scholarly journals PREDICTING USEFUL LIFE OF COCOPEAT IN A FILTER BED TREATING WASTEWATER WITH HEAVY METALS USING HYDRUS-1D

2019 ◽  
Vol 9 (2) ◽  
pp. 44-56
Author(s):  
Jessie Samaniego ◽  
Maria Antonia Tanchuling
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Ball Mill ◽  
Remaining Useful Life ◽  
Small Scale ◽  
Solute Transport Modeling ◽  
Useful Life ◽  
Filter Bed ◽  
Experimental Runs ◽  
Hydrus 1D

The effectiveness of cocopeat as an adsorbent for the treatment of wastewater containing heavy metals was reported in previous studies. In this study, cocopeat was used as an adsorbent in a filter bed system treating wastewater from a small scale gold mining (SSGM) ball mill facility. A total of 6,000 L of actual SSGM wastewater collected from a ball mill facility in Paracale, Camarines Norte were used in the experimental runs. The filter bed was evaluated by determining its heavy metal removal efficiencies for 50 days at a flow rate of 40 L/hr. After the experimental runs, HYDRUS1D was used to simulate the transport of lead (Pb) in the filter bed and predict the remaining useful life of cocopeat as a heavy metal adsorbent. Lead was selected for the solute transport modeling in HYDRUS-1D since Pb was the highest concentration in the wastewater and also exceeded the government effluent limit. Measured data from the experimental runs and water flow parameters of cocopeat were used as input values in the simulation with varying cocopeat thickness and initial concentration flux. Results showed that by increasing the thickness of the cocopeat layer, the useful life of cocopeat in the filter bed was extended. By using the actual concentration of Pb (0.0933 mg/L) in the wastewater, HYDRUS-1D was able to simulate Pb transport in the filter and predict that the useful life of cocopeat 50 cm thick treating an actual SSGM wastewater was 2.74 years.

scholarly journals Heavy Metals in the Soils of Placer Small-Scale Gold Mining Sites in Myanmar

2020 ◽  
Vol 10 (27) ◽  
pp. 200911
Author(s):  
Aung Zaw Tun ◽  
Pokkate Wongsasuluk ◽  
Wattasit Siriwong
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Gold Mining ◽  
Soil Samples ◽  
Small Scale ◽  
Mining Activities ◽  
Mining Operations ◽  
Metal Concentrations ◽  
Mining Sites ◽  
Heavy Metal Concentrations

Background. Artisanal and small-scale mining activities are widely practiced globally. Concentrations of heavy metals associated with gold, such as copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) can increase in the environment as a result of mining activities, leading to environmental pollution and pose toxicity risks to humans and animals. Objectives. The aim of the present study was to investigate soil concentrations of toxic heavy metals in placer small-scale gold mining operations in Myanmar. Methods. Soil samples were collected from three placer small-scale gold mining sites: Site A located in the Hmawbon public protected forest, Site B and Site C, situated in the Nant-Kyin reserved forest around Nar Nant Htun village. At each site, soil samples were collected from four gold mining stages (ore processing, sluicing, panning, and amalgamation). Atomic absorption spectroscopy was utilized to examine the concentrations of As, Cd, Pb, and Hg. Results. The highest heavy metal concentrations were generally found in the amalgamation stages across all the gold mining sites. Across the three mining sites, the maximum heavy metal concentrations in the amalgamation stage were 22.170 mg.kg−1 for As, 3.070 mg.kg−1 for Cd, 77.440 mg.kg−1 for Hg, and 210.000 mg.kg−1 for Pb. Conclusions. The present study examined the concentrations of As, Cd, Hg and Pb in the soil of several small-scale gold mining sites in Banmauk Township, Myanmar. The results demonstrated the presence of high concentrations of heavy metals in the soil of the gold mining sites. Miners in this area work without proper personal protective equipment, and frequent exposure to heavy metals in the soil may cause adverse health effects. The present study provides baseline data for future risk assessment studies of heavy metal contamination in gold mines. Competing Interests. The authors declare no competing financial interests

scholarly journals Bioaccumulation of heavy metals in the black soldier fly, Hermetia illucens and effects on its life cycle

2015 ◽  
Vol 1 (4) ◽  
pp. 261-270 ◽  
Author(s):  
S. Diener ◽  
C. Zurbrügg ◽  
K. Tockner
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Life Cycle ◽  
Metal Concentration ◽  
Organic Waste ◽  
The Body ◽  
Small Scale ◽  
Black Soldier Fly ◽  
Hermetia Illucens ◽  
Collection Costs

