Treatment of wastewater by constructed wetland in small settlements

2000 ◽  
Vol 41 (1) ◽  
pp. 69-72 ◽  
Author(s):  
S.Ç. Ayaz ◽  
I. Akca
Keyword(s):  
Environmental Pollution ◽  
Constructed Wetland ◽  
Pilot Plant ◽  
Low Cost ◽  
Experimental System ◽  
Suspended Solid ◽  
Loading Conditions ◽  
Treatment Performance ◽  
Per Capita ◽  
One Year

The constructed wetland is a low-cost technology to control environmental pollution. The system is especially suitable for small settlements. An innovative constructed wetland technology is described in this paper. A pilot plant was used to assess the performance of the system. The experimental system consists of two serial connected tanks that settled up with fillers and Cyperus as treatment media. Wastewater is recycled periodically upward and downward between the two tanks. The treatment performance was monitored in different loading conditions in a one-year period. The average COD removal efficiency of 90% was observed at 122 g COD/m2.day average loading conditions. Other average removal values in the same conditions are as follows: suspended solid 95%, TKN 77%, total nitrogen 61%, PO4-P 39%. The land requirement for this system will be 0.82 m2 per capita when applying as full-scale system.

Constructed wetland as a low cost and sustainable solution for wastewater treatment adapted to rural settlements: the Chorfech wastewater treatment pilot plant

2011 ◽  
Vol 63 (12) ◽  
pp. 3006-3012 ◽  
Author(s):  
Ahmed Ghrabi ◽  
Latifa Bousselmi ◽  
Fabio Masi ◽  
Martin Regelsberger
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Pilot Plant ◽  
Low Cost ◽  
Oxygen Demand ◽  
Rural Settlement ◽  
Rural Settlements ◽  
Nitrogen And Phosphorus ◽  
In Series ◽  
Pre Treatment

The paper presents the detailed design and some preliminary results obtained from a study regarding a wastewater treatment pilot plant (WWTPP), serving as a multistage constructed wetland (CW) located at the rural settlement of ‘Chorfech 24’ (Tunisia). The WWTPP implemented at Chorfech 24 is mainly designed as a demonstration of sustainable water management solutions (low-cost wastewater treatment), in order to prove the efficiency of these solutions working under real Tunisian conditions and ultimately allow the further spreading of the demonstrated techniques. The pilot activity also aims to help gain experience with the implemented techniques and to improve them when necessary to be recommended for wide application in rural settlements in Tunisia and similar situations worldwide. The selected WWTPP at Chorfech 24 (rural settlement of 50 houses counting 350 inhabitants) consists of one Imhoff tank for pre-treatment, and three stages in series: as first stage a horizontal subsurface flow CW system, as second stage a subsurface vertical flow CW system, and a third horizontal flow CW. The sludge of the Imhoff tank is treated in a sludge composting bed. The performances of the different components as well as the whole treatment system were presented based on 3 months monitoring. The results shown in this paper are related to carbon, nitrogen and phosphorus removal as well as to reduction of micro-organisms. The mean overall removal rates of the Chorfech WWTPP during the monitored period have been, respectively, equal to 97% for total suspended solids and biochemical oxygen demand (BOD5), 95% for chemical oxygen demand, 71% for total nitrogen and 82% for P-PO4. The removal of E. coli by the whole system is 2.5 log units.

scholarly journals Lampiran 3B Paper Penurunan Konsentrasi BOD5, COD dan Padatan Tersuspensi pada Air Limbah dengan Menggunakan Teknologi Lahan Basah Buatan (Constructed Wetland)

2021 ◽  
Author(s):  
Philiphi de Rozari
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Suspended Solids ◽  
Hydraulic Retention Time ◽  
Low Cost ◽  
Domestic Wastewater ◽  
Suspended Solid ◽  
Vertical Flow ◽  
The Media ◽  
Promising Solution

Constructed wetlands are a promising solution technology to effectively treat domestic wastewater in developing countries at low cost. This paper reports the findings of the effectiveness of sand planted with Thypa latifolia with variation of the length of outflow measured from the bottom of the media in removing BOD5, COD, and suspended solids. The experimental design consisted of 12 vertical flow (VF) mesocosms. There were 3 treatments and one control based on the with variation of the length of outflow measured from the bottom of the media (7, 14, and 21 cm). During the five months, the mesocosms were loaded with syntethic wastewater. The influent had a 2-day hydraulic retention time. Samples were monitored for BOD5, COD and TSS. The results showed the concetration of BOD5, COD and TSS reduced significantly after the wastewater were treated with constructed wetland systems. The trend showed that the constructed wetland systems planted with Thypa latifolia had a better performance in comparison with the control. There were no significant differences of BOD5 COD, and suspended solid outflow among 7, 14 and 21 of constructed wetland systems. This indicated that the length of outflow measured from the bottom of the media did not influence the performance of constructed wetland systems in removing BOD5, COD and TSS

Regional household poverty and mobility analysis – a transition probability approach

