An ammonia capture and recovery system comprises five process steps, including an ammonia removal step, an ammonia recovery step, a product granulation step, a granulated product wax-coating step, and a granulated product encapsulation step. These steps are modular in that multiple approaches are valid for each step if it meets the process requirements for the next influent. Also, a method of taking ammonia-containing wastewater and producing several water fractions (preferably of decreasing volume and increasing purity) and a time-release ammonium-containing fertilizer, resulting in a sustainable nitrogenous fertilizer product that reduces fertilizer use and subsequent nutrient runoff while being produced from wastewater and not fossil fuel or hydrogen sources.

The invention relates to a sulfur coated granular fertilizer, having a polymer coating on the sulfur layer, wherein the polymer coating comprises polycaprolactone. The sulfur coated granular fertilizer may have an aliphatic polyester a polymer coating on the sulfur layer, and has the following characteristics when tested in a standardized water leach test: a. an initial release of about 20% nutrient or less in 24 h, preferably of about 15% or less; b. a release of more than 4% of the nutrient content between the days 14 and 21 from the beginning of the water leach test, preferable of about 5% or more.

The invention relates to a sulfur coated granular fertilizer, having a polymer coating on the sulfur layer, wherein the polymer coating comprises polycaprolactone. The sulfur coated granular fertilizer may have an aliphatic polyester a polymer coating on the sulfur layer, and has the following characteristics when tested in a standardized water leach test: a. an initial release of about 20% nutrient or less in 24 h, preferably of about 15% or less; b. a release of more than 4% of the nutrient content between the days 14 and 21 from the beginning of the water leach test, preferable of about 5% or more.

According to some demonstrative embodiments, there is provided herein a spherical fertilizer granule having a specific gravity of more than 1.94 g/cm.sup.2 and less than 3% porosity.

According to some demonstrative embodiments, there is provided herein a spherical fertilizer granule having a specific gravity of more than 1.94 g/cm.sup.2 and less than 3% porosity.

A controlled release fertilizer has been prepared comprising a nutrient core coated with one or more moisture barrier coatings, at least one of said moisture barrier coatings comprising: at least one polyethylene wax; and a thermoset polyurethane from the reaction of a polyol and a polyisocyanate. The weight ratio of thermoset polyurethane to polyethylene wax is from about 50:50 to about 98:2. The polyethylene wax is heated above the melt point of the polyethylene wax and mixed and dispersed into the polyol component of the thermoset polyurethane in a ratio of 90-70% polyol to 10-30% polyethylene wax before the thermoset polyurethane-forming mixture is applied to the surface of the nutrient core and cured. A coating of a high temperature microcrystalline wax can be applied prior to final curing of the thermoset polyurethane to the coated nutrient core particles.

A controlled release fertilizer has been prepared comprising a nutrient core coated with one or more moisture barrier coatings, at least one of said moisture barrier coatings comprising: at least one polyethylene wax; and a thermoset polyurethane from the reaction of a polyol and a polyisocyanate. The weight ratio of thermoset polyurethane to polyethylene wax is from about 50:50 to about 98:2. The polyethylene wax is heated above the melt point of the polyethylene wax and mixed and dispersed into the polyol component of the thermoset polyurethane in a ratio of 90-70% polyol to 10-30% polyethylene wax before the thermoset polyurethane-forming mixture is applied to the surface of the nutrient core and cured. A coating of a high temperature microcrystalline wax can be applied prior to final curing of the thermoset polyurethane to the coated nutrient core particles.

A process of granulation of a urea melt, comprising: adding a first additive containing carboxymethyl starch to one or more first stage(s) of the granulation process, to form a carcarboxymethyl starch containing inner layer of urea granules, and adding a second additive containing calcium lignosulfonate to one or more second stage(s) of the granulation process, downstream said first stages, to form granules with a coating containing calcium lignosulfonate.

A water submersible controlled release fertilizer particle comprising: (i) a fertilizer core material; (ii) a polyurethane coating layer encapsulates the fertilizer core material; and (iii) a hydrophilic outer layer encapsulates the polyurethane coating layer wherein the hydrophilic outer layer dissolves when subjected to water.

A controlled release fertilizer includes a core including plant nutrient particles and a biodegradable coating composition forming at least one layer surrounding the core, the composition comprising cellulose, the at least one layer being structured as a semi-permeable surface membrane configured to release the plant nutrients from the core in a linear manner.