Faecal sludge treatment and utilization by hydrothermal carbonization

2018 ◽  
Vol 216 ◽  
pp. 421-426 ◽  
Author(s):  
Krailak Fakkaew ◽  
Thammarat Koottatep ◽  
Chongrak Polprasert
Keyword(s):  
Hydrothermal Carbonization ◽  
Sludge Treatment ◽  
Faecal Sludge

scholarly journals Sewage Sludge Treatment by Hydrothermal Carbonization: Feasibility Study for Sustainable Nutrient Recovery and Fuel Production

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2697
Author(s):  
Gabriel Gerner ◽  
Luca Meyer ◽  
Rahel Wanner ◽  
Thomas Keller ◽  
Rolf Krebs
Keyword(s):  
Liquid Phase ◽  
Sewage Sludge ◽  
Hydrothermal Carbonization ◽  
Economic Feasibility ◽  
Phosphorus Recovery ◽  
High Yield ◽  
Nutrient Recovery ◽  
Waste Biomass ◽  
Sludge Treatment ◽  
Sewage Sludge Treatment

Phosphorus recovery from waste biomass is becoming increasingly important, given that phosphorus is an exhaustible non-renewable resource. For the recovery of plant nutrients and production of climate-neutral fuel from wet waste streams, hydrothermal carbonization (HTC) has been suggested as a promising technology. In this study, digested sewage sludge (DSS) was used as waste material for phosphorus and nitrogen recovery. HTC was conducted at 200 °C for 4 h, followed by phosphorus stripping (PS) or leaching (PL) at room temperature. The results showed that for PS and PL around 84% and 71% of phosphorus, as well as 53% and 54% of nitrogen, respectively, could be recovered in the liquid phase (process water and/or extract). Heavy metals were mainly transferred to the hydrochar and only <1 ppm of Cd and 21–43 ppm of Zn were found to be in the liquid phase of the acid treatments. According to the economic feasibility calculation, the HTC-treatment per dry ton DSS with an industrial-scale plant would cost around 608 USD. Between 349–406 kg of sulfuric acid are required per dry ton DSS to achieve a high yield in phosphorus recovery, which causes additional costs of 96–118 USD. Compared to current sewage sludge treatment costs in Switzerland, which range between 669 USD and 1173 USD, HTC can be an economically feasible process for DSS treatment and nutrient recovery.

scholarly journals Isotherm models and kinetics of copper adsorption by using hydrochar produced from hydrothermal carbonization of faecal sludge

2017 ◽  
Vol 7 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Thammarat Koottatep ◽  
Krailak Fakkaew ◽  
Nutnicha Tajai ◽  
Chongrak Polprasert
Keyword(s):  
Functional Groups ◽  
Low Cost ◽  
Hydrothermal Carbonization ◽  
Pollutant Removal ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Surface Functional Groups ◽  
Water And Wastewater Treatment ◽  
Copper Adsorption ◽  
Faecal Sludge

Low cost adsorbents have been extensively reported for use as a promising substitution for commercial adsorbents for pollutant removal in water and wastewater treatment. In this study, hydrochar produced from the hydrothermal carbonization (HTC) of faecal sludge (FS) (called HTC-hydrochar) was further chemically modified with KOH (called KOH-hydrochar) to improve its surface functional groups, which were suitable for copper (Cu) removal. The adsorption of Cu was conducted using the produced HTC-hydrochar and KOH-hydrochar as absorbents. Experimental results showed the KOH-hydrochar could adsorb Cu at the maximum adsorption capacity of 18.6 mg-Cu/g-hydrochar with Cu removal efficiency of 93%, relatively higher than the HTC-hydrochar and a commercial powdered activated carbon. The quantity of the surface functional groups of the adsorbents was more effective in Cu removal than the surface area. The Cu adsorption mechanism was found to follow the pseudo-second order and intra-particle diffusion models and fit well with Freundlich and Langmuir isotherms. Application of hydrothermal carbonization could be a novel candidate to convert FS into hydrochar which is pathogen free, and to employ the produced hydrochar as an adsorbent to remove Cu from industrial wastewaters.

