Operation and recovery of a seasonally-loaded UK waste stabilisation pond system

An intermittent discharge waste stabilisation pond system was trialled for treatment of a seasonal wastewater load from a campsite. The system showed rapid acclimatisation to incoming load, with chlorophyll-a exceeding 700 mg l−1 within 2 weeks and filtered and unfiltered effluent biochemical oxygen demand below 20 and 30 mg l−1 respectively. Good performance continued for some weeks, after which photosynthetic oxygenation capacity in the first pond was seriously impaired by a shock loading believed to include fatty material. Inflow to the system was suspended and a surface film was broken up, after which the pond recovered within an 8-day period. Laboratory experiments indicated that interventions such as artificial aeration and dilution with effluent had no beneficial effect although mixing may have increased the rate of recovery.

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Nutrients and Algal Growth in an Impounded River, Consequences for its Oxygen Balance and Nutrient Control Strategy

Water Science & Technology ◽

10.2166/wst.1982.0098 ◽

1982 ◽

Vol 14 (4-5) ◽

pp. 185-197 ◽

Cited By ~ 1

Author(s):

K R Imhoff ◽

D R Albrecht

Keyword(s):

Algal Blooms ◽

Algal Growth ◽

Oxygen Demand ◽

Quality Data ◽

Oxygen Balance ◽

Phosphate Content ◽

Water Quality Data ◽

Artificial Aeration ◽

The Past ◽

Oxygen Shortage

A series of impoundments occur on the final 46 km stretch of the Ruhr river where phosphorus, nitrogen, and organic carbon are present abundantly, causing several heavy algal blooms during the year. This is detrimental for the treatment capacity of the water works. Also, an oxygen shortage is always recorded in the river after algal decay at low flows, thus requiring artificial aeration. By balancing all oxygen supply and consumption it is shown that about 2/3 of the oxygen demand is due to algal decomposition. When evaluating the water quality data of the past 30 years and by conducting special laboratory tests, results show that phosphates initiate algal growth. Therefore, a phosphate model has been developed for the river which predicts the phosphate content for 1988 and 1998. It is expected that by reduction of this phosphate content maximum algal growth can be cut by about 50 %.

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Optimal location of artificial aeration in a tidal river for water quality improvement

Water Science & Technology ◽

10.2166/wst.2000.0409 ◽

2000 ◽

Vol 42 (3-4) ◽

pp. 397-402

Author(s):

S. Li ◽

G.H. Chen ◽

B.C. Yen

Keyword(s):

Water Quality ◽

Quality Improvement ◽

Oxygen Demand ◽

Reaction Rates ◽

Sediment Oxygen Demand ◽

Tidal River ◽

Optimal Position ◽

Water Quality Improvement ◽

Artificial Aeration ◽

Saint Venant Equations

Artificial aeration is one of the alternatives proposed for the improvement of DO level of the Shing Mun River in Hong Kong. This study employs Saint Venant equations and one-dimensional water quality models to simulate the hydrodynamics and DO distributions in the river, respectively. Processes affecting the river quality, such as biochemical degradation, oxygen production and consumption by algae and sediment oxygen demand are considered in the models. In-situ and laboratory tests were conducted to determine the values of reaction rates of these processes. By comparing the simulated results of DO concentration under different locations of the aeration equipment along the river with the present DO condition during spring and neap tides, the optimal position of artificial aeration is determined based on the effectiveness of water quality improvement. The effect of intermittent aeration and that of continuous aeration are compared and it is found that the increase of DO in the intermittent aerationcase is about 50% of that in the continuous case on the cross-section of aeration. The influence of water temperature on the aeration is also discussed.

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A reactivity continuum of particulate organic matter in a global ocean biogeochemical model

10.5194/bg-2016-374 ◽

2016 ◽

Cited By ~ 1

Author(s):

Olivier Aumont ◽

Marco van Hulten ◽

Matthieu Roy-Barman ◽

Jean-Claude Dutay ◽

Christian Ethé ◽

...