In developing countries, effective waste management strategies are constrained by high collection costs and lack of adequate treatment and disposal options. The organic fraction in particular, which accounts for more than 50% of the waste production, constitutes a great, yet mostly neglected, reuse potential. Concomitantly, the demand for alternative protein sources by the livestock feed industry is sharply increasing. A technology that effectively transforms organic waste into valuable feed is therefore a timely option. Larvae of the non-pest black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae), may be used to reduce the mass of organic waste significantly. Concurrently, larval feeding converts organic waste into prepupae (last larval stage) which is high in protein. In combination with a viable market, this potential animal feed may cover the waste collection costs and thus promote innovative, small-scale entrepreneurs to establish a profitable business niche. Organic waste, however, often contains persistent pollutants, such as heavy metals, that may accumulate in the larvae and prepupae of black soldier flies and consequently in the food chain. In this study, we fed black soldier fly larvae chicken feed spiked with heavy metals (cadmium, lead and zinc at three concentrations each) to examine the extent of metal accumulation in the different life stages and the effect of heavy metal concentration in the feed on the life cycle determinants of the flies. The cadmium accumulation factor in prepupae (metal concentration in the body divided by metal concentration in the food) ranged between 2.32 and 2.94; however, the lead concentration remained well below its initial concentration in the feed. The bioaccumulation factor of zinc in prepupae decreased with increasing zinc concentration in the feed (from 0.97 to 0.39). None of the three heavy metal elements had significant effects on the life cycle determinants (prepupal weight, development time, sex ratio).

scholarly journals Effective Removal of Cr(VI) from Wastewater Using Biochar Derived from Walnut Shell

2021 ◽  
Vol 18 (18) ◽  
pp. 9670
Author(s):  
Tanzeela Kokab ◽  
Hafiza Sumbal Ashraf ◽  
Muhammad Bilal Shakoor ◽  
Asim Jilani ◽  
Sajid Rashid Ahmad ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Large Scale ◽  
Walnut Shell ◽  
Small Scale ◽  
Toxic Heavy Metal ◽  
Modern Age ◽  
Effective Removal ◽  
Scale Levels ◽  
High Concentrations

Heavy metals are the major concern of the modern age. Among the heavy metals, chromium (Cr(VI)) is regarded as a highly toxic heavy metal released largely from leather tanning operations. To remove such high concentrations of Cr(VI), an advanced method is required urgently. Thus, biosorption using biochar, which is an organic material produced from various sources such as walnut shell, can be applied successfully for Cr(VI) abatement. The major objectives of this experiment were the remediation of the Cr(VI) heavy metal using walnut shell biochar and checking of the effect of pH, biochar dosage, Cr level, and shaking time. Remediation of Cr(VI) using walnut shell biochar was proved to be effective and removed the maximum concentration of Cr(VI) up to 93% at pH 5.5, 2 h agitation time, and the biochar amount of 1.1 g L−1 from an aqueous solution. Equilibrium modeling demonstrated that the chemisorption process was involved in adsorption of Cr(VI). The surface of the biochar was porous and provided numerous sites for Cr(VI) attachment, which was also confirmed by the presence of Cr(VI) onto the biochar after adsorption. Hence, the use of walnut shell biochar was highly effective as a sorbent, which could conveniently be applied to small-scale as well as large-scale levels.

scholarly journals Small scale photo bioreactor treatment of tannery wastewater, heavy metal biosorption and CO2 sequestration using microalga Chlorella sp.: a biodegradation approach

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
A. M. Rajalakshmi ◽  
T. Silambarasan ◽  
R. Dhandapani
Keyword(s):  
Waste Water ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Tamil Nadu ◽  
Waste Water Treatment ◽  
Small Scale ◽  
Infrared Analysis ◽  
Tannery Effluent ◽  
Metal Biosorption ◽  
Photo Bioreactor

