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Результаты 121-130 из 548
Aeration, Alum, and Kaolin Ore for Nutrient and Heavy Metal Removal from Urban Wastewater for the Purpose of Reuse and Conservation
2023
Soliman, Mohamed | Rashed, Mohamed | Soltan, Mohamed
Domestic and industrial wastewater contributed to some urban wastewater, which requires specific processing before being disposed into surface waters or reused for irrigation. This paper aimed to employ kaolin as an adsorbent to remove heavy metals from wastewater, as well as aeration and alum to remove nutrients. Experiment were conducted in three parts: first, involved using the aeration method to determine the ideal amount of time to remove or minimize the nutrients. Second, involves treating the solution with potassium alum using various alum doses at the obvious times to eliminate or minimize the nutrients, while third step involves treating the solution with kaolin ore with a size of < 63 µm at various doses, pH, and contact times to remove heavy metals. The findings showed that the aeration method completely removed CO3, OH, PO4, NO3, Ca, and Mn ions after contact time equal 120, 24, 192, 24, 120, and 48 hrs, respectively. Applaying alum treatment method can remove completely CO3, OH, PO4, NO3, and Mn, after contact time 120, 24, 120, 24, and 24 hrs, respectively. When Kaolin ore used as adsorbent, the removal efficiency of Fe, Cd, Cr, Cu, Sr, Mn, and Zn were; 92, 100, 100, 100, 94, 100, and 88 % ,respectively in 24 hours contact time. The experiment succeeds in treatment of industrial wastewater that was within the range of specified limitations for disposing into surface water or reuse in irrigation field as stated by Egyptian standard code using the three successive treatment techniques.
Показать больше [+] Меньше [-]The potential of organic wastes in eliminating old-aged petroleum pollution in saline soils: A case study in Khuzestan province
2023
Jafari Vafa, Hanye | Pourbabaee, Ahmad Ali | Alikhani, Hossein Ali | Yazdanfar, Najmeh | Khanali, Majid
Petroleum contains carcinogens and toxic substances that can have an unfavorable impact on environmental quality and human health when the soil becomes contaminated with crude oil. BBiostimulation and bioaugmentation are the main strategies in the bioremediation of oil-contaminated soils. To decompose old-aged petroleum pollution in saline soil, a full factorial experiment was utilized. The experiment was designed using a completely randomized design with four factors: bacterial inoculum, sugarcane bagasse, chemical fertilizer, and molasses. The application of these factors was conducted in four separate experiments: pretreatment of agricultural soil and spent mushroom compost, pretreatment of spent mushroom compost, pretreatment of agricultural soil, and no pretreatment. After a 60-day incubation period at 28 ˚C, the results showed that the organic wastes of molasses and spent mushroom compost in combination with bacterial inoculum reduced total petroleum hydrocarbons 38 and 33.3%, respectively. Molasses had a considerable impact on increasing the efficiency of bacterial inoculum 1 and bacterial inoculum 3. Similarly, spent mushroom compost was found to significantly affect bacterial inoculum 1. In addition, bagasse was observed to accelerate the bioremediation process by improving the physical conditions of the soil. In the pretreatment of agricultural soil, bagasse in combination with bacterial inoculum 1 and chemical fertilizer reduced the total petroleum hydrocarbons significantly (38%) compared to the control treatment. These results highlight the effectiveness of organic wastes as biostimulation agents in promoting the growth and reproduction of the soil microbial community, as well as establishing the bacterial inoculum.
Показать больше [+] Меньше [-]Identification and Quantification of Antibiotic Residues and Evaluation of Microbial Resistance to Antibiotics in Huatanay River Waters in Peru
2023
Del Castillo De Loayza, Tatiana | Maldonado, Ingrid | Zirena Vilca, Franz
The Huatanay River in Cusco-Peru, is affected by wastewater discharges along its course. In order to evaluate this impact, we evaluate antibiotic residues and their impact on the increase of bacterial resistance in the city of Cusco treatment plant. For this purpose, water samples from the influent and effluent of the treatment plant were analyzed by chromatographic methods; additionally, sensitivity tests were performed with three bacterial strains (Escherichia coli, Salmonella sp., and Klebsiella sp.), which were isolated from the same place. Six antibiotic residues were identified (ceftriaxone, amoxicillin, trimethoprim, sulfamethoxazole, dicloxacillin, and lincomycin). Those found in the highest concentration were: amoxicillin (91495 and 0 µg/L) and lincomycin (33970 and 10800 µg/L) in the influent and effluent, respectively. There is more resistance in the effluent than the influent in the case of E. coli shows resistance in the effluent to cephalexin (30 µg) and azithromycin (15 µg). Salmonella sp. is resistant to amoxicillin (15 µg), dicloxacillin (1 µg), lincomycin (2 µg), ceftriaxone (30 µg), cephalexin (30 µg), and ciprofloxacin (5 µg). Finally, Klebsiella sp. is sensitive to ceftriaxone (30 µg), amoxicillin (15 µg), and cephalexin (30 µg). This confirms that the antibiotic residues contained in the wastewater of Cusco generate resistance in the isolated bacteria.
