The Sulfur Cycle in Wastewater Systems
- Sulfate Reducing Bacteria - these bacteria under anoxic conditions use sulfate as electron acceptor to degrade organics.
- Sulfur Reducing Bacteria - these chemotrophic bacteria obtain energy by reducing sulfur into sulfide. In most...
- Sulfur Oxidizing Bacteria - chemotrophic bacteria with the metabolic ability to convert reduced...
Why is aluminum sulfate used in water treatment?
You can also use alum to:
- Remineralize and clarify water for soft drinks or beer
- You can control the pH levels of tomatoes and beets as well as any other vegetables.
- Purification of sugar beet juices
- Control the pH and color of wine and liquor
- Use as a leavening agent for cake mix (baking soda).
- Curdle and thicken the cheese
Is it bad to drink sulfur water?
When sulfur is in the drinking water of your home, you and your family may not be able to avoid consuming too much sulfur. Such over consumption can lead to serious health problems such as diarrhea and dehydration. The most common way of dealing with sulfur in drinking water is the use of chlorine.
How do you dissolve ferric ammonium sulphate in water?
How do you prepare ferric ammonium sulphate solution?
- Dissolve 50 g of ferric ammonium sulfate in a mixture of 300 ml of water and 6 ml of sulphuric acid.
- Dilute with sufficient freshly boiled and cooled water to produce 1000 ml.
- Standardise the solution in the following manner.
How does potassium sulfate dissolve in water?
- Very soluble: less than 1 part (i.e. it takes less than 1 mL of solvent to dissolve 1g of material)
- Freely soluble: from 1 to 10 parts
- Soluble: from 10 to 30 parts
- Sparingly soluble: from 30 to 100 parts
- Slightly soluble: from 100 to 1000 parts
- Very slightly soluble: from 1000 to
What does sulfate reduce to?
sulphideSulphate is reduced to sulphide by sulphate-reducing bacteria in bioreactor one using hydrogen as an electron donor. Subsequently, the sulphide is used to precipitate the heavy metals. An excess of sulphide is converted to elemental sulphur by sulphide-oxidizing bacteria in bioreactor two.
How does reducing sulfate reduce bacteria?
Biocide compounds are often added to water to inhibit the microbial activity of sulfate-reducing microorganisms, in order to but not limited to, avoid anaerobic methane oxidation and the generation of hydrogen sulfide, ultimately resulting in minimizing potential production loss.
How is sulfate removed from wastewater?
Membrane filtration (like reverse osmosis (RO), nanofiltration (NF), and ultrafiltration (UF)), is one of the most effective technologies for removing sulfates from industrial process and wastewaters.
Where does sulfate reduction take place?
These sulfate-reducing conditions are found in soils, sediments, and stratified waters due to the limited penetration of oxygen. Sulfide produced in the anoxic compartment will be partly transported to the aerobic compartment where sulfide is oxidized back to sulfate, and vice versa [5, 6].
Is sulfate reducing bacteria aerobic or anaerobic?
anaerobicSulfate-reducing bacteria, primarily of the genus Desulfovibro, are responsible for anaerobic corrosion. These bacteria appear to cause corrosion by producing a highly corrosive product in addition to hydrogen sulfide.
What are the two effects of reducing sulfates in acid mine drainage?
Sulfate-reducing microorganisms play a vital role in the control and treatment of mine waste, generating alkalinity and neutralizing the acidic waste.
How are sulfates removed?
Ways to Treat Sulfate Reverse osmosis pushes water through a membrane with tiny pores. The membrane stops many contaminants, including sulfate, while allowing water to pass through. Reverse osmosis usually removes between 93 and 99 percent of the sulfate in drinking water, depending on the type of treatment unit.
How do you remove sulfate from a solution?
How can sulfate be removed from water? Three types of treatment systems will remove sulfate from drinking water: reverse osmosis, distillation, or ion exchange. Water softeners, carbon filters, and sediment filters do not remove sulfate.
How do you remove sulfur from wastewater?
In order to remove sulphide from wastewater streams, a number of physicochemical processes are in common use today, which involve direct air stripping, chemical precipitation and oxidation.
Which group contains sulfate reducers?
Sulfate and sulfur reducers group of prokaryotes includes mostly mesophilic species but also archaean thermophilic taxa and thermophilic bacteria, such as the sulfate-reducer Thermodesulfobacterium and the sulfur-reducer Desulfurella.
Does sulfur reduce fermentation?
The most important fluxes in the sulfur cycle are biological and abiological sulfur oxidation, biological sulfur reduction (a form of anoxic respiration), production of sulfide by fermentation, disproportionation, and metal pyrite precipitation and deposition.
