## 3 Results and Discussion
### Potential Applications of Biochar in the NEA
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Category** & **Benefits of the Use of Biochar (1)** & **References** \\ \hline \multirow{7}{*}{Soil} & - Increases water-holding capacity, cation exchange capacity, and organic matter & \\  & content. Reduces irrigation water consumption. & - Alters soil pH, especially if the soil is overly acidic. \\  & - Provides a suitable medium for the reproduction and maintenance of soil & \\  & microorganisms. & microorganisms. \\  & - Reduces bioavailability and ecotoxicological impacts of heavy metals (Cu, Ni, Cd, Pb). & [23; 26; 27; 76; 77; 78; 79; 80] \\  & - Retains natural and added soil nutrients (N, P, K, Si, Ca) against leaching, such that they can be absorbed again by plants. Increases crop yields. \\  & - Improves the organic waste composting process. & - Adsorptive removal of chemicals including pharmaceuticals and antibiotics, inks (e.g., methylene blue), and other inorganic pollutants from water. \\ Water & - prevents the eutrophication of aquatic environments when applied on land, by keeping the nutrients there. It can be also used in filtering bags in the river runoff. & - Supplements feed for ruminants (cattle and goats), pigs, poultry (chicken and duck), and fish. \\ Animal husbandry & - Improves ruminal fermentation and feed efficiency. & [86; 87; 88; 89] \\  & - Positively affects growth performance, blood profiles, egg yield, abdominal fat & \\  & weight, meat quality, carcass weight, and nutrient excretion. & - Can also be used as bedding material in stables. \\  & - Source of thermal energy in the production of iron or steel. & \\ Energy & - Fuel in boilers and cogeneration facilities. & \\  & - Cooking fuel, barbecue charcoal. & \\  & - Increases methane yield when used as an additive in anaerobic digestion systems. & - When used as a substrate in rooftop and vertical gardens, decreases the weight and corresponding load of these infrastructures. \\  & - Preserves the ecosystems services linked to urban greenery (when used as a soil conditioner). & \\ Green infrastructure & - Improves the water retention of rain gardens and helps to control & \\  & stormwater runoff. & \\  & - When used as a soil conditioner in urban greenery, as well as vertical and rooftop & \\  & gardens, reduces infiltration and inflow of rainwater controlling sanitary sewer & \\  & - The addition of small fractions of biochar (<5 wt.%) increases the strength and & \\  & toughness of the cement and mortar, as well as the flexural strength. & \\ Gray infrastructure: & - Decreases density of cement mortar, making it more porous and lightweight). & [96; 97; 98] \\  & cement and mortars & - Reduces thermal conductivity. & \\  & - Reduces carbon footprint of infrastructures made with cement. & \\  & - Turns gray infrastructure into long-term carbon sinks. & \\  & - Biochar is recalcitrant in the soils turning them into a long-term carbon sink with & \\ Carbon sequestration & & several co-benefits for crops (see soil above). & [41; 99; 100; 101; 102] \\  & - Transfers carbon from the atmosphere into the soils. & \\ \hline \hline \end{tabular}  
* This column presents the results of studies with biochar produced from different feedstocks and operating conditions. Differences in the context and characteristics of these studies should be considered before extrapolation of results. Any field application must be previously studied experimentally.  
\end{table} 
Table 4: Applications of biochar in the NEA considering five categories: soil, water animal husbandry, energy, green and gray infrastructure, and carbon sequestration. For the bioeconomy, the creation of value for agricultural waste is important if it results in the emergence of new production processes. In this regard, biochar is a versatile material that can be appropriate for the sustainable management of environmental resources in the NEA and as an input material in major sectors of the region.