scholarly journals The Romanian Map of Organic Pollution from Domestic Wastewaters � Seasonal Variations of Anionic Surfactants And Organic Load (COD)

2020 ◽  
Vol 71 (4) ◽  
pp. 317-324
Author(s):  
Daniel Mitru ◽  
Gheorghe Nechifor ◽  
Stefania Gheorghe ◽  
Iuliana Paun ◽  
Lucian Ionescu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Anionic Surfactants ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Organic Pollution ◽  
Organic Load ◽  
Spatial And Temporal Variation ◽  
North West ◽  
North East

Surfactants represent the major class of chemicals used in the composition of detergents where the predominant groups are anionic surfactants. Because of the large utilization of detergents in different activities (agricultural, industrial, domestic) an important amount of surfactants can accumulate in the domestic and industrial wastewaters, that are discarded to wastewater-treatment plants (WWTP). Furthermore, surfactants could affect the process of biological wastewater treatment due the inhibition of activated sludge and subsequently the water bodies quality through discharge of WWTPs` effluents. In addition, the soil quality decreased through various modes of sludge applied. The concentrations of organic matters discharged in the wastewater systems from Romania have raised the attention of environmental authorities regarding the toxic impact of their components such as anionic surfactants on the environment. The present paper proposed to highlight the background of organic pollution from Romania through the monitoring of the organics amount in water by Chemical Oxygen Demand (COD) and by the specific indicator � Anionic Surfactants (AS). Temporal (winter, spring and summer, 2019) and spatial (six areas: West, North-West, North-East, East, South and South-West) monitoring of organic matter was performed. It has been found that the spatial and temporal variation of AS concentrations were well correlated with COD load, leading to the conclusion that surfactants represented an important part of the global organic matter.

scholarly journals Excessive greenhouse gas emissions from wastewater treatment plants by using the chemical oxygen demand standard

2021 ◽  
Author(s):  
Zongqing Lv ◽  
Xiaoyu Shan ◽  
Xilin Xiao ◽  
Ruanhong Cai ◽  
Yao Zhang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Carbon Sink ◽  
Oxygen Demand ◽  
Organic Pollution ◽  
Municipal Wastewater Treatment ◽  
Recalcitrant Organic Matter

AbstractChemical oxygen demand (COD) is widely used as an organic pollution indicator in wastewater treatment plants. Large amounts of organic matter are removed during treatment processes to meet environmental standards, and consequently, substantial greenhouse gases (GHGs) such as methane (CH4) are released. However, the COD indicator covers a great amount of refractory organic matter that is not a pollutant and could be a potential carbon sink. Here, we collected and analysed COD data from 86 worldwide municipal wastewater treatment plants (WWTPs) and applied a model published by the Intergovernmental Panel on Climate Change to estimate the emission of CH4 due to recalcitrant organic compound processing in China’s municipal wastewater treatment systems Our results showed that the average contribution of refractory COD to total COD removal was 55% in 86 WWTPs. The amount of CH4 released from the treatment of recalcitrant organic matter in 2018 could have been as high as 38.22 million tons of carbon dioxide equivalent, which amounts to the annual carbon sequestered by China’s wetlands. This suggests that the use of COD as an indicator for organic pollution is undue and needs to be revised to reduce the emission of GHG. In fact, leaving nontoxic recalcitrant organic matter in the wastewater may create a significant carbon sink and will save energy during the treatment process, aiming at carbon neutrality in the wastewater treatment industry.

scholarly journals Effect of sewage sampling frequency on determination of design parameters for municipal wastewater treatment plants

2020 ◽  
Author(s):  
T. Gehring ◽  
E. Deineko ◽  
I. Hobus ◽  
G. Kolisch ◽  
M. Lübken ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Sampling Frequency ◽  
Organic Load ◽  
Design Parameters ◽  
Data Sets ◽  
Municipal Wastewater Treatment

