Recovery of Biodegradable Bioplastics from Different Activated Sludge Processes during Wastewater Treatment

Structure Synthesis ◽

Simultaneous Process ◽

Activated Sludge Processes

To overcome the environmental hazards of petroleum based plastics, synthesis and use of microbial bioplastics became popular. Polyhydroxyalkanoates (PHAs) are biodegradable biopolymers having plastic like properties mainly used in tissue engineering and packaging. Bacteria can produce bioplastics in carbon abundance. Activated sludge process is a simultaneous process for treating wastewater and producing PHAs. Wastewaters are treated by using mixed sludge, aerobic granular sludge and chemically treated sludge which provided more than 40% PHA yield. This chapter describes the PHA structure, synthesis pathways, types of wastewaters and activated sludge processes used with reactor parameters and environmental factors effecting PHA productions.

Textile wastewater treatment: Aerobic granular sludge vs activated sludge systems

Water Research ◽

10.1016/j.watres.2014.01.055 ◽

2014 ◽

Vol 54 ◽

pp. 337-346 ◽

Cited By ~ 53

Author(s):

Adriana Maria Lotito ◽

Marco De Sanctis ◽

Claudio Di Iaconi ◽

Giovanni Bergna

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Granular Sludge ◽

Textile Wastewater ◽

Aerobic Granular Sludge ◽

Textile Wastewater Treatment ◽

Activated Sludge Systems

The limits and ultimate possibilities of technology of the activated sludge process

10.2166/wst.2008.545 ◽

2008 ◽

Vol 58 (8) ◽

pp. 1671-1677 ◽

Cited By ~ 3

Author(s):

A. F. van Nieuwenhuijzen ◽

A. G. N. van Bentem ◽

A. Buunnen ◽

B. A. Reitsma ◽

C. A. Uijterlinde

Keyword(s):

Wastewater Treatment ◽

The Netherlands ◽

Activated Sludge ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Treatment Method ◽

Municipal Wastewater Treatment ◽

Nitrogen And Phosphorus ◽

Activated Sludge Processes

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.

Unwanted mainstream nitritation-denitritation causing massive N2O emissions in a continuous activated sludge process

10.2166/wst.2021.127 ◽

2021 ◽

Author(s):

A. Kuokkanen ◽

K. Blomberg ◽

A. Mikola ◽

M. Heinonen

Keyword(s):

Nitrous Oxide ◽

Wastewater Treatment ◽

Activated Sludge ◽

Nitrogen Removal ◽

Municipal Wastewater ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Municipal Wastewater Treatment ◽

Activated Sludge Processes

Abstract Nitrous oxide emissions can contribute significantly to the carbon footprint of municipal wastewater treatment plants even though emissions from conventional nitrogen removal processes are assumed to be moderate. An increased risk for high emissions can occur in connection with process disturbances and nitrite (NO2−) accumulation. This work describes the findings at a large municipal wastewater treatment plant where the levels of NO2− in the activated sludge process effluent were spontaneously and strongly increased on several activated sludge lines which was suspected to be due to shortcut nitrogen removal that stabilized for several months. The high NO2− levels were linked to a dramatic increase in nitrous oxide (N2O) emissions. As much as over 20% of the daily influent nitrogen load was emitted as N2O. These observations indicate that highly increased NO2− levels can occur in conventional activated sludge processes and result in high nitrous oxide emissions. They also raise questions concerning the risk of increased greenhouse gas (GHG) emissions of the nitritation-denitritation processes – although the uncontrolled nature of the event described here must be taken into consideration – and underline the importance of continuous monitoring and control of N2O emissions.

Enhanced settling in activated sludge: design and operation considerations

10.2166/wst.2018.287 ◽

2018 ◽

Vol 78 (2) ◽

pp. 247-258 ◽

Cited By ~ 2

Author(s):

Glen T. Daigger ◽

Eric Redmond ◽

Leon Downing

Keyword(s):

Activated Sludge ◽

Quality Criteria ◽

Granular Sludge ◽

Aerobic Granular Sludge ◽

Water Quality Criteria ◽

Subsequent Removal ◽

Solids Concentration ◽

Activated Sludge Processes ◽

Sludge Settleability ◽

Activated Sludge Systems

Abstract Settling of activated sludge particles has long been the key to successfully achieving secondary treatment. While soluble products can be converted to particulate components via microbial reactions in the activated sludge process, it is the subsequent removal of these particulate components that is the key to achieving ultimate water quality criteria. An understanding of the operating parameters for selecting good settling activated sludge particles was first documented in the 1970s and 1980s. An understanding of the growth pressures that can be imposed on filamentous organisms, and the impacts of selector zones in general, allowed the design and operation of activated sludge processes to routinely achieve good sludge settleability. More recently, research has identified what could be the next evolution in flocculant growth, with the growing interest in aerobic granular sludge. Aerobic granular sludge is purported to provide superior settling properties, and many of the growth pressures identified for aerobic granular sludge are also present in activated sludge systems. These enhanced settling sludge systems are gaining significant interest, but the factors leading to enhanced sludge settleability could be present in historical and existing systems. Three facilities were evaluated that exhibited enhanced settleability (i.e. sludge volume indices of less than 70 mL/g the majority of the time) to determine how these enhanced settling sludges compare to typical settling curves from the literature. The enhanced settling sludge facilities exhibit key differences related to surface overflow rate, return activated sludge (RAS) pumping requirements, and sensitivity to solids concentration that are critical for developing effective settling designs for enhanced settling sludge facilities. As more facilities aim to achieve enhanced settling sludge for intensification of infrastructure, it will be important to carefully consider historic settling curves and to develop site-specific settling criteria when possible.

