The Impact of Christchurch City (New Zealand) on Heavy Metals in Sediments of the Avon-Heathcote Estuary

1993 ◽  
Vol 28 (8-9) ◽  
pp. 369-382 ◽  
Author(s):  
J. Deely
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Heavy Metal Contamination ◽  
Clay Fraction ◽  
Clay Content ◽  
Sediment Surface ◽  
Core Sediment ◽  
Depth Profiles ◽  
Western Area ◽  
The Impact

This paper reviews heavy metal (Cr, Cu, Fe, Mn, Ni, Pb, Zn) content in the clay fraction (<4 µm) of soils, suspended sediment, surface sediment, and core sediment associated with the Avon-Heathcote Estuary. Despite the estuary's low clay content (<10%), significant metal and organic matter trends are apparent in the clay fraction, which are less obvious in parallel studies of silt (4-63 µm), sand (>63 µm), and total sediment. Clay fraction depth profiles record periods of high heavy metal input in sediments deposited slowly but not in sediments deposited rapidly. Most metals, organic matter, mud, and Fe oxides accumulate in a broad anaerobic band across the western area of the estuary. Organic matter and metal concentrations are increasing towards the surface in depth profiles of this zone. This pattern combined with the increasingly eutrophic state of the estuary suggests more serious heavy metal contamination in the future.

Functional role of earthworms to control the hydraulic conductivity of constructed wetlands 

2021 ◽  
Author(s):  
Océane Gilibert ◽  
Dan Tam Costa ◽  
Sabine Sauvage ◽  
Didier Orange ◽  
Yvan Capowiez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Hydraulic Conductivity ◽  
Constructed Wetlands ◽  
Hyporheic Zone ◽  
Riparian Zone ◽  
Water Flux ◽  
Sediment Surface ◽  
Deep Soil ◽  
The Impact ◽  
Organic Matter Input

<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>

Impact of Heavy Metals on Benthic Oligochaete Communities in the River Ill and Its Tributaries

1994 ◽  
Vol 29 (3) ◽  
pp. 241-248 ◽  
Author(s):  
A. Rosso ◽  
M. Lafont ◽  
A. Exinger
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Organic Matter ◽  
Reproductive Strategy ◽  
Organic Micropollutants ◽  
Rhine Basin ◽  
Metal Contents ◽  
The Impact ◽  
The City

The aim of this research is to describe the impact of heavy metals contaminating sediments on oligochaete communities. Sediments were collected three times (June, August, October 1991) for chemical and biological analyses in 15 sites situated in the river I11 and its tributaries (Rhine Basin, France). The sediments are characterized by high contents of heavy metals, mainly Hg, Cu, Cr, Pb, Zn from below the city of Mulhouse. The majority of sediments are heavily loaded with organic matter and organic micropollutants are also present. Oligochaete communities are rich in species. However five species only, considered as pollution-tolerant or opportunist, are significantly present and abundant. The percentages of Tubificidae without hair setae are positively related to heavy metal contents of the sediments, and the percentages of Tubificidae with hair setae are negatively related. Several species such as N. communis, N. barbata, D. digitata and Bothrioneurum sp. are considered as tolerant to heavy metals; on the contrary L. claparedeanus, L. udekemianus, Stylodrilus sp. and S. josinae are considered as intolerant. The reproductive strategy of oligochaetes in contaminated areas and the role of organic matter are discussed. Several recommendations are given for the rehabilitation of the investigated sites.

scholarly journals Assessment of Heavy Metals in Soil, Paddy Straw and SEM analysis of the soil for the impact of wastewater irrigation in Girudhumal Sub basin of Tamil Nadu, India

2018 ◽  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Contamination ◽  
Soil Structure ◽  
Heavy Metal Contamination ◽  
Sem Analysis ◽  
Wastewater Irrigation ◽  
Urban Region ◽  
Paddy Straw ◽  
The Impact

