Search results for "Recovery"
showing 10 items of 876 documents
End-of-life and waste management of disposable beverage cups.
2021
Different human activities have caused and currently cause catastrophic environmental phenomena, and unfortunately, a significant negative contribution to these catastrophic phenomena can be attributed to uncontrolled plastic production, use and release everywhere. On the other hand, the plastics offer numerous comforts and advantages, and for this reason, the modern life is unthinkable without plastic. Currently, numerous scientific papers and large audience advertisings, related to the production and use of polymers made by natural sources, i.e. bio-based polymers, as a valid alternative to the petroleum-based counterparts, have been published. Therefore, for production of daily disposabl…
Optimizing the H3PO4 leaching conditions of post-precipitated sewage sludge using response surface methodology
2018
The leaching procedure of post-precipitated aluminium phosphate sludge with dilute phosphoric acid was developed. The leaching offers a route to recover both critical phosphorous from sewage sludge and the metal used in precipitation. Using phosphoric acid as leaching solution makes it possible to continue the recovery process without the need to remove chloride or sulfate anions. The optimization of the leaching was based on experimental three-level-four-variable central composite face-centered design. The four variables included were acid concentration, volume of acid, temperature and time of leaching. The leaching was conducted for dewatered and water-containing sludge (total solid conte…
Influence of volatile solids and pH for the production of volatile fatty acids: batch fermentation tests using sewage sludge
2021
The aim of this work was to study the effect of volatile suspended solid (VSS) and pH on volatile fatty acids (VFA) production from waste activated sludge (WAS) fermentation by means of batch tests. The final goal was to gain insights to enhance VFA stream quality, with the novelty of using WAS with high sludge retention time. Results revealed that the optimum conditions to maximize VFAs and minimize nutrients and non-VFA sCOD are a VSS concentration of 5.9 g/L and initial pH adjustment to pH 10. The WAS bacterial community structures were analysed according to Next Generation Sequencing (NGS) of 16S rDNA amplicons. The results revealed changes of bacterial phyla abundance in comparison wit…
Energy reserves mobilization in the yellow eel as herbicide exposure effect.
2015
Abstract Thiobencarb and propanil are two of the most extensive used herbicides worldwide in rice cultivation. Especially scanty is the available information regarding the effect of herbicides on fish energy resources. In the present study, the effect of sublethal exposure to these herbicides on the energy reserves of juvenile eel Anguilla anguilla was compared. Eels were exposed to 72 h to the herbicide thiobencarb (0.22 mg L −1 ) or Propanil (0.63 mg L −1 ), and allowed to recover in clean water (144 h). Caloric content was determined in liver and skeletal muscle. Fish exposed to thiobencarb rapidly mobilized energy. Reserves from liver were depleted (21%) compared to control values (2.50…
Measurements of organochloro compounds at a metal reclamation plant
1993
Abstract Kuusakoski Ltd is a metal reclamation company operating world wide. Metals recovered are mainly aluminium, copper and different steels. NaCl and KCl are used in processes. Sampling and emission analysis of PCP's, PCB's, PCDD/PCDF's and PAH's were made from seven processes at plant. Emissions indicate, that large part of chlorinated aromatic compounds are formed due to PVC-plastic in cables and car components. On the basis of this study, we suggest, that chlorinated benzenes, -naphtalens and -diphenyl ethers should also be measured in the emissions.
Maximising resource recovery from wastewater grown microalgae and primary sludge in an anaerobic membrane co-digestion pilot plant coupled to a compo…
2021
[EN] A pilot-scale microalgae (Chlorella spp.) and primary sludge anaerobic co-digestion (ACoD) plant was run for one year in an anaerobic membrane bioreactor (AnMBR) at 35 °C, 70 d solids retention time and 30 d hydraulic retention time, showing high stability in terms of pH and VFA concentration. The plant achieved a high degree of microalgae and primary sludge substrate degradation, resulting in a methane yield of 370 mLCH4·gVSinf¿1. Nutrient-rich effluent streams (685 mgN·L¿1 and 145 mgP·L¿1 in digestate and 395 mgNH4-N·L¿1 and 37 mgPO4-P·L¿1 in permeate) were obtained, allowing posterior nutrient recovery. Ammonium was recovered from the permeate as ammonia sulphate through a hydrophob…
Methane recovery efficiency in a submerged anaerobic membrane bioreactor (SAnMBR) treating sulphate-rich urban wastewater: Evaluation of methane loss…
2012
The present paper presents a submerged anaerobic membrane bioreactor (SAnMBR) as a sustainable approach for urban wastewater treatment at 33 and 20 C, since greenhouse gas emissions are reduced and energy recovery is enhanced. Compared to other anaerobic systems, such as UASB reactors, the membrane technology allows the use of biogas-assisted mixing which enhances the methane stripping from the liquid phase bulk. The methane saturation index obtained for the whole period (1.00 ± 0.04) evidenced that the equilibrium condition was reached and the methane loss with the effluent was reduced. The methane recovery efficiency obtained at 20 C (53.6%) was slightly lower than at 33 C (57.4%) due to …
Nutrient recovery from wastewater treatment by ultrafiltration membrane for water reuse in view of a circular economy perspective
2022
The study aims to recover nitrogen from wastewater by employing ultrafiltration membrane in water reuse for agriculture purpose. To such aim, a new reclaimed water quality index (RWQI) is proposed and applied including an innovative protocol for its assessment. Specifically, the influence of filtration and backwashing times for an ultrafiltration system aimed to nutrient recovery has been analyzed. The final goal was to pin down the trade-off between operation costs and effluent quality. Results show that backwashing time play a crucial role in reducing the operation costs; indeed, low values (i.e., 0.5 min) lead to an increase in the number of required chemical cleanings and consequently o…
Editorial: Sustainable wastewater treatment and resource recovery
2020
Water
Sewage sludge acidogenic fermentation for organic resource recovery towards carbon neutrality: an experimental survey testing the headspace influence
2022
Volatile fatty acids (VFAs) produced by acidogenic digestion of sewage sludge are very interesting bio-products which can contribute to carbon neutrality of wastewater treatment plants. Studies on the production of VFAs from sewage sludge from fermenters with membrane are limited. In view of above, VFAs from a fermenter pilot plant equipped with a membrane bioreactor and fed with real sewage sludge has been monitored. The effect of headspace volume (HdV) on VFA production was studied for the first time to elucidate the optimal operation conditions. Specifically, three fermenter HdV values (namely, 20, 40 and 60% of the total volume) have been investigated. Results revealed that the HdV of 2…