Simulation of Aerobic Granular Sludge Process Efficiency

Revista de Chimie ◽

10.37358/rc.17.8.5752 ◽

2017 ◽

Vol 68 (8) ◽

pp. 1723-1725

Author(s):

Elena Elisabeta Manea ◽

Costel Bumbac ◽

Olga Tiron ◽

Razvan Laurentiu Dinu ◽

Valeriu Robert Badescu

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Batch Reactor ◽

Granular Sludge ◽

Process Efficiency ◽

Aerobic Granular Sludge ◽

Organic Load ◽

Batch Reactors ◽

Conventional Activated Sludge ◽

Pollutants Removal

Using aerobic granular sludge for wastewater treatment has multiple advantages compared to conventional activated sludge systems, most important being the ability of simultaneous removal of the pollutants responsible for eutrophication: organic load, compounds of nitrogen (NH4+; NO3-) and phosphorus (PO43-). The advantages are currently exploited for developing the next generation of wastewater treatment systems while the identified limitations are approached by experimental and theoretical researches worldwide. The aim of the study consists in evaluating the possibility of predicting the system�s response to different changes in the influent wastewater loadings. The paper presents simulations results backed up by experimental data for pollutants removal efficiencies evaluation for a sequential batch reactor (SBR) with aerobic granular sludge. The mathematical model is based on the activated sludge model no. 3, which was updated by considering the simultaneous biological nitrification (NH4+NO3) and denitrification (NO3-N2) processes, thus complying with the biochemical reactions occurring in aerobic granular sludge sequential batch reactors. The model developed was validated by the experimental results obtained on a laboratory scale SBR monitored for over a month.

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

Performance of Aerobic Granular Sludge for Domestic Wastewater Treatment

10.35940/ijitee.l3360.1081219 ◽

2019 ◽

Vol 8 (12) ◽

pp. 3851-3854

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Batch Reactor ◽

Biomass Concentration ◽

Domestic Wastewater ◽

Granular Sludge ◽

Volume Index ◽

Aerobic Granular Sludge ◽

Domestic Wastewater Treatment ◽

Low Strength

Aerobic granular sludge can be used to treat various types of wastewater, such as industrial, municipal and domestic wastewater. This study investigated the treatment of low-strength domestic wastewater while simultaneously developed aerobic granular sludge in a sequencing batch reactor (SBR). Activated sludge was used as the seeding for granulation. The results indicated good COD and ammoniacal nitrogen removal at 72% and 73%, respectively. Aerobic granular sludge was successfully developed with low sludge volume index (SVI30) of 29 mL/g, which demonstrated an excellent settling property of aerobic granular sludge. Biomass concentration increased significantly compared to the seed sludge, indicating high biomass density in the SBR system. Settling velocity of aerobic granular sludge was significantly higher compared to the conventional activated sludge. This study showed the feasibility of aerobic granular sludge to be developed using low-strength domestic wastewater. Moreover, this study demonstrated the long-term application of aerobic granular sludge in domestic wastewater treatment.

DESIGN PLANNING WASTEWATER TREATMENT PLANT OF NATA DE COCO INDUSTRY WITH THE ACTIVATED SLUDGE PROCESS

Jurnal Rekayasa Lingkungan ◽

10.29122/jrl.v9i2.1994 ◽

2016 ◽

Vol 9 (2) ◽

Author(s):

Dinda Rita K. Hartaja ◽

Imam Setiadi

Keyword(s):

Waste Water ◽

Wastewater Treatment ◽

Activated Sludge ◽

Waste Water Treatment ◽

Treatment Plant ◽

Water Treatment Plant ◽

Appropriate Technology ◽

Waste Water Treatment Plant ◽

High Level

Generally, wastewater of nata de coco industry contains suspended solids and COD were high, ranging from 90,000 mg / l. The high level of of the wastewater pollutants, resulting in nata de coco industry can not be directly disposed of its wastewater into the environment agency. Appropriate technology required in order to process the waste water so that the treated water can meet the environmental quality standards that are allowed. Designing the waste water treatment plant that is suitable and efficient for treating industrial wastewater nata de coco is the activated sludge process. Wastewater treatment using activated sludge process of conventional (standard) generally consists of initial sedimentation, aeration and final sedimentation.Keywords : Activated Sludge, Design, IPAL

