scholarly journals Simultaneous adsorption behaviour of heavy metals from Oil Mill Wastewater onto natural clay

2021 ◽  
Vol 314 ◽  
pp. 08002
Author(s):  
Hanane Ait Hmeid ◽  
Mustapha Akodad ◽  
Mourad Baghour ◽  
Abdelmajid Moumen ◽  
Ali Skalli ◽  
...  

The present work reports the synergistic and inhibitory adsorption effects involved in the multicomponent adsorption of heavy metal ions (Fe (II), Pb (II)), and major elements from oil mill liquid waste (OMW) using natural bentonite as adsorbent cames from Nador (North-East Morocco). Morocco is one of the most olive oil producing Mediterranean countries. This industry, which is so beneficial to the national economy, leaves two toxic and non-biodegradable residues (liquid/solid). OMW or margin is a current liquid pollutant that has been listed by the United States Environmental Protection Agency (EPA). The classical methods used for phenol removal are expensive or limited to large-scale applications such as biological and thermal decomposition methods. The margins used in the studies were collected from a semimodern oil mill (Nador-Morocco). The results of the physicochemical analyses showed that the effluents of the oil mills showed that they are highly polluted, in particular the suspended solids, COD, and iron contents of around 154.82 (mg/l) and copper 31.72 (mg/l). Samples of OMW mixed with raw bentonites at different percentages vary between 10 % and 80 %. Different interactions between bentonite and metal ions dealing with the decrease of the concentrations. This study proves that this bentonite is an effective adsorbent for the elimination of heavy metals from OMW.

2021 ◽  
pp. 074823372110195
Author(s):  
Fatemeh Dehghani ◽  
Fariborz Omidi ◽  
Reza Ali Fallahzadeh ◽  
Bahman Pourhassan

The present work aimed to evaluate the health risks of occupational exposure to heavy metals in a steel casting unit of a steel plant. To determine occupational exposure to heavy metals, personal air samples were taken from the workers’ breathing zones using the National Institute for Occupational Safety and Health method. Noncancer and cancer risks due to the measured metals were calculated according to the United States Environmental Protection Agency procedures. The results indicated that the noncancer risks owing to occupational exposure to lead (Pb) and manganese were higher than the recommended value in most of the workstations. The estimated cancer risk of Pb was also higher than the allowable value. Moreover, the results of sensitivity analysis indicated that the concentration, inhalation rate, and exposure duration were the most influencing variables contributing to the calculated risks. It was thus concluded that the present control measures were not adequate and further improvements were required for reducing the exposure levels.


2021 ◽  
Vol 904 (1) ◽  
pp. 012009
Author(s):  
A W Abd Byty ◽  
M A Gharbi ◽  
A H Assaf

Abstract Toxic metal pollutants in groundwater should be identified to prevent future health risks. In this paper, the presence of heavy metals in groundwater in the western region of Iraq was investigated. The heavy metals concentrations, including Ni2+, Co2+, Zn2+, Pb2+, Cr3+, Cd2+, As3+ and Hg2+ were explored in twenty selected aquifers near Rutba City and the results were presented as spatial distribution maps. Findings indicate that contamination with the investigated heavy metal ions possesses a serious threat to the study area’s groundwater quality when compared to WHO and IEPA guideline values. Thus, a new approach to remove or adsorb heavy metal ions can be developed for large-scale production and the safe use of these aquifers water. Results revealed that the highest concentrations in mg/L1 of 2.312 in w19, 1.098 in w2, 5.78 in w17, 0.292 in w9, 3.349 in w5, 0.32 in w13, 0.074 in w11 and 5.622 in w1 for Zn2+, Cr3+, As3+, Pb2+, Ni2+, Co2+, Cd2+ and Hg2+ were recorded, respectively.


2019 ◽  
Vol 6 (1) ◽  
pp. 1-7
Author(s):  
Reza Shokoohi ◽  
Samira Moradi ◽  
Zhila Ghavami ◽  
Azam Nadali ◽  
Raheleh Amiri

In this study, qualitative characteristics of the sludge produced in Hamadan wastewater treatment plant and the feasibility of its application in agricultural lands were investigated. Samples were taken from the primary and secondary sludge and indices such as VS/TS, PH, TKN, COD, TKN, SOUR, Na, Ca, SAR, heavy metals and biological properties (the mean fecal coliform count and the number of parasitic eggs) were measured. The results were compared with the United States Environmental Protection Agency (US EPA) standards (40 FCR-503). The results showed that the VS/TS ratio of the raw sludge was 0.8, 0.55, and 0.55 and that of the secondary sludge was 0.65, 0.28, and 0.32 for fall, winter, and summer, respectively. The average concentration of COD, TKN, SOUR, Na, and Ca for the initial sludge was 51283, 107, 0.50, 609, and 952 and for secondary sludge, it was 35595, 81, 4.90, 306, and 493 mg/L, respectively. The MPN for primary and secondary sludge was determined to be 19.83 × 106 and 186 × 106 , respectively and the average number of parasite eggs in primary and secondary sludge was 7.05 and 7.2 in 4 g of dry solids. Entamoeba coli had the highest number of parasite. The results of this study showed that the highest concentration of heavy metals in the sludge was 21396 mg/kg. The values obtained for the above-mentioned indices and heavy metals were in standards range. The results of this study show that none of the primary and secondary sludge samples has been properly stabilized. The values obtained for biological characteristics of sludge were not in the standard range. Therefore, it was revealed that the use of sludge for agriculture needed more stabilization.