Preliminary Study on the Potential Use of Fly Ash as a Ventilated Improved Pit Latrine Additive

2019 ◽  
Vol 45 (4) ◽  
pp. 395-402
Author(s):  
Dylan Collings ◽  
Roman Tandlich ◽  
Cyril S. Dube ◽  
Phindile Madikizela ◽  
Nosiphiwe P. Ngqwala ◽  
...  
Keyword(s):  
Fly Ash ◽  
Laboratory Experiments ◽  
Oxygen Demand ◽  
Total Organic Matter ◽  
Sludge Treatment ◽  
Faecal Material ◽  
Preliminary Study ◽  
Pit Latrine ◽  
Faecal Sludge ◽  
Potential Use

This study describes the results of a series of laboratory experiments on aimed at developing of a protocol for the use of fly ash as a pit additive in the ventilated improved pit latrines (VIPs) in South Africa. Model VIP vaults were prepared in the laboratory and filled with synthetic faecal sludge; and dosed with fly ash in amounts ranging from 5 to 20 % (w/w). The maximum leachable chemical oxygen demand (COD) accounted for 3.2 % of the total organic matter, while the maximum leachable ammonium accounted for 1.4 % of the leachable ammonium present in the synthetic faecal sludge. All phosphate in the synthetic faecal material was leachable. Mixing of the 20 % dose of fly ash into the synthetic faecal sludge resulted a minimum 98.9 % reduction (or about two log units) in the faecal coliform concentration after 28 days of incubation. As a result, addition of fly ash can decrease microbial threats to public and environmental health threats from the VIP faecal wastes, but can cause environmental contamination with phosphate. The fly ash dose and the duration of the faecal sludge treatment require further optimisation. Relationship between the chemical composition of the fly ash used as an additive to stabilise the VIP faecal sludge and the leaching of phosphorus from the sludge will also have to be investigated further.

scholarly journals Estimation of the Amount of Electrical Energy Available From the Biogas Produced at the Faecal Sludge Treatment Plant in the City of Sokodé

2021 ◽  
Vol 1 ◽  
Author(s):  
Nitale M'Balikine Krou ◽  
Gnon Baba ◽  
Ogouvidé Akpaki
Keyword(s):  
Solid Waste ◽  
Methodological Approach ◽  
Treatment Plant ◽  
Electric Energy ◽  
Electrical Energy ◽  
Sludge Treatment ◽  
One Year ◽  
The City ◽  
Recoverable Energy ◽  
Faecal Sludge

 The purpose of this study is to estimate the amount of energy produced from biogas at the faecal sludge treatment plant in the city of Sokodé. The methodological approach consisted in producing biogas by co-digestion of faecal sludge with the fermentable fractions of solid waste then in estimating the quantity of energy available from the produced biogas. Tests of co-digestion of faecal sludge and fermentable fractions of solid waste, showed that from 2258 tons/DM of biomass in one year, 44476 m3 of biogas, or 29177 m3 of methane could be produced. The methane content, which is 65.6 %, is a very interesting source of energy. Several techniques for producing energy from biogas exist, one of which is the production of electricity. In this study, it is a question of making the choice of an adequate electric motor which will allow to produce electric energy from the biogas on the faecal sludge treatment plant. Thus, it was necessary to estimate the quantity of energy available from the biogas produced. To do so, it was calculated the quantity of energy that can be produced by the biogas in one year, the quantity of recoverable energy produced in a year and the quantity of energy supplied by biogas in one hour. The results showed that by 2035, the co-digestion of fermentable solid waste and faecal sludge from the city of Sokodé, would produce 534,246 kWh. The recoverable part would be 507,534 kWh and the energy supplied is 58 kWh.

scholarly journals Coupling Hydrothermal Carbonization with Anaerobic Digestion for Sewage Sludge Treatment: Influence of HTC Liquor and Hydrochar on Biomethane Production

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6262 ◽  
Author(s):  
Roberta Ferrentino ◽  
Fabio Merzari ◽  
Luca Fiori ◽  
Gianni Andreottola
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Wastewater Treatment Plants ◽  
Hydrothermal Carbonization ◽  
Digested Sludge ◽  
Sludge Treatment ◽  
Secondary Sludge ◽  
Sewage Sludge Treatment ◽  
Biomethane Production

The present study addresses the coupling of hydrothermal carbonization (HTC) with anaerobic digestion (AD) in wastewater treatment plants. The improvement in biomethane production due to the recycling back to the anaerobic digester of HTC liquor and hydrochar generated from digested sludge is investigated and proved. Mixtures of different compositions of HTC liquor and hydrochar, as well as individual substrates, were tested. The biomethane yield reached 102 ± 3 mL CH4 g−1 COD when the HTC liquor was cycled back to the AD and treated together with primary and secondary sludge. Thus, the biomethane production was almost doubled compared to that of the AD of primary and secondary sludge (55 ± 20 mL CH4 g−1 COD). The benefit is even more significant when both the HTC liquor and the hydrochar were fed to the AD of primary and secondary sludge. The biomethane yield increased up to 187 ± 18 mL CH4 g−1 COD when 45% of hydrochar, with respect to the total feedstock, was added. These results highlight the improvement that the HTC process can bring to AD, enhancing biomethane production and promoting a sustainable solution for the treatment of the HTC liquor and possibly the hydrochar itself.

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