scholarly journals Electrocoagulation: A Promising Method to Treat and Reuse Mineral Processing Wastewater with High COD

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 595 ◽  
Author(s):  
Gaogui Jing ◽  
Shuai Ren ◽  
Yuesheng Gao ◽  
Wei Sun ◽  
Zhiyong Gao
Keyword(s):  
Current Density ◽  
Water Reuse ◽  
Removal Rate ◽  
Mining Industry ◽  
Mineral Processing ◽  
Sulfide Mineral ◽  
Industrial Applications ◽  
Promising Method ◽  
Treated Wastewater ◽  
Untreated Wastewater

Mineral processing wastewater contains large amounts of reagents which can lead to severe environmental problems, such as high chemical oxygen demand (COD). Inspired by the wastewater treatment in such industries as those of textiles, food, and petrochemistry, in the present work, electrocoagulation (EC) is applied for the first time to explore its feasibility in the treatment of wastewater with an initial COD of 424.29 mg/L from a Pb/Zn sulfide mineral flotation plant and its effect on water reuse. Typical parameters, such as anode materials, current density, initial pH, and additives, were characterized to evaluate the performance of the EC method. The results showed that, under optimal conditions, i.e., iron anode, pH 7.1, electrolysis time 70 min, 19.23 mA/cm2 current density, and 4.1 g/L activated carbon, the initial COD can be reduced to 72.9 mg/L, corresponding to a removal rate of 82.8%. In addition, compared with the untreated wastewater, EC-treated wastewater was found to benefit the recovery of galena and sphalerite, with galena recovery increasing from 25.01% to 36.06% and sphalerite recovery increasing from 59.99% to 65.33%. This study confirmed that EC is a promising method for the treatment and reuse of high-COD-containing wastewater in the mining industry, and it possesses great potential for wide industrial applications.

scholarly journals Electrochemical treatment for greywater reuse: effects of cell configuration on COD reduction and disinfection byproduct formation and removal

2018 ◽  
Vol 19 (3) ◽  
pp. 891-898 ◽  
Author(s):  
Dina M. Drennan ◽  
Raji E. Koshy ◽  
David B. Gent ◽  
Charles E. Schaefer
Keyword(s):  
Current Density ◽  
Water Reuse ◽  
Energy Demand ◽  
Removal Rate ◽  
Cod Removal ◽  
Haloacetic Acids ◽  
Mixed Metal Oxide ◽  
Disinfection Byproduct ◽  
Cell Configuration ◽  
Ec Cells

Abstract Electrochemical (EC) treatment presents a low-energy, water-reuse strategy with potential application to decentralized greywater treatment. This study focused on evaluating the impacts of cell configuration, current density, and cathode material on chemical oxygen demand (COD) removal and disinfection byproduct (DBP) formation in greywater. The formation and/or cathodic removal of active chlorine, perchlorate, haloacetic acids, and trihalomethanes were assessed during EC treatment. DBP formation was proportional to current density in undivided EC cells. Sequential anodic-cathodic treatment in divided EC cells resulted in COD removal in the catholyte and anolyte. The anodic COD removal rate (using a mixed metal-oxide anode) was greater than the cathodic removal rate employing boron-doped diamond (BDD) or graphite cathodes, but anodic and cathodic COD removal was similar when a stainless-steel cathode was used. The overall energy demand required for 50% COD removal was 24% less in the divided cells using the graphite or BDD cathodes (13 W-h L−1) compared to undivided cells (20 W-h L−1). Perchlorate formation was observed in undivided experiments (>50 μg/L), but not detected in divided experiments. While haloacetic acids (HAAs) and trihalomethanes (THMs) were generated anodically; they were removed on the cathode surface in the divided cell. These results suggest that divided configurations provide potential to mitigate DBPs in water reuse applications.

scholarly journals Machine Learning Approach to Predict Quality Parameters for Bacterial Consortium-Treated Hospital Wastewater and Phytotoxicity Assessment on Radish, Cauliflower, Hot Pepper, Rice and Wheat Crops

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 116
Author(s):  
Aneeba Rashid ◽  
Safdar A. Mirza ◽  
Ciara Keating ◽  
Umer Z. Ijaz ◽  
Sikander Ali ◽  
...  
Keyword(s):  
Water Reuse ◽  
Low Cost ◽  
Treatment Method ◽  
Bacterial Consortium ◽  
Treated Wastewater ◽  
Hot Pepper ◽  
Hospital Wastewater ◽  
Untreated Wastewater ◽  
Physico Chemical ◽  
Crop Irrigation

