Factors affecting paddy soil arsenic concentration in Bangladesh: Prediction and uncertainty of geostatistical risk mapping

Rice (Oryza sativa L.) is one of the major food crops in many countries. As the cultivation of rice requires huge volume of water, long term use of Arsenic contaminated groundwater for irrigation may result in the increase of arsenic concentration in the agricultural soil and eventually accumulation in rice grains. A micro level study was conducted to investigate the transfer of arsenic from irrigation water and soil to rice plants in the arsenic affected 8 unions of Chandina upazilla, Comilla district. The level of arsenic in irrigation water (0.12±0.08 and 0.67±0.07 mg l-1) was much above the WHO permissible limit of 0.01 mg l-1 for drinking water and FAO permissible limit of 0.10 mg l-1 for irrigation water. The total soil arsenic concentrations ranged from 3.21±0.80 to 8.74±2.83 mg kg-1 dry weight of soil, which was below the maximum acceptable limit for agricultural soil of 20.0 mg kg-1 as recommended by the European Community. The accumulation of arsenic in the grain ranged from 0.12±0.04 to 0.58±0.06 mg kg-1 in Boro and 0.16±0.04 to 1.06±0.20 mg kg-1 in T. Aman. Except grain sample (T. Aman) of one union, the grains in both Boro and T. Aman of all unions did not exceed 1.0 mg kg-1 dry weight of arsenic (the permissible limit of arsenic in rice according to WHO recommendation). Thus, till now rice has remained harmless for consumption in the study area. The results clearly showed that the arsenic content in the grains of Boro rice is correlated to the intensity of arsenic contamination of irrigation water and soil. The Agriculturists 2014; 12(2) 74-82

Download Full-text

Long-term nitrogen fertilization shaped the nifH, nirK and nosZ gene community patterns in red paddy soil in south China。

Canadian Journal of Microbiology ◽

10.1139/cjm-2020-0300 ◽

2020 ◽

Author(s):

Cunzhi Zhang ◽

Kaixun Cao ◽

Yue Li ◽

Juan Zhao ◽

Wentao Peng ◽

...

Keyword(s):

Paddy Soil ◽

Gene Diversity ◽

Nifh Gene ◽

Community Patterns ◽

Factors Affecting ◽

Nitrogen Fixers ◽

Potential Link ◽

Chemical Factors ◽

Red Paddy Soil

To understand the diversities of diazotrophs and denitrifiers in red paddy soil under long-term fertilization conditions, nifH, nirK and nosZ libraries were constructed based on the PCR-RFLP method. nirK gene diversity proved to be lower than that of nosZ and nifH, and nirK and nosZ genes were more sensitive to different fertilization treatments than those with the nifH gene. Diverse microbes including the α-, β-, γ- and δ- subclasses of the Proteobacteria dominated the three libraries. Long-term addition of urea with straw-mulching and azophoska increased the abundance of non-symbiotic diazotrophs, which indicated that non-symbiotic diazotrophs were responsible for the majority of the nitrogen-fixing ability in paddy soil. In addition, a potential link between nifH and nosZ was found due to the existence of nitrogen fixers, such as Bradyrhizobium and Ralstonia in the nosZ library. The main chemical factors affecting the three genes were identified, pH was the most important factor of nifH community, and nirK genes were more affected by pH and organic matter, available potassium and carbon to nitrogen ratio significantly influenced the community structure of the nosZ genes.

Download Full-text

The contents of risk elements, arsenic speciation, and possible interactions of elements and betalains in beetroot (Beta vulgaris, L.) growing in contaminated soil

Open Life Sciences ◽

10.2478/s11535-010-0050-0 ◽

2010 ◽

Vol 5 (5) ◽

pp. 692-701 ◽

Cited By ~ 1

Author(s):

Jiřina Száková ◽

Jaroslav Havlík ◽

Barbora Valterová ◽

Pavel Tlustoš ◽

Walter Goessler

Keyword(s):