AbstractRecently, mass production of lipid along with heavy metal reduction is gaining momentum due to their cost-effective and greener approach towards waste water treatment. The purpose of this study is to investigate the small scale photo bioreactor treatment of tannery effluent using Chlorella sp. isolated form Yercaud lake, Tamil Nadu, India. The results showed a significant decrease in the heavy metals content in the tannery effluent after the treatment. Maximum reduction of the heavy metal Chromium (Cr) of 10.92 mg L−1 was recorded, followed by Cobalt (Co)-7.37 mg L−1, Nickel (Ni)-9.15 mg L−1, Cadmium (Cd)-8.48 mg L−1, Lead (Pb)-12.54 mg L−1, Zinc (Zn)-11.56 mg L−1 and Copper (Cu)-10.71 mg L−1 at the end of the 20th day of treatment. The microalgae, Chlorella sp. was analyzed for their biosorption ability and the maximum biosorption capacity (qmax) rate against heavy metals was 81.36, 70.53, 82.15, 63.29, 58.92, 83.43, 64.83 µg L−1 for Cr, Pb, Ni, Cd, Co, Zn, and Cu respectively. It matched with the Langmuir and Freundlich kinetics models. The maximum CO2 utilization was found to be 60.50% and maximum concentration of lipid, carbohydrate and protein was found to be 0.95 g L−1, 250 µg mL−1 and 160 µg mL−1, respectively. The presence of various groups such as hydroxyl, alkyl, carbonyl and carboxylic acids was confirmed using Fourier transform infrared analysis. Thus, the isolated microalgae showed good biosorption ability towards the various heavy metal pollutants from tannery waste water.

scholarly journals Heavy Metals Accumulation in Surface Waters, Bottom Sediments and Aquatic Organisms in Lake Mainit, Philippines

2020 ◽  
Vol 79 ◽  
pp. 40-49
Author(s):  
Emalina L. Ebol ◽  
Carlos H. Donoso ◽  
Rex Bombet D. Saura ◽  
Rolit Joan C. Ferol ◽  
Juliet Ruth D. Mozar ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Aquatic Organisms ◽  
Speciation Analysis ◽  
The Philippines ◽  
Small Scale ◽  
Safe Limits ◽  
Trace Concentrations ◽  
Metal Monitoring

Lake Mainit is one of the largest lakes recognized as Key Biodiversity Areas (KBA) in the Philippines with rich fishery resources. However, the lake is at risk from heavy metal contamination due to inputs of industrial, agricultural effluents and small-scale mining activities. The present work evaluated levels of heavy metals namely cadmium, lead, and mercury from key aquatic fauna and sediments from seven strategic sections of the lake in 2018. Muscle samples of all seven fish species assessed were below detections limits (BDL) for tHg and Cd. Trace concentrations of Pb in the muscles were detected in Oreochromis niloticus, Glossogobius giuris, Channa striata and Vivipara angularis but values were within safe ranges. Trace concentrations of Pb in the riverine crab (Sundathelpusa sp) exceeded safe limits. Both Cd and tHg were below detection limits in the three invertebrates assessed. Traces of Pb were detected in S4 (Magtiaco) and S5 (Jaliobong) below standard limits (0.05 ppm) only during the southwest (SW) monsoon but Pb were not detected across all stations during the NE monsoon of 2018. For Cd, however, trace concentrations were detected only during the NE monsoon wherein Cd in S2 (Mayag), S3 (Magpayang), S4 (Magtiaco), S5 (Jaliobong), S6 (Dinarawan) and S7 (Kalinawan) exceeded standard limits for Cd in waters (0.01 ppm). Concentrations of tHg in the water were not detected across the two sampling seasons in all seven tributary stations. In sediments, Pb were all detected during the southwest monsoon with highest Pb concentrations in S6 (Dinarawan) and S7 (Kalinawan) which exceeded safe limits. Trace Cd in sediments were mostly below detectable limits. Concentrations of tHg in sediments exceeded safe limits during the SE monsoon in S4 (Magtiaco) and S7 (Kalinawan) areas. These findings recommended that continuous heavy metal monitoring must be conducted. It is also strongly suggested to evaluate the presence of heavy metals in other aquatic organisms and assess the ecological risk posed by these heavy metals though heavy metal speciation analysis.

scholarly journals Determination of the Heavy Metal Contents and the Benefit/Cost Analysis of Hypericum salsugineum in the Vicinity of Salt Lake

2021 ◽  
Vol 50 (12) ◽  
pp. 3493-3503
Author(s):  
Aynur Demir ◽  
Gökçen Baysal Furtana ◽  
Mehtap Tekşen ◽  
Rukiye Tipirdamaz
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Salt Lake ◽  
Benefit Cost Analysis ◽  
Metal Contents ◽  
Copper Zinc ◽  
Useful Life ◽  
Benefit Cost ◽  
Potential Use