2020 ◽  
Vol 63 (3) ◽  
pp. 286-302
Author(s):  
Damian Mowczan ◽  
Keyword(s):  
Transition Probability ◽  
General Level ◽  
Transition Matrices ◽  
Equivalent Unit ◽  
Central Statistical ◽  
Per Capita ◽  
Probability Matrices ◽  
General Mobility ◽  
One Year ◽  
The One

The main objective of this paper was to estimate and analyse transition-probability matrices for all 16 of Poland’s NUTS-2 level regions (voivodeship level). The analysis is conducted in terms of the transitions among six expenditure classes (per capita and per equivalent unit), focusing on poverty classes. The period of analysis was two years: 2015 and 2016. The basic aim was to identify both those regions in which the probability of staying in poverty was the highest and the general level of mobility among expenditure classes. The study uses a two-year panel sub-sample of unidentified unit data from the Central Statistical Office (CSO), specifically the data concerning household budget surveys. To account for differences in household size and demographic structure, the study used expenditures per capita and expenditures per equivalent unit simultaneously. To estimate the elements of the transition matrices, a classic maximum-likelihood estimator was used. The analysis used Shorrocks’ and Bartholomew’s mobility indices to assess the general mobility level and the Gini index to assess the inequality level. The results show that the one-year probability of staying in the same poverty class varies among regions and is lower for expenditures per equivalent units. The highest probabilities were identified in Podkarpackie (expenditures per capita) and Opolskie (expenditures per equivalent unit), and the lowest probabilities in Kujawsko-Pomorskie (expenditures per capita) and Małopolskie (expenditures per equivalent unit). The highest level of general mobility was noted in Małopolskie, for both categories of expenditures.

Treatment of wastewater from oil manufacturing plant by yeasts

1996 ◽  
Vol 34 (11) ◽  
pp. 51-58 ◽  
Author(s):  
K. Chigusa ◽  
T. Hasegawa ◽  
N. Yamamoto ◽  
Y. Watanabe
Keyword(s):  
Pilot Plant ◽  
Removal Rate ◽  
Oil Removal ◽  
Oxidation Activity ◽  
Single Strain ◽  
Manufacturing Plants ◽  
Yeast Strains ◽  
Hexane Extracts ◽  
One Year ◽  
Raw Wastewater

Nine strains of yeasts capable of decomposing oil were isolated in order to directly treat wastewater from oil manufacturing plants with no pretreatment. The oil decomposing ability of these yeast strains was evaluated in terms of lipase activity and β-oxidation activity. Since the mixture of the isolated yeasts was superior to any single strain in the oil removal rate, a pilot plant utilizing the mixed strains was operated at the soybean oil factory. Following a one year pilot plant operation, it was found that 10,000 mgℓ−1 of hexane extracts in the raw wastewater could be reduced by yeast treatment to a concentration of about 100 mgℓ−1. This concentration was further treated by the activated sludge process to 2 mgℓ−1. The dominant yeasts in the pilot plant were found to form mycelial or pseudomycelial pellets and have low fermenting ability.

Pilot-plant experiments for improvement of polluted canal/klong water by rock-bed filtration

1997 ◽  
Vol 35 (8) ◽  
pp. 83-90
Author(s):  
Shigeo Fujii ◽  
Chiaki Niwa ◽  
Mitsuo Mouri ◽  
Ranjna Jindal
Keyword(s):  
Organic Matter ◽  
Pilot Plant ◽  
Horizontal Flow ◽  
Removal Mechanism ◽  
Soluble Organic Matter ◽  
Filter Media ◽  
Canal Water ◽  
Rock Bed ◽  
One Year ◽  
Filtration Technique

Applicability of the rock-bed filtration technique was investigated through pilot-plant experiments in Bangkok, Thailand. Polluted canal water was used as horizontal flow influent to two reactor channels filled with rocks. During one year operation, HRT, filter media, and aeration mode, were changed in several runs. The results showed that 1) the rock-bed filtration with aeration and the HRT more than 6 h can successfully improve polluted klong water by reducing the pollutants (e.g. 60-120mg/L of SS to 20-40 mg/L and 15-30 mg/L of BOD to 5-20 mg/L); 2) main removal mechanism seems to be the sedimentation resulting from the settleability enhanced by aeration, and the biofilm attached onto rocks also works in the reduction of soluble organic matter; 3) a combination of three rock sizes arranged in descending order showed best results; 4) longer HRT (13 h) produces better effluent but is not so effective if it exceeds 9 hours; 5) 60-70% of sediment IL was decomposed in a year, and porosity in rock beds reduced approximately 16%.

scholarly journals A 40 Mb/s VLC System Reusing an Existing Large LED Panel in an Indoor Office Environment

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1697
Author(s):  
Xicong Li ◽  
Zabih Ghassemlooy ◽  
Stanislav Zvánovec ◽  
Paul Anthony Haigh
Keyword(s):  
Modulation Depth ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Data Communication ◽  
Experimental System ◽  
Digital Signal ◽  
Visible Light Communication ◽  
Cost Driver ◽  
Limiting Factors ◽  
Light Sources

