Microscopic characteristic of biological iron sulfide composites during the generation process and the association with treatment effect on heavy metal wastewater

2014 ◽  
Vol 70 (7) ◽  
pp. 1292-1297 ◽  
Author(s):  
Yang Yang ◽  
Yifei Xie ◽  
Xudong Li ◽  
Jingchao Zhou ◽  
Jingwei Liu
Keyword(s):  
Heavy Metal ◽  
Stationary Phase ◽  
Iron Sulfide ◽  
Treatment Time ◽  
Environmental Concern ◽  
Morphological Changes ◽  
Generation Process ◽  
Toxic Heavy Metals ◽  
Practical Applications ◽  
Heavy Metal Wastewater

Heavy metal pollution is a serious environmental concern worldwide, resulting in both environmental and human harm. Recently, studies have shown that environmental biotechnologies based on sulfate reduction offer a potential for removal of toxic heavy metals. Biological iron sulfide composites are iron sulfide compounds generated in situ by sulfate-reducing bacteria. In this study, microscopic morphological changes during the composites' generation process were studied, and the effect of biological iron sulfide composites in different generation phases on treatment of heavy metal wastewater was investigated to establish the correlation between macro-effect and micro-properties. The results revealed that the generation process of biological iron sulfide composites occurs in three phases: the formation phase, stationary phase, and agglomeration phase. The stationary phase can be divided into a pre-stationary phase and post-stationary phase. It was found that the best treatment time for Cr6+ is in the pre-stationary phase, while the best treatment time for Cu2+and Cd2+ is in the post-stationary phase. The results of this study further prove the benefits of treatment of heavy metal wastewater using biological sulfide composites and provide theoretical guidance in practical applications.

ASSESSMENT OF HEAVY METAL CONCENTRATION IN COCONUT WATER

1970 ◽  
pp. 07-10
Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Concentration ◽  
Coconut Water ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Toxic Heavy Metal ◽  
Low Concentration ◽  
Wet Ashing ◽  
Aas Method

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 

scholarly journals A Short Review on Recent Advances of Hydrogel-Based Adsorbents for Heavy Metal Ions

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 864
Author(s):  
Suguna Perumal ◽  
Raji Atchudan ◽  
Thomas Nesakumar Jebakumar Immanuel Edison ◽  
Rajendran Suresh Babu ◽  
Petchimuthu Karpagavinayagam ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Large Scale ◽  
Water Bodies ◽  
Dimensional Structure ◽  
High Porosity ◽  
Adsorption Method ◽  
Toxic Heavy Metal ◽  
Practical Applications

The growth of industry fulfills our necessity and promotes economic development. However, pollutants from such industries pollute water bodies which pose a high risk for living organisms. Thus, researchers have been urged to develop an efficient method to remove toxic heavy metal ions from water bodies. The adsorption method shows promising results for the removal of heavy metal ions and is easy to operate on a large scale, thus can be applied to practical applications. Numerous adsorbents were developed and reported, among them hydrogels, which attract great attention because of the reusability, ease of preparation, and handling. Hydrogels are generally prepared by the cross-linking of polymers that result in a three-dimensional structure, showing high porosity and high functionality. They are hydrophilic in nature because of the functional groups, and are non-toxic. Thus, this review provides various methods of hydrogel adsorbents preparation and summarizes recent progress in the use of hydrogel adsorbents for the removal of heavy metal ions. Further, the mechanism involved in the removal of heavy metal ions is briefly discussed. The most recent studies about the adsorption method for the treatment of heavy metal ions contaminated water are presented.

scholarly journals Heavy metal composition of maize and tomato grown on contaminated soils

2018 ◽  
Vol 3 (1) ◽  
pp. 414-426
Author(s):  
A.O. Adekiya ◽  
A.P. Oloruntoba ◽  
S.O. Ojeniyi ◽  
B.S. Ewulo
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soils ◽  
Heavy Metal Contamination ◽  
Mining Area ◽  
Atomic Absorption Spectrophotometry ◽  
Toxic Heavy Metals ◽  
Mining Site ◽  
Solanum Lycopersicum L ◽  
Sources Of Pollution