In this study, Hypericum salsugineum, an endemic halophytic plant growing around Salt Lake, was analyzed to determine the heavy metals (chromium, lead, copper, zinc and nickel) on it and on the soil it grew. The phytoremediation potential of H. salsugineum was evaluated. In addition, the benefit cost (B/C) analysis was performed for its potential use in phytoremediation. The plant and soil samples were collected from Eskil and Cihanbeyli between May and September in 2016. A total of 300 soil and plant samples were analysed for heavy metal content. Statistical and standard benefit/cost analyses were performed for assessment. The capacity of accumulating the aforementioned heavy metals was found to be high in H. salsugineum. It was found that Ni and Pb ratio exceeded optimum values in its habitat, and H. salsugineum accumulated available Ni and Pb. When the plant was evaluated in terms of benefit/cost, B/C ratio was greater than 1 during the useful life of the study. This conclusion increases the ecological and economical values of H. Salsugineum, effecting its potential use in phytoremediation.

Dynamic Modeling and Wear-Based Remaining Useful Life Prediction of High Power Clutch Systems

2005 ◽  
Vol 48 (2) ◽  
pp. 208-217 ◽  
Author(s):  
Matthew Watson ◽  
Carl Byington ◽  
Douglas Edwards ◽  
Sanket Amin
Keyword(s):  
Dynamic Modeling ◽  
High Power ◽  
Life Prediction ◽  
Remaining Useful Life ◽  
Useful Life

INFLUENCE OF THE ECOLOGICAL STATE OF THE SEREPOK RIVER (VIETNAM) ON ACCUMULATION OF HEAVY METALS IN ORGANS OF FISH

2017 ◽  
pp. 98-105
Author(s):  
Ngo The Cuong ◽  
Tran Hoan Quoc ◽  
Svetlana Vasilievna Zolotokopova
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
River Water ◽  
Bottom Sediments ◽  
Heavy Metal Concentration ◽  
Industrial Areas ◽  
Industrial Regions ◽  
Cadmium Lead ◽  
Sarotherodon Galilaeus ◽  
Water Bottom

The article focuses on the study of change of containing heavy metals (zinc, copper, iron, cadmium, lead, arsenic) in the abiotic and biotic components of the Serepok river (Vietman) influenced by wastewater discharge from industrial areas. Heavy metal content was determined in the river water and bottom sediments in the four zones: above and within the boundaries of industrial regions Xoa Phu and Tam Thang and in two water reservoirs situated below the boundaries of those industrial areas. Tilapia Galilean ( Sarotherodon galilaeus ), Hemibagrus ( Hemibagrus ), and sazan ( Cyprinus carpio ) caught in these areas were the hydrobionts under study in which liver, gills, skeleton and muscles accumulation of heavy metals was detected. In the organs of fish caught in the river within industrial region, heavy metals concentration was 3-7 times higher. The greatest concentration of heavy metals was found in the liver and gills of fish caught in the boundaries of industrial regions, the least concentration was in the muscles. In most cases, significant correlation between heavy metal concentration in organs of fishes and in river water, bottom sediments has been revealed.

Using A Segmented Voltage Sweep Mode and A Gaussian Curve Fitting Method to Improve Heavy Metal Measurement System Performance

2012 ◽  
Vol 19 (2) ◽  
pp. 381-394
Author(s):  
José Pereira ◽  
Octavian Postolache ◽  
Pedro Girão
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Measurement System ◽  
Curve Fitting ◽  
System Performance ◽  
Redox Potentials ◽  
Voltage Sweep ◽  
Gaussian Curve ◽  
Fitting Method ◽  
Curve Fitting Method

Using A Segmented Voltage Sweep Mode and A Gaussian Curve Fitting Method to Improve Heavy Metal Measurement System PerformanceThis paper presents a voltammetric segmented voltage sweep mode that can be used to identify and measure heavy metals' concentrations. The proposed sweep mode covers a set of voltage ranges that are centered around the redox potentials of the metals that are under analysis. The heavy metal measurement system can take advantage of the historical database of measurements to identify the metals with higher concentrations in a given geographical area, and perform a segmented sweep around predefined voltage ranges or, alternatively, the system can perform a fast linear voltage sweep to identify the voltammetric current peaks and then perform a segmented voltage sweep around the set of voltages that are associated with the voltammetric current peaks. The paper also includes the presentation of two auto-calibration modes that can be used to improve system's reliability and proposes the usage of a Gaussian curve fitting of voltammetric data to identify heavy metals and to evaluate their concentrations. Several simulation and experimental results, that validate the theoretical expectations, are also presented in the paper.

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