Biological power generation and earthworm assisted sludge treatment wetland to remove organic matter in sludge and synchronous power generation

Abstract Sediment microbial fuel cells (SMFCs) are bio-electrochemical devices generating electricity from redox gradients occurring across the sediment–water interface. Sediment microbial carbon-capture cell (SMCC), a modified SMFC, uses algae grown in the overlying water of sediment and is considered as a promising system for power generation along with algal cultivation. In this study, the performance of SMCC and SMFC was evaluated in terms of power generation, dissolved oxygen variations, sediment organic matter removal and algal growth. SMCC gave a maximum power density of 22.19 mW/m2, which was 3.65 times higher than the SMFC operated under similar conditions. Sediment organic matter removal efficiencies of 77.6 ± 2.1% and 61.0 ± 1.3% were obtained in SMCC and SMFC, respectively. With presence of algae at the cathode, a maximum chemical oxygen demand and total nitrogen removal efficiencies of 63.3 ± 2.3% (8th day) and 81.6 ± 1.2% (10th day), respectively, were observed. The system appears to be favorable from a resources utilization perspective as it does not depend on external aeration or membranes and utilizes algae and organic matter present in sediment for power generation. Thus, SMCC has proven its applicability for installation in an existing oxidation pond for sediment remediation, algae growth, carbon conversion and power generation, simultaneously.

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Short communication: Cyclodextrin nanosponges in the removal of organic matter to produce water for power generation

Water SA ◽

10.4314/wsa.v34i5.180666 ◽

2018 ◽

Vol 34 (5) ◽

pp. 657 ◽

Cited By ~ 24

Author(s):

B.B. Mamba ◽

R.W. Krause ◽

T.J. Malefetse ◽

G Gericke ◽

S.P. Sithole

Keyword(s):

Power Generation ◽

Organic Matter ◽

Short Communication ◽

Produce Water ◽

Cyclodextrin Nanosponges

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Greenhouse gas production in wastewater treatment: process selection is the major factor

Water Science & Technology ◽

10.2166/wst.2003.0626 ◽

2003 ◽

Vol 47 (12) ◽

pp. 43-48 ◽

Cited By ~ 69

Author(s):

J. Keller ◽

K. Hartley

Keyword(s):

Power Generation ◽

Wastewater Treatment ◽

Greenhouse Gas ◽

Fossil Fuels ◽

Treatment Process ◽

Sludge Treatment ◽

Anaerobic Processes ◽

Aerobic Processes ◽

Wastewater Pollutants ◽

Aerobic Sludge

Many practical design and operating decisions on wastewater treatment plants can have significant impacts on the overall environmental performance, in particular the greenhouse gas (GHG) emissions. The main factor in this regard is the use of aerobic or anaerobic treatment technology. This paper compares the GHG production of a number of case studies with aerobic or anaerobic main and sludge treatment of domestic wastewater and also looks at the energy balances and economics. This comparison demonstrates that major advantages can be gained by using primarily anaerobic processes as it is possible to largely eliminate any net energy input to the process, and therefore the production of GHG from fossil fuels. This is achieved by converting the energy of the incoming wastewater pollutants to methane which is then used to generate electricity. This is sufficient to power the aerobic processes as well as the mixing etc. of the anaerobic stages. In terms of GHG production, the total output (in CO2 equivalents) can be reduced from 2.4 kg CO2/kg CODremoved for fully aerobic treatment to 1.0 kg CO2/kg CODremoved for primarily anaerobic processes. All of the CO2 produced in the anaerobic processes comes from the wastewater pollutants and is therefore greenhouse gas neutral, whereas up to 1.4 kg CO2/kg CODremoved originates from power generation for the fully aerobic process. This means that considerably more CO2 is produced in power generation than in the actual treatment process, and all of this is typically from fossil fuels, whereas the energy from the wastewater pollutants comes primarily from renewable energy sources, namely agricultural products. Even a change from anaerobic to aerobic sludge treatment processes (for the same aerobic main process) has a massive impact on the CO2 production from fossil fuels. An additional 0.8 kg CO2/kg CODremoved is produced by changing to aerobic sludge digestion, which equates for a typical 100,000 EP plant to an additional production of over 10 t CO2 per day. Preliminary cost estimates confirm that the largely anaerobic process option is a fully competitive alternative to the mainly aerobic processes used, while achieving the same effluent quality.