<p>The objective of the study is to determine accumulation and translocation of heavy metals from soil to paddy straw irrigated with urban sewage wastewater in peri-urban region of Girudhumal subbasin area in Madurai. The soil samples were collected in seven locations irrigated with treated and untreated wastewater and analyzed for physical properties like pH, EC, bulk density, soil type, major (N,P,K) and micronutrients (Fe, Mn, Cu, Zn) and heavy metals Ni, Cd, Pb. SEM analysis showed that soil structure is significantly influenced by wastewater irrigation. It confirms that the wastewater irrigation disturbs soil structure and affecting the plant growth in long run.&nbsp; Pb content was higher than the prescribed safe limits in S5 and S6 location, similarly, Ni also was higher than the safe limit in all the locations. Pollution Load Index values are in the range of 0.08-0.56 for all sites, and it indicated that chance of heavy metal contamination is less. The EF values show moderate enrichment to Ni and Zn, Significant enrichment for Cd and Cu, Extremely high for Pb and deficiency for Mn. All these results confirmed that there is no immediate risk of heavy metal pollution, however with respect to Pb and Ni the plant tissues are showing higher values. The transfer factor for heavy metals from soil to paddy straw is less than 0.5 for Cd and for others is more than 0.5 indicated greater chances for heavy metal contamination.</p>

Comparison of three methods of measuring surface area of soils

1999 ◽  
Vol 79 (2) ◽  
pp. 345-351 ◽  
Author(s):  
E. de Jong
Keyword(s):  
Organic Matter ◽  
Surface Area ◽  
External Surface ◽  
Clay Mineralogy ◽  
Clay Content ◽  
Sorptive Capacity ◽  
Measuring Surface ◽  
Glycol Monoethyl Ether ◽  
Highly Correlated ◽  
The Impact

Surface area (SA) is an important property of soils, but different methods can give widely different estimates of SA, and of the contribution of organic matter to SA. This study was undertaken to compare two common methods of measuring SA (EGME [ethylene glycol monoethyl ether] and N2 sorption) with SA estimates using H2O sorption on selected Saskatchewan soils; some soils from Kenya were included to show the impact of clay mineralogy. For the Saskatchewan soils, the three estimates of SA were highly correlated to each other and to clay content, but SA EGME was 2 to 3 times SA H2O and 7 to 52 times SA N2. Organic matter did not appear to contribute to SA EGME, increased SA H2O and decreased SA N2. Clearly the three methods differ in their access to internal and external surface area and this should affect their utility as indices of the sorptive capacity of field soils. Key words: Surface area, EGME, N2 sorption, water sorption

scholarly journals It Takes Time to Unravel the Ecology of War in Gaza, Palestine: Long-Term Changes in Maternal, Newborn and Toddlers’ Heavy Metal Loads, and Infant and Toddler Developmental Milestones in the Aftermath of the 2014 Military Attacks

2020 ◽  
Vol 17 (18) ◽  
pp. 6698 ◽  
Author(s):  
Nabil al Baraquoni ◽  
Samir R. Qouta ◽  
Mervi Vänskä ◽  
Safwat Y. Diab ◽  
Raija-Leena Punamäki ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Contamination ◽  
Inductively Coupled Plasma ◽  
Infant Health ◽  
Heavy Metal Contamination ◽  
In Utero ◽  
World Health ◽  
Infants And Toddlers ◽  
Hair Samples ◽  
The Impact

Toxicant, teratogen and carcinogen metal war remnants negatively affect human health. The current study analyzes, first, the persistence of heavy metal contamination in newborn hair in four cohorts across time in Gaza Palestine; second, the change in mothers’ and infants’ heavy metal contamination from birth to toddlerhood; and third, the impact of heavy metal contamination on infants’ and toddlers’ growth and development. The hair of newborns was analyzed for twelve heavy metals by Inductively Coupled Plasma Mass Spectrometry (ICP/MS) in cohorts recruited at delivery in 2011, 2015, 2016, and 2018–2019. In the 2015 cohort, mothers’ hair samples were taken at delivery, and toddlers and mothers hair were also analyzed 18 months later. Growth levels of infants at six months and toddlers at 18 months were assessed according to World Health Organization (WHO) standards according to a mother report and pediatric check-up, respectively. 1. The level of metal contamination in utero was persistently high across 8 years, 2011, 2015, 2016, 2019, following three major military attacks (2009, 2012, 2014). 2. The 2015 cohort babies exposed in utero to attacks in 2014 at six months showed association of high load at birth in mother of arsenic and in newborn of barium with underweight, of barium and molybdenum in newborn with stunting. 3. Eighteen months after birth, toddlers had a higher level of metals in hairs than when they were born, while, in their mothers, such levels were similar to those at delivery, confirming persistence in the environment of war remnants. Underweight and stunting, both in infants and toddlers, were higher than reported for previous years, as well as being progressive within the cohort. Severe environmental factors, metal contamination and food insecurity put Gaza’s infant health at risk.

