scholarly journals New Approach in COD Fractionation Methods

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1484 ◽  
Author(s):  
Ewelina Płuciennik-Koropczuk ◽  
Sylwia Myszograj
Keyword(s):  
Degradation Rate ◽  
Oxygen Demand ◽  
Quality Parameters ◽  
Treated Wastewater ◽  
Detailed Knowledge ◽  
New Approach ◽  
High Compliance ◽  
The Difference ◽  
Biochemical Degradation ◽  
Raw Wastewater

Conventional quality parameters such as Chemical Oxygen Demand (COD) or Biochemical Oxygen Demand (BOD) give information about the quantity of organic matter present in wastewater, but do not give a clear indication of the biodegradability of the pollutants flowing in the WWTP. Detailed knowledge can be obtained by dividing the total COD into fractions. Fractionation and balancing of COD can be determined in various ways and with varying accuracy. Good wastewater characteristics are obtained on the basis of COD fractionation in accordance with ATV-A 131 guidelines, especially when the wastewater characteristics are in high compliance with the assumptions of the method. The article proposes a modification of the ATV-A131 method that increases the accuracy of determining the COD fraction. In order to reduce errors in the calculation of COD fractions, the value of fraction XS was calculated on the basis of the biochemical degradation rate determined in studies (k) for raw wastewater, whereas the SI fraction was calculated from the difference between SCOD and BODTot of filtered treated wastewater. BODTot of the treated wastewater was calculated taking into account the rate of biochemical degradation determined in the studies (k) for treated wastewater. The shares of individual COD fractions in raw wastewater calculated on the basis of the standard and modified procedure differed by approx. 10% in the case of suspension fractions. Modification of the methodology to determine the COD of the treated wastewater SS fraction significantly influenced the contents of all fractions in treated wastewater.

scholarly journals A new approach for the removal of unfixed dyes from reactive dyed cotton by Fenton oxidation

2019 ◽  
Vol 9 (2) ◽  
pp. 133-141
Author(s):  
Sana Islam ◽  
Irfan Ahmed Shaikh ◽  
Nabeela Firdous ◽  
Azhar Ali ◽  
Yumna Sadef
Keyword(s):  
Treatment Time ◽  
Color Difference ◽  
Quality Parameters ◽  
Water Levels ◽  
Fenton Oxidation ◽  
Color Strength ◽  
New Approach ◽  
Reactive Dyeing ◽  
The Difference ◽  
Day By Day

Abstract The use of fresh water in the textile wash-off process is becoming more expensive day by day due to declining water levels in the region. In this study, the potential of using Fenton oxidation in wash-off cotton reactive dyeing was investigated. The spent wash-off wastewater from one dyeing was first treated with Fenton oxidation, and then reused in several washing-offs employing widely used reactive dyes, C.I. Reactive Yellow 145, C.I. Reactive Blue 21, and C.I. Reactive Red 195. Experimental results showed that at acidic pH (3) using optimized quantities of FeSO4 and H2O2, Fenton process yielded a significant reduction (90–95%) of color in 30 minutes of treatment time. New washing-offs were then carried out in Fenton decolorized wash-off wastewater, and dyed cotton fabric samples were subjected to quality evaluations in terms of color difference properties (ΔL*, Δc*,Δb*, Δa*, ΔE*cmc) and wash fastness properties. This study concluded that after Fenton oxidation, treated liquor can be effectively reused subsequent washing-offs without compromising fabric quality parameters as ΔE*cmc was less than 1, and washing and crocking was also in the range of 4.5–5 which is commercially acceptable. Moreover, the difference in color strength in terms of k/s was also negligible.

scholarly journals Suitability of reclaimed wastewater effluent from decentralized wastewater plant for irrigation

2021 ◽  
Vol 11 (11) ◽  
Author(s):  
Nour Al Hadidi ◽  
Majeda Al Hadidi
Keyword(s):  
Water Quality ◽  
Oxygen Demand ◽  
Cost Effective ◽  
Sodium Content ◽  
Quality Parameters ◽  
Treated Wastewater ◽  
Moderate Degree ◽  
Reclaimed Wastewater ◽  
Study Results ◽  
Quality Guideline

