher amounts of organic matter content and, therefore, higher amounts of TN and TS content in the soils of the SCA. In addition, due to the fact that wheat contains more cellulose – which takes longer to decompose – the TC content of the soil in the WCA were found to be higher than that of the SCA. The results also revealed that the WCA had a higher carbon storage capacity.


2020 ◽  
Vol 4 (2) ◽  
pp. 416-425
Author(s):  
Teuku Muhammad Afrizal ◽  
Hairul Basri ◽  
Muhammad Rusli Alibasyah

Abstrak. Gambut mengandung bahan organik yang tinggi. Gambut yang didrainase rentan terhadap kebakaran. Pemanfaatan gambut di Aceh sangat luas. Umumnya, gambut sering dibakar agar dapat dengan cepat dimanfaatkan., khususnya di Kecamatan Tripa Makmur Kabupaten Nagan Raya. Penelitian ini bertujuan untuk melihat seberapa jauh tingkat perubahan sifat fisika gambut terbakar Rawa Tripa Kabupaten Nagan Raya. Hasil penelitian menunjukkan bahwa rata-rata berat volume tertinggi terdapat pada sampel T1 (top soil) yaitu  0,36 g cm-3 dan terendah pada T0 (sub soil) yaitu  0,17 g cm-3. Kadar air tertinggi  terdapat pada sampel T0 (sub soil)  yaitu 234,82% dan terendah pada T1 (top soil) yaitu 81,96%. Porositas tertinggi terdapat pada sampel gambut T0  (sub soil) yaitu 94,93% dan terendah pada T1 (top soil) yaitu 65,28%. Permeabilitas tertinggi terdapat pada T0 (sub soil) yaitu 33,80 cm/jam dan terendah pada T1 (top soil) yaitu 16,10 cm/jam. Hasil uji statistik menunjukkan bahwa ada perbedaan yang signifikan pada parameter berat volume dengan t hitung (3,482) t tabel (1, 943), sedangkan pada parameter lainnya tidak ada perbedaan yang signifikan. Tingkat kematangan gambut di kawasan Tripa Makmur adalah hemik. Kedalaman gambut sebesar 3 meter.  Subsiden tertinggi adalah 100 cm pada gambut terbakar di tahun 2015. Warna  gambut adalah coklat kehitaman. The Effect of Burning Peat on Some of The Physical Porperties of Peat Soil in The Tripa Makmur Sub DistrictAbstract. Peat contains high organic matter. Drained peat is susceptible to fire. The use of peat in Aceh is very broad. Peat is often burned so that it can be quickly utilized especially in Tripa makmur Sub Districk, Nagan Raya Districk. This study aims to see how far the rate of change in the physical properties of peat is burning Rawa Tripa in Nagan Raya District. The results showed that the highest average of volume weight was found in T1(top soil) 0,36 g cm-3 and the lowest in T0(sub soil) 0,17 g cm-3. The highest water content was found inT0(sub soil) 234,82%  and the lowest was on T1(top soil) 81,96%. The highest porosity was found T0(sub soil) 94,93% and the lowest in T1(top soil) 65,28%. The highest permeability is found in T0(sub soil) 33,80 cm/hour and the lowest is on T1(top soil) 16,10 cm/hour. The results of statistical tests show that there is a significant difference in the parameters of volume weight with t count 3,482 t table 1,943, while in the other parameters have no significant differences. The level of maturity in the Tripa Makmur area is hemik. Peat depth of 3 meters. The highest subsidance is 100 cm on burning peat in 2015. The color of this peat is blackish brown. 


2018 ◽  
Vol 36 (0) ◽  
Author(s):  
M. SAJID ◽  
S. AHMAD ◽  
M.J. JASKANI ◽  
M. YASIN

ABSTRACT: Going towards sustainable fruit culture, it is very important that soil fertility should maintain by adopting the proper weeds control and adding the organic matter. This research was carried out to identify the most suitable weed control method for Kinnow orchard. The plants of Kinnow at the age of 6 years grown under drip irrigation were selected. Weeds of orchard were managed by mulching (wood chip and black polyethylene), mechanical (cultivator and rotavator) and chemical (glyphosate) methods. Mechanical weed control was taken as control treatment. The plants where wood chip mulching was used for weed control showed maximum increase in shoot length (24.00 cm), chlorophyll contents (84.00 SPAD value) and yield (11.88 ton ha-1) followed by the plants where weeds were controlled with chemical control while lowest shoot length (12.00 and 12.33 cm), chlorophyll contents (41.00 and 42.67 SPAD value) and yield (3.80 and 4.70 ton) was achieved in cultivator and rotavator treatment respectively. Wood chip mulch also improved soil physical properties by reducing bulk density (1.49 Mg m-3), soil penetration resistance (785.33 kPa) and by enhancing soil organic matter (1.17%), hydraulic conductivity (34.50 mm/hr-1) and soil microbial biomass carbon (159.68 g kg-1) followed by glyphosate control while lowest values of soil physical properties were obtained in cultivator and rotavator weed control. Wood chip mulch also reduced weed dry weight (45.25 g) and efficiently controlled weeds (95.66%) as compared to other weed control methods. In this case, wood chip mulch performed better in all studied parameters than plastic mulch, rotavator, cultivator and glyphosate weed control. So, wood chip mulch should be recommended to citrus grower for improving soil physical properties and yield.


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