Abstract The study investigated the level of heavy metal contamination in plants {maize (Zea mays) and tomato (Solanum lycopersicum L.)} from thirty soil samples of three locations (Epe, Igun and Ijana) in the Ilesha gold mining area, Osun State, Nigeria. Total concentrations of As, Cd, Co, Cr, Cu, Ni, Pb and Zn were determined using atomic absorption spectrophotometry. Spatial variations were observed for all metals across the locations which was adduced to pH and the clay contents of the soils of each location. The results showed that heavy metals are more concentrated in the areas that are closer to the mining site and the concentrations in soil and plants (maize and tomato) decreased with increasing perpendicular distance from the mining site, indicating that the gold mine was the main sources of pollution. The mean concentrations of heavy metals in plants (tomato and maize) samples were considered to be contaminated as As, Cd and Pb respectively ranged from 0.6 - 2.04 mg kg-1, 0.8 - 5.2 mg kg-1, 0.8 - 3.04 mg kg-1 for tomato and respectively 0.60 - 2.00 mg kg-1, 1.50 - 4.60 mg kg-1 and 0.90 - 2.50 mg kg-1 for maize. These levels exceeded the maximum permissible limits set by FAO/WHO for vegetables. In conclusion, monitoring of crops for toxic heavy metals is essential for food safety in Nigeria.

scholarly journals Metalliferous content of drinking water and sediments in storage tanks of some schools in Erbil city, Iraq

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Hawraz Sami Khalid ◽  
Hoshyar Saadi Ali ◽  
Dhary Almashhadany
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Heavy Metal ◽  
Drinking Water ◽  
Water Samples ◽  
World Health ◽  
Storage Tanks ◽  
Quality Indices ◽  
Toxic Heavy Metals ◽  
Water Quality Indices

The present study was conducted to evaluate the quality of drinking water in randomly selected schools in Erbil city, Kurdistan Region, Iraq. The water quality indices such as the Heavy metal Pollution Index (HPI) and Heavy metal Evaluation Index (HEI) were applied to characterize water quality. Eighteen schools were incorporated and sampled for their water storage tanks available to students. Water samples and sediment samples from tanks floor were analyzed by Inductively Coupled Plasma Optical Emission Spectrometer for the determination of twenty-two metal elements. In drinking water samples, all detected metals did not exceed the permissible limits of the World Health Organization. The results of this study showed that the average values of HPI and HEI for As, Cd, Cr, Cu, Fe, Pb, Mn, Ni, and Zn were 54.442 and 0.221, respectively. According to data of the water quality indices, the schools drinking water quality are good and suitable for drinking in terms of heavy metals. However, sediments samples contained high concentrations of all elements including the toxic heavy metals (As, Cd, Cr, and Pb). Re-suspension of sediments into water column after refilling storage tanks can pose a serious threat to students drinking water from such vessels. It is therefore recommended that proper storage tanks are provided to the schools accompanied by continuous sanitation and hygiene practice to mitigate the corrosion of tanks to avoid health risks of toxic metal

scholarly journals Spatial distribution of heavy metals in surface sediments of Kalametiya Lagoon in southern Sri Lanka; insight towards pollution status and socio-economic interactions

2021 ◽  
Author(s):  
Sunanda Kodikara ◽  
Hossein Tiemoory ◽  
Mangala Chathura De Silva ◽  
Pathmasiri Ranasinghe ◽  
Sudarshana Somasiri ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Spatial Distribution ◽  
Sri Lanka ◽  
Suspended Sediments ◽  
Potential Effect ◽  
Toxic Heavy Metals ◽  
Threshold Effect Level ◽  
Effect Level ◽  
Economic Interactions