Author(s):  
Richard J. Gelting ◽  
Steven C. Chapra ◽  
Paul E. Nevin ◽  
David E. Harvey ◽  
David M. Gute

Public health has always been, and remains, an interdisciplinary field, and engineering was closely aligned with public health for many years. Indeed, the branch of engineering that has been known at various times as sanitary engineering, public health engineering, or environmental engineering was integral to the emergence of public health as a distinct discipline. However, in the United States (U.S.) during the 20th century, the academic preparation and practice of this branch of engineering became largely separated from public health. Various factors contributed to this separation, including an evolution in leadership roles within public health; increasing specialization within public health; and the emerging environmental movement, which led to the creation of the U.S. Environmental Protection Agency (EPA), with its emphasis on the natural environment. In this paper, we consider these factors in turn. We also present a case study example of public health engineering in current practice in the U.S. that has had large-scale positive health impacts through improving water and sanitation services in Native American and Alaska Native communities. We also consider briefly how to educate engineers to work in public health in the modern world, and the benefits and challenges associated with that process. We close by discussing the global implications of public health engineering and the need to re-integrate engineering into public health practice and strengthen the connection between the two fields.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 381
Author(s):  
Mayeen Uddin Khandaker ◽  
Nwokoma Oliver Chijioke ◽  
Nurul’ Adillah Binti Heffny ◽  
David A. Bradley ◽  
Abdullah Alsubaie ◽  
...  

While the consumption of seaweed and seaweed-based products is very common amongst East Asian nations, forming a notable component of the daily diet, relatively very few studies have concerned the concentrations of heavy metals in these together with potential effects on human health. The present study analyses the concentrations of 17 elements in locally resourced seaweed, also assessing potential noncarcinogenic and carcinogenic risks. The samples were ground, homogenized, and quantified using the ICP-OES technique. It has been found that the essential elements K, Ca, Mg, Zn, and Na typically show concentrations somewhat greater than a number of potentially toxic metals, in particular, Cd, Pb, Ag, and As, with exceptions being Ni, Cr-VI, and Si. Statistical analysis indicates all of the latter to have similar origin, with increased concentration of these metals within the marine ecosystem. While the daily estimated intake of most metals is seen to be within the daily dietary allowance level recommended by various international organizations, the noncarcinogenic risk shows a value greater than unity, estimated via the hazard quotient. This indicates a potential for adverse effects to health arising from consumption of the sampled seaweed. The carcinogenic risk resulting from nonessential elements shows values greater than the United States Environmental Protection Agency (US-EPA) reference limit of 10−4. Considering the nonbiodegradability of heavy metals and metalloids and their potential accumulation in seaweed, there is need for critical examination of metal levels in the seaweeds obtained from the present study locations, together with the introduction of practices of removal of heavy metals via bio-adsorbent techniques.


2020 ◽  
Vol 14 (3) ◽  
pp. 420-429
Author(s):  
Guiping Xu ◽  
Chaobing Deng ◽  
Wei Guo ◽  
Hongxiang Zhu ◽  
Xiaofei Wang ◽  
...  

Seven varieties of sugarcane were grown on soil polluted with heavy metals, including Pb, Cd, and As. Sugarcane growth, the heavy metal contents in different sugarcane tissues, and the subcellular distributions of the heavy metals in the roots and leaves were analyzed. The purpose of this investigation was to study sugarcane growth tolerance, the accumulation of heavy metals and the mechanism of sugarcane tolerance to heavy metals at the subcellular level. Health risk assessments were performed according to the models recommended by the United States Environmental Protection Agency (US EPA). The patterns of heavy metal storage were demonstrated to differ among different tissues in all sugarcane varieties investigated. Most of the heavy metals that were absorbed accumulated in the roots of the sugarcane, and the heavy metals in the root cells were mostly located in the cell wall. The health risk index was used to analyze the juice and indicated that the consumption of sugarcane juice by adults and children posed no significant health risks. This study shows that sugarcane grown on heavy metal-contaminated farmland is safe for consumption. The results of this study revealed an important and positive implication regarding the cultivation of sugarcane on farmland that is polluted by heavy metals and the potential to simultaneously achieve sustainable economic output and potential environmental restoration.