Raw hospital wastewater is a source of excessive heavy metals and pharmaceutical pollutants. In water-stressed countries such as Pakistan, the practice of unsafe reuse by local farmers for crop irrigation is of major concern. In our previous work, we developed a low-cost bacterial consortium wastewater treatment method. Here, in a two-part study, we first aimed to find what physico-chemical parameters were the most important for differentiating consortium-treated and untreated wastewater for its safe reuse. This was achieved using a Kruskal–Wallis test on a suite of physico-chemical measurements to find those parameters which were differentially abundant between consortium-treated and untreated wastewater. The differentially abundant parameters were then input to a Random Forest classifier. The classifier showed that ‘turbidity’ was the most influential parameter for predicting biotreatment. In the second part of our study, we wanted to know if the consortium-treated wastewater was safe for crop irrigation. We therefore carried out a plant growth experiment using a range of popular crop plants in Pakistan (Radish, Cauliflower, Hot pepper, Rice and Wheat), which were grown using irrigation from consortium-treated and untreated hospital wastewater at a range of dilutions (turbidity levels) and performed a phytotoxicity assessment. Our results showed an increasing trend in germination indices and a decreasing one in phytotoxicity indices in plants after irrigation with consortium-treated hospital wastewater (at each dilution/turbidity measure). The comparative study of growth between plants showed the following trend: Cauliflower > Radish > Wheat > Rice > Hot pepper. Cauliflower was the most adaptive plant (PI: −0.28, −0.13, −0.16, −0.06) for the treated hospital wastewater, while hot pepper was susceptible for reuse; hence, we conclude that bacterial consortium-treated hospital wastewater is safe for reuse for the irrigation of cauliflower, radish, wheat and rice. We further conclude that turbidity is the most influential parameter for predicting bio-treatment efficiency prior to water reuse. This method, therefore, could represent a low-cost, low-tech and safe means for farmers to grow crops in water stressed areas.

scholarly journals Integrated System for Recycling and Treatment of Hazardous Pharmaceutical Wastewater

2021 ◽  
Author(s):  
Ashraf Moursi El-Shamy ◽  
Ibrahim Abdelfattah ◽  
Abuarab ◽  
Ehab Mostafa ◽  
El-Awady ◽  
...  
Keyword(s):  
Calcium Oxide ◽  
Water Reuse ◽  
Biological Treatment ◽  
Suspended Solids ◽  
Treatment Process ◽  
Integrated System ◽  
Treated Wastewater ◽  
Pharmaceutical Wastewater ◽  
Untreated Wastewater ◽  
Nile Water

Abstract This study aimed to investigate an integrated system that can deal with different pharmaceutical wastewater. Pharmaceutical wastewater was subjected to biological, chemical, and advanced oxidation according to its pollutant’s nature. Wastewater with high Total Suspended Solids (TSS 480 mg/l) was subjected to a conventional chemical treatment process utilizing different coagulants. The best results obtained by using Calcium Oxide and Alum aided with Calcium Oxide where, the removal efficiency of COD was 46.8% and 51 %. Highly loaded pharmaceutical wastewater (COD 9700 mg/l, BOD/COD 0.16) had been subjected to Fenton oxidation, removal of COD reached 80.4%, and the ratio of BOD/COD is enhanced to 0.6. Photocatalysis by using different nanomaterials was applied to pharmaceutical wastewater containing 10 mg/l of phenols. Phenol is completely removed by using Mesoporous TiO2 after 90 min irradiation and after 120 min in the case of TiO2/P25 and TiO2/UV 100 nanocomposites while it is removed by 40% in case of using Mesoporous TiO2/Ta2O5. Effluent treated water from previous routes was subjected to biological treatment and followed with disinfection by using UV as post-treatment. Final COD was 40 and it matches with Egyptian practice code for water reuse in agriculture. Results showed also using treated wastewater in irrigation of Barley and Bean seeds achieved germination ratio up to 71% in Barely and 70% in Bean compared with that irrigated with Nile water which reached 70% and 75%, while it was about 16.6% and 30% in case of irrigation with untreated wastewater.

