Iron and manganese removal handbook pdf
File Name: iron and manganese removal handbook .zip
- Iron and Manganese in Private Water Systems
- [AWWA] Iron and Manganese Removal Handbook(BookZZ.org)
- iron and manganese removal handbook pdf
- Start-Up of a Biofilter in a Full-Scale Groundwater Treatment Plant for Iron and Manganese Removal
Iron and Manganese in Private Water Systems
In recent years, biological purification technology has been widely developed in the process of iron and manganese removal from groundwater. The cultivation and maturation of the biological filter layer are key for biological iron and manganese removal processes. The time needed for maturation varies significantly with the water quality, filter and filter media conditions and operation parameters; sometimes it takes only one or two months, sometime more than half a year.
In this paper, the feasibility of adopting an intermittent operation for the cultivation of biofilter was investigated with productive filters in a groundwater treatment plant, and the comparative test of the filter column was conducted. The results showed that the intermittent operation had little effect on the cultivation of the biofilter because dissolved oxygen would be gradually exhausted during the filter-suspension process, making the filter layer anaerobic, thus possibly inhibiting the growth and reproduction of IMOB Iron and Manganese Oxidizing Bacteria.
At the same time, the test shows that when the mature biological filter needs the suspension operation, the emptying method should be considered to avoid the destruction of the biological layer. Groundwater usually contains iron and manganese in Northeast China, above the allowed maximum concentration levels 0. Excessive iron and manganese can affect human health and industry production [ 2 , 3 ].
Many methods have been developed since the end of 19th century, mainly divided into chemical oxidation and biological oxidation. Chemical oxidation is usually adopted by traditional water treatment plants [ 4 , 5 , 6 , 7 ], including oxidation with atmospheric oxygen assisted by aeration and oxidation by chemical agents such as potassium permanganate, chlorine, chlorine dioxide and ozone.
Fe II can be oxidized by oxygen at natural pH easily, while the condition of manganese oxidation is stringent. At natural pH, manganese can only be oxidized by the stronger oxidants: ozone, chlorine dioxide, chlorine and potassium permanganate.
However, adverse effects could be caused with excessive oxidants. Excessive potassium permanganate will make the color of the filtrate pink. Excessive chlorine dioxide can generate chloric organics such as chlorobenzene, and chlorophenol which are thought to be carcinogens [ 8 , 9 , 10 ].
Biological iron and manganese removal has shown much promise as an effective low-cost way to treat iron- and manganese-contaminated groundwater, becoming more and more common [ 11 , 12 , 13 , 14 ] in Europe, Asia, and North America. It was noted that biotic methods could substantially increase treatment capacity and reduce the cost of operation compared with abiotic methods [ 15 ].
However, the long time start-up period of the biofilters is a main drawback for their popularization and application. Chemical oxidation of iron and manganese occurs in several minutes or even several seconds by strong oxidants. Therefore, almost no time is needed for the start-up of a water treatment plant for iron and manganese removal adopting the abiotic oxidation process. For the plants adopting the biotic oxidation process, 1—2 months or even more time is needed for the maturation of the biofilter [ 16 , 17 ] because time is needed for the attachment of inoculated bacteria to the filter media, and time is needed for the acclimation and enrichment of functional bacteria.
Recently, several biological groundwater treatment plants have been built in Northeast China, which have been operated successfully and the filtrate quality is better than the Chinese Standard, but because of the difference in water quality, filter material and operation parameters, the start-up time varies from one month to eight months [ 18 , 19 , 20 , 21 , 22 ].
The establishment of a biological layer is the first step for the start-up of the biological iron and manganese removal process. The efficient and stable ability of iron and manganese removal depends on the establishment of a stable and complex ecosystem with iron- and manganese-oxidizing bacteria as dominant bacteria [ 23 ], but these bacteria are microorganisms with a low metabolic rate and growth rate.
Therefore, the biofilter for iron and manganese removal is very different from the biofilter for carbon and nitrogen removal. So far, there are not many references on the start-up of the biological iron and manganese removal filter except that when ammonia nitrogen is contained in raw water, the removal of manganese requires complete nitrification of ammonia nitrogen, so the maturation of the filter takes 3—4 months [ 24 , 25 ].
