Anaerobic co-digestion of sludge with other organic wastes and phosphorus reclamation in wastewater treatment plants for biological nutrients removal

2006 ◽  
Vol 53 (12) ◽  
pp. 177-186 ◽  
Author(s):  
D. Bolzonella ◽  
P. Pavan ◽  
P. Battistoni ◽  
F. Cecchi

This paper deals with the performances obtained in full scale anaerobic digesters co-digesting waste activated sludge from biological nutrients removal wastewater treatment plants, together with different types of organic wastes (solid and liquid). Results showed that the biogas production can be increased from 4,000 to some 18,000 m3 per month when treating some 3–5 tons per day of organic municipal solid waste together with waste activated sludge. On the other hand, the specific biogas production was improved, passing from 0.3 to 0.5 m3 per kgVS fed the reactor, when treating liquid effluents from cheese factories. The addition of the co-substrates gave minimal increases in the organic loading rate while the hydraulic retention time remained constant. Further, the potentiality of the struvite crystallisation process for treating anaerobic supernatant rich in nitrogen and phosphorus was studied: 80% removal of phosphorus was observed in all the tested conditions. In conclusion, a possible layout is proposed for designing or up-grading wastewater treatment plants for biological nutrients removal process.

2006 ◽  
Vol 53 (8) ◽  
pp. 203-211 ◽  
Author(s):  
D. Bolzonella ◽  
P. Battistoni ◽  
C. Susini ◽  
F. Cecchi

The paper presents the results of two full-scale applications of the anaerobic co-digestion process of waste activated sludge together with the organic fraction of municipal solid wastes. The experiences were carried out at Viareggio and Treviso wastewater treatment plants (Italy). In the first plant, 3 tons per day of source sorted OFMSW were co-digested with waste activated sludge, increasing the organic loading rate from 1.0 to 1.2 kgTVS/m3d. This determined a 50% increase in biogas production. At Treviso WWTP, which has been working for 2 years, some 10 tons per day of separately collected OFMSW are treated using a low-energy consumption sorting line, which allows the removal of 99% and 90% of metals and plastics respectively. In these conditions, the biogas yield increased from 3,500 up to 17,500 m3/month. Industrial costs were evaluated less than 50 € per ton of organic waste, while the payback time was calculated as two years.


Author(s):  
Yongkui Yang ◽  
Longfei Wang ◽  
Feng Xiang ◽  
Lin Zhao ◽  
Zhi Qiao

Controlling wastewater pollution from centralized industrial zones is important for reducing overall water pollution. Microbial community structure and diversity can adversely affect wastewater treatment plant (WWTP) performance and stability. Therefore, we studied microbial structure, diversity, and metabolic functions in WWTPs that treat industrial or municipal wastewater. Sludge microbial community diversity and richness were the lowest for the industrial WWTPs, indicating that industrial influents inhibited bacterial growth. The sludge of industrial WWTP had low Nitrospira populations, indicating that influent composition affected nitrification and denitrification. The sludge of industrial WWTPs had high metabolic functions associated with xenobiotic and amino acid metabolism. Furthermore, bacterial richness was positively correlated with conventional pollutants (e.g., carbon, nitrogen, and phosphorus), but negatively correlated with total dissolved solids. This study was expected to provide a more comprehensive understanding of activated sludge microbial communities in full-scale industrial and municipal WWTPs.


2013 ◽  
Vol 69 (3) ◽  
pp. 525-531 ◽  
Author(s):  
C. Cavinato ◽  
C. Da Ros ◽  
P. Pavan ◽  
F. Cecchi ◽  
D. Bolzonella

Waste activated sludge production and management plays an important role in wastewater treatment plants (WWTPs), especially from an economic point of view. One possible approach is the anaerobic co-digestion of waste activated sludge with others organic substrates in mesophilic and thermophilic conditions in order to exploit the spare volume of existing reactors, recover energy from biogas production, and obtain a fertilizer as final product. The anaerobic trials were carried out at pilot scale, applying two organic loading rates (2.8 and 4.5 kg chemical oxygen demand (COD)/(m3·d)) with a hydraulic retention time of 16 and 21 days. Among agro-wastes, wine lees were chosen because of their continuous availability throughout the year, and their high COD content (up to 200–300 g/l, 70% soluble, on average). The addition of wine lees to activated sludge determined a higher biogas production (best yield was 0.40 Nm3/kgCODfed) improving the energetic balance of the sludge line of the WWTP. The characterization of both substrates fed and digester effluents was carried out in terms of heavy metals; comparison with EC proposed limits showed that, due to high content of Cu in wine lees, the loading rate of this agro-waste should be limited to maintain good characteristics of final biosolids.


2008 ◽  
Vol 58 (8) ◽  
pp. 1671-1677 ◽  
Author(s):  
A. F. van Nieuwenhuijzen ◽  
A. G. N. van Bentem ◽  
A. Buunnen ◽  
B. A. Reitsma ◽  
C. A. Uijterlinde

