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United States Department of Agriculture

Agricultural Research Service

Research Project: INNOVATIVE BIORESOURCE MANAGEMENT TECHNOLOGIES FOR ENHANCED ENVIRONMENTAL QUALITY AND VALUE OPTIMIZATION

Location: Coastal Plain Soil, Water and Plant Conservation Research

Title: Phosphorus recovery and reuse from waste streams

Authors
item Karurranithi, Rajasekhar -
item Boland, Nanthi -
item Naidu, Ravi -
item Szogi, Ariel

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 2, 2014
Publication Date: N/A

Technical Abstract: Phosphorus (P) is an important macro-nutrient required by higher plants for growth and development. Phosphate rock is the main raw material for P fertilizers and the global rock phosphate production stands at 191,000 thousand tonnes (t) in the year 2011 (Jaisinski, 2012). Phosphate rock is a scarce and finite resource only available for the next 50-100 years (Cordell et al., 2009). In Pre industrial era, farm and domestic waste materials produced were returned back to the farm so that the nutrients were recycled and represented sustainable agriculture. Increasing population and the need for ensuring food security resulted in Green revolution and characterised by improved high yielding varieties with better fertilizer response, irrigation facilitates and more area brought under cultivation. On-farm wastes were replaced by industrial manufactured and subsidised fertilizers and were applied almost every year to increase the yield. Farmers avoided recycling of farm waste and other wastes, and the valuable nutrients ended in non-agricultural land, thereby resulting in permanent loss (Allsopp, 2012). Mined rock phosphate is the main source for all P fertilizers and its reserve is available only with handful of countries. Increasing demand and price of P fertilizer and dwindling quality phosphate rock are indication of P peak. Unlike oil peak, which can be tackled by the use of alternate energy sources, P peak is difficult to manage as there is no alternative for P in living systems (Cordell et al., 2009). The United Nations Food and Agriculture Orgainzation (FAO) predicts that the World population in 2050 estimated to be 9 billion people and there is a tough task ahead for Agriculture and Fertilizer industry to ensure food availability including meat based food stuffs. Only 15-20% of applied P is used by the crops and animals, the remaining amounts of P are wasted into various waste streams (Roy et al., 2006). The P present in these waste streams pose a threat to environment by way of nutrient enrichment resulting in various ecological problems. The world livestock population of 65 billion produce huge quantities of manures and the traditional approaches to using waste streams including manures, farm effluents and bio solids as a nutrient source are not currently economically viable due to the sheer volume required to obtain adequate nutrient levels. Optimum use of these waste streams as a source of nutrients and water requires knowledge of their composition not only in relation to beneficial uses but also to environmental implications. These waste streams can be very well utilized for recovery and reuse of P for a sustainable future. Annually, large quantities of waste streams that are rich in nutrients such as nitrogen (N) and P are produced in each country. For example, the quantity of P present in these waste streams produced in the US (t/annum): poultry manure-610,000; sheep manure-5,000; cattle manure-154,000; pig manure-54,000; and in Biosolids-127,000 (Thangarajan et al., 2013). The P present in waste streams can be recovered by various processes that include: (a) Precipitation as calcium and magnesium phosphate. The industrial by product such as lime, fly ash can be used for precipitation. (b) Nucleation of P present in the waste streams using nano materials. (c) Dissolved P in waste stream can be adsorbed and recovered using suitable adsorbent which are having high affinity to phosphate ions. Alum, red mud, slag can be used as adsorbents. Ion exchangers such as resins are generally used in waste water treatment plant to reduce P concentration in effluent. (d) Thermo-chemical combustion techniques involve incineration of municipal bio solids followed by a wet extraction and recovery of P from ashes. (e) Enhanced biological phosphorus removal (EBPR) and denitrifying P removal are the two methods of biological P removal techniques.

Last Modified: 10/23/2014
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