With advances in solid-state lighting, visible light communication (VLC) has emerged as a promising technology to enhance existing light-emitting diode (LED)-based lighting infrastructure by adding data communication capabilities to the illumination functionality. The last decade has witnessed the evolution of the VLC concept through global standardisation and product launches. Deploying VLC systems typically requires replacing existing light sources with new luminaires that are equipped with data communication functionality. To save the investment, it is clearly desirable to make the most of the existing illumination systems. This paper investigates the feasibility of adding data communication functionality to the existing lighting infrastructure. We do this by designing an experimental system in an indoor environment based on an off-the-shelf LED panel typically used in office environments, with the dimensions of 60 × 60 cm2. With minor modifications, the VLC function is implemented, and all of the modules of the LED panel are fully reused. A data rate of 40 Mb/s is supported at a distance of up to 2 m while using the multi-band carrierless amplitude and phase (CAP) modulation. Two main limiting factors for achieving higher data rates are observed. The first factor is the limited bandwidth of the LED string inside the panel. The second is the flicker due to the residual ripple of the bias current that is generated by the panel’s driver. Flicker is introduced by the low-cost driver, which provides bias currents that fluctuate in the low frequency range (less than several kilohertz). This significantly reduces the transmitter’s modulation depth. Concurrently, the driver can also introduce an effect that is similar to baseline wander at the receiver if the flicker is not completely filtered out. We also proposed a solution based on digital signal processing (DSP) to mitigate the flicker issue at the receiver side and its effectiveness has been confirmed.

scholarly journals Tracking the Evolution of Riverbed Morphology on the Basis of UAV Photogrammetry

2021 ◽  
Vol 13 (4) ◽  
pp. 829
Author(s):  
Teresa Gracchi ◽  
Guglielmo Rossi ◽  
Carlo Tacconi Stefanelli ◽  
Luca Tanteri ◽  
Rolando Pozzani ◽  
...  
Keyword(s):  
Management Practices ◽  
Low Cost ◽  
3D Models ◽  
Vegetation Coverage ◽  
Detection Analysis ◽  
Digital Terrain ◽  
Fluvial Dynamics ◽  
Aerial Vehicle ◽  
One Year ◽  
Short Time

Unmanned aerial vehicle (UAV) photogrammetry has recently become a widespread technique to investigate and monitor the evolution of different types of natural processes. Fluvial geomorphology is one of such fields of application where UAV potentially assumes a key role, since it allows for overcoming the intrinsic limits of satellite and airborne-based optical imagery on one side, and in situ traditional investigations on the other. The main purpose of this paper was to obtain extensive products (digital terrain models (DTMs), orthophotos, and 3D models) in a short time, with low costs and at a high resolution, in order to verify the capability of this technique to analyze the active geomorphic processes on a 12 km long stretch of the French–Italian Roia River at both large and small scales. Two surveys, one year apart from each other, were carried out over the study area and a change detection analysis was performed on the basis of the comparison of the obtained DTMs to point out and characterize both the possible morphologic variations related to fluvial dynamics and modifications in vegetation coverage. The results highlight how the understanding of different fluvial processes may be improved by appropriately exploiting UAV-based products, which can thus represent a low-cost and non-invasive tool to crucially support decisionmakers involved in land management practices.

scholarly journals A Fast Calibration and Compensation Method for Magnetometers in Strap-Down Spinning Projectiles

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4157 ◽  
Author(s):  
Dafeng Long ◽  
Xiaoming Zhang ◽  
Xiaohui Wei ◽  
Zhongliang Luo ◽  
Jianzhong Cao
Keyword(s):  
Low Cost ◽  
Experimental System ◽  
Calibration Method ◽  
Attitude Estimation ◽  
Attitude Measurement ◽  
Angle Error ◽  
Estimation Errors ◽  
Zero Bias ◽  
Launch Site ◽  
Spinning Projectile

Attitude measurement is an essential technology in projectile trajectory correction. Magnetometers have been used for projectile attitude measurement systems as they are small in size, lightweight, and low cost. However, magnetometers are seriously disturbed by the artillery magnetic field during launch. Moreover, the error parameters of the magnetometers, which are calibrated in advance, usually change after extended storage. The changed parameters have negative effects on attitude estimation of the projectile. To improve the accuracy of attitude estimation, the magnetometers should be calibrated again before launch or during flight. This paper presents a fast calibration method specific for a spinning projectile. At the launch site, the tri-axial magnetometer is calibrated, the parameters of magnetometer are quickly obtained by optimal ellipsoid fitting based on a least squares criterion. Then, the calibration parameters are used to compensate for magnetometer outputs during flight. The numerical simulation results show that the proposed calibration method can effectively determine zero bias, scale factors, and alignment angle errors. Finally, a semi-physical experimental system was designed to further verify the performance of the calibration method. The results show that pitch angle error reduces from 3.52° to 0.58° after calibration. The roll angle error is reduced from 2.59° to 0.65°. Simulations and experimental results indicate that the accuracy of magnetometer in strap-down spinning projectile has been greatly enhanced, and the attitude estimation errors are reduced after calibration.

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