What is the end product of Dissimilatory sulfate reduction?
The key difference between assimilatory and dissimilatory sulphate reduction is that assimilatory sulphate reduction produces cysteine as an end product while dissimilatory sulphate reduction produces sulfide as an end product.
What is sulphite reducing clostridia?
Sulfite-reducing clostridia are normal inhabitants of the intestinal microbiota of humans and other mammals. These microorganisms may form endospores, which allow the bacteria to survive in almost any habitat, either terrestrial or aquatic, waiting for favorable conditions for growth.
Does sulfur reduce fermentation?
The most important fluxes in the sulfur cycle are biological and abiological sulfur oxidation, biological sulfur reduction (a form of anoxic respiration), production of sulfide by fermentation, disproportionation, and metal pyrite precipitation and deposition.
What is sulfate in water?
Sulfates are a form of salt that cause scaling in equipment, resulting in reduced performance and premature equipment failure. This is a particular concern in feed water for boiler furnaces and condensers in power generation facilities.
How does biological sulfate reduction work?
Biological sulfate reduction requires a large input of energy to raise the temperature of feed water, and generates a residual waste that can be toxic. Passive biological systems leave a large environmental footprint, and are suitable for only small flows of water.
Why are sulfates bad for the environment?
In addition to process water concerns, many jurisdictions are imposing tighter discharge limits for sulfate because of concerns about the impact on the surrounding environment, with evidence that the presence of sulfates can negatively impact crop yields and fertility in livestock. Although not considered harmful to humans except at very high levels, sulfate imparts a bitter taste and odor that makes it undesirable for drinking water.
Why is water recovery rate low?
First, water recovery rates can be low because of the complex cocktail of contaminants typically found in industrial wastewater. It is not uncommon to have up to 50 percent of the water end up in the waste product stream. Second, membrane processes can have high energy costs.
What is the area of growing interest in water quality legislation?
One area of growing interest is the presence of sulfates.
Is sulfate bad for you?
Although not considered harmful to humans except at very high levels, sul fate imparts a bitter taste and odor that makes it undesirable for drinking water. The growing legislative focus on sulfates will have an impact on virtually all industries -- from power generation to municipal water systems.
Can membrane systems treat contaminated water?
Typically these technologies are either not able to treat contaminated water to a level which complies with new regulations and standards that are being imposed on industry, or they bring either environmental or economic disadvantages. For example, membrane systems have been used for treating wastewater streams in a number of industries, ...
What are some ways to prevent growth of sulfate reducing bacteria?
Adding alternative electron acceptors to prevent growth of sulfate reducing bacteria - common additions include nitrate, liquid oxygen, and hydrogen peroxide. All work by giving a higher energy electron acceptor than sulfate/sulfide for bacteria in the system.
How to keep sulfides in water?
Sulfides can be kept in water phase by increasing pH, adding ferric or sulfide scavengers to the collection system. This is a quick fix, but does not solve generation of sulfides in anoxic/anaerobic zones.
What bacteria use sulfate as an electron acceptor?
Sulfate Reducing Bacteria - these bacteria under anoxic conditions use sulfate as electron acceptor to degrade organics. If you have oxygen or nitrate in the system, sulfate reducing bacteria are outcompeted by harmless bacteria that obtain more energy using oxygen or nitrate as an electron acceptor.
What bacteria convert sulfur to sulfuric acid?
Sulfur Oxidizing Bacteria - chemotrophic bacteria with the metabolic ability to convert reduced sulfur species into sulfur and sulfate. While some species can use nitrate as the electron acceptor, most sulfur oxidizers require oxyen as the terminal electron acceptor. If taken to conclusion, you produce sulfuric acid (H2SO4). These are the well documented sewer corrosion bacteria that can form if a vapor phase H2S concentration reaches sufficient levels. In wastewater, Sulfur Oxidizing Bacteria (SOB) are vital to removing reduce sulfides. This does require alkalinity to buffer the system from pH drop. Common genera of wastewater SOB include Thiobacillus, Anwoodia, Paracoccus, and Thiosphaera.
How do sulfur reducing bacteria obtain energy?
Sulfur Reducing Bacteria - these chemotrophic bacteria obtain energy by reducing sulfur into sulfide. In most wastewater, these are less common than the Sulfate Reducing Bacteria that use sulfur as an alternative electron acceptor. You would find these organisms in mines, subsea volcanic vents, hot springs, and oil formations.
What is the sulfur cycle?
