H2bid provides users with many types of Liquid Chlorine Bids and other Chemical Bids. This will be explained further below.
First, it is important to understand how chemicals are used to treat water and wastewater.
Drinking water is treated by water purification. Water purification is the process of removing biological contaminants, undesirable chemicals, suspended solids and gases from contaminated water. The purpose of this process is to produce water that is fit for human consumption (drinking water). There are several methods of purifying water, including filtration, sedimentation, and distillation, biological processes such as slow sand filters or biologically active carbon, chemical processes such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light.
The process of purifying drinking water reduces the concentration of particulate matter including suspended particles, parasites, bacteria, algae, viruses, fungi; and a range of dissolved and particulate material that may be present in the water.
Chlorine is an important chemical used to purify drinking water. Permanent water chlorination began in 1905, when a faulty slow sand filter and a contaminated water supply led to a serious typhoid fever epidemic in Lincoln, England. Dr. Alexander Cruickshank Houston used chlorination to purify the water and stop the epidemic from spreading. Houston fed a concentrated solution of chloride of lime to the water being treated. The chlorinated water supply helped stop the epidemic and as a precaution, the chlorination was continued until 1911 when a new water supply system was implemented.
Chlorine dioxide is another chemical used to disinfect water. It is faster-acting than elemental chlorine. It is relatively rarely used, because in some situations it may create excessive amounts of chlorite, which is a by-product regulated to low allowable levels in the United States. Chlorine dioxide is supplied as an aqueous solution and added to water to avoid gas handling problems. Particular care must be taken with this chemical because chlorine dioxide gas accumulations may spontaneously detonate.
Another chemical disinfectant is chloramine. Chloramine is becoming more common as a chemical used to disinfect water. On one hand, chloramine is not as strong an oxidant, on the other hand, it does provide a longer-lasting residual than free chlorine and it will not form THMs or haloacetic acids. Chlorine can be converted to chloramine by adding ammonia to the chlorinated water. Chlorine and ammonia react to create chloramine. Water utilities that disinfected with chloramines may experience nitrification, because ammonia is a nutrient for bacterial growth, with nitrates produced as a by-product.
Chemical Used in the Wastewater Treatment Process
Similar to drinking water purification, chemicals are used during wastewater treatment to expedite disinfection. There are multiple distinct chemical unit processes which can be applied to wastewater during cleaning. A few are highlighted below.
Chemical Precipitation to Remove Toxic Metals
Chemical precipitation is perhaps the most common method for removing dissolved metals from wastewater solution containing toxic metals. A precipitation reagent is added to wastewater to convert the dissolved metals into solid particle form. A chemical reaction, triggered by the reagent, causes the dissolved metals to form solid particles. Filtration can then be used to remove the particles from the mixture. The effectiveness of this process is influenced by the kind of metal present, the concentration of the metal, and the kind of reagent used. For example, in hydroxide precipitation, a frequently used chemical precipitation process, calcium or sodium hydroxide is used as the reagent to create solid metal hydroxides. It should be noted that it can be difficult to create hydroxides from dissolved metal particles in wastewater because many wastewater solutions contain mixed metals.
Chemical Coagulation to Destabilize Wastewater Particles
Chemical Coagulation involves destabilizing wastewater particles so that they aggregate during chemical flocculation. Fine solid particles contained in wastewater carry negative electric surface charges (in their normal stable state), which prevent them from forming larger groups and settling. Chemical coagulation destabilizes these particles by introducing positively charged coagulants that work to reduce the negative particles’ charge. Once the charge is reduced, the particles are able to form larger groups. In the next step, an anionic flocculant is introduced into the wastewater. Because the flocculant reacts against the positively charged mixture, it either neutralizes the particle groups or creates bridges between them to bind the particles into larger groups. Once the larger particle groups are formed, sedimentation is used to remove the particles from the wastewater.
Chemical Oxidation and Advanced Oxidation for Structural Modification
Introducing an oxidizing agent during chemical oxidation allows electrons to move from the oxidant to the pollutants in wastewater. The pollutants then undergo structural modification, turning into less destructive compounds. Alkaline chlorination uses chlorine as an oxidant against cyanide. However, care must be takent because alkaline chlorination as a chemical oxidation process can lead to the creation of toxic chlorinated compounds, requiring additional steps. Advanced oxidation can be used to remove organic compounds produced as a byproduct of chemical oxidation – the processes include steam stripping, air stripping, or activated carbon adsorption.
