A method for recovering phosphate from sludge includes the processes of treating sludge drawn from a water treatment system at a sewage treatment plant in an anaerobic condition to release polyphosphate accumulated in the sludge into solution, and recovering phosphate in the solution using a seed crystal material. A system for recovering phosphate from sludge includes a phosphorus-releasing means for treating sludge drawn from a water treatment system at a sewage treatment plant in an anaerobic condition to release phosphate into the bulk liquid, a dewatering and separating means for separating the sludge containing the solution including the released phosphate into dewatering effluent and dewatered sludge, a calcium ion concentration-adjusting means for adjusting the calcium ion concentration in the dewatering effluent, a pH-adjusting means for adjusting the pH of the dewatering effluent, and a crystallizing means for recovering phosphate from the calcium ion concentration-adjusted, pH-adjusted effluent of dewatering apparatus.
An apparatus and method for removing phosphorus from a wastewater effluent stream from a hog waste lagoon. The wastewater effluent is introduced to the bottom of an inverted cone-shaped continuous crystallizer including a fluidized bed of struvite therein. An effective amount of ammonia is introduced to the wastewater effluent at the bottom of the crystallizer to elevate the pH of wastewater effluent a predetermined amount. An effective amount of magnesium is also introduced to the wastewater effluent at the bottom of the crystallizer. The composition adjusted wastewater effluent is then continuously passed upwardly through the fluidized bed of struvite to reduce the total phosphorus content of the wastewater effluent a predetermined amount of up to about 80% or more. The treated wastewater effluent stream is removed from the top of the crystallizer, and struvite crystals that grow large enough to sink from the bottom of the crystallizer are periodically removed from a collection chamber therebeneath.
An apparatus and method for removing phosphorus from a wastewater effluent stream from a hog waste lagoon. The wastewater effluent is introduced to the bottom of an inverted cone-shaped continuous crystallizer including a fluidized bed of struvite therein. An effective amount of ammonia is introduced to the wastewater effluent at the bottom of the crystallizer to elevate the pH of wastewater effluent a predetermined amount. An effective amount of magnesium is also introduced to the wastewater effluent at the bottom of the crystallizer. The composition adjusted wastewater effluent is then continuously passed upwardly through the fluidized bed of struvite to reduce the total phosphorus content of the wastewater effluent a predetermined amount of up to about 80% or more. The treated wastewater effluent stream is removed from the top of the crystallizer, and struvite crystals that grow large enough to sink from the bottom of the crystallizer are periodically removed from a collection chamber therebeneath.
A method of treating wastewater to increase effluent volatile fatty acid content consisting of providing wastewater to a primary treatment vessel and adding a select quantity of a chemical, typically an aluminum or iron salt, to the wastewater, enhancing the separation of organic matter. Separated organic matter is then removed from the chemically treated wastewater forming a primary sludge and a primary effluent. A portion of the primary sludge is fermented to form a volatile fatty acid rich liquor. The volatile fatty acid rich liquor may then be used with the primary effluent, directed to a bioreactor, thereby forming a volatile fatty acid enriched bioreactor feed. The volatile fatty acid enriched influent may be further treated through known biological phosphorous and nitrogen removal methods.
A thermal sensing bulb for an expansion valve, the bulb containing a ballast material, the ballast material including a plurality of particles including a calcium silicate hydrate.