The Sulfur Cycle in Wastewater Systems 1 Sulfate - one of the most common forms of sulfur found in the environment. Sulfate is used by plants and is an important micronutrient for life. 2 Sulfur - the yellow powder or rock form of sulfur. 3 Reduced Sulfides - often seen as S= or in analytical tests as Total Reduce Sulfides. This form of sulfide can bind with iron and give the dark gray to black color seen in septic wastewater. Sulfides are more soluble in water with a higher pH. Reduced sulfides in wastewater have a high chemical oxygen demand and are toxic to Ammonia Oxidizing Bacteria (AOB) that are required for ammonia removal. 4 Hydrogen Sulfide - a corrosive, highly toxic gas, H2S is released from water into the atmosphere as pH drops in wastewater. (This is why one of the collection system odor control methods is to increase sewer line pH).
What is the color of sulfide in septic system?
This form of sulfide can bind with iron and give the dark gray to black color seen in septic wastewater. Sulfides are more soluble in water with a higher pH. Reduced sulfides in wastewater have a high chemical oxygen demand and are toxic to Ammonia Oxidizing Bacteria (AOB) that are required for ammonia removal.
How to remove cyanide from wastewater?
Alkaline chlorination, an oxidation process with chlorine (Cl {sub 2}) or hypochlorite (ClO { sup {minus}}), is the most widely accepted method of cyanide treatment. However, removal of cyanide from wastewater to the extent required by the effluent limits imposed by Federal and State regulatory authorities is practically impossible, especially when the majority of the cyanide is present as an iron-cyanide complex. One potential treatment method being further investigated uses ferrous (Fe {sup 2+}) compounds to react with free and complex cyanide ions and produce insoluble iron-cyanide complexes. However, sludges generated by this treatment method contain cyanide wastes which may be considered a hazardous more » waste by the US Environmental Protection Agency (US EPA). The studies reported in this paper demonstrate that ferrous (Fe {sup 2+}) precipitation can remove cyanide ions (both free and complex) to a concentration within the range of 1 to 2 mg/L. The wastewaters utilized in these tests were collected from a coke plant facility. Synthetic cyanide solutions were used in the studied as well. Ferrous compounds used in the studies included commercial-grade ferrous sulfate, commercial-grade ferrous chloride, and spent pickle liquor (containing ferrous ion). The desired effluent quality was successfully attained in the treatment of the above-mentioned wastewaters by using ferrous compounds as well as spent pickle liquor. « less
How much hydrocarbons are in Arun waste water?
The Arun waste water contains about 2,000 ppm of liquid hydrocarbons in the form of a very stable oil-in-water emulsion. Stability of the emulsion is enhanced by the small diameters of the oil droplets, low salt content of the water and low pH.
Can cyanide be removed from wastewater?
However, removal of cyanide from wastewater to the extent required by the effluent limits imposed by Federal and State regulatory authorities is practically impossible, especially when the majority of the cyanide is present as an iron-cyanide complex.
What is sulfate select?
Request More Information Learn More SulfateSelect removes sulfates from wastewater, in some cases without brine by-products, thereby removing the expense of brine management. We offer a suite of sulfate processes,
When will sulfate be available?
June 2, 2020. There are many sulfate treatments available, with different advantages and disadvantages. Factors for consideration include capital and operational costs, solid vs. liquid brine reject for disposal, if the need is seasonal or year-round, and suitability for adverse operating conditions.
How do you precipitate sulfates?
Sulfates can be precipitated by adding low solubility counter ions such as barium or calcium. Our BrineRefine system performs chemical precipitation in a smart, automated way to prevent overdosing. If inlet water chemistry changes, so does chemical dosing. BrineRefine enables smart selective precipitation and is:
Can sulfates be removed?
Sulfates can be targeted for removal, without needing to treat all dissolved mass in an entire flow. Targeted treatment saves money. For seasonal sulfate challenges, chemical precipitation treatment may keep capital investment low, with chemical addition operating costs for only part of the year.
Is sulfate dangerous to humans?
Sulfate Challenges. Sulfates are of concern in many processes e.g. mining, oil & gas, fertilizers, and more. Although not generally very dangerous to humans, high sulfate levels can be regulated to protect the environment. Sulfates can be targeted for removal, without needing to treat all dissolved mass in an entire flow.
Can saltworks be regulated?
Sulfates can be regulated in some discharges and require cost-effective management. Saltworks can help you to monitor and moderate sulfate levels in wastewater flows.
Overview
With our sulfate removal process system, you can streamline your sulfate treatment and water recycling. This technology ensures efficient sulfate and calcium control in process streams, resulting in water that meets discharge water quality criteria and allows for the reuse of treated water.