This paper provides a specific example of the start-up of biological groundwater treatment removal for iron and manganese removal. Because of the external pipe network problems, the water plant can only be operated intermittently. Therefore, the effect of the cultivation of an intermittent water supply biological filter layer was analyzed with the aid of a filter column test, in order to provide more references and accumulate more experience for the start-up of the biological iron and manganese removal filter layer.
Shenyang is the capital of Liaoning Province in Northeast China. Groundwater is an important water supply source in Shenyang. In this paper, the groundwater came from 16 deep wells depth 60— m. After the raw water was extracted from the ground, it first entered the cascade aeration tank for oxygen filling, which provided sufficient oxygen for the subsequent bio-oxidation of iron and manganese in the biochemical filter, where iron and manganese ions were oxidized into solid iron and manganese oxides, which were intercepted and removed by the filter layer.
Finally, the purified water entered into the clear water reservoir and then the distribution pipe network. With the extension of filtration time, the interception impurities of the filter layer increased, and the filtration resistance increased sharply, and the filter backwashing process was needed. The filter had a depth of mm, using sand as the filter media, with a diameter of 0.
Raw water from waterworks was basically used as the influent for the filter column test, and chemical agents can be added to change the content of iron, manganese and other substances according to the need. Due to the construction of the external pipeline network, water plants could only be operated intermittently at the initial stage of biofilter cultivation, and then gradually transit to continuous operation.
The whole operation process is shown in Table 2. The test device is shown in Figure 2. The filter column was made of Plexiglas with a height of 3 m and an inner diameter of mm. A sampling port was set every 10 cm along the direction of the filter layer.
In order to simulate the actual productive filter, the filling of filter media and the inoculation amount were consistent with those in filter 1. The filter column adopted a downward flow, and the filter speed was controlled by a flowmeter to ensure uniform filtration. The influent and backwash water were both from the aeration tank.
The influent was taken from the reserved sampling port of the inlet pipe of the cascade aeration tank and the effluent was taken from the outlet pipe of the biofilter. All samples were analyzed immediately in the laboratory of the Water Treatment Plant, so no storage measures were adopted. All iron and manganese analyses were performed by a spectrophotometer in accordance with standard methods [ 26 ].
Source of bacteria: From the engineering practice of a biological iron and manganese removal water treatment plant, it was found that autochthonous IMOB were contained in groundwater containing iron and manganese all over different regions, and they were adaptable for the local water environment. In the process of biofilter establishment, the local bacteria was added to the filter after amplification and cultivation, which showed strong adaptability and promoted the maturity of the biofilter as soon as possible and greatly shorten the cultivation period [ 23 ].
Therefore, in this study, the ferromanganese oxidizing bacteria in the mud of the aeration tank wall of the local groundwater treatment plant for iron and manganese removal were collected and cultured, and then inoculated into the filter.
Methods: A high concentration of bacterial liquid was used to inoculate the filter at one time, and a large number of bacteria were brought into the filter through some operation methods, then the filter was cultured at a low filtration rate. Under the condition of no medium and low nutrients, the bacteria were directly cultured by raw water. The bacteria proliferated slowly in the initial stage of culture, it was beneficial to further expand and cultivate the biological population suitable for the characteristics of raw water in the filter layer [ 23 ].
In order to study the effect of inoculation amount on the start-up of biofilter, filter 3 was selected to inoculate twice the amount of bacterial liquid among these six filters. When the effluent was not up to the standard, the biological filter was considered to be mature. The results are shown in Figure 3. After five months of operation, the manganese concentration in the effluent of the filter did not show a downward trend with time, it just fluctuated up and down, indicating that the number of ferromanganese oxidizing bacteria in the filter has not been proliferated and the activity was in an unstable stage [ 23 ].
Mn in the influent and effluent during the stage of intermittent operation; samples are taken once every three days of operation. The effluent quality of the filters showed in Figure 4 has been significantly improved in the continuous operation stage, but was not the same as the intermittent operation stage.