Beta Vulgaris ◽

Contaminated Soil ◽

Phosphate Buffer ◽

Arsenic Speciation ◽

Arsenic Concentration ◽

Dimethylarsinic Acid ◽

Total Arsenic ◽

Soil Arsenic ◽

Risk Element

AbstractThe effect of enhanced soil risk element contents on the uptake of As, Cd, Pb, and Zn was determined in two pot experiments. Simultaneously, transformation of arsenic and its compounds in beetroot (Beta vulgaris L.) plants was investigated. The mobile fractions of elements were determined in 0.05 mol L−1 (NH4)2SO4 extracts and did not exceed 2% of total soil arsenic, 9% of total cadmium, 3% of total lead, and 8% of total zinc, respectively. Although the soils were extremely contaminated the mobile portions of the elements represented only a small fragment of the total element content. Arsenic contents in beet plants reached up to 25 mg As kg−1 in roots and 48 mg As kg−1 in leaves in the soil characterized by the highest mobile arsenic portion. Arsenic portions extractable with water and phosphate buffer from the beetroot samples did not show significant differences between the extraction agents but the extractability was affected by the arsenic concentration. Arsenic was almost quantitatively extractable from the samples with the lowest total arsenic concentration, whereas in the samples with the highest total arsenic concentration less than 25% was extractable. Arsenate was the dominant arsenic compound in the extracts (70% in phosphate buffer, 50% in water extracts). A small portion of dimethylarsinic acid, not exceeding 0.5%, was detected only in the sample growing in the soil with the highest arsenic concentration. The role of betalains (betanin, isobetanin, vulgaxanthin I and vulgaxanthin II) in transformation/detoxification of arsenic in plants was not confirmed in this experiment because the plants were able to grow in the contaminated soil without any symptoms of arsenic toxicity.

Download Full-text

Stabilization of Soil Arsenic with Iron and Nano-Iron Materials: A Review

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2021.18476 ◽

2021 ◽

Vol 21 (1) ◽

pp. 10-21

Author(s):

Changsheng Yue ◽

Huili Du ◽

Yan Li ◽

Naiyi Yin ◽

Ben Peng ◽

...

Keyword(s):

Chemical Stabilization ◽

Environmental Friendliness ◽

Factors Affecting ◽

Binary Oxides ◽

Soil Arsenic ◽

Coprecipitation Process ◽

Iron Iron ◽

High Reduction ◽

Capacity Cost ◽

Reduction Capacity

Soil arsenic (As) contamination is an important environmental problem, and chemical stabilization is one of the major techniques used to remediate soil As contamination. Iron and iron nanoparticle materials are widely used for soil As stabilization because they have one or more of the following advantages: high adsorption capacity, high reduction capacity, cost effectiveness and environmental friendliness. Therefore, this review introduces the stabilization of soil As with iron and iron nanoparticles, including zero-valent iron, iron oxides/hydroxides, some iron salts and Fe-based binary oxides and the nanoparticles of these iron materials. The mechanism of chemical soil As stabilization, which involves adsorption and the coprecipitation process, is discussed. The factors affecting the chemical stabilization process are presented, and challenges to overcome in the future are also discussed in this review.

Download Full-text

Assessment of Human Productivity Drivers for Construction Labor through Importance Rating and Risk Mapping

Sustainability ◽

10.3390/su12208614 ◽

2020 ◽

Vol 12 (20) ◽

pp. 8614

Author(s):

Murat Gunduz ◽

Abdulrahman Abu-Hijleh

Keyword(s):