Keyword(s):

Laboratory Experiments ◽

Critical Role ◽

Oxygen Demand ◽

Sediment Oxygen Demand ◽

Global Ocean ◽

Biogeochemical Model ◽

Mesopelagic Zone ◽

Ocean Biogeochemical Model ◽

The Impact ◽

Reactivity Continuum

Abstract. The marine biological carbon pump is dominated by the vertical transfer of Particulate Organic Carbon (POC) from the surface ocean to its interior. The efficiency of this transfer plays an important role in controlling the amount of atmospheric carbon that is sequestered in the ocean. Furthermore, the abundance and composition of POC is critical for the removal of numerous trace elements by scavenging, a number of which such as iron are essential for the growth of marine organisms, including phytoplankton. Observations and laboratory experiments have shown that POC is composed of numerous organic compounds that can have very different reactivities. Yet, this variable reactivity of POC has never been extensively considered, especially in modeling studies. Here, we introduced in the global ocean biogeochemical model NEMO-PISCES a description of the variable composition of POC based on the theoretical Reactivity Continuum Model proposed by (Boudreau and Ruddick, 1991). Our model experiments show that accounting for a variable lability of POC increases POC concentrations in the ocean’s interior by one to two orders of magnitude. This increase is mainly the consequence of a better preservation of small particles that sink slowly from the surface. Comparison with observations is significantly improved both in abundance and in size distribution. Furthermore, the amount of carbon that reaches the sediments is increased by more than a factor of two, which is in better agreement with global estimates of the sediment oxygen demand. The impact on the major macro-nutrients (nitrate and phosphate) remains modest. However, iron (Fe) distribution is strongly altered, especially in the upper mesopelagic zone as a result of more intense scavenging: Vertical gradients in Fe are milder in the upper ocean which appears to be closer to observations. Thus, our study shows that the variable lability of POC can play a critical role in the marine biogeochemical cycles which advocates for more dedicated in situ and laboratory experiments.

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

The Journal of Solid Waste Technology and Management ◽

10.5276/jswtm/2019.395 ◽

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.

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Detoxification potential and rehabilitation of activated sludge after shock loading of Sofia's wastewater treatment plant ‘Kubratovo’ with mazut

Water Science & Technology ◽

10.2166/wst.2018.329 ◽

2018 ◽

Vol 78 (3) ◽

pp. 588-601

Author(s):

Yana Topalova ◽

Yovana Todorova ◽

Irina Schneider ◽

Ivaylo Yotinov ◽

Vesela Stefanova

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Succinate Dehydrogenase ◽

Shock Loading ◽

Treatment Plant ◽

Oxygen Demand ◽

Volume Index ◽

Biotic Index ◽

Ring Cleavage ◽

Strong Increase

AbstractThe shock loading of wastewater treatment plants (WWTPs) with toxic pollutants remains a critical problem with crucial significance for the technologies. On 5 November 2014, 30 tons of mazut were emitted in Sofia's WWTP ‘Kubratovo’, passing through equipment and damaging the functioning of the technological modules. The rehabilitation of activated sludge (AS) after shock loading as well as the development of detoxification activity were investigated. The hydrocarbon index of petroleum products, filamentous index (FI), sludge biotic index, sludge volume index (SVI), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), oxygenases and succinate dehydrogenase activities were analyzed for a period of two weeks. The results show that independently from prolonged rehabilitation period, AS remained with filamentous bulking (SVI over 200 ml/g and FI over 1.107 μm/mg). At the same time, the detoxification potential of the AS was developed. Although the morphological and functional structure was still not fully recovered, the AS developed two adaptive mechanisms. First, activation of shorter, more effective ways for benzene ring cleavage, operated by catechol 2,3-dioxygenase; second, strong increase of succinate dehydrogenase activity, which is consistent with the activation of the degradation of trivial substrates for energy generating to overcome the intoxication and synthesis of oxygenases.

