Effluent Storage Research Articles

Expanding the horizons of pond technology and application in an environmentally conscious world

Waste stabilisation pond technology has advanced greatly in terms of application and reliability and this has come from the wealth of modern research. Pond technology can be designed to meet exacting effluent standards and can treat both domestic sewage and a wide range of industrial wastewaters. They are now very much on a par with other wastewater treatment technologies. A wide range of pond types now exist allowing for flexibility in design and optimisation of the process to meet a particular applications or set of conditions. Ponds can be made to combine treatment and effluent storage and are the best and cheapest option for treating wastewaters for subsequent reuse in aquaculture and agriculture. Ponds can be designed to produce large quantities of algal biomass for animal and potential human consumption and for energy production via methane. Ponds are thus a modem wastewater reclamation and resource recovery technology in tune with current environmental thinking.

Process performance of an experimental deep effluent storage reservoir under different organic loadings in northeast Brazil

The performance of a pilot-scale effluent storage reservoir was evaluated on the basis of data from two experiments carried out at EXTRABES in northeast Brazil. The reservoir was filled with the effluent of an anaerobic pond in 35 and 18 days for Experiments 1 and 2, respectively. Once full, the reservoir was allowed to rest until the faecal coliform level reached 100 per 100ml, that is 10 times below the WHO guideline for unrestricted irrigation. After a rest period of 33 and 52 days, in Experiments 1 and 2, respectively, faecal coliform numbers throughout the water column were <100 per 100ml, and the unfiltered BOD was also reduced to <2S mg/l.

Pathogen removal in experimental deep effluent storage reservoirs

Studies on batch loaded pilot-scale deep effluent storage reservoirs (ESR) in NE Brazil using the operating regime of Fill, Rest and Use, rapidly produced a high microbiological quality effluent suitable for unrestricted irrigation ie. within 28 days at water temperatures of 25°C. There was little vertical variation in water quality in the ESR as the water column turned over at night. Physico-chemical quality rather than microbiological quality of the effluent was more likely to control effluent re-usc strategies and purification times as there were persistantly high ammonia and sulphide levels. ESR's could be organically loaded at rates similar to those used for facultative lagoons either using anaerobic pond effluent or raw sewage but the latter involved slightly longer purification times. The ESR's produced no odour problems. FC proved a good indicator of microbiological effluent quality and helminths could not be detected in the water column by the time the reservoir was full.

Effluent re-use in a tourist resort - larnaca sewage treatment and irrigation project - cyprus

Designs for sewerage, sewage treatment and effluent disposal prepared in the 1980's, included for marine disposal of secondary treated and disinfected effluent via a 1.5 km long sea outfall. A reappraisal of the scheme in 1990 reviewed alternative options with a view to reducing costs and utilising effluent. An economic comparison showed that effluent storage and irrigation was an attractive alternative to marine disposal. A scheme was designed whereby all effluent will be given secondary treatment, stored in reservoirs until required for irrigation, withdrawn through sand filters, disinfected and pumped to an irrigation distribution system serving public amenity areas throughout Larnaca, including parks, gardens, road verges and hotel areas. A sea outfall will not be provided. The advantages of the scheme are conservation of water, improvement to the environment and prevention of marine pollution at a reduction in cost compared to the originally proposed scheme.

Removal of trace metals from wastewater during long-term storage in seasonal reservoirs

The removal of five metals (Cu, Zn, Cr, Pb, Al) was studied in two reservoirs in series used for the seasonal storage of wastewater effluents for irrigation. The evaluation was made by two methods: (1) an anual budget which includes inputs and outputs and. (2) sediment traps. The concentrations of metals were reduced between 20 and 75%, to the base level found in unpolluted groundwater in the region. The amount of Pb was reduced in 5%, Cu in 10%, Al in 30%, Cr in 50%, and Zn in 90%. Sedimentation has an irregular pattern due to the effect of wind induced longshore and rip-currents. The release of bottom sediments in the outflow means a direct release of trace metals and other settling pollutants and clogging particles. It is recommended to take the effluents for irrigation from the uppermost water layer, to avoid strong outflow rates which may drag out part of the sediments by hydraulic turbulence, and to locate the outlet away from the dominant wind axis. The main tools to improve the removal of trace metals in seasonal reservoirs are not the control of the age distribution of the effluents and/or the loading of the reservoirs, but the proper location, design and flow rate of the outlet.