2016 ◽  
Vol 16 (2) ◽  
pp. 36-41
Author(s):  
W. K. Buah ◽  
J. R. Dankwah

A study on sorption of heavy metal ions: Lead (Pb2+), Copper (Cu2+) and Cadmium (Cd2+) from mine wastewater by activated carbons prepared from coconut husk was conducted.  The activated carbons were prepared by carbonisation of the husk at 900 ºC pyrolysis temperature, followed by steam activation of the pyrolysis derived char. Activation was also performed at 900 ºC for various durations at steam addition rate of 0.2 mol/h/g in a Gas Fired Static Bed Pyrolysis-Activation Reactor. The derived activated carbons were contacted with mine wastewater containing heavy metal ions to assess their heavy metal ions adsorption potential. The results show that the activated carbons efficiently adsorbed the heavy metal ions from solution, reducing concentrations of  Pb2+, Cu2+ and Cd2+ from 1.56 mg/L, 1.87 mg/L and 0.69 mg/L respectively to below Ghana Environmental Protection Agency (GEPA) standards of  0.10 mg/L, 1.30 mg/L and 0.03 mg/L for Pb2+, Cu2+ and Cd2+ respectively. The significances of this study are that, the conversion of the coconut husk to activated carbons provides a solution to environmental problems associated with dumping of the waste and also provides valuable products capable of reducing the effects of heavy metals in wastewater.  Keywords: Coconut Husk, Activated Carbon, Heavy Metal, Adsorption


Author(s):  
Mahdi Sadeghi ◽  
Mina Noroozi

Introduction: Contamination of water with heavy metals has turned into a health concern, particularly in the developing countries. In this study, concentration of heavy metals and associated carcinogenic and non- carcinogenic risk was investigated in water samples collected from Gonbad-e Kavus, a high-risk area for cancer. Materials and Methods: Samples were collected from Gorgan River, Golestan reservoir and wells around villages with high prevalence in 2018. Samples were analysed through inductively coupled plasma mass spectrometry. After determining the concentration of heavy metals in water samples from different sources, health risk assessment was carried out according to the Environmental Protection Agency.  Results: Arsenic in samples 6-9 was higher than 10 µg/L, calcium and magnesium in sample 5 was higher than 200 mg/L and 150 mg/L respectively, and sodium in all samples was higher than 50 mg/L.  According to the findings, these concentrations were higher than the maximum allowed limit in most water samples. Hazard quotient (HQ) in samples 8 and 9 were associated with arsenic and health risk in sample 1 was related to antimony. Furthermore, since all samples contained high amounts of lithium, water from this area better should not be consumed by children older than one year. Conclusion: Given the high rate of arsenic contamination, consumption of water in the study area could be health threatening for all individuals and is not recommended for children. This highlights the need for taking immediate actions to review the water treatment process and ensure safety of the drinking water in this area.


1993 ◽  
Vol 162 (S19) ◽  
pp. 6-6 ◽  
Author(s):  
Julian Leff

In July 1983 the Regional Medical Officer of the North East Thames Regional Health Authority (NETRHA) appeared on television to announce the closure of Claybury Hospital and much of Friern Hospital over a ten-year period.When NETRHA announced its decision, the policy to be pursued was innovative because it involved psychiatric hospitals serving inner-city populations, and because there was apparently no intention to achieve its aim by decanting patients into other psychiatric hospitals, as had been done with the closures of St Wulstan's and Banstead Hospitals. Although the run-down of psychiatric hospitals had been occurring at a steady rate in the United States and in England and Wales since the early 1950s, there had been few attempts to evaluate the policy, and none had been in any sense comprehensive (this supplement, paper 7). Clinicians and research workers in the field of social psychiatry were well aware of the need for large-scale evaluative studies, since protagonists and opponents of the policy of deinstitutionalisation were locked in a polemical argument which was pursued with increasing stridency through lack of reliable information.


2010 ◽  
Vol 55 (S18) ◽  
pp. 203-233
Author(s):  
Lucigleide Nery Nascimento ◽  
Mimi Larsen Becker

SummaryThe São Francisco River provided very obvious, close-by forms of sustenance for local communities. Beginning in the mid-1950s, the river became the place for large hydro-electric facilities, large-scale flooding, and population resettlement. A decade later, the federal government began working on pilot irrigation projects that would lead to areas described today as the Brazilian California. Hydro-power for Brazilian cities such as Recife and Salvador and irrigation for grapes and mangoes destined for the United States and Europe are among the eco-system services this river supplies. The purpose of federal policies for the north-east went beyond mitigation of the consequences of droughts, the hydraulic approach, and started to follow an economic approach based upon development; as a consequence, river and user came to be distant from one another. The two major intensive uses of the river, electricity and irrigation, threaten the long-term sustainability of this system.


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