Wastewater Reuse for River Recovery in Semi-Arid Israel

1999 ◽  
Vol 40 (4-5) ◽  
pp. 43-50 ◽  
Author(s):  
Marcelo Juanico ◽  
Eran Friedler
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
Water Reuse ◽  
Water Quality Management ◽  
Wastewater Reuse ◽  
Water Source ◽  
Treated Wastewater ◽  
Reclaimed Wastewater ◽  
Pollution Impacts ◽  
Semi Arid

Most of the water has been captured in the rivers of Israel and they have turned into dry river-beds which deliver only sporadic winter floods. In a semi-arid country where literally every drop of water is used, reclaimed wastewater is the most feasible water source for river recovery. Two topics are addressed in this paper: water quality management in rivers where most of the flowing water is treated wastewater, and the allocations of reclaimed wastewater required for the recovery of rivers and streams. Water quality management must consider that the main source of water to the river has a pollution loading which reduces its capability to absorb other pollution impacts. The allocation of treated wastewater for the revival of rivers may not affect negatively the water balance of the region; it may eventually improve it. An upstream bruto allocation of 122 MCM/year of wastewater for the recovery of 14 rivers in Israel may favor downstream reuse of this wastewater, resulting in a small neto allocation and in an increase of the water resources available to the country. The discharge of effluents upstream to revive the river followed by their re-capture downstream for irrigation, implies a further stage in the intensification of water reuse.

scholarly journals Towards Water and Energy Self-Sufficiency: a Closed-Loop, Solar-Driven, Low-Tech Laundry Pilot Facility (LaundReCycle) for the Reuse of Laundry Wastewater

2021 ◽  
Author(s):  
Devi Buehler ◽  
Nadine Antenen ◽  
Matthias Frei ◽  
Christoph Koller ◽  
Diederik P. L. Rousseau ◽  
...  
Keyword(s):  
Water Quality ◽  
Energy Consumption ◽  
Second Life ◽  
Removal Rate ◽  
Treated Wastewater ◽  
Water Losses ◽  
Batch Mode ◽  
Self Sufficiency ◽  
Cod Removal Rate ◽  
Photovoltaic Plant

AbstractIn the scope of this study, a pilot facility for the recycling of laundry effluent was developed and tested. With the aim to enable nearly complete energy and water self-sufficiency, the system is powered by a photovoltaic plant with second-life batteries, treats the wastewater within the unit and constantly reuses the treated wastewater for washing in a closed cycle. The technology for wastewater treatment is based on a low-tech approach consisting of a physical/mechanical pre-treatment and biological treatment in trickling filter columns. The treatment process is operated in batch mode for a capacity of five washing cycles per day. During five weeks of operation water quality, energy consumption and production, water losses and washing performance were monitored. The system recovered 69% of the used water for the washing machine while treating the wastewater to the necessary water quality levels. The average COD removal rate per cycle was 92%. Energy analysis was based on modelled data of the monitored energy consumption. With the current set-up, an internal consumption rate of 80% and self-sufficiency of 30% were modelled. Future developments aim at increasing water and energy self-sufficiency and optimizing the water treatment efficiency.

Study on the Recovery of Sulfur from Multi-Metals Tailings

2013 ◽  
Vol 734-737 ◽  
pp. 1110-1113
Author(s):  
Xiang Wen Lv ◽  
Xiong Tong ◽  
Xian Xie ◽  
Qing Hua Zhou ◽  
Yong Cheng Zhou ◽  
...  
Keyword(s):  
Experimental Research ◽  
Copper Sulfate ◽  
Mineral Processing ◽  
Sulfide Mineral ◽  
Economic Benefits ◽  
Processing Technology ◽  
Environmental Benefit ◽  
New Type ◽  
Concentrate Grade ◽  
Sulfur Containing

A beneficiation experimental research is conducted on sulfur-containing 18.17% multi-metals tailings. On the basis of the traditional mineral processing technology, it introduces X-51, a new type sulfide mineral activator, to instead of copper sulfate. Eventually, the sulfur concentrate grade is 47.51% with the recovery of 92.11%. The effectively recovery of the sulfur is creating good economic benefits and environmental benefit.

