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Slag and Al/Mg oxide modified Douglas fir biochar (AMOB) were compared for their phosphate adsorbing abilities for use individually or in combination for simulated agriculture run-off remediation in wetlands. Aqueous batch and column sorption experiments were performed for both low-cost materials. AMOB was prepared in bulk using a novel green method. Material analyses included XRD, elemental analysis, SEM, EDX, and BET. Biochar and slag have different phosphate removal mechanisms. In short residence times (≤2 h), adsorption phenomena dominate for both adsorbents. Surface area likely plays a role in adsorption performance; slag was measured to be 4.1 m2/g while biochar’s surface area was 364.1 m2/g. In longer residence times (>2 h), the slow leaching of metals (Ca, Al, and Mg) from slag continue to remove phosphate through the precipitation of metal phosphates. In 24 h, slag removed more free phosphate from the solution than AMOB. Preliminary fixed bed column adsorption of slag or AMOB alone and in tandem was performed adopting a scaled-up model that can be used to remediate agricultural runoff with high phosphate content. Additionally, a desorption study was performed to analyze the efficiency of material regeneration. While AMOB does not release any adsorbed phosphates, slag slowly releases 5.7% adsorbed phosphate over seven days. 

The new material [RuGa]@NU-1000 incorporates Ru and Ga in 1.2 and 1.8 wt% respectively (molar ratio 1 : 2). It stems from the grafting of the heterobimetallic ruthenium gallate complex, [MeRu(η 6 -C 6 H 6 )(PPh 3 ) 2 ][GaMe 2 Cl 2 ] into the MOF material NU-1000. [RuGa]@NU-1000 shows enhanced adsorption of SO 2 , specially at low pressures (10 −3 bar) even when compared with other materials employing more expensive precious metals. Additionally, [RuGa]@NU-1000 samples need not be exposed to such harsh conditions for reactivation as they retain their adsorption properties after several cycles and preserve their porosity and structure. Thus, [RuGa]@NU-1000 is an excellent, selective material suitable for detection and precise quantification of SO 2 , with a lower cost compared to other MOFs incorporating precious metals.