Effects of brine addition on effluent toxicity and marine toxicity identification evaluation (TIE) manipulations

AbstractLittle information is available concerning the effect of salinity adjustment on effluent storage and toxicity identification evaluation (TIE) performance. These factors are important for accurate assessments of potential toxicity to marine organisms. The objective of this study was to determine (a) the effect of salinity adjustment (to 30 ppt), using hypersaline brine (100 ppt), on the toxicity of effluents stored up to 40 d, and (b) to determine the effect of salinity adjustment on TIE manipulations. Changes in effluent toxicity over time were examined by using a municipal and an industrial effluent. A toxicity time series was performed for 16 d for the industrial effluent and 40 d for the municipal effluent. Toxicity was measured with modified 48‐h acute Mysidopsis bahia and Menidia beryllina tests Results indicate that, compared to day 0 test results, effluent stored with brine had fewer significant changes in toxicity than did effluent stored without brine To determine the effects of brine addition on TIE manipulations, we conducted a series of manipulations in which one aliquot of an effluent had brine added prior to the TIE manipulations and the other aliquot had brine added after the TIE manipulation The manipulations conducted were EDTA addition, sodium thiosulfate addition, C18 extraction, aeration, filtration, and graduated pH manipulations Toxicity was measured with the modified 48‐h acute mysid test. Addition of brine had no effect on the outcome of TIE manipulations. We have concluded that it is operationally easier to add brine as soon as possible after sampling and that effluent tests should be conducted as soon as practical

Effluent re-use in a tourist resort — Larnaca sewage treatment and irrigation project — Cyprus

Designs for sewerage, sewage treatment and effluent disposal prepared in the 1980′s, included for marine disposal of secondary treated and disinfected effluent via a 1.5 km long sea outfall. A reappraisal of the scheme in 1990 reviewed alternative options with a view to reducing costs and utilising effluent.An economic comparison showed that effluent storage and irrigation was an attractive alternative to marine disposal.A scheme was designed whereby all effluent will be given secondary treatment, stored in reservoirs until required for irrigation, withdrawn through sand filters, disinfected and pumped to an irrigation distribution system serving public amenity areas throughout Larnaca, including parks, gardens, road verges and hotel areas. A sea outfall will not be provided.The advantages of the scheme are conservation of water, improvement to the environment and prevention of marine pollution at a reduction in cost compared to the originally proposed scheme.

Designing Septic Tank Filter Fields Based on Effluent Storage during Climatic Stress

AbstractSeptic tank filter fields (FFs) in many soils undergo seasonal hydraulic failure due to climatic stress. We investigated the hydraulic behavior of an experimental FT with a 61 cm wide, 9.0 m long, and 76 cm deep bed constructed in a loamy‐skeletal, siliceous, mesic, Typic Fragiudult with a perched seasonal water table. The true water table was estimated to be deeper than 30 m. The FF was loaded with 15 L m−2 d−1 of septic tank effluent and monitored for 5 yr. At times each year, in response to rainfall, effluent rose within the bed to near the soil surface and spread laterally into the adjoining soil. This effluent was “stored” until climatic stress ceased. The experimental FF stored an estimated 20 d of effluent input; 220 L (14%) could be stored in the bed and 1410 L (86%) in the soil adjacent to the bed. Hydraulic stress events were the design‐limiting periods for FF loading. The experimental FF operated without detection of surfaced effluent for 5 yr, so 20 d of storage was chosen as the design goal for evaluating FF designs in this soil. The loading rate for noninteracting beds was inversely proportional to bed width, so the most efficient FFs should consist of narrow beds. When 61 cm wide beds were placed closer together than 5.9 m center‐to‐center, their storage volumes began to interact and loading rates had to be reduced accordingly. This approach to FF design for soils with perched seasonal water tables suggests that loading rates be determined either by effluent storage or by the rate of effluent movement out of the beds, whichever is most limiting.

Sequential Batch-Fed Effluent Storage Reservoirs: A New Concept of Wastewater Treatment Prior to Unrestricted Crop Irrigation

A modification of the Israeli system of holding pond effluents in single storage reservoirs prior to restricted irrigation is presented which enables the treated wastewater to be used for unrestricted irrigation. The modification comprises the use of 3 or 4 sequential batch-fed effluent storage reservoirs, each of which is operated on a cycle of fill, rest, use. The rest period permits the faecal coliform levels to drop below 1000 per 100 ml, in accordance with the current WHO recommendations for unrestricted irrigation. The number of storage reservoirs and the timing of the fill/rest/use cycle depends on the length of the irrigation season; design examples are presented for irrigation seasons of 12, 6 and 4 months, and these are compared with a conventional pond design.

Inactivation of poliovirus 1, as a function of temperature, in mixed human and dairy animal wastes

Mixing septic tank effluent with stored animal waste for discharge to land has been proposed as an alternative on-site sewage treatment and disposal method. Potential hazards to public health include parasites, bacteria, and viruses. The inactivation of a human enteric virus (poliovirus 1) was studied in a laboratory model simulating the storage of septic tank effluent combined with dairy animal waste. D values (times for 90% reduction of titer) at 5, 15 and 25 °C for inoculated poliovirus 1 were 102, 71 and 22 days in phosphate-buffered saline; 80, 72 and 19 days in septic tank effluent; and 19, 20 and 17 days for septic tank effluent mixed with dairy manure slurry. Temperature and the mixed waste treatment appear to be the dominant factors in viral inactivation in these experiments.