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Effect of plant species on water quality at the outlet of a sludge treatment wetland

Water Research ◽

10.1016/j.watres.2012.07.007 ◽

2012 ◽

Vol 46 (16) ◽

pp. 5305-5315 ◽

Cited By ~ 41

Author(s):

Vincent Gagnon ◽

Florent Chazarenc ◽

Margit Kõiv ◽

Jacques Brisson

Keyword(s):

Water Quality ◽

Plant Species ◽

Treatment Wetland ◽

Sludge Treatment

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Optimization of Operating Conditions for Maximizing Power Generation and Organic Matter Removal in Microbial Fuel Cell

Journal of Environmental Engineering ◽

10.1061/(asce)ee.1943-7870.0001179 ◽

2017 ◽

Vol 143 (4) ◽

pp. 04016090 ◽

Cited By ~ 9

Author(s):

Manaswini Behera ◽

M. M. Ghangrekar

Keyword(s):

Power Generation ◽

Organic Matter ◽

Fuel Cell ◽

Microbial Fuel Cell ◽

Operating Conditions ◽

Organic Matter Removal

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Sewage sludge and waterworks sludge stabilization in sludge treatment reed bed systems

Water Science & Technology ◽

10.2166/wst.2017.155 ◽

2017 ◽

Vol 76 (2) ◽

pp. 355-363 ◽

Cited By ~ 5

Author(s):

Grazia Masciandaro ◽

Eleonora Peruzzi ◽

Steen Nielsen

Keyword(s):

Organic Matter ◽

Point Of View ◽

Pyrolysis Gas ◽

Organic Matter Quality ◽

Sludge Treatment ◽

Chromatography Analysis ◽

Sludge Stabilization ◽

Study Results ◽

Reed Bed ◽

Waterworks Sludge

In this study, results about sludge stabilization in sludge treatment reed bed (STRB) systems in two different systems, Hanningfield STRB 1 (England), treating waterworks sludge, and Stenlille STRB 2 (Denmark), treating surplus activated sludge, are presented. The study mainly focused on the effectiveness of the STRBs systems in stabilizing sludge organic matter; in fact, parameters correlated to biochemical and chemico-structural properties of organic sludge matter were determined. Dewatering and sludge stabilization were effective in both STRBs, as highlighted by total and volatile dry solids trend. β-glucosidase, phosphatase, arylsulphatase, leucine amino-peptidase and butyrate esterase activities, enzymes related to C, P, S, N and overall microbial activity, respectively, significantly declined along the profile in both STRBs. The determination of humic carbon highlighted the formation of a stable nucleus of humified organic matter in both STRBs in the deepest layers, thus meaning the successful stabilization of sludge organic matter for both kind of sludges. Similar conclusions can be drawn from pyrolysis gas chromatography analysis (Py-GC), which enables the characterization of soil organic matter quality from a chemical-structural point of view. The pyrolytic indices of mineralization and humification showed that in both STRBs the sludge organic matter is well stabilized.

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Denitrificiation in a Non-Nitrifying Activated Sludge System

Water Science & Technology ◽

10.2166/wst.1992.0551 ◽

1992 ◽

Vol 26 (5-6) ◽

pp. 1097-1104 ◽

Cited By ~ 6

Author(s):

A. Lyngå ◽

P. Balmér

Keyword(s):

Organic Matter ◽

Activated Sludge ◽

Nitrogen Removal ◽

Cost Effective ◽

Pilot Scale ◽

Anoxic Zone ◽

Sludge Treatment ◽

Activated Sludge System ◽

Cost Effective Method ◽

Nitrate Supply

Post-nitrification and recycling of the nitrified effluent to an anoxic zone in an activated sludge system for denitrification is proposed as a potentially cost-effective method for nitrogen removal in existing activated sludge treatment plants. Denitrification in a non-nitrifying activated sludge system with a SRT of 3-4 days has been studied in pilot scale. The results show that denitrification rates of at least 10 g N03-N/(kgVSS h) can be achieved. At COD/NO3-N ratios above 15, nitrate supply appears to control the denitrification rate while at COD/NO3-N ratios below 15 the rate appears to be controlled by the supply of easily biodegradable organic matter.

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