The effect of aeration and effluent recycling on domestic wastewater treatment in a pilot-plant system of duckweed ponds

2013 ◽  
Vol 69 (2) ◽  
pp. 350-357 ◽  
Author(s):  
Miriam Ben-shalom ◽  
Semion Shandalov ◽  
Asher Brenner ◽  
Gideon Oron

Three pilot-scale duckweed pond (DP) wastewater treatment systems were designed and operated to examine the effect of aeration and effluent recycling on treatment efficiency. Each system consisted of two DPs in series fed by pre-settled domestic sewage. The first system (duckweed+ conventional treatment) was ‘natural’ and included only duckweed plants. The second system (duckweed aeration) included aeration in the second pond. The third system (duckweed+ aeration+ circulation) included aeration in the second pond and effluent recycling from the second to the first pond. All three systems demonstrated similarly efficient removal of organic matter and nutrients. Supplemental aeration had no effect on either dissolved oxygen levels or on pollutant removal efficiencies. Although recycling had almost no influence on nutrient removal efficiencies, it had a positive impact on chemical oxygen demand and total suspended solids removals due to equalization of load and pH, which suppressed algae growth. Recycling also improved the appearance and growth rate of the duckweed plants, especially during heavy wastewater loads.

2018 ◽  
Vol 13 (3) ◽  
pp. 457-464
Author(s):  
PRIYANAND AGALE ◽  
PARAG SADGIR

Rural wastewater treatment is mostly ignored in developing and undeveloped countries. The most important barrier for addressing to this problem is cost of treatment and simplified technology. Aerobic Brickbat Grit Sand (ABGS) purifier consists of four stages. Wastewater flows gravitationally through partition walls in zigzag pattern with brick bats filter; Pebble sand filter and charcoal and grit filter which facilitate removal of contaminants from domestic wastewater. In the present study, experimental model for domestic wastewater treatment was setup in the Environmental Engineering laboratory at Government College of Engineering Aurangabad, Maharashtra. Physiochemical analysis was done in August and September of 2016 the percentage removal of contaminants results shows Biological Oxygen Demand (BOD) 92% - 87%, Chemical Oxygen Demand (COD) 93 - 89%, Total Suspended Solids( TSS) 80 - 78% and Turbidity 95 - 85%. The process is considered eco-friendly and easy to install technology for domestic wastewater treatment with use of locally available material. ABGS purifier is decentralized approach of domestic wastewater treatment. Hence ABGS as an alternative solution to tackle over the problem of rural wastewater treatment.


2004 ◽  
Vol 50 (6) ◽  
pp. 95-101
Author(s):  
C. Chiemchaisri ◽  
C. Liamsangoun

This paper presents the performance of a multi-stage biodrum system applied to domestic wastewater treatment. The organic stabilization and nitrogen removal efficiency in the system was investigated at different hydraulic retention times (HRT) of 12, 6 and 3 hours. The rotational speed of the biodrum was examined at 2,4 and 8 rpm. Average organic removal efficiencies in the system at different HRTs of 12, 6 and 3 hours were 96.3, 94.4 and 90.9%. Simultaneously, average nitrogen removal efficiencies were 91.5, 90.6 and 81.0%. The effect of rotational speed on nitrogen removal efficiencies in the system was clearly observed at a low HRT of 3 hours. The experimental results suggested that optimum HRT in the system was 6 hours. Moreover, they revealed that nitrogen removal efficiencies in the reactors operated at different rotational speed were in the same degree when considering the effluent nitrogen concentration. However, the reactors operated at lower rotational speed needed to employ higher numbers of biodrums (4 stages) than the others with higher rotational speed (3 and 2 stages at 4 and 8 rpm.) in order to achieve similar effluent qualities. At a rotational speed of 2 rpm, maximum nitrogen removal rate was found to be 0.2 kg/m3/d.


2002 ◽  
Vol 46 (9) ◽  
pp. 263-270 ◽  
Author(s):  
P. Dama ◽  
J. Bell ◽  
K.M. Foxon ◽  
C.J. Brouckaert ◽  
T. Huang ◽  
...  

Large proportions of South Africans live in areas with inadequate sanitation and a poor infrastructure for waterborne sanitation. Service providers are looking for alternative wastewater treatment options. The anaerobic baffled reactor is being considered as a decentralised sanitation option in these areas. A 3,200 L reactor was built and is currently being evaluated at a wastewater treatment works. The reactor was built based on experiences gained from working with a laboratory reactor (10 L) and predicted flow patterns observed on a computational fluid dynamics model. The design and construction of the reactor will be discussed in this paper. The feed to the reactor consists of screen degritted sewage and the flow to the reactor is maintained by means of a programmable logic controller. The pilot-plant layout is discussed in this paper. Samples are analysed for chemical oxygen demand, pH, alkalinity, ammonia, phosphorus, solids and ash content. Reductions of between 70 and 80% are obtained for COD and the pH values for the effluent samples are within the discharge limits.


2020 ◽  
Vol 81 (4) ◽  
pp. 656-667 ◽  
Author(s):  
Serdar Koyuncu ◽  
Sema Arıman

Abstract In this study, domestic wastewaters originating from a settlement with a population of 17,500 were treated by electrocoagulation process in a real-scale EC plant and the economic applicability of the process was investigated. The removal efficiencies of control parameters in the influent and effluent of the real-scale treatment plant such as suspended solids (SS), biological oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP) and changes of pH and conductivity parameters were monitored for 12 months. The obtained data were evaluated according to European Urban Wastewater Treatment Directive, Turkish Water Pollution Control Regulation and Turkish Urban Wastewater Treatment Regulation. According to the results obtained, the removal efficiencies of the pollutant parameters were achieved in the range of 72–83% for SS, 67–80% for COD, 69–81% for BOD, 21–47% for TN and 27–46% for TP. Considering the Turkish wastewater discharge regulations, it can be concluded that the discharge standards for SS, COD and BOD parameters were achieved while they were not achieved in certain periods for TN and TP. In addition, the energy consumption and the operating cost of this real-scale plant were determined to be 0.49–0.54 kWh/m3 and 0.24–0.28 EUR/m3, respectively.


2019 ◽  
Vol 44 ◽  
pp. 101670 ◽  
Author(s):  
Maxence Plouviez ◽  
Paul Chambonnière ◽  
Andy Shilton ◽  
Michael A. Packer ◽  
Benoit Guieysse

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