Adsorption of Chloridazon by Soils and their Components

Weed Science ◽  
1991 ◽  
Vol 39 (3) ◽  
pp. 417-422 ◽  
Author(s):  
Maria J. Sánchez-Martín ◽  
Maria Sáanchez-Camazano
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Clay Fraction ◽  
Organic Matter Content ◽  
Clay Content ◽  
Matter Content ◽  
Soil Composition ◽  
Active Components ◽  
Central Spain ◽  
Natural Soils

The effect of soil composition on adsorption of chloridazon by 18 samples of natural soils, with different chemical and textural characteristics, obtained from west-central Spain, was investigated. The effect of removal of organic matter on adsorption and adsorption of the herbicide by the active components of the soils (montmorillonite and humic acid) was also studied. A highly significant correlation was found between the distribution coefficient (Kd) and organic matter content when all the soils or the soils with organic matter content >2% were considered. According to the determination coefficients (r2), organic matter content accounted for 72% of the variance in adsorption in the former case and 92% in the latter. In soils with an organic matter content <2%, there was no correlation between Kd and organic matter content. A significant correlation was observed between Kd and smectite content for soils containing smectite in their clay fraction. Both simple and multiple correlations showed that clay content, excluding the smectite fraction, had a relatively small effect on adsorption of the herbicide. Adsorption of chloridazon by oxidized soils, montmorillonite, and humic acid confirms the effect of organic matter and smectite on adsorption in natural soils.

scholarly journals Fractionation of heavy metals in yellow latosol cultivated with vegetables

2018 ◽  
Vol 39 (5) ◽  
pp. 1921
Author(s):  
Laércio Santos Silva ◽  
Izabel Cristina de Luna Galindo ◽  
Vinícius Augusto Filla ◽  
Romário Pimenta Gomes ◽  
Milton César Costa Campos ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Organic Matter ◽  
Heavy Metal Contamination ◽  
Soil Samples ◽  
Chemical Fractionation ◽  
Human Consumption ◽  
Native Forest ◽  
Metal Levels ◽  
Toxic Potential

Sequential extraction or chemical fractionation of heavy metals allows inferences to be made about their origin, occurrence, bioavailability, toxic potential and environmental contamination. Thus, the present study aimed to assess the distribution of Cu, Mn, Ni, Pb and Zn among the different soil fractions and landscape compartments of a yellow latosol cultivated with vegetables. Soil samples were collected from five areas cultivated with tomato (Lycopersicon esculentum, Mill.), lettuce (Lactuca sativa), chili pepper (Capsicum annuum L.) and chard (Beta vulgaris L.) in different slope positions (upper, middle, lower), and four reference areas (native forest), at a depth of 0.00 - 0.20 m. Heavy metal levels were also assessed in water used to irrigate the crops and for human consumption by collecting 200 ml of water samples from reservoirs. The soil samples were sequentially fractionated to quantify the concentrations of adsorbed Cu, Mn, Ni, Pb and Zn in the exchangeable (EF), organic matter (OF), amorphous and crystalline iron oxide fractions (AFeOx and CFeOx). Landscape position only interfered significantly in heavy metal adsorption in the soil for Cu and Ni associated with CFeOx and Zn bound to the EF in the farming areas. The highest Cu, Ni, Pb and Zn levels were found in the fractions with less stable chemical bonds (bound to organic matter), in addition to a strong affinity between Cu, Zn and Mn and the oxide fractions (AFeOx + CFeOx). The low affinity of Pb and Ni for the AFeOx and CFeOx fractions indicates greater contamination potential for the water reservoirs. In the short term, organic matter is the main source of remediation for heavy metal contamination in soil, making it important to adopt conservation practices aimed at reducing OM losses.

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