The potential for facilitating spring discharge from continental climate waste stabilisation ponds by carry-over of treated wastewater: concepts and experimental findings

2007 ◽  
Vol 55 (11) ◽  
pp. 219-227 ◽  
Author(s):  
C. Whalley ◽  
L.N. Pak ◽  
S. Heaven
Keyword(s):  
Operating Regime ◽  
Pilot Scale ◽  
Treated Wastewater ◽  
Winter Period ◽  
Spring Discharge ◽  
Waste Stabilisation Ponds ◽  
Carry Over ◽  
Set Up ◽  
Experimental Findings ◽  
Continental Climate

The research investigated some factors influencing the rate of stabilisation of wastewater in the spring period in continental climate waste stabilisation ponds, and in particular the potential for bringing forward the discharge date by optimising storage capacity and dilution. Experiments using pilot and model-scale ponds were set up in Almaty, Kazakhstan. These simulated operating regimes for a facultative and storage/maturation pond system subject to ice cover from late November until late March. Two pilot-scale facultative ponds were operated at hydraulic retention times (HRT) of 20 and 30 days, with surface loading rates of 100 and 67 kg BOD ha−1 day−1. Effluent from the 20-day HRT facultative pond was then fed to two pilot-scale storage/maturation ponds which had been partially emptied and allowed to refill over the winter period with no removal of effluent. The paper discusses the results of the experiments with respect to selection of an operating regime to make treated wastewater available early in the spring. Preliminary results indicate that there may be potential for alternative operating protocols designed to maximise their performance and economic potential.

scholarly journals Influence of annual climate variability on design and operation of waste stabilisation ponds for continental climates

2007 ◽  
Vol 55 (11) ◽  
pp. 37-46 ◽  
Author(s):  
S. Heaven ◽  
A.M. Salter ◽  
D. Clarke
Keyword(s):  
Oxygen Demand ◽  
Major Effect ◽  
Treated Wastewater ◽  
Local Climate ◽  
Climate Conditions ◽  
Effluent Quality ◽  
Waste Stabilisation Ponds ◽  
First Order Kinetics ◽  
Standard Design ◽  
Continental Climate

WSPs are widely used in North America, and offer huge potential for other continental climate regions. The standard design and operating protocol is robust even at high latitudes, but may be conservative elsewhere. A simple model based on first-order kinetics for biochemical oxygen demand (BOD) is used to consider some alternative design and operating protocols, using long-term daily climate records for cities across continental central Asia. Options include changing the discharge period; retaining treated water in the pond over the winter; and changing the facultative pond loading. Annual variability in climate parameters has a major effect, in particular on the date at which treated wastewater meets appropriate standards for discharge or re-use: the earlier the discharge, the greater the variability in effluent quality. Skilful management of these systems may therefore be required to maximise their performance. While current models require development, it is clear modelling could provide tools and guidelines that would allow the design of continental climate WSP to be tailored to specific regional and local climate conditions.

Costs of tertiary treatment of municipal wastewater by rapid sand filter with coagulants and UV

2003 ◽  
Vol 3 (4) ◽  
pp. 145-152 ◽  
Author(s):  
H. Heinonen-Tanski ◽  
P. Juntunen ◽  
R. Rajala ◽  
E. Haume ◽  
A. Niemelä
Keyword(s):  
Total Phosphorus ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Treated Wastewater ◽  
Tertiary Treatment ◽  
Sand Filter ◽  
Physico Chemical ◽  
Bathing Waters ◽  
Filtration Unit ◽  
Microbial Groups

Municipal treated wastewater has been tertiary treated in a pilot-scale rapid sand filter. The filtration process was improved by using polyaluminium coagulants. The sand-filtered water was further treated with one or two UV reactors. The quality changes of wastewater were measured with transmittance, total phosphorus, soluble phosphorus, and somatic coliphages, FRNA-coliphages, FC, enterococci and fecal clostridia. Sand filtration alone without coagulants improved slightly some physico-chemical parameters and it had almost no effect on content of microorganisms. If coagulants were used, the filtration was more effective. The reductions were 88-98% for microbial groups and 80% for total phosphorus. The wastewater would meet the requirements for bathing waters (2,000 FC/100 ml, EU, 1976). UV further improved the hygiene level; this type of treated wastewater could be used for unrestricted irrigation (2.2 TC/100 ml, US.EPA 1992). The improvement was better if coagulants were used. The price for tertiary treatment (filtration + UV) would have been 0.036 Euro/m3 according to prices in 2001 in 22 Mm3/a. The investment cost needed for the filtration unit was 0.020 Euro/m3 (6%/15a). Filtration with coagulants is recommended in spite of its costs, since the low transmittance of unfiltered wastewater impairs the efficiency of the UV treatment.

