Our results identified several classes of substances used to recover nutrients from waste/wastewater. They include "elements", "oxides/hydroxides", "metal salts", "minerals" and "polymers". Table summarizes the main substances employed in nutrient recovery from waste and wastewaters research. The class of elements is mostly represented by carbon (13,787 publications). Carbon stands for all types of activated carbons including biochars. Carbon is the most popular adsorbent known for its efficiency and low cost and it is often used for nutrient recovery from wastewater. Oxides are mostly represented by silica (1,214 publications), calcia (917 publications) and magnesia (882 publications). They can be employed not only as sorbents but also as flocculants (SiO2) and precipitating agents (CaO, MgO). Most frequently cited hydroxides including calcium, magnesium and aluminum hydroxides are well known as precipitating agents. Metal salts are another class of broadly employed substances for nutrient recovery. Calcium carbonate (1,820 publications) is the most frequently reported compound which is used as precipitating agent and sorbent. Other calcium salts along with magnesium, iron and zinc salts are frequently used as precipitating agents and flocculants. A variety of natural minerals that have been used for nutrient recovery and nutrient delivery are reported. Gypsum is a popular additive (1,182 publications) applied as a nutrient delivery improver and a nutrient loss inhibitor. Dolomite, calcite, magnesite, and biotite are precipitating agents. Vermiculite, montmorillonite, and clinoptilolite are ion-exchangers and sorbents. Biopolymers greatly contribute to nutrient recycling and recovery. Starch-based sorbents are the most frequently reported (1,597 publications). Cellulose (999 publications) is employed as an important component of filtration membranes. Hemicellulose is used in ion-exchange membranes. Chitosan is used as a flocculant. 47, 275, 329-333 Integrated processes and multipurpose systems utilizing wastes: Biorefineries & more Recovery of nutrients using combinations of physical, chemical, and biological processes at biorefineries promotes an alternative approach to sustainable fertilizer production. Biorefineries, farms which combine the production of biofuels, chemicals, and food with the use of the byproducts for energy and fertilizers, are a potential perspective to reduce the environmental impact of manufacturing. In biorefineries, the recovery/recycling of nutrients from wastewater, the non-fuel fraction of algal biomass and other bio-waste makes a closed loop system. Locally produced bio-based wastes that are not utilized for other purposes on-site must be transported for disposal or other processing, adding to costs to farming, food production and other industrial processes which utilize biological sources. Integrating systems on-site for recycling and recovery of products from these wastes instead of transporting them for disposal improves the circularity of the economy and thus sustainability. Such a locally adaptable, multipurpose system referred to as an automated "zero waste" system was recently patented in which a modular system was designed to be mobile and transportable. Waste inputs are converted to fertilizers, biogas/biofuels, chemicals, and/or clean water depending on which and how many modules are combined. Using separate process modules for separation and extraction, blend-heat, hydrolysis, and acidification, first in, first out anaerobic digestion, aerobic-boost-blend, and formulation of the products to control nutrient release allows the system to respond effectively to local needs.