CHEMICAL BID – SAMPLE SPECIFICATIONS 1
Liquid Chlorine Bid:
The undersigned agrees to supply the named water utility with liquid chlorine that is 99% pure in the amount of 100 1-ton cylinders. Liquid Chlorine supplied under this specification shall conform to all provisions of AWWA B-301-04 Standard.
This specification covers liquid chlorine for use in water treatment. The estimated annual usage is 100 tons. Delivery will be in 1-ton cylinders and pricing is per pound chlorine. There will be no cylinder deposits or fees paid under this specification.
CHEMICAL BID – SAMPLE SPECIFICATIONS 2
Sodium Hypochlorite Bid:
The undersigned agrees to supply the named water utility with sodium hypochlorite solution (11.5% to 13.5%) in the amount of five – 330 gallon containers.
CHEMICAL BID – SAMPLE SPECIFICATIONS 3
Fluorosilicic Acid Bid:
The undersigned agrees to supply the named water utility with Fluorosilicic Acid in the amount of 50,000 pounds. Hydrofluorosilicic acid (H2SiF6) supplied under the contract shall conform to all provisions of ANSI/AWWA B703-06 Standard or the latest revision.
This specification covers hydrofluorosilicic acid (HFS) for water supply service applications. The estimated annual usage is 50,000 pounds. The bid price and billing price on this product will be on a wet weight basis for 23% HFS.
CHEMICAL BID – SAMPLE SPECIFICATIONS 4
Liquid Aluminum Sulfate Bid:
The undersigned agrees to supply the named water utility with Liquid Aluminum Sulfate (8.3%) in the amount of 1000 dry tons. Liquid Aluminum Sulfate supplied under the contract shall conform to all provisions of ANSI/AWWA B403-03 Standard or the latest revision.
This specification covers purified aluminum sulfate in liquid form for use in water treatment. The estimated annual usage is 1000 dry tons. Pricing is requested for full truck loads (TTL) on a dry weight basis
CHEMICAL BID – SAMPLE SPECIFICATIONS 5
Sodium Hypochlorite Bid:
The undersigned agrees to supply the named water utility with Sodium Hypochlorite (15%) in the amount of 250,000 lbs.
Sodium hypochlorite supplied under this specification shall conform to all provisions of AWWA B-300-04 Standard. This specification covers sodium hypochlorite for use in water treatment. The estimated annual usage is 250,000 gallons for full truck loads (TTL) and 14,500 gallons for less than truck loads (LTL). Pricing is requested for full truck loads (TTL) on a price per lb. available chlorine basis. Pricing for (LTL) will be on per gallon basis.
CHEMICAL BID – SAMPLE SPECIFICATIONS 6
Sodium Chlorite Bid:
The undersigned agrees to supply the named water utility with Sodium Chlorite (25%) in the amount of 235,000 lbs. Sodium chlorite supplied under this specification shall conform to all provisions of AWWA B-303-05 Standard. This specification covers sodium chlorite for use in the generation of chlorine dioxide for use in water treatment. The estimated annual usage is 235,000 pounds. Pricing is requested for full truck loads (TTL).
CHEMICAL BID – SAMPLE SPECIFICATIONS 7
Sodium Hydroxide Bid:
The undersigned agrees to supply the named water utility with sodium hydroxide (50%). The sodium hydroxide supplied for water plant use under this specification shall conform to all provisions of AWWA B-501-03 Standard.
This specification covers sodium hydroxide for use in water and wastewater treatment. The estimated annual usage is (a) 200 dry tons (water plant) for full truck loads (TTL) and,( b) 30,000 gallons (wastewater plants) for less than truck loads (LTL). Sodium Hydroxide for the water and wastewater plants can be diaphragm grade. Pricing will be per dry ton TTL and per gallon LTL.
CHEMICAL BID – SAMPLE SPECIFICATIONS 8
Sulfuric Acid Bid:
The undersigned agrees to supply the named water utility with sulfuric acid (93%) in the amount of 800,000 pounds. Sulfuric acid supplied for the water plant use under this specification shall conform to all provisions of applicable AWWA Standards.
This specification covers sulfuric acid (93%) for use in water treatment. The estimated annual usage is 800,000 pounds. Pricing is requested for full (TTL) and (LTL).