scholarly journals Characteristics of greywater from different sources within households in a community in Durban, South Africa

2016 ◽  
Vol 7 (4) ◽  
pp. 520-528 ◽  
Author(s):  
B. F. Bakare ◽  
S. Mtsweni ◽  
S. Rathilal

The reuse of greywater is steadily gaining importance in South Africa. Greywater contains pollutants that could have adverse effects on the environment and public health if the water is not treated before reuse. Successful implementation of any greywater treatment process depends largely on its characteristics in terms of the pollutant strength. This study investigated the physico-chemical characteristics of greywater from different sources within 75 households in a community in Durban, South Africa. The study was undertaken to create an understanding of greywater quality from different sources within and between households. Greywater samples were collected from the kitchen, laundry and bathing facilities within each of the households. The samples were analysed for: pH, conductivity, turbidity, total solids, chemical oxygen demand (COD) and biological oxygen demand (BOD). There was a significant difference in the parameters analysed between the greywater from the kitchen compared with the greywater from the bathtub/shower and laundry. It was also observed that the characteristics of greywater from the different households varied considerably. The characteristics of the greywater obtained in this study suggest that the greywater generated cannot be easily treatable using biological treatment processes and/or technologies due to the very low mean BOD : COD ratio (<0.5).

2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le

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.


1986 ◽  
Vol 18 (7-8) ◽  
pp. 289-296
Author(s):  
C. F. Ouyang ◽  
T. J. Wan

This study investigated and compared the treatment characteristics of three different kinds of biological wastewater treatment plants (including rotating biological contactor, trickling filter and oxidation ditch) which are currently operated in Taiwan. The field investigation of this study concentrated on the following items: the performance of biological oxygen demand (BOD) and suspended solids (SS) removal; the sludge yield rate of BOD removal; the settleability of sludge solids; the properties of sludge thickening; the power consumption and land area requirement per unit volume of wastewater. Finally, based on the results of the field investigation, a comparison of the treatment characteristics of the three different biological treatment processes was evaluated.


2021 ◽  
Vol 3 (2) ◽  
pp. 130-140
Author(s):  
Maria Diana Puiu ◽  

The food industry wastewater is known to present a high organic matter content, due to specific raw materials and processing activities. Even if these compounds are not directly toxic to the environment, high concentrations in effluents could represent a source of pollution as discharges of high biological oxygen demand may impact receiving river's ecosystems. Identifying the main organic contaminants in wastewater samples represents the first step in establishing the optimum treatment method. The sample analysis for the non-target compounds through the GC-MS technique highlights, along with other analytical parameters, the efficiency of the main physical and biological treatment steps of the middle-size Wastewater Treatment Plant (WWTP). Long-chain fatty acids and their esters were the main abundant classes of non-target identified compounds. The highest intensity detection signal was reached by n-hexadecanoic acid or palmitic acid, a component of palm oil, after the physical treatment processes with dissolved air flotation, and by 1-octadecanol after biological treatment.


2014 ◽  
Vol 69 (8) ◽  
pp. 1720-1727 ◽  
Author(s):  
E. N. P. Courtens ◽  
F. Meerburg ◽  
V. Mausen ◽  
S. E. Vlaeminck

Water is not enough. Nowadays, numerous chemicals are used for fire extinction. After use, however, these may unintentionally enter sewerage systems. In order to safely treat firefighting wastewater (FFWW), knowledge of the potential effects of these chemicals on biological treatment processes is essential. This study characterized and mimicked the composition of FFWW containing two powders, three foams and one foam degrader. Nitrogen (162–370 mg NH4+-N L−1) and phosphorus (173–320 mg PO43−-P L−1) concentrations exceeded discharge limits, whereas chemical and biological oxygen demand, suspended solids and detergent concentrations remained sufficiently low. Adequate nutrient removal could be obtained through FeCl3 addition and nitrification/denitrification with acetate as substrate. In batch tests, residual nitrifying activities of 84, 81, 89, 95 and 93% were observed in the presence of powders, foams, foam degrader, synthetic and real FFWW, respectively. All categories showed higher denitrification rates than the control. Although the powders at first seemed to inhibit anammox activity at 82%, after pH correction anammox was fully feasible, allowing nitrogen removal through oxygen-limited nitrification/denitrification (OLAND). Detailed cost calculations indicated that OLAND could save 11% of capital and 68% of operational costs compared to nitrification/denitrification, identifying OLAND as the most recommendable process for nitrogen removal from firefighting wastewaters.