scholarly journals An evaluation of the Kemtek 1000 sample processor

1988 ◽  
Vol 10 (1) ◽  
pp. 37-42 ◽  
Author(s):  
M. J. Wheeler ◽  
Linzi Waiters
Keyword(s):  
Probe System ◽  
Carry Over ◽  
Set Up ◽  
Accuracy Speed ◽  
Better Than ◽  
The Way

The Kemtek 1000 Sample Processor has been evaluated for precision, accuracy, speed and reliability. Precision was better than 1.0% at all volumes tested and accuracy within ±5%. A l00-tube assay could be set up within 15 min when patient specimens plus two reagents were sampled using a two probe system. Carry-over could be reduced to <0.01% by using a sufficient number of wash steps, the latter being related to the assay requirements. Evidence was found for adsorption of protein to the probe tubing but inaccuracies due to this could be reduced by introducing wash steps between samples. Problems over 12 months have been minor and quickly resolved. The authors were pleased with the way the processor performed and their staffhave confidence in leaving it to set up their assays.

scholarly journals Nitrification–denitrification in waste stabilisation ponds: a mechanism for permanent nitrogen removal in maturation ponds

2010 ◽  
Vol 61 (5) ◽  
pp. 1137-1146 ◽  
Author(s):  
M. A. Camargo Valero ◽  
L. F. Read ◽  
D. D. Mara ◽  
R. J. Newton ◽  
T. P. Curtis ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Inorganic Nitrogen ◽  
Isotope Analysis ◽  
Pilot Scale ◽  
Intermediate Step ◽  
Nitrogen Transformations ◽  
Waste Stabilisation Ponds ◽  
Molecular Microbiology ◽  
Denitrification Process ◽  
Ammonia Oxidising Bacteria

A pilot-scale primary maturation pond was spiked with 15N-labelled ammonia (15NH4Cl) and 15N-labelled nitrite (Na15NO2), in order to improve current understanding of the dynamics of inorganic nitrogen transformations and removal in WSP systems. Stable isotope analysis of δ15N showed that nitrification could be considered as an intermediate step in WSP, which is masked by simultaneous denitrification, under conditions of low algal activity. Molecular microbiology analysis showed that denitrification can be considered a feasible mechanism for permanent nitrogen removal in WSP, which may be supported either by ammonia-oxidising bacteria (AOB) or by methanotrophs, in addition to nitrite-oxidising bacteria (NOB). However, the relative supremacy of the denitrification process over other nitrogen removal mechanisms (e.g., biological uptake) depends upon phytoplanktonic activity.

Microstructured Reactors for Gas Phase Reactions

2008 ◽  
Author(s):  
Steffen Schirrmeister
Keyword(s):  
Gas Phase ◽  
Flow Distribution ◽  
Pilot Scale ◽  
Gas Phase Reactions ◽  
Process Technology ◽  
Safety Issues ◽  
Catalyst Coating ◽  
Coating Flow ◽  
Set Up ◽  
Micro Technology

Pilot-scale micro-process technology for heterogeneously catalyzed gas phase reactions is generally highly demanding towards the methods of catalyst coating, flow distribution, reactor manufacturing and assembly, safety issues and other factors. Yet, first cost analysis have shown that economical processes can be developed using micro-technology. For this matter, it is necessary to improve and simplify the laboratory set-up, meaning that the stacked architectures at the meter-scale must be brought down to the micron-scale. This in return calls for specific methods of catalyst coating and a particularly precise assembly of the operation unit.