AbstractDecentralized wastewater plants have been proven to be cost-effective, easy to construct and operate and widely used in small ruler communities. The suitability of reclaimed wastewater for irrigation purpose was evaluated in this study based on the various water quality parameters, international water quality standards and water–irrigation water quality guideline (JS 1766). Twenty-seven samples were collected from a decentralized wastewater plant that is located in Balqa Governorate in Salt city, Jordan. Samples were analyzed for pH, electrical conductivity, major anions and cations, as well as biological oxygen demand, chemical oxygen demand and total suspended solids. Study results show that water is slightly alkaline in nature. According to Jordanian domestic reclaimed wastewater standard, the use of water for irrigation has a mild-to-moderate degree of restriction. Using the US Salinity Laboratory classification scheme, there is high salinity and medium sodium water, 50% of samples falls in the area of (C3-S2) and this water is suitable for irrigation for many types of soil with low risk of increasing exchangeable sodium content. According to chloride hazards, the water for irrigation can be used for moderately tolerant plants. 74% of the samples have the residual sodium carbonate (RSC) less than 1.25 meq/L and hence suitable for irrigation. The study recommends that treated wastewater from decentralized wastewater a plant is considered as non-conventional source for irrigation.

scholarly journals Application of activated effective microorganism, mudball and biosand filter for the treatment of dye wastewater

2021 ◽  
Vol 9 (1) ◽  
pp. 41-48
Author(s):  
Anisha Maharjan ◽  
Anish Ghimire
Keyword(s):  
Retention Time ◽  
Oxygen Demand ◽  
Industrial Effluents ◽  
Quality Parameters ◽  
Treated Wastewater ◽  
Feeding Time ◽  
Dye Wastewater ◽  
Effective Microorganisms ◽  
Biosand Filter ◽  
Final Treatment

A study was carried out to evaluate the application of Activated Effective Microorganisms (AEM) solution and EM Mudballs (mixture of soil, rice bran, and EM) to wastewater generated from wool and cotton dyeing unit at Kumbeshwar Technical School (Lalitpur, Bagmati Province, Nepal). Furthermore, the AEM treated wastewater was treated through a Biosand filter as a final treatment and polishing step before discharge in a nearby sewerage system. The wastewater samples collected for 27 days were analyzed for the wastewater quality parameters such as pH, Electrical Conductivity (EC), Total Solids (TS), and Chemical Oxygen Demand (COD) using the standard methods. The average values of pH, conductivity, COD, and TS after the EM combined with Biosand (final) treatment were observed to be 7.49±1.15, 1.39±0.25 mS/cm, 1,669.4 ±858.14 mg/L, and 264±25.29 mg/L, respectively. TS and COD removal were observed to be 43.97±22.3% and 15.26±10.06%, respectively. The results show that the dye wastewater is difficult to remove by a simple biological process like the addition of EM. Combined EM and biosand filters can be an inexpensive way of treating industrial effluents. However, the existing treatment system needs to be optimized by the integration with the proper EM: water: molasses ratio, optimal feeding time and design, hydraulic retention time, solids retention time, organic loading rates in EM reactor, and COD/BOD ratio in wastewater among other important components to meet the national effluent discharge requirements.

DECOLOURIZATION AND COD REMOVAL OF WASEWATER FROM ETHANOL PRODUCTION PROCESS FROM MOLASSES BY COAGULANTION USING INORGANIC ALUM

2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le
Keyword(s):  
Ethanol Production ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Treatment Processes ◽  
Physico Chemical ◽  
Biological Methods ◽  
Treatment Step ◽  
Main Material

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.

