Effect of exogenous carbon on the sorption and movement of atrazine and 2,4-D by soils

Soil Research ◽  
1996 ◽  
Vol 34 (4) ◽  
pp. 609 ◽  
Author(s):  
S Baskaran ◽  
NS Bolan ◽  
A Rahman ◽  
RW Tillman

Sorption and movement of 2 ionic herbicides (2,4-D and atrazine) by 3 soil materials (Tokomaru silt loam, Egmont silt loam, mine tailings) which were amended with different levels of exogenous carbon (C) materials (poultry manure, sewage sludge, mushroom compost, peat, pig manure) were examined using 14C-labelled compounds. The sorption of herbicides was measured using a batch technique and the movement was examined using soil columns in which a pulse of 14C-labelled herbicide was leached with dissolved organic C (DOC). Sorption of herbicides, as measured by the distribution coefficient (Kd), increased with increasing C addition, and varied between the C sources. The difference in the effect of C sources on the sorption of herbicides was related to the difference in the amount of DOC and the pH. The increase in the Kd values per unit C addition decreased with increasing amounts of both the exogenous C addition and the indigenous C in the soil material. In a separate study, the addition of DOC to solutions of herbicides prior to sorption measurements decreased the sorption of herbicides, whereas the addition of DOC to soil increased the sorption of herbicides. Column studies have shown that DOC enhanced the movement of herbicides in soils. The effect of DOC on the movement of herbicides varied between the soil materials and may be related to the difference in the sorption of both the herbicides and the DOC.

2002 ◽  
Vol 713 ◽  
Author(s):  
François Carona ◽  
Michael K. Haas ◽  
Edward L. Cooper ◽  
David E. Robertson

ABSTRACTContaminated groundwater from a former liquid waste discharge area at the Chalk River Laboratories was treated with ion exchange resins to isolate aqueous extracts of selected radionuclides (60Co, 106Ru, 137Cs, 238Pu, 239/240Pu, 241Am and 244Cm). The extracts were then mixed with native uncontaminated soil material to determine their liquid-solid partitioning coefficients (Kd). Separate Kd values of the same elements were also obtained with the usual short-term “batch” technique for comparison, but using different radioisotopes as tracers (57Co and 134Cs), spiked to the extracts. The comparison included separate Kd determinations with 239/240Pu and 241Am as tracers, added to uncontaminated groundwater.In all cases, the radionuclides originally present in the contaminated groundwater extracts exhibited low Kd values, compared to the values obtained in the “batch” method with tracers (57Co, 134Cs, 239/240Pu and 241Am). The difference was up to two orders of magnitude. This was attributed to differences in aqueous speciation of the nuclides in the contaminated groundwater, allowing limited interactions of complexed radionuclide species with soil material. Our results indicated that all the radionuclides were predominantly in anionic form in the groundwater, whereas in the tracer “batch” experiment, 57Co and 134Cs were predominantly cationic, Pu and Am were predominantly anionic. Hydrolysis partially explains the dominant anionic character of Am and Pu in the tracer experiments, however dissolved organics are suspected to dominate the speciation of the radionuclides in contaminated groundwater. Our experiment implies that in some cases, if Kd values obtained using the “batch” method with tracers are used in transport models, radionuclide transport could be underestimated.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 750D-750
Author(s):  
Juluri Rao* ◽  
John Moore ◽  
Andrew Stewart

The EU Regional Draft Waste Management Plan (1999-2004) identified pig slurry (501,590 tonnes), poultry manure (217,110 tonnes) and spent mushroom compost (221,665 tonnes) as the main contributors to the 3.5 million tonnes of waste generated annually in Ireland. Current legislative restrictions prevent pig wastes from intensive pig units and horticultural wastes mainly spent compost produced in mushroom farms being disposed via landspreading due to pollution threat from nutrient run-off and the health hazards due to animal and human risk pathogen contents in wastes. Composting is a world-wide popular option for environmentally sustainable means of recycling farm wastes. In Ireland, profitable conversion of farm wastes such as pig slurry solids and spent mushroom compost has not yet been fully explored for their economic viability as `green' fertilizers. In this study, we produced pelleted formulations of the composted pig waste solids, (20%) blended with spent mushroom compost (26%), turkey litter (26%) cocoa husks (18%) and shredded paper (10%) to an environmentally safe, organic-based fertiliser resulting in N:P:K = 3:5:10, ideally suitable for use on amenity grassland such as golf course fairways and greens in Ireland, wherein spring and summer fertilizers with slow release of nutrients would aid an even growth of grass. We describe the composting methods used, processing technology developed and additional amendments such as dried blood or feather meal that were used during the pelletisation operation yielding specific N:P:K target ratios from the pig manure and spent compost wastes. We also report on the rigorous microbiological tests carried out throughout the composting phase and ascertained the pathogen-free status of the final pelletised fertilser products.