Inactivation of Poliovirus 1, as a Function of Temperature, in Mixed Human and Dairy Animal Wastes

Mixing septic tank effluent with stored animal waste for discharge to land has been proposed as an alternative on-site sewage treatment and disposal method. Potential hazards to public health include parasites, bacteria, and viruses. The inactivation of a human enteric virus (poliovirus 1) was studied in a laboratory model simulating the storage of septic tank effluent combined with dairy animal waste. D values (times for 90% reduction of titer) at 5, 15 and 25°C for inoculated poliovirus 1 were 102, 71 and 22 days in phosphate-buffered saline; 80, 72 and 19 days in septic tank effluent; and 19, 20 and 17 days for septic tank effluent mixed with dairy manure slurry. Temperature and the mixed waste treatment appear to be the dominant factors in viral inactivation in these experiments.

On-line low-level radiometric detectin of [ 14]remoxipride in liquid chromatographic effluents : Application to urine samples

A method for on-line radiometric detection in liquid chromatography (LC) is described that permits the detection of low levels of radioactivity in LC effluents by using solvent segmentation and storage of the segmented effluent in a capillary storage loop. The object of the method is to make the flow-rate in the on-line radioactivity monitor (and hence the mean residence time in the monitor) independent fof the separation process. Therefore, after storage of the complete chromatogram, the segmented effluent is led through the monitor at flow-rates that can be chosen according to the residence time desired for accurate and precise radioactivity determination. In this system, it is possible to use a flow-cell volume small enough to preserve the chromatographic integrity, while maintaining the possibility of increasing the counting time. Tests have been performed on the reproducibility of 14C detection and the influence of the flow-rate through the monitor on the standard deviation in 14C peak area and, thus, on the detection limit, using 14C-labelled remoxipride. As an application, analyses of urine samples ofr [ j14C]remoxipride and one of its potential metabolites are reported.

METHODS

LPP solve problem of acidic effluent storage. Laminated Plastic Products were approached by a company who manufacture castings and pressings in aluminium and other non ferrous metals. One of their processes involves the use of various very corrosive acids. Specifically these include nitric, hydrofluoric, sulphuric and chromic acids at concentrations of up to 30%. After use these acids are run to an effluent pit where they are held prior to their removal by tanker for disposal.

Facility for bituminizing liquid radioactive wastes from the Leningrad nuclear power plant

This paper describes the facility at the Leningrad nuclear power plant for the bituminization and storage of the radioactive effluents from the four RBMK reactors at the site. Chemical compositions, isotope ratios, and radioactivities are established for the wastes, and all aspects of the bituminuzation process, including process control and appropriate bitumen selection, are detailed. The equipment and operating specifications of the facility are given along with fire and radiation protection activities.

Radiometric detection of beta-labelled polar compounds using an effluent storage principle based on solvent segmentation

A new method is presented for the on-line detection of beta-labelled compounds of high polarity in reversed-phase column liquid chromatography. The aqueous column effluent containing the 14C-labelled amino acids alanine, valine, isoleucine and/or leucine is segmented with a non-water-miscible liquid scintillator. This two-phase system is introduced into the beta-detector without phase separation, where the betas emitted in the aqueous phase are detected in the scintillator phase. The detector effluent is collected in a storage capillary tube. At the end of the chromatographic process, the contents of the storage capillary tube are introduced into the beta-detector by reversing the direction of the flow. The two phases are homogenized by adding a water-miscible liquid scintillator. By lowering the flow-rates the signal increases, depending on the flow-rates used.

Nutrient changes during storage of anaerobic digester effluent and fresh dairy cattle manure with phosphoric acid

The effects of phosphoric acid additions on nitrogen losses from fresh manure and effluent from a dairy cattle manure anaerobic digester during aerated and non-aerated storage were evaluated over a 60-day period. Phosphoric acid at 2·24 g P per kilogram of slurry, which lowered the slurry pH to ≤6·0 throughout the storage period, was most effective in reducing nutrient transformations and losses and showed potential for conserving biologically available nitrogen in these animal wastes.

Low-level radiometric detection in LC using solvent segmentation and an effluent storage loop

In this study a new approach is presented for on-line radiometric detection in reversed phase LC of medium to low polarity compounds labelled with14C.

3',5'-diiodothyronine release from perfused dog thyroids.