Abstract The uncertainty associated with the determination of load parameters, which is a key step in the design of wastewater treatment plants (WWTPs), was investigated on basis on data sets from 58 WWTPs. A further analysed aspect was the organic load variations associated with variable sewage temperatures. Data from 26 WWTPs with a high inflow sampling frequency was used to simulate scenarios to investigate the effect of lower sampling frequencies through a Monte Carlo approach. The calculation of 85-percentile values for chemical oxygen demand (COD) loadings based on only 26 samples per year is associated with a variability of up to ±18%. Approximately 90 samples per year will be necessary to reduce this uncertainty for estimation of COD loadings below 10%. Hence, a low sampling frequency can potentially lead to under- or overestimation of design parameters. Through an analogous approach, it was possible to identify uncertainties of ±11% in COD loading when weekly average data was used with 4 samples per week. Finally, a tendency of lower COD input loads with increasing temperatures was identified, with a reduction of about 1% of the average loading per degree Celsius.

Multi-stage constructed wetland systems for municipal wastewater treatment

2013 ◽  
Vol 67 (7) ◽  
pp. 1590-1598 ◽  
Author(s):  
F. Masi ◽  
S. Caffaz ◽  
A. Ghrabi
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Average Concentration ◽  
Organic Load ◽  
Municipal Wastewater Treatment ◽  
Multi Stage ◽  
Disinfection Process ◽  
Municipal Wastewater Treatment Plants

In the present paper the detailed design and performances of two municipal wastewater treatment plants, a four-stage constructed wetlands (CW) system located in the city of Dicomano (about 3,500 inhabitants) in Italy, and a three-stage CW system for the village of Chorfech (about 500 inhabitants) in Tunisia, are presented. The obtained results demonstrate that multi-stage CWs provide an excellent secondary treatment for wastewaters with variable operative conditions, reaching also an appropriate effluent quality for reuse. Dicomano CWs have shown good performances, on average 86% of removal for the Organic Load, 60% for Total Nitrogen (TN), 43% for Total Phosphorus (TP), 89% for Total Suspended Solids (TSS) and 76% for Ammonium (NH4+). Even the disinfection process has performed in a very satisfactory way, reaching up to 4–5 logs of reduction of the inlet pathogens concentration, with an Escherichia coli average concentration in the outlet often below 200 UFC/100 mL. The mean overall removal rates of the Chorfech CWs during the monitored period have been, respectively, equal to 97% for TSS and Biochemical Oxygen Demand (BOD5), 95% for Chemical Oxygen Demand (COD), 71% for TN and 82% for TP. The observed removal of E. coli by the CW system was in this case 2.5 log units.

scholarly journals Evaluación del funcionamiento de un prototipo de electrofloculación para el tratamiento de agua residual proveniente de procesos de biodigestión y biocompostaje

2019 ◽  
pp. 8-15
Author(s):  
Juan Antonio Alfonso-Alvarez ◽  
Myriam Tatiana Montaño-Soto ◽  
Bernardino Ricardo Eaton-González ◽  
Ana Karina Véliz-Zamorano
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Pathogenic Bacteria ◽  
Oxygen Demand ◽  
Fats And Oils ◽  
Fecal Coliforms ◽  
Organic Load ◽  
The Government ◽  
A Company

Introduction. In recent years, the Government of Baja California has promoted not to discharge wastewater with high content of fats and oils. A company in the region dedicated to the collection of sludge, installed a horizontal centrifugation system for the extraction of oil, generating a sludge with 5% fat and oil. The result of this process is sent to a process of biodigestion and vermicompost for the generation of solid and liquid humus, which generates wastewater with high organic load that require a treatment before disposal. Objective. Develop an experimental prototype of electroflocculation to wastewater treatment with a high content of organic matter. Methodology was divided into 4 stages: 1) Physicochemical and biological characterization of the wastewater; 2) Assembly of the electroflocculation prototype; 3) Experimental assessment 4) Verification of system operation. Contribution. Through the elaboration of the prototype, the effectiveness of the electroflocculation process was confirmed for the wastewater treatment (WT) with a high content of organic matter (OM) and pathogenic bacteria, since a greater than 50% decrease of the biochemical oxygen demand (BOD5), chemical demand of oxygen (COD), fecal coliforms and Salmonella.