Novel biofilm reactor for denitrification of municipal wastewater

2018 ◽  
Vol 78 (7) ◽  
pp. 1566-1575 ◽  
Author(s):  
S. S. Rathnaweera ◽  
B. Rusten ◽  
K. Korczyk ◽  
B. Helland ◽  
E. Rismyhr
Keyword(s):  
Carbon Source ◽  
Municipal Wastewater ◽  
Low Cost ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Treated Wastewater ◽  
Removal Rates ◽  
Good Filter ◽  
Solids Removal

Abstract A pilot-scale CFIC® (continuous flow intermittent cleaning) reactor was run in anoxic conditions to study denitrification of wastewater. The CFIC process has already proven its capabilities for biological oxygen demand removal with a small footprint, less energy consumption and low cost. The present study focused on the applicability for denitrification. Both pre-denitrification (pre-DN) and post-denitrification (post-DN) were tested. A mixture of primary treated wastewater and nitrified wastewater was used for pre-DN and nitrified wastewater with ethanol as a carbon source was used for post-DN. The pre-DN process was carbon limited and removal rates of only 0.16 to 0.74 g NOx-N/m²-d were obtained. With post-DN and an external carbon source, 0.68 to 2.2 g NO3-Neq/m²-d removal rates were obtained. The carrier bed functioned as a good filter for both the larger particles coming with influent water and the bio-solids produced in the reactor. Total suspended solids removal in the reactor varied from 20% to 78% (average 45%) during post-DN testing period and 9% to 70% (average 29%) for pre-DN. The results showed that the forward flow washing improves both the DN function and filtration ability of the reactor.

scholarly journals A study to set-up a technological process for purification of Zinc scraps by using liquation method

2021 ◽  
Vol 8 (1) ◽  
pp. 36-43
Author(s):  
Ngoc Vuong Tran ◽  
Manh Hung Luong ◽  
Dinh Dang Nguyen
Keyword(s):  
Zinc Oxide ◽  
Raw Materials ◽  
Time Factors ◽  
Pilot Scale ◽  
Raw Material ◽  
Optimal Time ◽  
Fe Content ◽  
Technology Process ◽  
Zn Content ◽  
Set Up

Zinc scrap is a source of raw material for zinc oxide production. However, to qualify the requirement of raw material for zinc oxide (99.5%) production, refining this source is needed. Many methods are considered such as rectification, chemical method, etc., but difficult to apply on an industrial scale. This workfocused on the investigation of the influence of temperature and time factors for asessing the possibility of applying liquation method for the purification of impurities from scrap zinc.The experiment results show that the optimum temperature of liquation to remove Pb,Fe from zinc scrap is in the range of 440-450°C, the optimal time of the process is 8h for the pot with 8cm in height and 6cm in diameter (the quantity of raw zinc sample is about 2kg / batch), then we can obtain about 80% of zinc metal with an average Zn content of about 97, 0%, both Pb and Fe content decreased to a range from 0.35 to 0.4%, and 1.0 to 1.1%, respectively, which meet the requirement of raw materials for the production of high quanlity ZnO ( 99,5 %). Based on the parameters obtained on lab-scale, a trial on pilot scale of 250 kg / batch was conducted, The result confirms that the quality of the products meets the requirement of raw materials for production of high quality ZnO (99.5%) and a technology process for refining zinc scrap by the liquation was proposed.

Sulphur Neutralization by Lignite Ash: Pilot-Scale Combustion Experiments

1979 ◽  
Vol 101 (4) ◽  
pp. 615-619 ◽  
Author(s):  
T. D. Brown ◽  
G. K. Lee ◽  
H. A. Bambrough
Keyword(s):  
Nitric Oxide ◽  
Flue Gas ◽  
Solid Phase ◽  
Coal Ash ◽  
Pilot Scale ◽  
Controlled Experiments ◽  
Excess Air ◽  
Nitric Oxide Emissions ◽  
Carry Over ◽  
Lime Addition

A pilot-scale research boiler (750 kg steam/hr) has been used to study the degree of sulphur neutralization during combustion experiments with three lignites. A series of four closely controlled experiments showed that sulphur balances close to 100 percent could be achieved in the pilot-scale system burning Gascoyne lignite; in these experiments the sulphur retained in solid phase residues varied between 21 and 24 percent of the input sulphur. It was also demonstrated with Utility lignite that external recirculation of flue-gas was moderately effective in reducing nitric oxide emissions at the expense of major increased in the carry-over of unburnt carbon. However, sulphur dioxide neutralization by the coal-ash cations remained essentially unchanged as the recirculation ratio increased. Enhancement of sulphur neutralization by dry lime addition to Poplar River lignite was only found to be effective at addition rates above 1/2 percent lime by weight. The effectiveness of the lime was found to increase as the excess-air level increased.