Labor Productivity ◽

Construction Projects ◽

Rank Correlation ◽

Weather Conditions ◽

Risk Mapping ◽

Importance Rating ◽

Factors Affecting ◽

Importance Index ◽

The Impact ◽

Productivity Factors

Labor constitutes a significant portion of the overall cost of a construction project, where labor productivity is often the main driver of the cost. Although studies on labor productivity factors exist, their frequency of occurrence in terms of their ranking remains unexplored. This study differs from other studies in the literature by introducing the frequency component to the productivity factors, a more realistic ranking of the factors by adjusting the importance by frequency (frequency adjusted importance index) and risk mapping of the factors. Moreover, this study is the first to apply risk mapping on labor productivity drivers. The aim of this paper is to identify the project factors affecting the labor productivity in construction projects and to rank these factors considering the perception of the industry on project performance. A literature review of past relevant studies was performed to identify and draft a list of factors affecting labor productivity in construction projects. Thirty-seven labor productivity factors were presented in a questionnaire to investigate the impact and frequency of their occurrence in construction projects. A 9-point scale structured questionnaire was constructed to measure the importance and the frequency of the factors and to evaluate the ranking for different categories. The frequency adjusted importance index (FAII), Spearman’s rank correlation, and risk mapping were used to study and analyze the 105 completed responses. The participants rated the following factors as the five most significant labor productivity-influencing factors: (1) poor labor supervision, (2) delays in payments, (3) poor work environment, (4) lowly skilled labor, and (5) bad weather conditions.

Download Full-text

Factors affecting arsenic concentration in groundwaters from Northwestern Chaco-Pampean Plain, Argentina

Environmental Geology ◽

10.1007/s00254-006-0564-y ◽

2006 ◽

Vol 52 (7) ◽

pp. 1261-1275 ◽

Cited By ~ 19

Author(s):

María Gabriela García ◽

Ondra Sracek ◽

Diego Sebastián Fernández ◽

Margarita del Valle Hidalgo

Keyword(s):

Arsenic Concentration ◽

Factors Affecting ◽

Pampean Plain

Download Full-text

Lead and Arsenic in Two Apricot Cultivars and in `Gala' Apples Grown on Lead Arsenate-contaminated Soils

HortScience ◽

10.21273/hortsci.27.12.1277 ◽

1992 ◽

Vol 27 (12) ◽

pp. 1277-1278 ◽

Cited By ~ 17

Author(s):

Timothy L. Creger ◽

Frank J. Peryea

Keyword(s):

Contaminated Soils ◽

Human Health Risk ◽

Arsenic Concentration ◽

Prunus Armeniaca ◽

Fresh Weight ◽

Lead Arsenate ◽

Soil Arsenic ◽

Tree Fruits ◽

Extractable Soil

Concerns about food safety prompted a case study of the arsenic and Pb contents of tree fruits grown on lead arsenate-contaminated soil. The arsenic concentration in apricot (Prunus armeniaca L.) and `Gala' apple (Malus domestica Borkh.) fruit was positively related to concentrated HCl-extractable soil arsenic. Fruit arsenic in both species did not exceed 70 μg·kg-1 fresh weight (fw). Fruit Pb was below the limits of detection of 20 μg·kg-1 fw for apricot and 24 μg·kg-1 fw for apple. All of these concentrations are substantially below levels associated with human health risk. `Riland' apricot trees did not show arsenic phytotoxicity at soil, fruit, and leaf arsenic concentrations associated with phytotoxicity symptoms in `Goldrich' apricots. The apple trees showed no visual symptoms of arsenic phytotoxicity.

Download Full-text

Remediating Lead, Zinc, Cadmium and Arsenic Contaminated Steel Smelting Site with Hydrochloric Acid and Sodium Hydroxide

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.137.322 ◽

2011 ◽

Vol 137 ◽

pp. 322-327

Author(s):

Yan Mei Li ◽

Mei Lei ◽

Tong Bin Chen

Keyword(s):

Hydrochloric Acid ◽

Sodium Hydroxide ◽

Cadmium Concentration ◽

Arsenic Concentration ◽

Soil Washing ◽

Steel Smelting ◽

Soil Arsenic ◽

Zinc Cadmium ◽

Lead Zinc ◽

Soil Cadmium

A-two step soil washing experiment was conducted to search an effective washing technique for the remediation of the contaminated soil from a steel smelting site. Our results indicated that 0.5M of hydrochloric acid alone could reduce soil cadmium concentration to lower than 1 mg kg-1, 1M of hydrochloric acid alone could reduce soil lead concentration to lower than 140 mg kg-1, 2M of hydrochloric acid combined with 0.2M of sodium hydroxide could reduce soil zinc concentration to lower than 200 mg kg-1 and reduce soil arsenic concentration to lower than 20 mg kg-1, the washed soil could be safely reused according to the national exhibition land quality standards of grade A.

Download Full-text