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Effects of hydraulic loading rate and aeration mode on nitrogen removal and nitrogen functional gene abundances in subsurface wastewater infiltration systems

Water Science & Technology ◽

10.2166/wst.2017.208 ◽

2017 ◽

Vol 76 (1) ◽

pp. 210-218 ◽

Cited By ~ 4

Author(s):

Yafei Sun ◽

Jing Pan ◽

Shiyue Qi ◽

Hexin Fei

Keyword(s):

Nitrogen Removal ◽

Loading Rate ◽

Oxygen Demand ◽

Functional Gene ◽

Intermittent Aeration ◽

Anaerobic Conditions ◽

Loading Rates ◽

Hydraulic Loading ◽

Artificial Aeration ◽

Operation Cost

Matrix dissolved oxygen, nitrogen removal and nitrogen functional gene abundances in two artificial aeration modes, continuous aeration (CA) and intermittent aeration (IA), in subsurface wastewater infiltration systems (SWISs) under different hydraulic loading rates (HLRs) were investigated. Aeration not only successfully created aerobic conditions at 50 cm depth, but also did not change anoxic or anaerobic conditions at 80 and 110 cm depths. Meanwhile, aeration significantly enhanced chemical oxygen demand, NH4+-N, and total nitrogen (TN) removal and the enrichment of nitrogen removal functional genes (amoA, nxrA, napA, narG, nirK and qnorB) compared to the non-aerated SWIS, especially for high HLRs. IA SWIS (79.7%–85.8%) had a better performance on TN removal compared with CA SWIS (73.8%–82.2%) when the HLRs ranged from 0.06 to 0.3 m3/(m2 d). Intermittent aeration is a sensible strategy to achieve high HLR, good nitrogen removal performance and comparatively low operation cost for SWISs.

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The development of an onsite sanitation system based on vermifiltration: the ‘Tiger Toilet’

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2015.167 ◽

2015 ◽

Vol 5 (4) ◽

pp. 608-613 ◽

Cited By ~ 9

Author(s):

C. Furlong ◽

W. T. Gibson ◽

M. R. Templeton ◽

M. Taillade ◽

F. Kassam ◽

...

Keyword(s):

Chemical Oxygen Demand ◽

Laboratory Experiments ◽

Oxygen Demand ◽

Daily Basis ◽

Rural India ◽

System Configuration ◽

Effluent Quality ◽

Laboratory Results ◽

The Uk ◽

Further Development

This paper describes the development of a novel onsite sanitation system based on vermifiltration, the ‘Tiger Toilet’. Initial laboratory experiments demonstrated that feed distribution was not required, a worm density of 2 kg/m2 could be used, worms preferred wetter environments, and system configuration did not affect effluent quality. Installing the first prototype in the UK proved that the process functioned when scaled, i.e., chemical oxygen demand and thermotolerant coliform reduction were found to be comparable with the laboratory results. Ten prototypes were then tested by households in rural India; all were working well after six months. The vermifilters were processing the amount of faeces entering the system on a daily basis, so faeces was not accumulating. It was estimated that they would require emptying after approximately five years, based on the depth of the vermicompost generated. With further development, it is believed that the Tiger Toilet has the potential to become a superior form of onsite sanitation, when compared with traditional onsite sanitation technologies.

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Performance of methane fermentation pits in advanced integrated wastewater pond systems

Water Science & Technology ◽

10.2166/wst.1994.0628 ◽

1994 ◽

Vol 30 (12) ◽

pp. 287-295 ◽

Cited By ~ 13

Author(s):

William J. Oswald ◽

F. Bailey Green ◽

Tryg J. Lundquist

Keyword(s):

Suspended Solids ◽

Oxygen Demand ◽

University Of California ◽

Halogenated Hydrocarbons ◽

Reclaimed Wastewater ◽

Methane Fermentation ◽

Photosynthetic Oxygenation ◽

Beneficial Uses ◽

And Performance ◽

The University

Advanced Integrated Wastewater Pond Systems (AIWPSs) involve a series consisting of Advanced Facultative Ponds with internally located fermentation pits; secondary ponds with either photosynthetic oxygenation or mechanical aeration; tertiary ponds for sedimentation of either algae or aeration solids; and, quaternary ponds for controlled discharge, irrigation storage, aquaculture, or other beneficial uses of reclaimed wastewater. This paper deals mainly with design and performance of Advanced Facultative Ponds containing internally located fermentation pits. Experiences with a 1,894 m3 day−1 (0.5 MGD) AIWPS and a 7,576 m3 day−1 (2.0 MGD) AIWPS indicate that primary facultative ponds with internal fermentation pits require less land than do conventional anaerobic ponds and that sludge removal is postponed for many years. New, more detailed, and controlled scientific studies on a 133 m3 day−1 (0.035 MGD) demonstration AIWPS at the University of California, Berkeley, Environmental Engineering and Health Sciences Laboratory in Richmond, California provide evidence that these simple pits remove suspended solids and biochemical oxygen demand more effectively than do comparably loaded conventional anaerobic ponds and produce much less odor. In addition they improve removal of parasites, bacteria, viruses, heavy metals, and halogenated hydrocarbons. The reliability and cost effectiveness of AIWPS is compared with more conventional ponds and with mechanical wastewater treatment systems.