Soil Research ◽  
1999 ◽  
Vol 37 (3) ◽  
pp. 445 ◽  
Author(s):  
N. S. Bolan ◽  
M. A. R. Khan ◽  
R. W. Tillman ◽  
R. Naidu ◽  
J. K. Syers

The effect of chloride, sulfate, nitrate, and phosphate anions on the sorption and leaching of cadmium was examined in 2 soils (Manawatu silt loam and Egmont clay loam) which differ in their variable charge components. There was a larger sorption of cadmium in the presence of phosphate than in the presence of sulfate, nitrate, and chloride, and the difference was more pronounced in the Egmont soil. In soils, specific sorption of phosphate increases the negative charge. The increase in negative charge per unit amount of phosphate sorbed decreased with increasing phosphate sorption. The sorption of cadmium increased in response to phosphate sorption. The phosphate-induced cadmium sorption resulted from the increase in negative charge due to phosphate sorption. Column studies indicated that cadmium was less susceptible to leaching in the presence of phosphate than in the presence of nitrate.


2021 ◽  
Vol 11 (10) ◽  
pp. 4589
Author(s):  
Ivan Duvnjak ◽  
Domagoj Damjanović ◽  
Marko Bartolac ◽  
Ana Skender

The main principle of vibration-based damage detection in structures is to interpret the changes in dynamic properties of the structure as indicators of damage. In this study, the mode shape damage index (MSDI) method was used to identify discrete damages in plate-like structures. This damage index is based on the difference between modified modal displacements in the undamaged and damaged state of the structure. In order to assess the advantages and limitations of the proposed algorithm, we performed experimental modal analysis on a reinforced concrete (RC) plate under 10 different damage cases. The MSDI values were calculated through considering single and/or multiple damage locations, different levels of damage, and boundary conditions. The experimental results confirmed that the MSDI method can be used to detect the existence of damage, identify single and/or multiple damage locations, and estimate damage severity in the case of single discrete damage.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
R Bosco ◽  
S Gambelli ◽  
V Urbano ◽  
G Cevenini ◽  
G Messina

Abstract Background Sanitizing the operating theatres (OT) is important to minimize risk of post-operative infections. Disinfection procedures between one operation and another is less aggressive than final cleaning procedures, at the end of the day. Aim was assessing the difference of contamination: i) between different levels of disinfection; ii) before and after the use of a UVC Device (UVC-D). Methods Between December 2019/February 2020 a cross sectional study was conducted in OT in a real clinical context. 94 Petri dishes (PD) were used in 3 OT. Three different sanitation levels (SL1-3) were compared pre- and post-use of UVC-D: i) No cleaning after surgery (SL1); ii) after in-between cleaning (SL2); iii) after terminal cleaning (SL3). UVC-D was employed for 6 minutes, 3 minutes per bed side. PD were incubated at 36 °C and colony forming unit (CFU) counted at 48h. Descriptive statistic, Wilcoxon and Mann-Whitney tests were performed to assess the contamination levels in total, pre/post use of UVC-D, and between different sanitation levels, respectively. Results In total we had a mean of 3.39 CFU/PD (C.I. 2.05 - 4.74) and a median of 1 CFU/PD (Min. 0 - Max. 39), after UVC-D use we had a mean of 2.20 CFU/PD (C.I. 0.69 - 5.09) and a median of 0 CFU/PD (Min. 0 - Max. 133). The UVC-D led to a significant reduction of CFU (p < 0.001). Without UVC-D we had a significant CFU drop (p < 0.05) between SL1 and SL3. Using UVC-D, we observed significant reductions of contamination (p < 0.05) between SL3 and SL1. Comparing SL1 (median 0) post UVC-D use vs SL2 pre UVC-D use (median 0.5), and SL2 post UVC-D use (median 0) vs SL3 pre UVC-D use (median 1) we had a significant reduction of contamination (p < 0.05). Conclusions UVC-D improved environmental contamination in any of the three sanitation levels. Furthermore, the use of UVC-D alone was better than in-between and terminal cleaning. Although these encouraging results, the cleaning procedures executed by dedicated staff has to be considered. Key messages UVC are efficient to decrease contamination in operating theatres regardless of sanitation levels. The additional use of UVC technology to standard cleaning procedures significantly improves sanitation levels.