Important Takeaways
In many wastewater flows, we need to carefully manage and control the sulfate levels. They are restricted because they pose a threat to the natural environment and animals when used in large amounts.
Sulfate Removal Treatment Options
To bring total sulfate levels into regulatory compliance, there are a number of treatment techniques available. It can be challenging to choose the best solution or combination, but specialists can assist you in evaluating and navigating your alternatives.
Bottom Line
When it comes to removing sulfates from your process and wastewater, your business may require multiple treatments using a variety of technologies. We have an expert team in designing and manufacturing water treatment systems to meet our client’s needs. Please do not hesitate to contact us if you have any questions.
How to remove sulfates from water?
Removing sulfates with distillation. With distillation, the sulfate-saturated liquids are heated to boiling, then the resulting water vapor is cooled in a condenser, and the purified water is captured in a sterile container. Where some separation processes remove the contaminant from the liquid stream, distillation removes the liquid from ...
How much reduction in sulfate with hydrated lime?
Many facilities will see an 80% reduction in sulfate with hydrated lime before they even need to start worrying about the metals, which will minimize the toxicity of initial secondary wastes and sludge created in the precipitation process.
What is the best ion exchange system for removing sulfates?
When it comes to the ideal ion exchange system for removing sulfates, you’ll typically want to see a resin system filled with a combination of cationic (to remove calcium and magnesium) and anionic resins (to then remove sulfates). IX process works best for polishing and with a background stream that is low in other competing salts.
How effective is adsorption?
Adsorption is effective for removing sulfates at relatively low concentration levels and can be achieved with technologies like granular activated carbon filtration. Although the technology is generally cost-effective, the media will likely need to be changed out often, which can add up in both cost and time.
What is the process of adsorption?
The process consists of passing a liquid stream through some type of porous, adsorbent media, and when the soluble contaminants are more attracted to the adsorbent media than they are to the water in the stream, the contaminants bind to the surface of the media while the liquid effluent flows through. Adsorption is effective for removing sulfates ...
Where are sulfates found?
These minerals typically include sulfates, which are present in almost every type of water found in nature, including groundwater, oceanwater, and rainwater, and even crude oil and brines. They are also present in many industrial wastes as a result of the facility’s process—mainly in mining and mineral processing applications where sulfates are ...
Is sulfate harmful to the environment?
In high concentrations, sulfates can be harmful to human health and the environment and corrosive to pipes and equipment, so they are something many industrial facilities look to remove whether the intent is for release into the local POTW or environment or reuse in the facility’s process. You might be wondering, what are ...
What is sulfate treatment?
Historically, sulfate treatment has primarily been applied to industrial water and wastewater treatment in industries such as mining, metal finishing, and wood products for the purposes of metals removal, total dissolved solids reduction, and sulfate removal. It is removed (as a component of dissolved solids removal) in many high-pressure industrial boiler applications as part of boiler feed water production. Municipal wastewater systems have not typically considered sulfate treatment (beyond considerations related to corrosion or odor control). Therefore, little information is available concerning the applicability of sulfate treatment technologies to municipal wastewater processes for the purpose of effluent limit compliance.
Why use biological treatment for sulfate?
Because municipal wastewater treatment plants use biological treatment for removal of common pollutants from wastewater (e.g., biochemical oxygen demand, suspended solids, and nutrients), it is logical to consider biological treatment options for sulfate removal. The literature review identified numerous biological treatment processes that are under development for sulfate removal, but few that are commercialized and have demonstrated reliability in full-scale applications as would be required for sulfate removal from municipal WWTPs. Biological treatment of sulfate has primarily been applied to mine water treatment, where metals removal by converting sulfate to sulfide is the primary goal, not sulfate removal; so in those settings, low-efficiency biological treatment systems like constructed wetlands and mine pit reactors are practical. Fundamentally, due to the slow growth of sulfate-reducing bacteria, a much longer retention time is required in the biological reactor than is typically practical in municipal wastewater treatment. This class of treatment technologies, overall, requires significant development of design and operational strategies to ensure the success of sulfate-reducing bacteria growth before they can be employed to full-scale implementation for municipal wastewater treatment. These limitations resulted in biological treatment receiving technology screening scores on the lowest end of the range compared to the other treatment technologies.
What are the treatment technologies for sulfate?