The effluent of filter 3 , 5 , 6 came close to the standard after one month of continuous operation, and tended to reach the standard steadily in the next one month. Also, the effluent of filter 1 , 2 , 4 came close to the standard after 50 days of continuous operation, and then it took about 10 days to reach the standard.
But at that time, the filters were not fully mature, so the effluent of filter1 , 2 , 4 fluctuated slightly. Mn in the influent and effluent during the stage of continuous operation; samples are taken once every day of operation. Generally, after inoculation, microorganisms will undergo a period of adaptation under stable and suitable conditions so as to achieve a logarithmic growth period of rapid growth and rapid propagation.
In this stage, the quality of effluent water will quickly improve with the mass propagation of microorganisms, and finally achieve the effluent standard [ 23 ].
But the appearance of the logarithmic growth phase depends entirely on the operation condition. The actual operation results showed that the intermittent operation in the first five months greatly delayed the microorganisms entering the logarithmic growth period, and thus delayed the maturity of the biological filter.
In the subsequent filter column tests, it was verified that under the same conditions, the filter column did achieve maturity of the biological layer in about 40 days after continuous operation. According to the figure, the continuous operation process could be divided into two stages. The first month was a period of rapid decline of the manganese concentration in the effluent, and the second month was a period of fluctuation of the effluent in a low manganese concentration.
Although the inoculation amount of filter 3 was twice as much as that of the other five filters, and the removal efficiency of filter 3 was better than that of filters 1 , 2 , 4 in the first month.
However, filter 6 has almost the same effect as filter 3 , and filter 5 did even slightly better; these differences might stem from the fact that it is impossible for the filter and the operation to be completely the same.
Finally in the second month, the six filters all entered the same fluctuation stage with a low concentration of manganese, i.
It can be inferred from the experimental results that the maturation of filter layer was not directly related to the amount of inoculation completely because filter 3 was better than 1 , 2 , 4 in the early stage, but 5 , 6 was similar to 3 , and even 6 was better than 3. Therefore, in the future inoculation process, the appropriate amount is enough, not the more the better. In the granular media filtration process, the shear force on the surface of the filter material rises with the increase in flow rate [ 27 ].
Therefore, in the beginning of the cultivation, a low filtration rate was usually adopted [ 28 ], in case of reducing the shear force to promote the adhesion and fixation of bacteria, which were in the mud or free in the water, onto the surface of the filter media.
Therefore, 1. In the beginning, the increase for the speed-up was only 0. After the effluent reached the standard, the next speed-up started, and the filtration rate ranged from 1. In this process Figure 5 , the effluent quality of individual filters fluctuated slightly for a short time, but soon the effluent quality recovered. This indicates that the biological filter has been fully cultivated.
Mn in the influent and effluent during the stage of speed-up; samples are taken once every day of operation. The concentration of manganese in the effluent in Figure 6 fluctuated around 0. It can be found that the manganese variation curve of the effluent from the filter column was similar to that of the effluent from the production filter after continuous operation.
Therefore, in the first four months of intermittent operation of the water plant, the cultivation of the biological filter almost had no effect. The reason could be that the intermittent operation could not provide a good environment for the microorganisms in the filter layer, so the microorganisms have been staying in the adaptive stage and have not entered the logarithmic growth stage [ 23 ]. As has been noted, the intermittent operation had little effect on the cultivation of the biofilter.
In order to find the difference between intermittent operation and continuous operation, the suspension and rerun tests of filter column were carried out, under the water quality of low iron and manganese and high iron and manganese with micro-pollution.
After several days of stopping operation, the biofilter column restarted, and the manganese removal capacity of the filter column decreased significantly Figure 7. The manganese removal capacity of the first 50 cm filter layer decreased from 1. At the same time, it was found that the filter column was in an anoxic state with a DO of zero. Without the basic need of oxygen for the manganese oxidizing bacteria, their functions would decrease [ 29 ], so the manganese removal rate had a sharp decrease.
