摘要:
An economical method for recovering phosphate or phosphate and nitrogen from liquid streams. A liquid containing phosphate is introduced into a culture of autotrophic microorganisms in the presence of natural or artificial light, thereby producing a liquid effluent with elevated pH and reduced alkalinity. The alkalinity is reduced through the consumption of bicarbonate/carbonate by the autotrophic microorganisms. The effluent is then chemically treated with low-cost chemicals to provide Ca++ or Mg++ ions necessary to form a phosphate precipitate such as calcium phosphate or magnesium-ammonium-phosphate (MAP). The autotrophic microorganisms can be cultivated in ponds, lagoons, or photobioreactors. The pH of the culture is adjustable within a preferred range of 7.5 to 10.5 by adjusting the photobioreactor operation. The process includes an economical flotation separator for solid, liquid, gas separation and a means of concentrating ammonia nitrogen that may also be removed during the process of phosphate reclamation.
摘要:
A porous and permeable composite for treatment of contaminated fluids characterized in that said composite includes a body of iron particles and 0.01-10% by weight of at least one functional ingredient distributed and locked in the pores and cavities of the iron body. Also, methods of making a permeable porous composite for water treatment. Also, use of a permeable porous composite for reducing the content of contaminants in a fluid, wherein said fluid is allowed to pass through the permeable composite.
摘要:
A method for concentration of phosphate compounds comprises dissolving (205) of sludge ash in hydrochloric acid. Insoluble residues are separated (210), thereby forming a first leach solution. A mole ratio of phosphorus to a sum of ferric iron and aluminium in the first leach solution is controlled (215) to be larger than 1. A base is added (220) to the first leach solution in an amount causing precipitation of phosphate compounds. The precipitated phosphate compounds are removed (225) from the first leach solution. Sulphuric acid is added (240) to the first leach solution, causing precipitation of sulphate compounds. The precipitated sulphate compounds are separated (245) from the first leach solution. At least a part of the leach solution is recycled (248) as the hydrochloric acid used for the dissolving of sludge ash. Further methods for processing the precipitated phosphate compounds are presented as well as arrangements for performing the methods.
摘要:
Nanoscale zero-valent iron (NZVI) particles or Ca-alginate-entrapped NZVI, are provided for use in environmental remediation, decontamination, and pollution control. When charged with a sorbed nutrient such as phosphate or selenium, they can be used as fertilizer.
摘要:
The present invention relates to a method for preparing an adsorbent for phosphorus adsorption and an adsorbent prepared by the method. More specifically, the present invention is based on the fact that phosphorus has a strong affinity for the surface of metal oxides or hydroxides, and relates to a method for preparing an adsorbent for phosphorus adsorption, which comprises absorbing and coating expanded vermiculite with aluminum and heating the coated vermiculite at high temperature to produce aluminum oxide on the surface of the expanded vermiculite so that the adsorption of phosphorus at the coordination of the oxide can be achieved with very high efficiency by a strong attraction between phosphorus ions and aluminum ions, and to an adsorbent prepared by the method.
摘要:
The instant disclosure is directed towards methods of treating wastewater and related systems, where the system includes: an aerated zone comprising media (e.g. with sufficient surface area and porosity to sustain microbial growth and retain bacteria) and a non-aerated zone comprising compost, wherein the system is configured to remove emulsified oil (e.g. and grease) from a wastewater stream.
摘要:
The present invention relates to improved wastewater treatment systems and methods. In one embodiment, the present invention utilizes microbial consortia and the final effluent of the treated wastewater is remarkably clean, and has low levels of hazardous chemicals, unwanted nutrient values and/or total solids. Advantageously, the wastewater treatment system and method of the present invention reduces the use of chemical compounds in the treatment process. Further, valuable biomasses can be produced from the wastewater using the treatment process of the present invention.
摘要:
Methods and systems for reducing a redox active contaminant in a waste stream in a waste treatment system involve performing a unit process of the waste treatment system by contacting redox active contaminant in the waste stream with oxyhydrogen-rich gas generated on-site by an oxyhydrogen gas generator that implements water dissociation technology. The oxyhydrogen gas generator involves applying a pulsed electrical signal to a series of closely spaced electrodes that are submerged in the waste stream to produce oxyhydrogen-rich gas from a water component of the waste stream. Operation of the oxyhydrogen gas generator in the waste stream may accomplish one or more unit processes for waste treatment, such as oxidation, stripping, floatation, disinfection, conditioning, stabilization, thickening, and dewatering, among others.
摘要:
The present invention relates to a process of remediating wastewaters, preferably agricultural wastewaters resulting from animal production or contained animal feeding operation sites. The water is treated to promote assimilation of nutrients into algal biomass, which can be harvested and sold, and the resultant wastewater is then purified. According to the invention, short wavelength UV radiation (less than 280 nm wavelength) is used to pretreat wastewater, with the dose determined by absorbance of the water, not by bacterial load. Pretreated water exhibits changes in chromophoric dissolved organic matter that allows for improved and increased algae production by as much as 88%.