Показать больше [+] Меньше [-]Low-Cost Fluoride Adsorbent Prepared from Renewable Bio-Waste: Synthesis, Characterization and Optimization Studies
2023
Mondal, Naba Kumar | Roy, Prateeti | Sen, Kamalesh | Mondal, Arghadip | Debnath, Priyanka
Elevated level of fluoride (> 1.0 mg/L) in drinking water leads to both dental and skeletal fluorides. Present research is dedicated to check the efficacy of duck shell dust towards removal of fluoride. Various analytical tools (XRF, XRD, SEM-EDAX and zero point charge) were used to characterize the present adsorbent. The entire batch mode study results were further optimized by Response Surface Methodology (RSM). The results revealed that Langmuire isotherm is best fitted (R2 = 0.819) with adsorption capacity 4.894 mg/g. However, kinetic study suggest that the fluoride adsorption followed pseudo-second-order kinetic equation (R2 = 0.956). Similarly, thermodynamic study revealed that the fluoride adsorption by duck shell dust is endothermic and entropy driven process. Finally, optimization study demonstrated the optimized condition such as initial concentration, adsorbent dose, contact time and pH are 89.29 mg/L, 1.112 g/100 mL, 42.5 min and 9.91, respectively. Therefore, it may be concluded that duck shell dust could be a promising adsorbent for decontamination of fluoride from contaminated body.
Показать больше [+] Меньше [-]Simulating of Clogging Process in the Leachate Collection System in the Municipal Solid Waste Landfill using Column Experiments
2023
Golhosseini, Zeynab | Jalili Ghazizade, Mahdi | Safari, Edwin
Clogging of the drainage layer is the main reason for the inefficiency and failure of the leachate collection system in municipal solid waste (MSW) landfills. One of the most important challenges in the design and operation of landfills is to identify the factors affecting the drainage layer clogging and the extent of their influence especially in the real scale. In this study, five experimental columns were designed to investigate the effective factors on the clogging of the drainage system in the MSW landfills, making it possible to measure the effect of different parameters on the drainage layer clogging through simulating the real conditions. The designed columns are capable to apply the boundary conditions of the MSW landfill including temperature, pressure, and leachate recirculation as well as measuring the permeability of drainage layer. High strength real leachate recirculated in the experimental columns to monitor the degree of drainage layer clogging through the regular measurement of permeability in the different columns. The results showed hydraulic conductivity of the drainage layer decreased between 20 to 50 percent in different samples over time. Although the particle size of drainage materials directly influences the reduction of hydraulic conductivity, the common concentration of calcium carbonate in the materials of the drainage layer does not considerably affect this issue. Formation of biofilm in the drainage layer was observed through scanning electron microscope (SEM) and visual inspection in all columns indicating the proper performance of clogging process simulator which is designed and developed in this research.
Показать больше [+] Меньше [-]Evaluation of the phytotoxicity of a pesticide (TRACTOR 10E) based on Alpha-cypermethrin in two plant species: lentils (Lens culinaris) and watercress (Lepidium sativum)
2023
Ayoub, Naamane | Nawal, Lamraouhi | Soumaya, Rafii | Nadia, Iounes | Amrani Souad, El
Tractor 10E is an Alpha-cypermethrin based insecticide. It is one of the commonly used insecticides. The toxic effect of this product was assessed using the Lens culinaris (edible lentil) and Lepidium sativum (watercress) test. The seeds of Lens culinaris and Lepidium sativum were subjected to 6 increasing concentrations of Tractor 10E (25, 50, 100, 200, 400 and 800mg/l) and the control (distilled water). After 7 days, weight, root and stem development were measured.The results of the statistical study revealed the notable effect of this toxic product on growth, especially at high concentrations for the two species which are the subject of plant toxicity tests. Stem length growth is the most sensitive parameter. IC50 is equal to 136.99mg/l for lentil and 136.42mg/l for watercress. The results of this study reveal that this alpha-cypermethrin insecticide has the ability to alter the growth of plants as non-target organisms, which imposes the effective use and management of these toxicants and even replacing them with biopesticides to preserve human health and the environment.