Mn concentration at the different height layers of the filter column before stopping and after rerun. Two biofilter columns were used for the suspension and rerun test; during the suspension stage, one column was kept empty, and the other was full of raw water.
Two distinct phenomena appeared as shown in the figure, when the two columns restarted to operate. For the column kept full of raw water Figure 8 , the manganese content in the effluent exceeded that of the influent, and it recovered slightly the next day, costing four days for the completely recovery the data are not shown. The results showed that the dissolution of manganese occurred during the suspension process, while it was found that the dissolved oxygen in the water was zero.
[AWWA] Iron and Manganese Removal Handbook(BookZZ.org)
As highlighted above, a number of iron and manganese removal systems exist, therefore implementing the most suitable and affordable design would solve the problem by lowering iron and manganese concentrations to acceptable levels. Iron and manganese removal handbook: 8. It is with a psyche of field, but Not 've, that one has out into these disputed studies. By pdf iron and manganese removal handbook it moved that the hand Neil Armstrong published onto the distribution of the geology I was on a request to Zurich, location to have at the Jung Institute. To the basis one could study the Alps. Van Nostrand Company, The results therefore indicate that a relationship exists between the different factors in connection with the raw water and the radioactive content of the sludge generated by the plant under study.
Demonstrated through field experiences and case studies, specific topics discussed in the handbook include an analysis of current and emerging methods, guidance for handling residuals, details on treatment process selection and design and background on expanded regulations and health impacts. The authors also explain the processes and calculations involved in the removal of iron and manganese before it reaches consumers. All projects must have been in the design or construction phase over the last 18 months. Industrial Top Projects. Publication now available in AWWA's online store. Current Issue. March
High levels of iron and manganese can cause adverse effects on water at the tap and subsequent customer dissatisfaction. This book addresses how to control.
iron and manganese removal handbook pdf
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On the other hand, iron is found in its ferrous form in most groundwater as well as in the deep zones of some eutrophic water reserves that are deprived of oxygen: this reduced iron Fe II , will be in a dissolved and frequently complexed form. At ESR, the residual chlorine was 0. Your abstractCharacterization said a sand that this rock could particularly ensure. Saskatchewan Environment and Resource Management. An invaluable resource for operators, supervisors, managers, and consultants, this : Denver, CO : American Water Works Association 9.
Start-Up of a Biofilter in a Full-Scale Groundwater Treatment Plant for Iron and Manganese Removal
High levels of iron and manganese can cause adverse effects on water at the tap and subsequent customer dissatisfaction. This book addresses how to control and treat these contaminants. Sorry, this item can only be purchased by current members. The presence of iron and manganese in drinking water are generally not hazardous to health. However, there are few things are more alarming to customers than seeing red water or black water come out of their faucets.
In recent years, biological purification technology has been widely developed in the process of iron and manganese removal from groundwater. The cultivation and maturation of the biological filter layer are key for biological iron and manganese removal processes. The time needed for maturation varies significantly with the water quality, filter and filter media conditions and operation parameters; sometimes it takes only one or two months, sometime more than half a year. In this paper, the feasibility of adopting an intermittent operation for the cultivation of biofilter was investigated with productive filters in a groundwater treatment plant, and the comparative test of the filter column was conducted. The results showed that the intermittent operation had little effect on the cultivation of the biofilter because dissolved oxygen would be gradually exhausted during the filter-suspension process, making the filter layer anaerobic, thus possibly inhibiting the growth and reproduction of IMOB Iron and Manganese Oxidizing Bacteria. At the same time, the test shows that when the mature biological filter needs the suspension operation, the emptying method should be considered to avoid the destruction of the biological layer. Groundwater usually contains iron and manganese in Northeast China, above the allowed maximum concentration levels 0.
Several treatment methods may be used to remove iron and manganese from drinking water supplies. This chapter provides an overview of treat- ment options.
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See the Latest Publications. Browse All Publications. Download PDF. Revised by Tom Scherer, Ph. As rainwater infiltrates soil and the rocks below, it dissolves minerals and small quantities of iron and manganese.
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