Inter-country inequality as a dynamic process and the problem of post-industrial development

2018 ◽  
pp. 5-29 ◽  
Author(s):  
L. M. Grigoryev ◽  
V. A. Pavlyushina
Keyword(s):  
Economic Growth ◽  
Political Institutions ◽  
Industrial Development ◽  
Modern World ◽  
New Approach ◽  
Development Level ◽  
The World ◽  
Long Time ◽  
The Difference ◽  
Post Industrial

The phenomenon of economic growth is studied by economists and statisticians in various aspects for a long time. Economic theory is devoted to assessing factors of growth in the tradition of R. Solow, R. Barrow, W. Easterly and others. During the last quarter of the century, however, the institutionalists, namely D. North, D. Wallis, B. Weingast as well as D. Acemoglu and J. Robinson, have shown the complexity of the problem of development on the part of socioeconomic and political institutions. As a result, solving the problem of how economic growth affects inequality between countries has proved extremely difficult. The modern world is very diverse in terms of development level, and the article offers a new approach to the formation of the idea of stylized facts using cluster analysis. The existing statistics allows to estimate on a unified basis the level of GDP production by 174 countries of the world for 1992—2016. The article presents a structured picture of the world: the distribution of countries in seven clusters, different in levels of development. During the period under review, there was a strong per capita GDP growth in PPP in the middle of the distribution, poverty in various countries declined markedly. At the same time, in 1992—2016, the difference increased not only between rich and poor groups of countries, but also between clusters.

Managing urban wastewater for maximising water resource utilization

1999 ◽  
Vol 39 (10-11) ◽  
pp. 353-356 ◽  
Author(s):  
Gideon Tredoux ◽  
Peter King ◽  
Lisa Cavé
Keyword(s):  
Water Resource ◽  
Industrial Wastewater ◽  
Water Resource Management ◽  
Quality Parameters ◽  
Base Flow ◽  
Treated Wastewater ◽  
Groundwater Exploitation ◽  
Trade Area ◽  
Management Scheme ◽  
Domestic Effluent

The Atlantis Water Resource Management Scheme uses artificial recharge of urban stormwater and treated wastewater to augment the natural groundwater resource. The key to the success of the scheme is the fractionation of the stormwater into components of distinctly different quality, and the separate treatment of domestic and industrial wastewater for different end-uses. The groundwater exploitation strategy is largely controlled by water quality requirements. Reuse of domestic and industrial wastewater depends on quality parameters. Tertiary treated domestic effluent is destined for indirect reuse via the aquifer, while treated industrial wastewater is used together with spent regenerant brine and stormwater from the noxious trade area for preventing seawater intrusion. Both residential and industrial stormwater is separated into the base flow and storm flow components and utilised for various purposes. The sustainable operation of the water resource scheme serves as a prototype for the optimal use of water and protection of the environment.

Non-steady variations of SOD and phosphate release rate due to changes in the quality of the overlying water

2000 ◽  
Vol 42 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
T. Inoue ◽  
Y. Nakamura ◽  
Y. Adachi
Keyword(s):  
Release Rate ◽  
Oxygen Demand ◽  
Phosphate Concentration ◽  
Sediment Oxygen Demand ◽  
Biochemical Reactions ◽  
Overlying Water ◽  
Phosphate Release ◽  
Do Concentration ◽  
The Difference

A dynamic model, which predicts non-steady variations in the sediment oxygen demand (SOD) and phosphate release rate, has been designed. This theoretical model consists of three diffusion equations with biochemical reactions for dissolved oxygen (DO), phosphate and ferrous iron. According to this model, step changes in the DO concentration and flow velocity produce drastic changes in the SOD and phosphate release rate within 10 minutes. The vigorous response of the SOD and phosphate release rate is caused by the difference in the time scale of diffusion in the water boundary layer and that of the biochemical reactions in the sediment. Secondly, a negative phosphate transfer from water to sediment can even occur under aerobic conditions. This is caused by the decrease in phosphate concentration in the aerobic layer due to adsorption.