2021 ◽  
Vol 7 (1) ◽  
pp. 331-341
Author(s):  
Urszula Chwesiuk

Abstract The aim of this study was an attempt to verify whether Polish speakers of English insert a vowel in the word-final clusters containing a consonant and a syllabic /l/ or /n/ due to the L1–L2 transfer. L1 Polish speakers are mostly unaware of the existence of syllabic consonants; hence, they use the Polish phonotactics and articulate a vocalic sound before a final sonorant which is deprived of its syllabicity. This phenomenon was examined among L1 Polish speakers, 1-year students of English studies, and the recording sessions were repeated a year later. Since, over that time, they were instructed with regard to phonetics and phonology but also the overall practical language learning, the results demonstrated the occurrence of the phenomenon of vowel insertion on different levels of advanced command of English. If the vowels were inserted, their quality and length were monitored and analysed. With regard to the English system, pronouncing vowel /ə/ before a syllabic consonant is possible, yet not usual. That is why another aim of this study is to examine to what extent the vowels articulated by the subjects differ from the standard pronunciation of non-final /ə/. The quality differences between the vowels articulated in the words ending with /l/ and /n/ were examined as well as the potential influence from the difference between /l/ and /n/ on the occurrence of vowel reduction. Even though Polish phonotactics permit numerous consonantal combinations in all word positions, it proved to be challenging for L1 Polish speakers to pronounce word-final consonantal clusters containing both syllabic sonorants. This result carries practical implications for the teaching methodology of English phonetics.


Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 345 ◽  
Author(s):  
G. D. Schwenke ◽  
D. R. Mulligan ◽  
L. C. Bell

At Weipa, in Queensland, Australia, sown tree and shrub species sometimes fail to establish on bauxite-mined land, possibly because surface-soil organic matter declines during soil stripping and replacement. We devised 2 field experiments to investigate the links between soil rehabilitation operations, organic matter decline, and revegetation failure. Experiment 1 compared two routinely practiced operations, dual-strip (DS) and stockpile soil, with double-pass (DP), an alternative method, and subsoil only, an occasional result of the DS operation. Other treatments included variations in stripping-time, ripping-time, fertiliser rate, and cultivation. Dilution of topsoil with subsoil, low-grade bauxite, and ironstone accounted for the 46% decline of surface-soil (0–10 cm) organic C in DS compared with pre-strip soil. In contrast, organic C in the surface-soil (0–10 cm) of DP plots (25.0 t/ha) closely resembled the pre-strip area (28.6 t/ha). However, profile (0–60 cm) organic C did not differ between DS (91.5 t/ha), DP (107 t/ha), and pre-strip soil (89.9 t/ha). Eighteen months after plots were sown with native vegetation, surface-soil (0–10 cm) organic C had declined by an average of 9% across all plots. In Experiment 2, we measured the potential for post-rehabilitation decline of organic matter in hand-stripped and replaced soil columns that simulated the DS operation. Soils were incubated in situ without organic inputs. After 1 year’s incubation, organic C had declined by up to 26% and microbial biomass C by up to 61%. The difference in organic C decline between vegetated replaced soils (Expt 1) and bare replaced soils (Expt 2) showed that organic inputs affect levels of organic matter more than soil disturbance. Where topsoil was replaced at the top of the profile (DP) and not ploughed, inputs from volunteer native grasses balanced oxidation losses and organic C levels did not decline.