scholarly journals Evaluation of Fecal Coliform Prevalence and Physicochemical Indicators in the Effluent from a Wastewater Treatment Plant in the North-West Province, South Africa

2020 ◽  
Vol 17 (17) ◽  
pp. 6381 ◽  
Author(s):  
Stenly Makuwa ◽  
Matsobane Tlou ◽  
Elvis Fosso-Kankeu ◽  
Ezekiel Green
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Microbial Pathogens ◽  
Toxic Heavy Metals ◽  
North West ◽  
The North ◽  
Regulatory Standards ◽  
Final Effluent

Compliance of the effluents from wastewater treatment plants (WWTPs) to the regulatory standards, which mostly entail the removal/reduction of organic waste and deactivation of the potential microbial pathogens is of great importance. The detection of indicator parameters can be used to determine the effectiveness of a WWTP and the level of compliance with the South African regulatory standards. The performance of the WWTP was assessed by biological, physical and chemical measures in wastewater final effluent. The Escherichia coli ranged from 0 and 2420 count/100 mL in the final effluent. The recorded values for the physicochemical parameters were within the following ranges: pH (7.03–8.49), electrical conductivity (81.63–126.5 mS/m), suspended solids (0.40–20.4 mg/L), ammonia (0–22.15 mg/L), Chemical Oxygen Demand (COD) (1–73 mg/L), nitrate (0–16.1 mg/L), ortho-phosphate (0–8.58 mg/L) and free chlorine (0–3.21 mg/L). Furthermore, the concentration of toxic heavy metals was recorded to be between 1–10 ug/L for arsenic, cadmium, lead and mercury. In conclusion, all the parameters that were evaluated in this study indicate that the studied WWTP is performing in accordance with the prescribed general limits.

Sludge minimization by disintegration at different wastewater treatment plants

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Luchien Luning ◽  
Paul Roeleveld ◽  
Victor W.M. Claessen
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
New Technologies ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Biological Degradation ◽  
Ongoing Research ◽  
Sludge Minimization

In recent years new technologies have been developed to improve the biological degradation of sewage sludge by anaerobic digestion. The paper describes the results of a demonstration of ultrasonic disintegration on the Dutch Wastewater Treatment Plant (WWTP) Land van Cuijk. The effect on the degradation of organic matter is presented, together with the effect on the dewatering characteristics. Recommendations are presented for establishing research conditions in which the effect of sludge disintegration can be determined in a more direct way that is less sensitive to changing conditions in the operation of the WWTP. These recommendations have been implemented in the ongoing research in the Netherlands supported by the National Institute for wastewater research (STOWA).

Controlling the Settling of Activated Sludge in Pulp and Paper Wastewater Treatment Plants

1999 ◽  
Vol 40 (11-12) ◽  
pp. 223-229 ◽  
Author(s):  
Frédéric Clauss ◽  
Christel Balavoine ◽  
Delphine Hélaine ◽  
Gaëtan Martin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Pulp And Paper ◽  
Organic Load ◽  
Forest Industry ◽  
Filamentous Bulking ◽  
Mineral Particles ◽  
Mineral Powder

Forest industry wastewaters are difficult to clean: hydraulic and organic load variations, filamentous bulking or pin-point flocs negatively impact depollution processes. The addition of a fine, mineral, talc-based powder, Aquatal, into the aeration tanks of wastewater treatment plants connected to pulp and paper factories has been successfully tested since end of '97. The first case-study presents full results obtained over a period of 18 months in a 20,000 p.e. plant connected to a paper factory. The mineral powder was regularly added to control sludge volume index, thereby ensuring low suspended solids concentration in the outfluent. Plant operators could easily adapt biomass concentration to match organic load variation, thereby maintaining pollution micro-organisms ratio constant. In a second case study, a trouble-shooting strategy was implemented to counteract filamentous bulking. A one-off, large dosage enabled the plant operator to deal effectively with poor settleability sludge and rapidly control sludge blanket expansion. In both cases, the main common characteristics observed were an increase in floc aggregation and the production of heavier and well-structured flocs. The sludge settling velocity increased and an efficient solid/liquid separation was obtained. After a few days, the mineral particles of Aquatal were progressively integrated into the sludge floc structure. When the mineral powder was added to the activated sludge in the aeration basin, chemical interactions frequently encountered with other wastewater treatment additives did not pose a problem. Moreover, with this mineral additive, the biological excess sludge displayed good thickening properties and dewatering was improved. Despite the addition of the insoluble mineral particles, the amount of wet sludge expelled did not increase. Aquatal offers a rapid solution to floc settleability problems which so frequently arise when physical or biological disorders appear in forest industry wastewater treatment plants.