A new radioimmunoassay for 3',5'-diiodothyronine (3',5'-T2) is described. The detection limit was 1-2 pmol/l with a sample size of 200 microliters. Cross-reaction with T4, T3, and rT3 was 0.005, 0.003, and 1.3% respectively. The intra- and interassay coefficients of variation were 5.1% and 9.2%. Dilution curves of effluent from perfused thyroid lobes of thyroid hydrolysate were parallel to the standard curve. By addition of 3',5'-T2 or rT3 standards to thyroid effluent sampling tubes or to thyroid homogenate before hydrolysis it was ascertained that no artifactual loss of 3',5'-T2 or generation of 3',5'-T2 from rT3 was taking place during collection and storage of thyroid effluent or during hydrolysis of thyroid homogenate. 3',5'-T2 was measured in effluent from perfused thyroids and in hydrolysate of the thyroids in six mongrel dogs. Only minute amounts of 3',5'-T2 was found: 1.66 +/- 0.41 pmol/mg thyroid wet weight (mean +/- SD) in hydrolysate, around 20 pmol/l in thyroid effluent during control perfusion and around 170 pmol/l during prolonged infusion of 100 micro U/ml bovine TSH. By measuring the apparent 3',5'-T2 concentration in perfusion medium with added T4 and rT3 standard corresponding to the amounts present in thyroid effluent samples, and dilutions of thyroid hydrolysates it was excluded that T4 and rT3 interference could account for more than maximally 20% of the measured 3',5'-T2. Thus 3',5'-T2 is present in the thyroid and secreted from the thyroid, but only in very small amounts.

Preservation of silage effluent

AbstractThree experiments have been carried out to investigate the storage of silage effluent and the value of formalin, formic acid and sulphur dioxide as preservatives. In the third experiment treatment with formalin was compared with sealing treatments using liquid paraffin, maize oil or polythene. This experiment was conducted on effluents with initial pH values of 3.8 and 4.6. All treatments except those sealed with polythene were challenged with a mould spore culture. The results obtained show that formic acid, formalin or sulphur dioxide can preserve silage effluent under aerobic conditions and appear to control mould growth. The higher the level of preservative the longer the interval to the onset of mould growth. None of the chemical measurements indicated when moulding would occur. Sealing provided an alternative storage method to chemical treatment and was particularly suitable when the pH of the effluent was higher than 4.5. The onset of mould growth appeared to accelerate the rate of chemical change in effluent.

The use of effluent from grass silage in the diet of finishing pigs. II. Assessment of nutritive value of fresh and stored effluent

Freshly collected effluent was treated with 2 ml formalin per litre and used to replace 150 g/kg of the dry matter of an all-meal control diet of bacon pigs. Diets containing effluent from either unwilted or wilted crops were compared with the control diet which was also given wet by adding water. Liveweight gains of 10 pigs per treatment from 65 to 86 kg on diets containing effluents from unwilted and wilted crops and on the control diet were 753, 715 and 719 ± 16.8 g/day, respectively, and in the same order feed conversion ratios (corrected to dry matter content of the control diet) were 2.94, 3.10 and 3.07 ± 0.075. None of these differences were significant. There were no significant differences in killing-out yield, in hardness of subcutaneous back-fat when measured by a penetrometer or in abnormal odour rating of subcutaneous back-fat. Formalin at levels of 1 and 2 ml/l and formic acid at levels of 1, 2 and 6 ml/l were added as potential preservatives to 1000 ml quantities of freshly collected silage effluent, which was then stored at 23°C. The 2 ml/l level of formalin and 6 ml/l level of formic acid prevented mould growth for 26 and 19 days, respectively. Freshly collected effluent was stored for 3.5, 14, 28, 56, 112 and 240 days after treatment, with formalin at the rate of 3 ml/l, and used in a pig-feeding trial. Pigs were fed either on a control all-meal diet or an equal dry matter intake of 150 g/kg effluent DM and 850 g/kg meal DM. A total of 120 animals were individually penned and fed twice daily on the experimental diets from 33 kg to slaughter at 82 kg liveweight. Overall mean liveweight gains for effluent and control diets were 646 and 656 ± 7.5 g/day, respectively, and the corresponding feed conversion ratios (DM basis) were 2.69 and 2.64 ± 0.030, neither of the differences being significant. Animal performance did not deteriorate with increasing period of effluent storage. No significant differences were found in carcase lean, back-fat thickness nor hardness of back-fat. A digestibility study was carried out on freshly collected effluent from another source. The level of dietary inclusion was equal to that in the previous experiments and the digestibility of dry matter was 0.831 and 0.819, and of nitrogen 0.822 and 0.827 for the control and effluent diets, respectively. A value of 11.4 MJ/kg dry matter was calculated by difference for the digestible energy of this effluent. In a further digestibility trial, digestible energy values of 14.6 and 14.2 MJ/kg dry matter were calculated by difference for effluents stored for 3.5 and 300 days, respectively.