Words are constructions, too: A construction-based approach to English ablaut reduplication

Linguistics ◽  
2020 ◽  
Vol 58 (6) ◽  
pp. 1701-1735
Author(s):  
Jeroen van de Weijer ◽  
Weiyun Wei ◽  
Yumeng Wang ◽  
Guangyuan Ren ◽  
Yunyun Ran
Keyword(s):  
New Approach ◽  
The Difference

AbstractIn this article we present a new approach to words of the type zigzag, chitchat, etc. in English. Such words form a formal (phonological) and functional (semantic) pattern in English. We argue that this pattern should be analysed in a construction-based approach, which has clear advantages over other approaches, e.g. analyses involving extragrammaticality or a synchronically productive reduplication process. We propose to extend the construction-based approach beyond its original scope (syntactic constructions) to words that may even no longer be morphologically complex. Finally, we make a tentative suggestion about how the difference between productive and unproductive patterns could be captured in the construction-based approach.

scholarly journals Efficiency and Technological Reliability of Contaminant Removal in Household WWTPs with Activated Sludge

2021 ◽  
Vol 11 (4) ◽  
pp. 1889 ◽  
Author(s):  
Agnieszka Micek ◽  
Krzysztof Jóźwiakowski ◽  
Michał Marzec ◽  
Agnieszka Listosz ◽  
Tadeusz Grabowski
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Treated Wastewater ◽  
Contaminant Removal ◽  
Nitrogen And Phosphorus ◽  
Wastewater Samples ◽  
Polish Law

The results of research on the efficiency and technological reliability of domestic wastewater purification in two household wastewater treatment plants (WWTPs) with activated sludge are presented in this paper. The studied facilities were located in the territory of the Roztocze National Park (Poland). The mean wastewater flow rate in the WWTPs was 1.0 and 1.6 m3/day. In 2017–2019, 20 series of analyses were done, and 40 wastewater samples were taken. On the basis of the received results, the efficiency of basic pollutant removal was determined. The technological reliability of the tested facilities was specified using the Weibull method. The average removal efficiencies for the biochemical oxygen demand in 5 days (BOD5) and chemical oxygen demand (COD) were 66–83% and 62–65%, respectively. Much lower effects were obtained for total suspended solids (TSS) and amounted to 17–48%, while the efficiency of total phosphorus (TP) and total nitrogen (TN) removal did not exceed 34%. The analyzed systems were characterized by the reliability of TSS, BOD5, and COD removal at the level of 76–96%. However, the reliability of TN and TP elimination was less than 5%. Thus, in the case of biogenic compounds, the analyzed systems did not guarantee that the quality of treated wastewater would meet the requirements of the Polish law during any period of operation. This disqualifies the discussed technological solution in terms of its wide application in protected areas and near lakes, where the requirements for nitrogen and phosphorus removal are high.

scholarly journals New glacier evidence for ice-free summits during the life of the Tyrolean Iceman

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pascal Bohleber ◽  
Margit Schwikowski ◽  
Martin Stocker-Waldhuber ◽  
Ling Fang ◽  
Andrea Fischer
Keyword(s):  
Elevation Gradient ◽  
Ice Age ◽  
Detailed Knowledge ◽  
New Approach ◽  
Radiocarbon Age ◽  
Alpine Glaciers ◽  
The Alps ◽  
Tyrolean Iceman ◽  
High Elevations ◽  
Age Constraints

AbstractDetailed knowledge of Holocene climate and glaciers dynamics is essential for sustainable development in warming mountain regions. Yet information about Holocene glacier coverage in the Alps before the Little Ice Age stems mostly from studying advances of glacier tongues at lower elevations. Here we present a new approach to reconstructing past glacier low stands and ice-free conditions by assessing and dating the oldest ice preserved at high elevations. A previously unexplored ice dome at Weißseespitze summit (3500 m), near where the “Tyrolean Iceman” was found, offers almost ideal conditions for preserving the original ice formed at the site. The glaciological settings and state-of-the-art micro-radiocarbon age constraints indicate that the summit has been glaciated for about 5900 years. In combination with known maximum ages of other high Alpine glaciers, we present evidence for an elevation gradient of neoglaciation onset. It reveals that in the Alps only the highest elevation sites remained ice-covered throughout the Holocene. Just before the life of the Iceman, high Alpine summits were emerging from nearly ice-free conditions, during the start of a Mid-Holocene neoglaciation. We demonstrate that, under specific circumstances, the old ice at the base of high Alpine glaciers is a sensitive archive of glacier change. However, under current melt rates the archive at Weißseespitze and at similar locations will be lost within the next two decades.

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