2022 ◽  
Vol 11 (6) ◽  
pp. 667-675
Author(s):  
Amina-Afaf MOUFFAK

Furfural is one of the petroleum products posing a potential danger to the environment and human health. However, the decontamination of these pollutants released into the environment is primarily governed by biodegra-dation processes. This study is based on biodegradation kinetics at increasing concentrations of furfural by natural mixed culture in order to assess the potential of this process in the elimination of furfural from petrochemical effluents from the ARZEW refinery. This biodegradation was measured through physicochemical parameters such as pH, electrical conductivity, con-centration of hydrocarbons, the chemical oxygen demand (COD), biochemi-cal oxygen demand (BOD5) and the concentration of furfural. The results obtained show at a concentration of 250ppm of injected furfural: a decrease in pH 4.9 and an increase in other parameters (conductivity 3450 μS.cm-1, HC 102 mg / l; furfural 210 ppm, COD 327mg / l, BOD5 98mgO2 / l. The study findings indicated that the injection of these effluents with concentrations greater than 180 ppm leads to values of pH, EC, HC, Furfural, COD, BOD5 which do not comply with direct discharge standards and disrupt biological treatment. The high levels of furfural not only cause a pollution problem but can also disrupt the functioning of bacteria at the biological treatment level. Therefore, dilution with the filtration wash water before switching to biologi-cal treatment is recommended in order to reduce the concentrations below 180 ppm.


2003 ◽  
Vol 38 (2) ◽  
pp. 243-265 ◽  
Author(s):  
Catherine N. Mulligan ◽  
Bernard F. Gibbs

Abstract Biological treatment of wastewater has been employed successfully for many types of industries. Aerobic processes have been used extensively. Production of large amounts of sludge is the main problem and methods such as biofilters and membrane bioreactors are being developed to combat this phenomenon. Anaerobic waste treatment has undergone significant developments and is now reliable with low retention times. The UASB, the original high rate anaerobic reactor, is now becoming less popular than the EGSB reactor. New developments such as the Annamox process are highly promising for nitrogen removal. For metal removal, processes such as biosorption and biosurfactants combined with ultrafiltration membranes are under development. Biosurfactants have also shown promise as dispersing agents for oil spills. If space is available, wetlands can be used to reduce biological oxygen demand (BOD), total suspended solids (TSS), nutrients and heavy metals. These innovative processes are described in this paper in terms of applications, the stage of development, and future research needs particular to Canada.


2012 ◽  
Vol 66 (1) ◽  
pp. 217-223 ◽  
Author(s):  
Mouhamed el khames Saad ◽  
Younes Moussaoui ◽  
Asma Zaghbani ◽  
Imen Mosrati ◽  
Elimame Elaloui ◽  
...  

The present paper presents the main results of the biodegradation study of paper industry wastewater through physico-chemical treatment. Indeed, around 60% of chemical oxygen demand (COD) removal can be achieved by electroflocculation treatment. Furthermore, a removal efficiency of the COD of almost 91% has been obtained by biological treatment, with activated amount of sludge for 24 h of culture. Concerning the physico-chemical pre-treatment of the untreated, filtered and electroflocculated rejection effluents, it has been investigated through the degradation curve of COD studies.