Abstract Heavy metal (HM) pollution has become a serious threat to coastal aquatic ecosystems. This study, therefore, aimed at assessing the spatial distribution of selected heavy metals/metalloids including Arsenic (As), Cadmium (Cd), Chromium (Cr), Lead (Pb), and Mercury (Hg) in surface sediment (0–15 cm) samples collected across Kalametiya Lagoon in southern Sri Lanka. Forty-one (41) grid points of the lagoon were sampled and the sediment samples were analyzed for HM content by using ICP-MS. A questionnaire survey was carried out to investigate the possible sources for HM pollution in Kalametiya Lagoon. Water pH and salinity showed significant variation across the lagoon. Overall mean value of pH and salinity were 6.68 ± 0.17 and 2.9 ± 2.2 PSU respectively. The spatial distribution of the heavy metals was not monotonic and showed a highly spatial variation. The kernel density maps of the measured heavy metals demarcated several different areas of the lagoon. The mean contents of As, Cd, Cr, Hg, and Pb were lower than that of threshold effect level (TEL) however, higher for Hg at the North Inlet. Nevertheless, it was still lower than potential effect level (PEL). Socio-economic interactions have dramatically reduced during the past two decades. Industrial sewage, river suspended sediments and agrochemicals such as fertilizers, pesticides were reportedly identified as the possible sources for heavy metal loads. Accumulation of toxic heavy metals can be minimized by detouring the water inflow to the lagoon.

scholarly journals Heavy Metals Removal from Water by Efficient Adsorbents

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2659
Author(s):  
Muhammad Zaim Anaqi Zaimee ◽  
Mohd Sani Sarjadi ◽  
Md Lutfor Rahman
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Water Treatment ◽  
Adsorption Process ◽  
Natural Occurrence ◽  
Toxic Heavy Metals ◽  
Major Purpose ◽  
Treatment Methods ◽  
Metals Removal ◽  
Harmful Effects

Natural occurrence and anthropogenic practices contribute to the release of pollutants, specifically heavy metals, in water over the years. Therefore, this leads to a demand of proper water treatment to minimize the harmful effects of the toxic heavy metals in water, so that a supply of clean water can be distributed into the environment or household. This review highlights several water treatment methods that can be used in removing heavy metal from water. Among various treatment methods, the adsorption process is considered as one of the highly effective treatments of heavy metals and the functionalization of adsorbents can fully enhance the adsorption process. Therefore, four classes of adsorbent sources are highlighted: polymeric, natural mineral, industrial by-product, and carbon nanomaterial adsorbent. The major purpose of this review is to gather up-to-date information on research and development on various adsorbents in the treatment of heavy metal from water by emphasizing the adsorption capability, effect of pH, isotherm and kinetic model, removal efficiency and the contact of time of every adsorbent.

Tolerance of Microorganisms to Heavy Metals

2021 ◽  
pp. 19-35
Author(s):  
Joan Mwihaki Nyika
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Metal Toxicity ◽  
Environmental Concern ◽  
Volume Ratio ◽  
Fungal Species ◽  
Wide Range ◽  
Bioremediation Processes

Heavy metal pollution is a growing environmental concern due to the increase in anthropogenic-based sources. Microorganisms have high adsorptive capacities and surface-area-to-volume ratio that enable the uptake of these contaminants and their conversion to innocuous complexes in the process of bioremediation. This chapter explores the mechanisms and specific microorganisms that are resistant to metal toxicity. A wide range of bacterial, algae, and fungal species used as biosorbents are highlighted. Mechanisms such as reduction of metal cations, their sequestration, and binding on cell barriers are discussed. To optimise the efficacy of microorganisms in bioremediation processes, adoption of genetic and nano-technologies is recommended.

scholarly journals Progress in Research and Application of Natural Polymer Coagulants

2020 ◽  
Vol 143 ◽  
pp. 02042
Author(s):  
Xiao Yu ◽  
Ying Fu
Keyword(s):  
Heavy Metal ◽  
Hot Spot ◽  
Development Trend ◽  
Status Quo ◽  
Dye Wastewater ◽  
Natural Polymer ◽  
Sludge Dewatering ◽  
Heavy Metal Wastewater ◽  
The Status ◽  
The Development Trend

In recent years, natural polymer coagulant has become a hot spot in the field of coagulants due to its safety, harmlessness and biodegradability. This paper introduced the status quo of research of natural polymer coagulants such as starch, chitosan, cellulose and lignin coagulants. And some hot applications in water treatment were discussed, such as heavy metal wastewater, dye wastewater, microalgae collection and sludge dewatering. Finally, the development trend of natural polymer coagulants was prospected.

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