De Jure ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Daniel Haman ◽  
◽  
◽  

The difference between intent (dolus) and negligence (culpa) was rarely emphasized in codified medieval laws and regulations. When compared to the legal statements related to intent, negligence was mentioned even more rarely. However, there are some laws that distinguished between the two concepts in terms of some specific crimes, such as arson. This paper draws attention to three medieval Slavic legal documents – the Zakon Sudnyj LJudem (ZSLJ), the Vinodol Law and the Statute of Senj. They are compared with reference to regulations regarding arson, with the focus being on arson as a crime committed intentionally or out of negligence. The ZSLJ as the oldest known Slavic law in the world shows some similarities with other medieval Slavic legal codes, especially in the field of criminal law, since most of the ZSLJ’s articles are related to criminal law. On the other hand, the Vinodol Law is the oldest preserved Croatian law and it is among the oldest Slavic codes in the world. It was written in 1288 in the Croatian Glagolitic script and in the Croatian Chakavian dialect. The third document – the Statute of Senj – regulated legal matters in the Croatian littoral town of Senj. It was written in 1388 – exactly a century after the Vinodol Law was proclaimed. When comparing the Vinodol Law and the Statute of Senj with the Zakon Sudnyj LJudem, there are clear differences and similarities, particularly in the field of criminal law. Within the framework of criminal offenses, the act of arson is important for making a distinction between intent and negligence. While the ZSLJ regulates different levels of guilt, the Vinodol Law makes no difference between dolus and culpa. On the other hand, the Statute of Senj strictly refers to negligence as a punishable crime. Even though the ZSLJ is almost half a millennium older than the Statute of Senj and around 400 years older than the Vinodol Law, this paper proves that the ZSLJ defines the guilt and the punishment for arson much better than the other two laws.


2016 ◽  
Vol 6 (3) ◽  
pp. 58 ◽  
Author(s):  
Dominic J. Udoh ◽  
Otobong B. Iren ◽  
Jeremiah E. Jonathan

<p class="1Body">Two field experiments were conducted from 2012 to 2013 cropping seasons to evaluate the efficacy and also determine the optimum rates of application for fish pond waste water in comparison with three other manures including one inorganic fertilizer and two organic manures under garden egg (<em>Solanum spp.</em>) crop.Garden egg was fertilized with pond waste water (PW), poultry manure (PM), pig manure (PG) and NPK15:15:15 at equivalent nitrogen (N) rates (0, 150, 300, 450 kg/ha). The treatments were arranged in a split plot under randomized complete block design (RCBD).The results obtained indicated a slight drop in soil pH but soil OM, total N, available P, exchangeable Ca and K increased generally with increasing rates of manures. The PW and PG treatments supported significantly (P&lt;0.05) the highest yields of the crop compared to PM and NPK with the 150 and 300 kg/ha treatments recording the highest increase. These results have shown that under the high rainfall and acidic soil conditions of Akwa Ibom State in Nigeria, PW is useful for the improvement of soil conditions and achievement of higher crop yields when applied at rates that supply N in the range of 150 – 300 kg/ha.</p>


2019 ◽  
Vol 3 (2) ◽  
pp. 447-461
Author(s):  
Ardina Fahriyanti Maharani ◽  
Erlina Prihatnani

In solid geometry needed the ability to visualize space that cannot be seen so differences in visual intelligence can trigger errors in solving geometry problems. Therefore, this study aimed to determine the types of errors made by students and the factors that cause errors in working on geometry problems based on Newman's Error Analysis (NEA) in terms of visual intelligence. This research chose the subjects of class XII high school who had studied the material distance points to lines in space with different levels of visual intelligence, namely high and low. The process of collecting data used visual intelligence test questions, geometry test questions, and interviews. The results of this study indicated that the level of students' visual intelligence affects the difference in location and the factor that causes errors in the stage of transformation especially on determining the distance in dimension 3. Students with high visual intelligence made mistakes at the stage of transformation and encoding that caused by the students’ carelessness. However, students with low visual intelligence made mistakes at the stage of comprehension, transformation, process skills, and encoding due to the concept of the point distance to the line and the concept of the Pythagorean theorem.


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