Volume 1

Report of the Commissioners appointed in 1898 to inquire and report what methods of treating and disposing of sewage (including any liquid from any factory or manufacturing process) may properly be adopted.

Great Britain. Royal Commission on Sewage Disposal.

Date:: 1902-1915

Credit: Report of the Commissioners appointed in 1898 to inquire and report what methods of treating and disposing of sewage (including any liquid from any factory or manufacturing process) may properly be adopted. Source: Wellcome Collection.

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$It is here shown that all suspended matters are re- moved; the total dissolved solids reduced by 33 per cent., whilé the organic matter-is reduced by 51 per cent. ; In all the other cases, whether total dissolved solids were much higher or much lower, there was a marked reduction, in both inorganic and organic matter. In rephy, then, to the questions asked supra, these figures and facts point unmistakably to precipitation being cheaper and more efficient than filtration, and I hope to be able to give details of a trial on a large scale, when the tanks now in progress at Messrs. Stanning’s, Leyland, are completed. B.—Dvyez anp Carico Print Waste. The foregoing analyses have shown calico, print, and dye wastes to be of a very objectionable character, too, and that they certainly demand treatment. Dr. Angus Smith showed that as a precipitant ferric chloride had a better effect on the colouration than ferrous sulphate (page 83, Report to the Local Government Board, 1882), with good results. Dated August 12th, 1889, Mr. Hunt, F.1.C., Leeds, presented a Report to the Leeds Leather Trade Associa- tion, on “The treatment of the effluent from the Bus- lingthorpe Tannery, with special reference to a week's work at the Tanks,” from which I am kindly permitted by the author to extract the following :— “Tn your report of 8th May, 1888, a description of the tank is given. Since then an improved method of agitating the contents of the tank during precipitation, has been adopted. Perforated pipes have been fixed near the floor of the tanks. ‘Through these pipes a : Il strong current of air is forced by one of Meldrum’ steam injectors. The air passing up through the water agitated it perfectly, and the process of precipitation is amproved and shortened. The smell during precipita- ition complained of before is not now noticeable. Sul- phate of iron (copperas) has been used for precipitating, a mixture of equal weights of copperas and aluwmino ferric cake giving good results.” More recently, 1892, Messrs. Mather and Platt, Salford, have brought out a similar arrangement for precipitating and aerating dye liquors, which I under- stand, has fulfilled all it. was expected to do, with alumino ferric and lime as precipitating agents. The system of aeration has also been practised successfully by Messrs. R. A. Sanderson and Co., Galashiels. In your laboratory at Preston experiments have been made on a small scale—and in the solution of this parti- cular problem, namely, removal of colouration, a small experiment is quite as conclusive as a large one—with ferric chloride and lime, the results being eminently satisfactory. The colouration was completely removed after fifteen minutes aeration, the effluent resembling distilled water in transparency.* The improvement in other respects can be noted from an analysis given below of the Whalley Abbey dye and print waste, before and after treatment. This sample is chosen as the one being most deeply coloured—red- dish purple—and though it contains but a small quantity of organic matter and solids, if small quanti- ties are affected the larger quantities are pretty safe. * The addition of a little sulphurous acid has a good bleaching effect often—the acidity being afterwards neutralised by lime. Dissolved Solids.| 5 3 Suspended Hey pe : : ny ea Nature of - a Solids. oD ia) “i a ‘e 5 a 22 | Date. Samol = ee Mra | BQ | 2S | -B ho & |Remarks. ce Bee ‘| Ra S2| 3 188/88 | 35 Ss j | j pls, ] ore 1 C = kyr = oF Minera eS Sis Mineral./Organic ay E & Se Pee 135 |9 Feb.| Print and Dye | Slightly 1893. Waste, Whal- 26°4 28°3 | 54°7 8°0 1°4 9-4] 64°71 | 4°79} -425 | -03 acid ley Abbey. J reaction.. 120 — | Same after treat: |. ment with i ; ee Obe) \vog-o*) 21-1149-3 | 0 0 0 | 493} 1-004] -042 | -o6 | Neutra’ (Fe, Clg), and aeration. Reduction percent. - .| — 26 10 100 EQG ae! ht Pag nh 2. Reyes | ee = I therefore beg to submit for your earnest considera- tion the advisability of recommending this course for manufacturers in the watershed, for the cost of running small, and the removal of coloration from our rivers, would, in the eyes of the general public, cover a multi- tude of other sins, and at the same time certainly be an Egat a step towards a more complete purification to -ollow. Tue Disposaut or PrecirrraTEp SLUDGE. The volume of sludge arising from the use of iron salts and lime is greater than that from the use of many other precipitants. At Messrs. Stanning’s, 60 gallons of liquor yielded with these agents 23lbs. of wet sludge— that is, about half-a-pound to a gallon, or about a 4oz. of dry solids if the water be deducted, which amounts to 95 per cent. By the cautiously sparing use of pre- cipitants these figures may be somewhat reduced, but not a great deal. Roughly speaking it will mean 4ewt. to 1,000 gallons treated, which is equivalent to some tons of sludge per diem in all cases.* * Messrs. Stanning calculated independently that they abstract 5 tons per diem of dry solids from fabrics. his, amounting to 100 tons wet sludge, about coincides with the figures given above. Effluent 500.000 gallons. 1213. Manufacturers who have made a life-long study of the subjects upon which I have presumed to make as curSory remarks as possible, are fully cognisant of this fact, is the stumbling block to the general adoption of pre- cipitation. From correspondence with manufacturers. up to the present it is to be gathered that the majority of them stand back on these grounds, while others have circumstantial reasons, and just a few still plead igno- rance, thinking perhaps, that “ where ignorance is bliss, tis folly to be wise.” Attempts have been made to utilise sludge for the manufacture of— 1.—Cement ; 2.—Manure ; 35.—Illuminating gas ; and 4.—For fettling puddling furnaces. In no cases as yet have the results been financially satisfactory, and in the fourth instance not satisfactory at all, the percentage of iron oxide in the sludge being: too small, Analyses of sludge from bleach liquor only, calico print waste onlv. and from the tanks of Woods’. at B 2$