کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5756781 1622626 2017 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Extraction and precipitation of phosphorus from sewage sludge
ترجمه فارسی عنوان
استخراج و بارگیری فسفر از لجن فاضلاب
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات مهندسی ژئوتکنیک و زمین شناسی مهندسی
چکیده انگلیسی
Raw sewage sludge from East Rand Water Care Association (ERWAT) had high phosphorus (P) content, approximately 15.2% (w/w) P2O5, which indicates a potential resource for the limiting nutrient. Leaching sewage sludge with 1 M sulphuric acid at 5% solid loading for 2 h resulted in an 82% phosphorus extraction. However, the phosphorus was recovered as iron phosphates, thus a further purification step using ion exchange to remove iron was required to increase the degree of P release. Magnesium oxide and ammonium hydroxide were used as magnesium and nitrogen sources, respectively, as well as pH regulators to precipitate P as struvite. 57% struvite was precipitated and the total phosphorus content of the precipitate was 25.9%. Kinetic studies showed that the leaching of phosphorus follows the Dickinson model for the first 100 min with a rate of reaction of about 2 × 10−5 s−1. The rate limiting step is controlled by diffusion. Phosphorus solubility in 2% critic acid was almost 96%, which is the amount of phosphorus available to plants if the precipitate is applied as a fertiliser. Environmental, gram-positive Bacillus subtilis were found in the precipitate, which are harmless to the environment since they already exist in the soil where the precipitate can be applied as a fertiliser.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Waste Management - Volume 60, February 2017, Pages 191-200
نویسندگان
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