Показать больше [+] Меньше [-]Bioaccumulation of Heavy Metals in Marcia recens, an Edible Bivalve of Ashtamudi Lake, a Ramsar Site (1204), India
2023
Narayanankutty, Parvathy | Balakrishnan Thamarakshi, Sulekha | Sasidharan, Sheeba
As a RAMSAR site (no.1204), Ashtamudi Lake has very productive and significant ecosystem services. Currently, the lake is being threatened by severe pollution stress, especially with heavy metals. Heavy metal pollution is a great concern of matter as it enters in the bioaccumulation and bio-magnification processes of the aquatic food chain. The present study seasonally investigated the bioaccumulation of seven heavy metals (Pb, Zn, Fe, Cu, Cr, Cd and Co) in the body tissues of an edible bivalve, Marcia recens, from three sampling stations (viz. Neendakara, Kureepuzha and Asramam) of the lake during the study period in 2019. The results showed that, as per the standard permissible limits (FAO/USEPA, 1989), some of the metal accumulations were extremely high in the bivalve tissues. Highest Metal Pollution Index was observed in station Ⅱ. There were significant spatial and temporal variations in the accumulation of heavy metals in the the examined bivalve. Two way ANOVA analysis also reveals a statistically significant differences (p<0.5), in the heavy metal accumulation in the bivalve, among the stations as well as seasons. The continual exposure to even a relatively low levels of these metals by regular consumption of contaminated bivalves, may entail adverse health issues. Implementation of appropriate scientific and sustainable conservation strategies will ensure the health of the estuaries and the sustainability of bio-resources.
Показать больше [+] Меньше [-]Study of Contaminants in Iranian Drinking Water and their Health Outcomes: A Review
2023
Fadaei, Abdolmajid
Contamination of ground and surface water resources with Nitrate (NO3), Fluoride (F), Trihalomethanes (THMs), radon, and heavy metals is the most important global concern due to its possible health risks to people. This study reviews the drinking water contaminants and their health outcomes examined in Iran. A review search was conducted using Scopus, Web of Knowledge, PubMed, and Embase databases for associated released articles from 2014 to 2023, resulting in 86 articles relevant to the objective of this study. According to the results of this review, different emerging contaminants were found in potable water, including THMs, NO3, F, radon and heavy elements (i.e., As, Pb, Ni, Cd, Zn, Cu, and Cr). Health outcomes of exposure to radon, F, NO3, THMs, and heavy metals in potable water have been expressed in various epidemiological research studies. More than 65% of the studies reported hazard index (HI) or hazard quotient (HQ) of heavy elements to be greater than one in potable water in Iran for infants, children, teenagers, and adults. Children and infants are at higher health risk than adults in these areas. The level of Arsenic, Cadmium, Lead, Nickel, Zinc, and Chromium, in 26, 26, 17.39, 13.04, 8.69, and 4.3% of the papers was more than the allowable limits, respectively. Various groups of emerging pollutants have been found in potable water in Iran, while epidemiological research studies on their health outcomes are still insufficient.
Показать больше [+] Меньше [-]Effect of Copper on Cadmium-Resistant Plants of Agrostis stolonifera
2023
Aleksandrovich Gladkov, Evgeny | Nikolaevna Gladkova, Olga
Environmental pollution with heavy metals has a negative impact on lawn grasses. Heavy metals are one of the priority pollutants of anthropogenic ecosystems. Earlier, plants Agrostis stolonifera, resistant to cadmium, were obtained using biotechnological method. Plants that are resistant to one heavy metal may be cross-resistant to another. The assessment of the resistance of plants obtained by biotechnological methods to other heavy metals is of practical value. The object of our study was to lawn grass - Agrostis stolonifera L. The aim of this work was to assess the tolerance of the next generation descendants of the regenerant Agrostis stolonifera, resistant to cadmium, to one of the most phytotoxic heavy metals - copper. Cadmium -tolerant plants were more resistant to copper. The tolerance of cadmium – resistant plants to copper is associated with nonspecific mechanisms. However, the increase in plant resistance was not very significant. Therefore, it is more expedient to obtain plants that are resistant to copper.
Показать больше [+] Меньше [-]Analytical Methods for Extraction, Determination and Degradation of Diazinon in Soil Samples
2023
Dehghan Abkenar, Shiva | khakipour, Nazanin | Ganjali, Mohammad Reza
Diazinon is an organophosphorus insecticide that was widely used in agriculture to control pests on crops. It acts as an acetylcholinesterase inhibitor, which means that it interferes with the normal functioning of the nervous system of insects, leading to their death. Diazinon can also have an impact on human health and the environment, as it can contaminate water and soil and pose a risk to non-target species, including humans and animals. This review paper shows the progress made in the last years in analytical methods applied for the purpose of extraction, detection and degradation of Diazinon as an important environmental pollutant. A variety of sampling and analytical methods have been developed to measure diazinon and its metabolites in different media. The most popular methods for the identification and analysis of Diazinon are liquid and gas chromatography, liquid-liquid extraction, and solid-phase extraction (SPE). The focus of this review is on the identification, measurement, and elimination of diazinon as a major soil pollutant. It begins with a discussion of analytical techniques, followed by an examination of methods for removing diazinon from soil.
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