Electrochemical treatment of chemical oxygen demand in produced water using flow-by porous graphite electrode

Onsite reuse of blackwater requires removal of considerable amounts of suspended solids and organic material in addition to inactivation of pathogens. Previously, we showed that electrochemical treatment could be used for effective pathogen inactivation in blackwater, but was inadequate to remove solids and organics to emerging industry standards. Further, we found that as solids and organics accumulate with repeated recycling, electrochemical treatment becomes less energetically sustainable. Here, we describe a pilot study in which concentrated blackwater is pretreated with ultrafiltration and granular activated carbon prior to electrochemical disinfection, and show that this combination of treatments removes 75-99% of chemical oxygen demand, 92-100% of total suspended solids, and improves the energy efficiency of electrochemical blackwater treatment by an order of magnitude.

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Degradation of distillery spent wash using monopolar parallel and monopolar series electrocoagulation process

Applied Research and Smart Technology (ARSTech) ◽

10.23917/arstech.v2i1.306 ◽

2021 ◽

Vol 2 (1) ◽

pp. 8-17

Author(s):

Sukanya Pujari ◽

Manoj Wagh ◽

Shila Dare

Keyword(s):

Chemical Oxygen Demand ◽

Waste Treatment ◽

Removal Rate ◽

Oxygen Demand ◽

Cost Effective ◽

Electrochemical Treatment ◽

Cod Removal ◽

Spent Wash ◽

Distillery Spent Wash ◽

The Impact

In waste treatment and water management issues, electrocoagulation (EC) is the most cost-effective and environmentally friendly option. In the study, EC treatment of distillery spent wash was carried out using new electrodes packed with aluminium foil scraps. These metal scraps were packed in a mesh to function as anode and cathode electrodes. Electrochemical treatment was carried out for 150 minutes, and samples were analysed regularly to determine the colour and chemical oxygen demand (COD). The impact of operating parameters such as pH, applied current, electrolysis time, agitation speed, and electrode distance on colour and COD removal was investigated. The EC processes were carried out in monopolar parallel (MP-P) and monopolar series (MP-S). The MP-S connection measured the potential difference between the amplified pair of electrodes, whereas the output signals in the MP-P connection were formed by several input electrodes, resulting in a high removal rate. The results indicated that the MP-P relationships enhance the COD removal rate by 4.16 to 8.06 %. An optimum chemical oxygen demand degradation is 77.29 % at pH 3, and decolourisation is 76.55 % at pH 8.3. TDS is reduced to a maximum of 58.32 %, while sulfate and chloride are reduced to 64.72 and 20.44 %, respectively.

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Optimization of process parameters for the electrochemical oxidation treatment of petroleum refinery wastewater using porous graphite anode

Al-Qadisiyah Journal for Engineering Sciences ◽

10.30772/qjes.v13i2.652 ◽

2020 ◽

Vol 13 (2) ◽

pp. 125-135

Author(s):

Ahmad Salah Fahim ◽

Ali H. Abbar

Keyword(s):

Removal Efficiency ◽

Current Density ◽

Petroleum Refinery ◽

Oxygen Demand ◽

Chloride Ion ◽

Electrochemical Reactor ◽

Electrochemical Treatment ◽

Operating Conditions ◽

Graphite Anode ◽

Porous Graphite

The present paper deals with the electrochemical treatment of wastewaters generated from Al-Diwaniyah petroleum refinery plant in a batch electrochemical reactor using stainless steel cathode and porous graphite anode. Effects of operating parameters such as current density (5-25mA/cm2), pH (3-9), addition of NaCl (0-2g/l), and time (20–60min) on the removal efficiency of chemical oxygen demand (COD) were investigated. The results revealed that both pH and NaCl addition have the main effect on the COD removal efficiency confirming that the system was governed by reaction conditions in the bulk of solution not upon the electro oxidation of chloride ion on the surface of the electrode. Parametric optimization was carried out using Response Surface Methodology (RSM) combined with Box–Behnken Design (BBD) to maximize the removal of COD. Under optimized operating conditions of initial pH: 3, current density = 25 mA/cm2, NaCl conc. = 2g/l, and time = 60 min, the removal efficiency of COD was found to be 98.16% with energy consumption of 9.85 kWh/kgCOD which is relatively lower than the previous works.

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Interaction Effect of Process Variables on Solar-Assisted Photocatalytic Phenol Degradation in Oilfield Produced Water Over ZnO/Fe2O3 Nanocomposites

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences ◽

10.37934/arfmts.78.1.100121 ◽

2020 ◽

Vol 78 (1) ◽

pp. 100-121

Author(s):

Omer Al Haiqi ◽

Abdurahman Hamid Nour ◽

Bamidele Victor Ayodele ◽

Rushdi Bargaa

Keyword(s):

Chemical Oxygen Demand ◽

Interaction Effect ◽

Produced Water ◽

Irradiation Time ◽

Phenol Degradation ◽

Oxygen Demand ◽

P Value ◽

Phenol Removal ◽

Process Variables ◽

Oilfield Produced Water

This study investigates the interaction effects of process variables on photocatalytic phenol degradation in oil produce water. A series of ZnO/Fe2O3 nanocomposite prepared using the sol-gel method and calcined at a temperature range of 400-600 oC were employed as photocatalysts. The characterization analysis using different instrument techniques revealed that the ZnO/Fe2O3 nanocomposites have suitable physicochemical properties as photocatalysts. The photocatalytic activity of the ZnO/Fe2O3 nanocomposite was examined in photo-reactor considering the degradation of the phenol and the reduction in chemical oxygen demand (COD) in the oilfield produced water under direct sunlight. It was ascertained that process variables such as irradiation time, calcination temperature of the ZnO/Fe2O3 nanocomposites, and the ZnO/Fe2O3 nanocomposites concentration significantly influenced the chemical oxygen demand and phenol removal. Based on the analysis of variance (ANOVA), the effects of the process variables on the phenol and COD removal can be ranked as irradiation time (p-value < 0.0001) > calcination temperature of the ZnO/Fe2O3 nanocomposite (p-value = 0.0003) > ZnO/Fe2O3 concentration (p-value = 0.0013). The interaction between the parameters was observed to have a substantial effect on COD and phenol removal. However, the interaction effect that produced the most significant influence on the COD and phenol removal was recorded between the irradiation time and the ZnO/Fe2O3 nanocomposite concentration.

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Analysis of chemical compositions contributable to chemical oxygen demand (COD) of oilfield produced water

Chemosphere ◽

10.1016/j.chemosphere.2005.04.033 ◽

2006 ◽

Vol 62 (2) ◽

pp. 322-331 ◽

Cited By ~ 43

Author(s):

Jinren Lu ◽

Xiulin Wang ◽

Baotian Shan ◽

Ximing Li ◽

Weidong Wang

Keyword(s):

Chemical Oxygen Demand ◽

Produced Water ◽

Oxygen Demand ◽

Chemical Compositions ◽

Oilfield Produced Water

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Boehmite nanopowder recovered from aluminum cans waste as a potential adsorbent for the treatment of oilfield produced water

Applied Petrochemical Research ◽

10.1007/s13203-021-00267-x ◽

2021 ◽

Author(s):

Adel Abdelkader ◽

Basem M. Hussien ◽

Eman M. Fawzy ◽

Asma A. Ibrahim

Keyword(s):

Activated Carbon ◽

Chemical Oxygen Demand ◽

Produced Water ◽

Treatment Time ◽

High Surface ◽

Oxygen Demand ◽

Good Efficiency ◽

Pollution Indicator ◽

Oilfield Produced Water ◽

Aluminum Cans

AbstractIn the present study, high surface area boehmite nanopowder was recovered from aluminum cans waste. The sodium aluminate solution was first prepared by dissolving aluminum cans in NaOH solution and then, H2O2 solution was added to precipitate boehmite. The prepared boehmite was characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption–desorption techniques. The thermal stability of the boehmite sample was investigated using thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques. The feasibility of using the prepared boehmite powder as a new low-cost adsorbent for the treatment of oilfield produced water was investigated. For comparison, commercial activated carbon was used for the treatment of the produced water under the same conditions. The efficiency of both of boehmite and activated carbon in the treatment of produced water was determined by monitoring the values of a number of pollution indicators [i.e. turbidity, sulfides, sulfates, total organic carbon (TOC), total petroleum hydrocarbon (TPH), and chemical oxygen demand (COD)] before and after the treatment. The boehmite powder showed very good efficiency in the treatment of the produced water, which is very close to that of commercial activated carbon under the same conditions. The effect of adsorbent dose, treatment time, and pH of the media on the adsorption efficiency of both of boehmite and activated carbon was examined at room temperature using chemical oxygen demand as a pollution indicator. The maximum capacity for COD reduction was 69.6% for boehmite and 83.5% for activated carbon at 40 g/l adsorbent dosage, pH7, and 24-h contact time. Graphic abstract

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