Nutrient Removal Using BauxsolTM for Treated Wastewater Reuse

2011 ◽  
Vol 695 ◽  
pp. 626-629 ◽  
Author(s):  
Jung Soo Mun ◽  
Sang Ho Lee ◽  
Jung Hun Lee ◽  
Jeong Yul Suh ◽  
Ree Ho Kim
Keyword(s):  
Water Quality ◽  
Heavy Metal ◽  
Nutrient Removal ◽  
Red Mud ◽  
Water Reuse ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Sewage Treatment Plant ◽  
Treated Wastewater ◽  
Treated Wastewater Reuse

Urban areas consume huge amounts of water and produce much wastewater, which deteriorate the aquatic environment and exhaust the country’s freshwater resources. Water reuse from sewage and wastewater is recognized as a good option for securing water. There are several kinds of processes for improving the water quality. Nutrient removal is very important for water reuse, especially in water supply for outdoor use, to prevent water quality deterioration via eutrophication. Moreover, low cost and easy maintenance should be considered for nutrient removal. In this study, red mud and BauxsolTM, a mixed mineral powder made of physicochemically modified red mud residue generated by the Bayer process for alumina refineries, was used for the removal of nitrate and heavy metals in artificial solution, and of phosphate in final effluent, from a sewage treatment plant in Dae-gu, Republic of Korea. Nitrate removal by red mud showed little efficiency while heavy metal removal showed high efficiency. The concentrations of the total phosphate in the effluent and treated water were 1.51 and 0.14 mg/L, respectively, which represent about 90.7% removal. Before and after the treatment, the pH was maintained at a neutral range of 6.5-7.2. BauxsolTM also showed a high heavy metal removal capacity. Therefore, BauxsolTM in powder and pellet form can be applied individually or mixed with soil to improve water quality for water reuse.

scholarly journals Study on the effect of electrocatalytic oxidation treatment of 2,4,6-Trinitrophenol wastewater

2018 ◽  
Vol 238 ◽  
pp. 03003
Author(s):  
Yaling Li ◽  
Wenqiang Jiang ◽  
Ruyu Li
Keyword(s):  
Current Density ◽  
Electrocatalytic Oxidation ◽  
Electrolyte Concentration ◽  
Removal Rate ◽  
Pharmaceutical Chemical ◽  
Oxidation Treatment ◽  
Titanium Electrode ◽  
First Order Kinetics ◽  
Oxidation Technology ◽  
Aromatic Nitro

2,4,6-Trinitrophenol is a toxic aromatic nitro-compounds that widely used in pharmaceutical, chemical and pesticide production. Due to its stable structure and poor biodegradability, advanced electrocatalytic oxidation technology was selected to treat simulated wastewater. The goal of the present work is to optimize the electrolysis conditions such as current density, electrolysis pH, and electrolyte concentration. A Pt modified TiO2 electrode was chosen as the anode accompanied with a titanium electrode of the same size as the cathode The results showed that the removal efficiency of 2,4,6-Trinitrophenol was the highest when the current density was 20mA/cm2, electrolyte pH=5, electrolyte concentration was 2 g/L. Under the optimal condition, the removal rate of 2,4,6-Trinitrophenol reached 99.76% after 120 minutes electrolysis. The decay of TNP could also be described by the pseudo-first-order kinetics formula with respect to TNP concentration. Therefore, electrocatalytic oxidation technology might provide an effective method for the degradation of nitroaromatic organic compounds.

Machining Feasibility of a New Developed Medium in Electrical Discharge Machining

2015 ◽  
Vol 656-657 ◽  
pp. 335-340 ◽  
Author(s):  
Fang Pin Chuang ◽  
Yan Cherng Lin ◽  
Hsin Min Lee ◽  
Han Ming Chow ◽  
A. Cheng Wang
Keyword(s):  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Environmentally Friendly ◽  
Industrial Applications ◽  
Deionized Water ◽  
Machining Parameters ◽  
Machining Performance ◽  
Machining Characteristics

The environment issue and green machining technique have been induced intensive attention in recent years. It is urgently need to develop a new kind dielectric to meet the requirements for industrial applications. The aim of this study is to develop a novel dielectric using gas media immersed in deionized water for electrical discharge machining (EDM). The developed machining medium for EDM can fulfill the environmentally friendly issue and satisfy the demand of high machining performance. The experiments were conducted by this developed medium to investigate the effects of machining parameters on machining characteristics in terms of material removal rate (MRR) and surface roughness. The developed EDM medium revealed the potential to obtain a stabilizing progress with excellent machining performance and environmentally friendly feature.

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