scholarly journals The control of small and medium sized public wastewater treatment plants in the Veneto region (North Italy): general situation, critical issues and case studies

2017 ◽  
Vol 12 (4) ◽  
pp. 761-779
Author(s):  
M. Ostoich ◽  
F. Serena ◽  
A. Pozzobon ◽  
L. Tomiato
Keyword(s):  
Wastewater Treatment ◽  
Case Studies ◽  
Wastewater Treatment Plants ◽  
Waste Water Treatment ◽  
River Basin Management ◽  
Critical Parameters ◽  
Organic Load ◽  
General Situation ◽  
Veneto Region ◽  
Critical Issues

Abstract Water bodies' quality objectives are defined in accordance with the Urban Wastewater Treatment Directive 91/271/EEC and the Water Framework Directive 2000/60/EC. For regulation and control of small-sized waste-water treatment plants (WWTPs), responsibility is delegated in Italy to Regional Authorities that fix specific regulations (Water Protection Plan WPP included in the River Basin Management Plan RBMP) in collaboration with the District Authorities. Small (<2,000 population equivalent – PE) and medium sized (2,000–10,000 PE) WWTPs in the Veneto Region (North Italy) represent about 10% of the total organic load (Imhoff systems included). This also comprises some industrial discharges. Due to the urban sprawl, plants are spread over the regional territory. In the Veneto Region, data from the official census reveals there are n. 248 plants under 2,000 PE and 135 plants in 2,000–10,000 range while the total number of authorized plants is 488 for a total potentiality of 9,141,572 PE. Data from institutional controls performed by the Veneto Regional Environmental Agency (ARPAV) on WWTPs has been recovered for all the WWTPs with up to 10,000 PE in the provinces of Venice, Treviso and Vicenza (for a total of 306,118 PE and for a total of 164 plants) in the period 2008–2015 and elaborated to assess critical parameters and plants. The general situation, critical issues and case studies have been presented and discussed. Organic load, nutrients and Escherichia coli are the most critical parameters considering the regional WPP.

scholarly journals Applicability of biological wastewater treatment for various industries

2021 ◽  
Vol 941 (1) ◽  
pp. 012001
Author(s):  
Basamykina Alena ◽  
Kurkina Ekaterina ◽  
Kameristaya Maria
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Organic Matter Content ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Matter Content ◽  
Biological Wastewater Treatment ◽  
Aerobic Treatment ◽  
Total Organic Matter ◽  
Inorganic Substances

Abstract Biological treatment methods are used to remove organic and some inorganic substances from wastewater using the simplest organisms that use these substances for nutrition, breaking them down using cellular processes. The article deals with the aerobic, anaerobic and anoxic stages of biological wastewater treatment. Their differences are explained and the best way to use biological processes is analyzed according to the type of industry/production. At wastewater treatment plants, anaerobic treatment is often used at first to remove a significant part of organic substances from wastewater before sending them for further aerobic treatment. Aerobic treatment is effective for various types of wastewater, especially with lower biochemical oxygen demand (BOD) and chemical oxygen demand (COD). A comparative analysis of wastewater composition from food, oil and gas processing, pharmaceutical and pulp and paper industries was carried out. In the presence of organic compounds, the technology is chosen depending on the total organic matter content or the total COD content, which characterizes the total organic matter in water. A combination of anaerobic and aerobic methods is possible, if a discharge into the sewer system or into water bodies is required. The grounds for the application of biological wastewater treatment of these industries are given.

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