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Biological Treatment of Wastewater from the Exploitation of Heavy Oil

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.807-809.1223 ◽

2013 ◽

Vol 807-809 ◽

pp. 1223-1226

Author(s):

Feng He ◽

Hua Zhou ◽

Hong Ru Liu

Keyword(s):

Biological Treatment ◽

Suspended Solids ◽

Shock Loading ◽

Oxygen Demand ◽

Biological Processes ◽

Waste Sludge ◽

Crude Oil Production ◽

Contact Oxidation ◽

Heavy Crude

Biological treatment of heavy crude oil production wastewater is well-established method for remediation of these wastes. We have developed effective biological treatments by (1) utilizing microbes with high oil-degrading abilities, (2) allowing greater organic loads while increasing both process stability and the resistance to shock loading, (3) minimizing the production of waste sludge byproducts, and (4) adopting anaerobic and aerobic biological processes to improve the biodegradation of the wastewater. Fixed-film bioreactors with 15h hydraulic retention times have decreased chemical oxygen demand by 74.8%, total suspended solids by 90.9%, oil by 80.6%, and phenols and sulfides by 100%. The results with anin situpilot system show that the bioreactor's hydrolytic acidulation and contact oxidation tanks are suitable for treating oilfield wastewater, and that water quality after treatment fully meets national drainage standards.

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Variable reactivity of particulate organic matter in a global ocean biogeochemical model

Biogeosciences ◽

10.5194/bg-14-2321-2017 ◽

2017 ◽

Vol 14 (9) ◽

pp. 2321-2341 ◽

Cited By ~ 21

Author(s):

Olivier Aumont ◽

Marco van Hulten ◽

Matthieu Roy-Barman ◽

Jean-Claude Dutay ◽

Christian Éthé ◽

...

Keyword(s):

Laboratory Experiments ◽

Critical Role ◽

Oxygen Demand ◽

Sediment Oxygen Demand ◽

Global Ocean ◽

Biogeochemical Model ◽

Mesopelagic Zone ◽

Modelling Studies ◽

Ocean Biogeochemical Model ◽

The Impact

Abstract. The marine biological carbon pump is dominated by the vertical transfer of particulate organic carbon (POC) from the surface ocean to its interior. The efficiency of this transfer plays an important role in controlling the amount of atmospheric carbon that is sequestered in the ocean. Furthermore, the abundance and composition of POC is critical for the removal of numerous trace elements by scavenging, a number of which, such as iron, are essential for the growth of marine organisms, including phytoplankton. Observations and laboratory experiments have shown that POC is composed of numerous organic compounds that can have very different reactivities. However, this variable reactivity of POC has never been extensively considered, especially in modelling studies. Here, we introduced in the global ocean biogeochemical model NEMO-PISCES a description of the variable composition of POC based on the theoretical reactivity continuum model proposed by Boudreau and Ruddick (1991). Our model experiments show that accounting for a variable lability of POC increases POC concentrations in the ocean's interior by 1 to 2 orders of magnitude. This increase is mainly the consequence of a better preservation of small particles that sink slowly from the surface. Comparison with observations is significantly improved both in abundance and in size distribution. Furthermore, the amount of carbon that reaches the sediments is increased by more than a factor of 2, which is in better agreement with global estimates of the sediment oxygen demand. The impact on the major macronutrients (nitrate and phosphate) remains modest. However, iron (Fe) distribution is strongly altered, especially in the upper mesopelagic zone as a result of more intense scavenging: vertical gradients in Fe are milder in the upper ocean, which appears to be closer to observations. Thus, our study shows that the variable lability of POC can play a critical role in the marine biogeochemical cycles which advocates for more dedicated in situ and laboratory experiments.

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