In-process tests of river water conditioning for domestic and drinking water supply in the city of Kurgan

2021 ◽  
pp. 52-59
Author(s):  
А.В. Селюков ◽  
М.Ю. Семенов ◽  
И.С. Байкова
Keyword(s):  
River Water ◽  
Pilot Plant ◽  
Pilot Scale ◽  
Manganese Concentration ◽  
Winter Period ◽  
Initial Water ◽  
Sand Filter ◽  
Polyaluminum Chloride ◽  
Water Composition ◽  
Ozone Dose

Рассматривается опыт применения озонирования речной воды в лабораторных и пилотных масштабах. Вода реки Тобол – жесткая минерализованная со средними значениями цветности 24 град, содержанием марганца в зимний период более 0,8 мг/дм3. После определения рабочих доз реагентов (коагулянт гидроксохлорид алюминия, флокулянт Praestol 650TR) проводилось пробное озонирование с последующей реагентной обработкой на лабораторном флокуляторе. Для достижения норматива по содержанию марганца в речной воде 0,1 мг/дм3 потребовались высокие дозы озона – от 35 мг/дм3. Подщелачивание исходной воды до рН 9 позволило снизить дозу озона до 23 мг/дм3. Снижение цветности до 15 град происходит при дозах озона 6–7 мг/дм3. Очистка речной воды на пилотной установке производительностью 50 л/ч проводилась по полной технологической схеме (озонирование, обработка коагулянтом и флокулянтом, отстаивание, фильтрование через песчаный фильтр, фильтрование через угольный фильтр, опреснение-умягчение обратным осмосом). Доза коагулянта составляла 5 мг/дм3, флокулянта – 0,3 мг/дм3. В стационарном режиме работы пилотной установки при дозе озона 25 мг/дм3 были достигнуты следующие показатели качества фильтрата песчаного фильтра: цветность 5–7 град; марганец 0,05–0,15 мг/дм3; железо общее 0,02–0,03 мг/дм3; алюминий 0,05–0,08 мг/дм3; перманганатная окисляемость 3–4 мг/дм3. Исходя из расчетных показателей состава воды р. Тобол, для концентрации марганца в воде 0,8 мг/дм3теоретическая доза озона составляет ≈ 8 мг/дм3, проектная доза озона может быть принята 10 мг/дм3 (г/м3). The experience of using ozonation of river water on a laboratory and pilot scale is considered. The water of the Tobol River is hard and mineralized with an average color value of 24 degrees, a manganese concentration in the winter period of more than 0.8 mg/dm3. After determining the operational doses of the chemicals (polyaluminum chloride coagulant, Praestol 650TR flocculant), test ozonation was carried out followed by the chemical treatment in a laboratory flocculator. To achieve the standard for manganese concentration in river water of 0.1 mg/dm3, high doses of ozone were required – from 35 mg/dm3. Alkalinization of the initial water to pH 9 provided for reducing the ozone dose to 23 mg/dm3. A decrease in color to 15 degrees occurred at ozone doses of 6–7 mg/dm3. River water purification at a pilot plant with a capacity of 50 l/h was carried out according to the complete process flow scheme (ozonation, treatment with coagulant and flocculant, sedimentation, filtration in a sand filter, filtration in a carbon filter, desalination-softening by reverse osmosis). The coagulant dose was 5 mg/dm3, and that of the flocculant – 0.3 mg/dm3. In the steady run of the pilot plant at an ozone dose of 25 mg/dm3, the following quality indicators of the sand filter filtrate were achieved: color 5–7 degrees; manganese 0.05–0.15 mg/dm3; total iron 0.02–0.03 mg/dm3; aluminum 0.05–0.08 mg/dm3; permanganate index 3–4 mg/dm3. Based on the estimate indicators of the Tobol River water composition related to the manganese concentration in water of 0.8 mg/dm3, the theoretic dose of ozone is ≈ 8 mg/dm3, the design dose of ozone can be assumed as 10 mg/dm3 (g/m3).

Sign in / Sign up

Export Citation Format

Share Document