Forward Osmosis (FO) can be applied to enhance nutrient recovery from wastewater. This technique uses an osmotic pressure gradient as a driving force and semi-permeable membranes to separate dissolved solutes from water. The use of selective osmotic membranes improves phosphate and ammonium nutrient recovery. 167, 169 A hybrid system containing both a FO apparatus and a-microbial electrolysis cell, allowed the recovery of >99% of nitrogen as ammonium and >79% of phosphorus as struvite. 170 99% of the available phosphate was recovered from digested swine wastewater by FO within situ struvite precipitation. The combination of low-pressure reverse osmosis and nanofiltration is a promising technique for phosphorus and nitrogen recovery from anaerobic digestates. Anaerobic osmotic membrane bioreactor in combination with membrane distillation improves nutrient recovery from wastewater. Over the years, natural adsorbents such as zeolites, clays, biopolymers, and biochar have been investigated for nutrient recovery. Adsorption and removal of phosphate from wastewater can be accomplished using adsorbents such as synthetic metal hydroxides/oxides, carbonate minerals, clay minerals, zeolites, mesoporous silica, synthetic polymers, and biopolymers. Activated carbons and many types of biochar derived from various feedstocks, that are modified or doped to alter their adsorption capacities have been described. The ability of engineered sorbents, including those derived from biowaste sources, to remove phosphates from a variety of waste streams has improved significantly. Biocharmediated adsorption was applied to recover 96% of ammonium and phosphorus from swine wastewater. The combination of biochar and clinoptilolite resulted in improved ammonium, potassium and dissolved organic content (DOC) removal efficiencies compared to biochar alone. Selective recovery and enrichment of phosphate from wastewater containing competing ions have been achieved by using adsorption combined with capacitive deionization. Simultaneous recovery of ammonium and phosphate from urban sewage sludge using Na-, K-zeolites and MgO has been achieved via formation of bobierrite (Mg3(PO4)2 or struvite (MgNH4PO)4. A hybrid adsorption -membrane ultrafiltration process was applied to the recovery of (N-P-K)-nutrients from potassium-rich sludge using reactive sorbents. Nazeolites were used for NH + 4 and K + recovery, Ca-zeolites were applied to improve the removal of P via formation of Ca-phosphates (CaHPO4), and MgO facilitated the formation of Mg/NH4/PO4 minerals (struvite and magnesium phosphates). Natural zeolites such as K-clinoptilolite impregnated with hydrated metal oxides were used to prepare hybrid reactive sorbents for ammonium and phosphate recovery from urban wastewater. Effective sorption of phosphate, nitrite and nitrate using chitosan hydrogel beads have been demonstrated. Simultaneous removal of ammonia-nitrogen and phosphate as crystallized struvite from simulated swine wastewater was achieved using Mg-modified zeolite. 181 Ammonia stripping and phosphate precipitation from wastewater in the form of struvite has been applied using magnesium modified adsorbents. Phosphorus removal from eutrophic waters using various functional nanomaterials such as carbon-based materials, zeolites, mesoporous silica, metal-organic frameworks, metal oxides and hydroxides, and biomass-derived materials were reviewed. An efficient phosphate recovery from eutrophic lakes (90%) has been achieved using hybrid adsorbent comprising diatomite modified with dispersed magnesium oxide nanoflakes. To recover nutrients from wastewater, oxides and hydroxides of divalent and trivalent metals (Ca 2+ , Fe 3+ , Al 3+ , Mg 2+ , La 3+ , and Mn 3+ have been widely investigated because of their porosity and high surface area and hence a high adsorption capacity. Use of membrane filtration is attracting increasing attention for nutrient recovery from anaerobically digested slurries. The combination of microfiltration, ultrafiltration and nanofiltration membranes allowed recovering >94% of nitrogen from digestate. The nanofiltration membrane NF270 permitted fractionation and recovery of ammonium (30-36%) and phosphate (83-95%) from dairy manure digestate across the 3 < pH < 11. 188 However, membrane fouling is a challenge. Irreversible membrane fouling was attributed to the adsorption of substances related to humic acids and tyrosine-like to membranes. Effects of different filtration modes on membrane fouling were examined considering various parameters including nutrients removal and sludge dewaterability. The addition of an inorganic coagulant (alum) improved phosphorus removal and reduced membrane fouling. 192 Pre-coagulation using poly-aluminum chloride (PACl) or iron chloride as a coagulant improved membrane flux from 0.8 to 27.6 mL/m 2 /s. PAClcoagulation combined with sponge-membrane filtration effectively removed humic substances, polysaccharides and other organic matter, preventing membrane fouling and improving nutrient removal. Two-dimensional (2D) material-based membranes have shown great promise in wastewater treatment. When laminated graphene oxide (GO)-cellulose nanocrystal hybrid membranes were fabricated and used, they allowed a high passage of desirable nutrients such as NO3 -and H2PO4 In physical methods, patents provide a significant contribution to the total number of publications during the 2001-2021 period (Fig. ). It shows how important physical processes for wastewater treatment especially in the early stages. Preliminary treatment of wastewater often includes dewatering, settling, filtration, adsorption, flocculation. Forward osmosis is emerging as a popular nutrient recovery technique. More than twice as many patents as journals were published in 2012. Another increase in patents is shown in 2017-2018. In 2020, the number of patents fell to the level of 2006, but due to journals, the total number of publications remained at the level of 2018. "Adsorptive wastewater treatment" is the main concept associated with physical wastewater treatment both in the case of struvite production and in general. This concept is found in 91% publications on physical methods in general (Fig. ) and it is found in 82.5% publications on struvite production (Fig. ). "Wastewater filtration" contributes greatly to overall physical wastewater treatment (77%) followed by "wastewater treatment settling" (54%), "wastewater dewatering" (49%), "separatory wastewater treatment" (46%), "flocculation wastewater treatment" (44%), 'osmosis wastewater treatment" (41%). For struvite production, only "wastewater filtration" and "wastewater treatment settling" are comparable with "adsorptive wastewater treatment" accounting for 41% and 36%, respectively. Other concepts account for less than 25%.