The (low loaded) biological nutrient removing activated sludge process is the generally accepted and applied municipal wastewater treatment method in the Netherlands. The hydraulical and biological flexibility, robustness and cost efficiency of the process for advanced removal of nutrients like nitrogen and phosphorus without (too much) chemicals results in a wide application of the activated sludge process within Dutch waterboards. Presumably, wastewater treatment plants will have to contribute to the improvement of the quality of the receiving surface waters by producing cleaner effluent. In this perspective, the Dutch research organisation STOWA initiated a research project entitled “The Boundaries of the Activated Sludge Process” to investigate the possibilities and limitations of activated sludge processes to improve the effluent quality. It is concluded that the activated sludge process as applied and operated at WWTP's in the Netherlands has the potential to perform even better than the current effluent discharge standards (10 mg Ntotal/l and 1 mg Ptotal/l). Reaching the B-quality effluent (<5mg Ntotal/l and <0.3 mg Ptotal/l) will be possible at almost all WWTPs without major adjustments under the conditions that:   the sludge load is below 0.06 kg BOD/kg TSS.d   the internal recirculation is above 20   the BOD/N ratio of the influent is above 3. Complying with the A-quality effluent (<2.2 Ntotal/l and <0.15 mg Ptotal/l) seems to be difficult (but not impossible) and requires more attention and insight into the activated sludge process. Optimisation measures to reach the A-quality effluent are more thorough and are mostly only achievable by additional construction works (addition of activated sludge volume, increasing recirculation capacity, etc.). It is furthermore concluded that the static HSA-results are comparable to the dynamic ASM-results. So, for fast determinations of the limits of technology of different activated sludge processes static modelling seems to by sufficient.


Author(s):  
Bilge Alpaslan Kocamemi ◽  
Halil Kurt ◽  
Ahmet Sait ◽  
Fahriye Sarac ◽  
Ahmet Mete Saatci ◽  
...  

Following the announcement of SARS-CoV-2 worldwide pandemic spread by WHO on March 11, 2020, wastewater based epidemiology received great attention in several countries: The Netherlands [Medama et al., 2020; K-Lodder et al., 2020], USA [Wu et al., 2020; Memudryi et al., 2020], Australia [Ahmed et al., 2020], France [Wurtzer et al., 2020], China [Wang et al., 2020], Spain [Randazzo et al., 2020; Walter et al., 2020], Italy (La Rosa et al., 2020; Rimoldi et al., 2020) and Israel [Or et al., 2020], performed analysis in wastewaters by using different virus concentration techniques. Turkey took its place among these countries on 7th of May, 2020 by reporting SARS-CoV-2 RT-qPCR levels at the inlet of seven (7) major municipal wastewater treatment plants (WWTPs) of Istanbul [Alpaslan Kocamemi et al., 2020], which is a metropole with 15.5 million inhabitants and a very high population density (2987 persons/km2) and having about 65 % of Covid-19 cases in Turkey. Sludges that are produced in WWTPs should be expected to contain SARS-CoV-2 virus as well. There has not yet been any study for the fate of SAR-CoV-2 in sludges generated from WWTPs. Knowledge about the existing of SARS-CoV-2 in sludge may be useful for handling the sludge during its dewatering, stabilizing and disposal processes. This information will also be valuable in case of sludges that are used as soil conditioners in agriculture or sent to landfill disposal. In wastewater treatment plants, generally two different types of sludges are generated; primary sludge (PS) and waste activated sludge (WAS). PS forms during the settling of wastewater by gravity in the primary settling tanks. Little decomposition occurs during primary sludge formation. Since most of the inorganic part of the wastewater is removed in the earlier grit removal process, the PS consists of mainly organic material that settles. The PS is about 1-2 % solids by weight. In the biological treatment part of the WWTPs, the biomass that forms in the anaerobic, anoxic and oxic zones of the process is settled in final clarifiers by gravity and returned to the beginning of the biological process so that it is not washed off. The waste activated sludge (WAS) is the excess part of the biomass that grows in this secondary treatment process. It has to be removed from the process not to increase the mixed liquor suspended solids concentration (bacteria concentration) in the secondary process more than a fixed value. The WAS is about 0.6 - 0.9 % solids by weight. This work aims to find whether SARS-CoV-19 is present in the PS and WAS before it is dewatered and sent to anaerobic or aerobic digester processes or to thermal drying operations. For this purpose, on the 7th of May 2020, two (2) PS samples were collected from Ambarlı and Tuzla WWTPs, seven (7) WAS samples were collected from Terkos, Ambarlı, Atakoy I & II, Pasakoy II, Buyukcekmece and Tuzla I WWTPs. Polyethylene glycol 8000 (PEG 8000) adsorption [Wu et al., 2020] SARS-Cov-2 concentration method was used for SARS-CoV-2 concentration after optimization. [Alpaslan Kocamemi et al., 2020]. Real time RT-PCR diagnostic panel validated by US was used to quantify SARS-CoV-2 RNA in primary and waste activated sludge samples taken from WWTPs in Istanbul. All samples were tested positive. Titers of SARS-CoV-2 have been detected ranging copies between 1.17E4 to 4.02x104 per liter.


2015 ◽  
Vol 72 (3) ◽  
pp. 463-471 ◽  
Author(s):  
Intira Pookpoosa ◽  
Ranjna Jindal ◽  
Daisy Morknoy ◽  
Kraichat Tantrakarnapa

Investigations were carried out on the occurrence and fate of bisphenol A (BPA) in five wastewater treatment plants (WWTPs) in Bangkok, namely, Rattanakosin, Chong Non Si, Din Daeng (DD), Nong Khaem and Thungkru (TK) during three sampling events between October 2013 and February 2014. Based on the results, the influent and effluent BPA concentrations ranged between 128.5 ng/L and 606.0 ng/L; and 38.7 ng/L and 270.5 ng/L, respectively. The effluent BPA concentrations of most of the five WWTPs were lower than the influent levels. TK had the highest removal efficiency in October 2013 (80.4%) and December 2013 (90.7%) and the second highest in February 2014 (69.2%). DD had the highest removal efficiency in February 2014 (91.8%). The treatment processes employed at TK and DD were vertical loop reactor activated sludge process and activated sludge with nutrients removal, respectively. Thus, these processes seem to be good for BPA degradation.


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