Deemulsification of Water-in-Oil Emulsion with Sludges

Water Quality Research Journal ◽

10.2166/wqrj.1987.034 ◽

1987 ◽

Vol 22 (3) ◽

pp. 437-443 ◽

Cited By ~ 5

Author(s):

N. Kosaric ◽

Z. Duvnjak

Keyword(s):

Activated Sludge ◽

Room Temperature ◽

Petroleum Refinery ◽

Treatment Plant ◽

Granular Sludge ◽

Sludge Treatment ◽

Oil Emulsion ◽

Water In Oil Emulsion ◽

Aerobic Sludge

Abstract Aerobic sludge from a municipal activated sludge treatment plant, sludge from a conventional municipal anaerobic digester, aerobic sludge from an activated sludge process of a petroleum refinery, and granular sludge from an upflow sludge blanket reactor (USBR) were tested in the deemulsification of a water-in-oil emulsion. All sludges except the last one, showed a good deemulsification capability and could he used for a partial deemulsification of such emulsions. The rate and degree of the deemulsifications increased with an increase in sludge concentrations. The deemulsifications were faster at 85°C and required smaller amounts of sludge than in the case of the deemulsifications at room temperature. An extended stirring (up to a certain limit) in the course of the dispersion of sludge emulsion helped the deemulsification. Too vigorous agitation had an adverse effect. The deemulsification effect of sludge became less visible with an increase in the dilution of emulsion which caused an increase in its spontaneous deemulsification.

Rehabilitation and Upgrading of the Beni Suef City Wastewater Treatment Plant

10.2166/wst.1990.0238 ◽

1990 ◽

Vol 22 (7-8) ◽

pp. 131-138

Author(s):

Ahmed Fadel

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Primary Treatment ◽

High Rate ◽

Shock Load ◽

Economic Evaluations ◽

Trickling Filter

Many of Egypt's cities have existing treatment plants under operation that have been constructed before 1970. Almost all of these treatment plants now need rehabilitation and upgrading to extend their services for a longer period. One of these plants is the Beni Suef City Wastewater Treatment Plant. The Beni Suef WWTP was constructed in 1956. It has primary treatment followed by secondary treatment employing intermediate rate trickling filters. The BOD, COD, and SS concentration levels are relatively high. They are approximately 800, 1100, and 600 mg/litre, respectively. The Beni Suef city required the determination of the level of work needed for the rehabilitation and upgrading of the existing 200 l/s plant and to extend its capacity to 440 l/s at year 2000 A description of the existing units, their deficiencies and operation problems, and the required rehabilitation are presented and discussed in this paper. Major problems facing the upgrading were the lack of space for expansion and the shortage of funds. It was, therefore, necessary to study several alternative solutions and methods of treatment. The choice of alternatives was from one of the following schemes: a) changing the filter medium, its mode of operation and increasing the number of units, b) changing the trickling filter to high rate and combining it with the activated sludge process, for operation by one of several possible combinations such as: trickling filter-solids contact, roughing filter-activated sludge, and trickling filter-activated sludge process, c) dividing the flow into two parts, the first part to be treated using the existing system and the second part to be treated by activated sludge process, and d) expanding the existing system by increasing the numbers of the different process units. The selection of the alternative was based on technical, operational and economic evaluations. The different alternatives were compared on the basis of system costs, shock load handling, treatment plant operation and predicted effluent quality. The flow schemes for the alternatives are presented. The methodology of selecting the best alternative is discussed. From the study it was concluded that the first alternative is the most reliable from the point of view of costs, handling shock load, and operation.

Activated Sludge Treatment of Kraft Mill Effluents from Conventional and Oxygen Bleaching

10.2166/wst.1991.0499 ◽

1991 ◽

Vol 24 (3-4) ◽

pp. 427-430 ◽

Cited By ~ 3

Author(s):

J. Nevalainen ◽

P.-R. Rantala ◽

J. Junna ◽

R. Lammi

Keyword(s):

Activated Sludge ◽

Kraft Pulp ◽

Chlorinated Phenols ◽

Pulp Mills ◽

Main Interest ◽

Sludge Treatment ◽

Kraft Pulp Mills ◽

Activated Sludge Processes ◽

Oxygen Bleaching

Conventional and oxygen bleaching effluents from hardwood kraft pulp mills were treated in laboratory-scale activated sludge processes. The main interest was the fate of organochlorine compounds in the activated sludge process. In the treatment of conventional bleaching wastewaters the BOD7-reduction was 80-91 % and in oxygen bleaching wastewaters 86-93 %. The respective CODCr removals were about 40 % and about 50 %. The AOX reductions were on average 22 % and 40 % in the treatment of conventional and oxygen bleaching effluents, respectively. The reductions of chlorinated phenols, guajacols and catecols were usually more than 50 % in both reactors. Very little accumulation of AOX into the sludge was observed. The stripping of AOX from aeration unit was insignificant.