In this study, treatment technologies for sulfate removal were reviewed and screened for their applicability and potential use by municipal wastewater treatment plants needing to reduce sulfate from their discharge in the future. The screening criteria included effectiveness, operability and maintainability, relative costs, degree and complexity of additional pre- and post-treatment, residuals management, and ability to remove other parameters of concern. The technologies reviewed were grouped into six general categories: chemical precipitation, ion exchange, membrane separation, electrochemical, biological, and evaporative treatment. Because removal of sulfate from municipal wastewater has not previously been widely implemented, technologies still in early stages of testing and development were also included for completeness and future reference and to gauge the “state of the industry” at this time.
What is the best way to remove sulfate?
The technology screening process results indicate that reverse osmosis and nanofiltration are the most well-developed and effective alternatives for sulfate removal. This class of technologies is able to remove
What is sulfur in wastewater?
Sulfur in wastewater is most commonly present as sulfate or sulfide, which originates primarily from drinking water sources, human waste, and industrial discharges. More than 95% of municipalities in Minnesota use groundwater as the source for their drinking water. The concentrations of sulfate in the groundwater vary geographically across the state from less than 10 mg/L to over 500 mg/L. Untreated domestic wastewater constituents typically add another 20 to 50 mg/L of sulfate [Ref. (1)], and some municipalities may have additional industrial contributions. The form of sulfur is dependent on the condition of the wastewater, with sulfate present in oxygen-rich waters and sulfide present in oxygen- depleted water. The environmental conditions that help determine the state of sulfur in wastewater may be readily transformed, either biologically or chemically, by natural and engineered processes. Both sulfate and sulfide provide pathways for the removal of sulfur from wastewater. However, the technologies available to remove sulfate and sulfide from wastewater have mostly been developed and employed in applications other than municipal wastewater treatment, including drinking water treatment, mine water treatment, power generation, and others.
How much sulfate is in Minnesota?
Municipal wastewater sulfate concentrations in Minnesota range from about 10 to over 1,500 mg/L and originate from a drinking water source (i.e., river or aquifer), human waste, or industrial sources [Ref. (2)]. As shown on
Does sulfate dissolve in water?
In the oxidized form of sulfate, solubility varies in relation to other chemicals in the water. Sodium, magnesium, and potassium sulfate all dissolve readily in water. In contrast, calcium sulfate (gypsum) has a
What is aluminum sulfate used for?
It is mainly used in municipal water treatment plants to treat wastewater and potable water. Aluminum sulfate is also important for lake treatment and restoration. Untreated wastewater and potable water have negatively charged ...
Why is aluminum sulfate important?
Aluminum sulfate is also important for lake treatment and restoration. Untreated wastewater and potable water have negatively charged suspended colloids, and water treatment systems use positively charged metallic salts, such as aluminum sulfate, to destabilize the colloidal particles. As a coagulant, aluminum sulfate enhances the removal ...
Does aluminum sulfate remove bacteria?
While aluminum sulfate helps remove large amounts of organic compounds in potable water and wastewater, it isn't enough to remove pathogens, such as bacteria and viruses. However, aluminum sulfate is a primary step in water purification, as it prepares the water for further filtration.
What is the best way to remove sulfate from water?
As a polishing step for sulfate removal, barium salts can be added to precipitate barium sulfate, which has a very low solubility in water, with the final sulfate concentration limited only by the amount of barium added and reaction time. Typical salts used are barium chloride and barium carbonate. The disadvantage of barium addition is the relatively high chemical cost; a recent price for barium chloride was about $2/lb.
How to reduce sulfate concentration?
The simplest technology for reducing high sulfate concentrations is lime precipitation. Adding calcium as pebble lime, hydrated lime, or limestone can precipitate calcium sulfate (gypsum) and reduce sulfate concentrations to the solubility limit of 1,500-2,000 mg/L. Concentrations already below this level will generally be unaffected by lime addition. Typical equipment requirements for this process are a lime silo, lime slaker, or other reagent feed system, reaction tank, and clarifier. If sulfate must be further reduced (“polished”), an add-on process such as barium, CESR, or SAVMIN is recommended.
What is the standard for sulfate in water?
However, the secondary standard for drinking water in the U.S. is 250 mg/L and concentrations above 600 mg/L may create laxative effects. In Minnesota, future sulfate discharges may be limited to as low as 10 mg/L (an unenforced standard that is currently under review) to protect wild rice habitat. Guidelines for sulfate levels around the world are shown in Table 1.
How is sulfide produced?
In the THIOPAQ process developed by the PAQUES company (Netherlands), sulfide is produced by contacting the sulfate-containing stream with sulfate-reducing bacteria (SRB) in the presence of a carbon source (electron donor) such as hydrogen gas or acetic acid. The reaction for hydrogen is:
Can sulfide be converted to sulfur?
Excess sulfide can then be converted to element al sulfur (S o) with aerobic bacteria as follows:
