scholarly journals Penyisihan Kandungan Kromium Hexavalen (Cr6+) pada Limbah Hasil Analisis COD dengan Metoda Presipitasi oleh NaoH dan Ca(OH)2

2020 ◽  
Vol 4 (1) ◽  
pp. 9-13
Author(s):  
Fadli Mulyadi ◽  
Yulianti Pratama ◽  
Lina Apriyanti
Keyword(s):  
Water Quality ◽  
Activated Carbon ◽  
Chemical Oxygen Demand ◽  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
High Efficiency ◽  
Oxygen Demand ◽  
Demand Analysis ◽  
Carcinogenic Effect ◽  
Laboratory Waste

ABSTRAKLimbah cair laboratorium pegujian kualitas air merupakan buangan limbah yang berasal dari kegiatan pengujian kualitas air di laboratorium. Salah satu limbah cair laboratorium yang mengandung Cr6+ adalah limbah cair dari hasil pengujian COD (Chemical Oxygen Demand) yang berpotensi mencemari lingkungan karena bersifat karsinogenik. Sehingga dilakukan penelitian untuk mengetahui efisiensi penyisihan Cr6+ pada limbah cair melalui proses presipitasi dengan penggunaan bahan yang minimum dan ekonomis serta efisien. Variasi terhadap jenis dan konsentrasi presipitan yang digunakan pada penelitian ini adalah NaOH dan Ca(OH)2 dengan nilai konsentrasi 50% serta variasi pH yaitu 8; 9; 10; 11. Hasil penelitian diperoleh efisiensi penyisihan Cr6+ pada proses presipitasi sebesar 44,93% pada variasi jenis presipitan Ca(OH)2 dengan konsentrasi 50% serta pada kondisi pH 8,23.Kata kunci: Limbah COD, Kromium Heksavalen, Presipitasi, Adsorpsi, Efisiensi Penyisihan, Karbon Aktif GranularABSTRACTLiquid laboratory waste generated from water quality examination activities especially from the COD (Chemical Oxygen Demand) analysis contains Cr6+ which potentially pollute the environment due to its carcinogenic effect. The research aimed to determine the removal efficiency of Cr6+ treated by precipitation with a minimum amount of precipitate and high efficiency. In this research, variations of pH were made at constant NaOH and Ca(OH)2 concentrations of 50% while pH levels were adjusted to be 8; 9; 10; 11, respectively. Results showed that the highest Cr6+ removal of 44,93% was obtained by Ca(OH)2 50% with the pH adjusted at 8,23.Keywords: COD contained wastewater, Hexavalent Chromium, Precipitation, Adsorption, Granular Activated Carbon.

Spatio-temporal Variations in Water Quality Parameter Trends in River Waters

2018 ◽  
Vol 69 (10) ◽  
pp. 2940-2952 ◽  
Author(s):  
Martina Zelenakova ◽  
Pavol Purcz ◽  
Radu Daniel Pintilii ◽  
Peter Blistan ◽  
Petr Hlustik ◽  
...  
Keyword(s):  
Water Quality ◽  
Chemical Oxygen Demand ◽  
Quality Indicators ◽  
Water Resource Management ◽  
Oxygen Demand ◽  
Temporal Variations ◽  
Water Quality Parameter ◽  
Agricultural Activity ◽  
Water Quality Indicators ◽  
Nitrite Nitrogen

Evaluating trends in water quality indicators is a crucial issue in integrated water resource management in any country. In this study eight chemical and physical water quality indicators were analysed in seven river profiles in the River Laborec in eastern Slovakia. The analysed water quality parameters were biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), pH, temperature (t), ammonium nitrogen (NH4+-N), nitrite nitrogen (NO2--N), nitrate nitrogen (NO3--N), and total phosphorus (TP). Data from the monitored indicators were provided by the Ko�ice branch of the Slovakian Water Management Company, over a period of 15 years from 1999 to 2013. Mann�Kendall non-parametric statistical test was used for the trend analysis. Biochemical and chemical oxygen demand, ammonium and nitrite nitrogen content exhibit decreasing trends in the River Laborec. Decreasing agricultural activity in the area has had a significant impact on the trends in these parameters. However, NO2--N was the significant parameter of water quality because it mostly exceeds the limit value set in Slovak legislation, Regulation No. 269/2010 Coll. In addition, water temperature revealed an increasing trend which could be caused by global increase in air temperature. These results indicate that human activity significantly impacts the water quality.

scholarly journals Simultaneous nitrate and organic matter removal from a dairy effluent by biodenitrification

2018 ◽  
Vol 31 (2) ◽  
pp. 97-107
Author(s):  
Ahmed Hamdani ◽  
Mohammed Mountadar ◽  
Omar Assobhei
Keyword(s):  
Organic Matter ◽  
Chemical Oxygen Demand ◽  
Electron Donor ◽  
High Efficiency ◽  
Oxygen Demand ◽  
Nitrite Accumulation ◽  
Simultaneous Removal ◽  
Optimal Conditions ◽  
Dairy Effluent ◽  
Organic Removal

In order to study the simultaneous removal of nitrate and organic matter from a dairy effluent containing 670 mg∙L-1 of nitrate (NO3--N) and 5 760 mg∙L-1 of dissolved chemical oxygen demand (CODd), denitrification in a laboratory scale bioreactor consisting of an immersed bacterial bed colonized by an heterotrophic denitrifying flora (HDF) selected for NO3- reduction, COD consumption and adapted to grow on an effluent produced by a dairy industry was investigated. The obtained results indicated that at the optimal conditions of temperature (30°C), pH (7), COD/NO3--N ratio (5), the operation lasted 108h with total reduction of nitrate in 72h, no nitrite accumulation, and 92% of soluble COD removal in 96h. This indicates that the biodenitrification was accompanied with a high efficiency of matter organic removal as an electron donor, and thereby satisfies the applicable standards.

Removal of phenol from steel wastewater by combined electrocoagulation with photo-Fenton

2018 ◽  
Vol 78 (6) ◽  
pp. 1260-1267 ◽  
Author(s):  
Mohammad Malakootian ◽  
Mohammad Reza Heidari
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Current Density ◽  
Steel Industry ◽  
High Efficiency ◽  
Oxygen Demand ◽  
Optimal Conditions ◽  
Suitable Alternative ◽  
Steel Mills ◽  
Real Wastewater

Abstract Phenol and its derivatives are available in various industries such as refineries, coking plants, steel mills, drugs, pesticides, paints, plastics, explosives and herbicides industries. This substance is carcinogenic and highly toxic to humans. The purpose of the study was to investigate the removal of phenol from wastewater of the steel industry using the electrocoagulation–photo-Fenton (EC-PF) process. Phenol and chemical oxygen demand (COD) removal efficiency were investigated using the parameters pH, Fe2+/H2O2, reaction time and current density. The highest removal efficiency rates of phenol and COD were 100 and 98%, respectively, for real wastewater under optimal conditions of pH = 4, current density = 1.5 mA/cm2, Fe2+/H2O2 = 1.5 and reaction time of 25 min. Combination of the two effective methods for the removal of phenol and COD, photocatalytic electrocoagulation photo-Fenton process is a suitable alternative for the removal of organic pollutants in industry wastewater because of the low consumption of chemicals, absence of sludge and other side products, and its high efficiency.

scholarly journals Assessment of the Water Quality Characteristics of Kaduna River Receiving Wastewater Discharges

2019 ◽  
Vol 3 (1) ◽  
pp. 56-61
Author(s):  
H. Garba ◽  
C. A. Elanu
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Chemical Oxygen Demand ◽  
Biochemical Oxygen Demand ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Quality Characteristics ◽  
Chemical Characteristics ◽  
Mean Concentration ◽  
Concentration Levels

An assessment of the chemical characteristics of industrial and domestic wastewater discharges on seven parameters into Kaduna River on a bimonthly basis was carried out. PH, dissolved oxygen (DO), chloride, nitrite, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and iron were analyzed to determine their concentration levels. From the analysis, the highest mean concentration of the parameters were 8.24 of pH, 7.7 mg/l of DO, 233.4 mg/l of chloride, 55.68 mg/l of COD, 27.95 mg/l of nitrite, 122.22 mg/l of BOD, and 17.05 mg/l of iron. After comparing with prescribed standards, it can be concluded that there is evidence of organic and inorganic accumulation of contaminants into River Kaduna.

Application of Molecular Topology to the Prediction of Water Quality Indices of Alkylphenol Pollutants

2013 ◽  
pp. 1-10
Author(s):  
Jorge Gálvez ◽  
Miriam Parreño ◽  
Jordi Pla ◽  
Jaime Sanchez ◽  
María Gálvez-Llompart ◽  
...  
Keyword(s):  
Water Quality ◽  
Regression Analysis ◽  
Mathematical Models ◽  
Chemical Oxygen Demand ◽  
Cross Validation ◽  
Oxygen Demand ◽  
Molecular Topology ◽  
Quality Indices ◽  
Randomization Tests ◽  
Internal Validation

In this paper, topological-mathematical models based on multilineal regression analysis have been built as a model of the degradability of 26 alkylphenols through the Chemical Oxygen Demand (COD) and Biochemical Oxigen Demand (BOD5). Two models with three-variable were selected (r2= 0.8793 and q2=0.8075 for log(1/COD) and r2= 0.8928 and q2=0.8327 for log(1/BOD5). The models were validated by cross-validation, internal validation and randomization tests. The results, which stand in good accordance with the obtained results, confirm the robustness of the method.

scholarly journals Innovative Effluent Capture and Evacuation Device that Increases COD Removal Efficiency in Subsurface Flow Wetlands

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 418 ◽  
Author(s):  
Pedro Cisterna-Osorio ◽  
Verónica Lazcano-Castro ◽  
Gisela Silva-Vasquez ◽  
Mauricio Llanos-Baeza ◽  
Ignacio Fuentes-Ortega
Keyword(s):  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Cod Removal ◽  
Discharge Device ◽  
The Impact ◽  
Real Scale ◽  
Conventional Device

The objective of this work is to evaluate the impact of innovative modifications made to conventional effluent capture and discharge devices used in subsurface flow wetlands (SSFW). The main modifications that have been developed extend the influence of the capture and discharge device in such a way that the SSFW width and height are fully covered. This improved innovative device was applied and evaluated in two subsurface flow wetlands, one on a pilot scale and one on a real scale. To evaluate the impact of the innovative device with respect to the conventional one in the operational functioning of subsurface flow wetlands, the elimination of chemical oxygen demand (COD) was measured and compared. The results show that for the innovative device, the COD removal was 10% higher than for the conventional device, confirming the validity and effectiveness of the modifications implemented in the effluent capture and discharge devices used in SSFW.

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