Specification of David Forbes and Astley Paston Price : treating sewage and producing manure.

  • Forbes, David.
Date:
1870
Catalogue details

Licence: Public Domain Mark

Credit: Specification of David Forbes and Astley Paston Price : treating sewage and producing manure. Source: Wellcome Collection.

    6/10 (page 4)
    Forbes fy Price's Impts. in Treating Sewage and Producing Manure. into a soluble condition, or haying obtained a solution of the phosphates of alumina they may either be employed in their concentrated form, or a solution of the same may be diluted with water, and they are then in a fit and proper condition to be employed for the treatment of sewage. Whilst the sewage is contained in a cistern or reservoir or whilst it is 5 in the act of flowing thereinto the requisite proportion of the soluble phosphates of alumina is to be added thereto, and after thorough admixture with the sewage by the use of agitators or other well known means, the sewage so treated may be allowed to remain tranquil in the reservoir, in order that subsidence of the resulting precipitate may be 10 effected, or after having added to the sewage the requisite amount of the soluble phosphates of alumina a base, such as lime or carbonate of lime (by preference milk of lime), is to be added in such quantity as that the phosphates in solution shall be precipitated. This result will be known by the sewage acquiring a neutral or alkaline reaction, 15 or the lime may be firstly added, and the solution of the phosphates of alumina added subsequently, but we prefer the former process, or the soluble phosphates of alumina may be firstly decomposed by means of abase such as lime or carbonate of lime, and the resulting precipitate may be employed for the purpose of effecting the separation of certain 20 constituents of sewage. In conjunction with any of the before mentioned methods of carrying out our Invention, deodorising agents, such, for example, as animal or vegetable charcoal, may be employed, but good results will be obtained by the employment of the phosphates of alumina alone or in conjunction 25 with a base, such as lime or carbonate of lime as before mentioned. The sewage after treatment by either of the before mentioned processes is allowed to settle and the clear or supernatant water may then be run .off, and the deposit or precipitate being collected and removed may be employed for agricultural or other purposes either in the moist condition 30 or after having been submitted to a drying or desiccating process. Or the precipitated phosphates may be again submitted to the action of hydrochloric acid or to a mixture of hydrochloric and sulphuric acids, and the solution be again employed for the treatment of sewage in a manner similar to that before described. The proportions in which 35 the soluble phosphates of alumina may be employed will vary with the sewage to be operated upon and the quality of the manure desired to be obtained, we have obtained good results by the employment of about