Author(s):  
D. K. Nkeeh ◽  
A. I. Hart ◽  
E. S. Erondu ◽  
N. Zabbey

Water plays a key role in the survival, growth and reproduction of aquatic organisms. Therefore maintaining good quality of water physico-chemical parameters would ensure optimum productivity of aquatic fauna. The study evaluated water physical and chemical parameters (temperature, hydrogen ion concentration (pH), conductivity, dissolved oxygen (DO) and biochemical oxygen demand (BOD) of Bodo Creek. Sample was collected for 5 months (July 2020 – November 2020) at locations previously studied (before-spill baseline studies, 3 years, 5 years, and 7 years after-spill); by using the sampling methods used in previous studies. Spatially, there was no statistically significant difference in temperature (p > 0.05 = 0.997), pH (p > 0.05 = 0.496), DO (p > 0.05= 0.34) and BOD (p > 0.05 = 0.644). However, the difference in conductivity between the stations was statistically significant (p < 0.05 = 0.006). On monthly basis, there was a significant difference in temperature (p < 0.05 = 0.000) and pH (p < 0.05 = 0.005). In contrast, there was no statistically significant difference in conductivity (p > 0.05 = 0.633), DO (p > 0.05 = 0.559) and BOD (p > 0.05 = 0.75). Most of the physico-chemical parameters were not within the WHO recommended levels for the survival of aquatic lives, indicating a high level of environmental pollution in Bodo Creek. This study provides dataset for future evaluation of the water physico-chemistry of Bodo Creek.


Author(s):  
Ju-Hee Hong ◽  
Jun-Yeon Lee ◽  
Hyun-Ju Ha ◽  
Jin-Hyo Lee ◽  
Seok-Ryul Oh ◽  
...  

Levels of synthetic musk fragrances (SMFs) and various personal care products (PCPs) were measured in the Han River and its tributaries in Seoul, Korea. The most abundant SMF in all river and PCP samples was 4,6,6,7,8,8-hexamethyl-1,3,4,7-tetrahydrocyclopenta[g]isochromene (HHCB), followed by 1-(3,5,5,6,8,8-hexamethyl-6,7-dihydronaphthalen-2-yl)ethanone (AHTN), musk ketone (MK), and 1,1,2,3,3-pentamethyl-2,5,6,7-tetrahydroinden-4-one (DPMI). There was a significant correlation between the SMF concentration in the PCPs and the Han River samples. Moving from upstream to downstream in the Han River, the median SMF concentration was 6.756, 2.945, 0.304, and 0.141 μg/L in the sewage treatment plant (STP) influent, effluent, tributaries, and mainstream, respectively, implying that effective SMF removal was achieved during the sewage treatment process, followed by dilution in the receiving water. Four STPs using advanced biological treatment processes had removal efficiencies of 55.8%, 50.6%, 43.3% for HHCB, AHTN, and MK, respectively. The highest SMF concentrations in the tributaries were observed at locations close to the STPs. Our study confirmed that the main source of SMFs in the receiving water were sewage effluent containing untreated SMFs, which are largely originated from household PCPs, especially hair care products (e.g., shampoo) and perfumes.


2017 ◽  
Author(s):  
Essi Malinen ◽  
Nico Id ◽  
Sanni Valtonen ◽  
Janne Hakala ◽  
Tiina Mononen ◽  
...  

The purpose of this study was to examine how efficient a biological treatment process is in purifying car wash waste waters. Two Finnish automatic car washes having rotating bed biofilm reactors for waste water treatment were included in the study. Both of them are using 87 % of recycled water per car wash and only from 35 to 60 liters of fresh water. Samples were taken from the purified water tank every second week altogether seven times between the beginning of February and the end of May, 2012. The reduction of surfactants was at least 95 % and reduction of chemical oxygen demand (COD) between 87 and 95 % during the sampling period. Outdoor temperature seems not to have any significant effect on purification efficiency. Other water quality parameters such as conductivity, pH, oxygen concentration, total solids, and biological oxygen demand (BOD) were found to be on acceptable level based in comparison to values found in the literature. The high concentration of total nitrogen and total phosphorus in the purified water was caused by nutrients added to the bioreactor for optimal conditions for the microbes. In the studied car washes, the waste water treatment process managed to reduce input load considerably. The main challenges for the quality of purified water seems to be optimal nutrient input as well as on-line monitoring system for water quality.


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