# Mdpj _sciences_
## 4 Comparative Analysis of Experimental and Simulation Approaches
### Experimental Analysis of \"In Situ\" Performance
#### 4.1.1 Indoor Performance Trials  
[PERSON] et al. (2017) conducted their experiment in offices within a railway station depot undergoing maintenance, which caused high localized pollutant levels. Two offices were examined: one with an active green wall (AGW) installed and the other left empty as a control. Concentrations of PM2.5, NO2, and O3 were measured over a 42-day sampling period, along with temperature, relative humidity, and dew point. The single pass removal efficiency (SPRE) was evaluated by calculating the ratio of ambient pollutant concentrations to filtered concentrations. Results showed lower concentrations in the room with the AGW, with a removal efficiency of 80% for O3 and 75% for PM, but only 40% for NO2.  
Similarly, [PERSON] et al. (2017) achieved positive results in reducing PM and VOC levels using an AGW tested in a residential room. A sensor installed in the center of the room, maintained at 20-25 \({}^{\circ}\)C, detected pollutants over eight trials per pollutant, each lasting 32-37 min. The green system provided better air quality compared to a standard HVAC system.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Authors** & **Pollutant** & **Construction Type** & **Vegetation** & **Growing Medium** & **Performance Metrics** \\ \hline [PERSON] et al. (2017) & VOC & Modular & Money tree, Staghorn & & \\  & & & fern, Chinese & Cloth & High VOC \\  & & & Evergreen, etc. & & \\ \hline [PERSON] et al. (2017) & PM & Modular & \begin{tabular}{c} _Chlorophyllum_ \\ _orchidestrum_, _Ficus_ \\ _lyrata_, _Nematanthus_ \\ _glyarb_, etc. \\ \end{tabular} & Soil & \begin{tabular}{c} High PM \\ _reduction efficiency_ \\ \end{tabular} \\ \hline [PERSON] et al. (2017) & PM & - & \begin{tabular}{c} _Geranium_ \\ _mavrorhizum_ L, _Hedera_ \\ _helix_ L ivy, _Hehe albicans_, etc. \\ \end{tabular} & Soil & \begin{tabular}{c} High PM \\ _reduction efficiency_ \\ \end{tabular} \\ \hline [PERSON] et al. (2017) & PM, TE & - & \begin{tabular}{c} _Tzus hucatta L., Pinus_ \\ _nigra Arm.,_ \\ _Carpins lethulus_ \\ \end{tabular} & - & \begin{tabular}{c} High PM and \\ TE accumulation \\ \end{tabular} \\ \hline [PERSON] et al. (2017) & PM, O3, SO2, NO2 & - & \begin{tabular}{c} _Ijomnea planta,_ \\ _Aristolichia elegans_, \\ _Thunbergai_ \\ _grandiflora_, etc. \\ \end{tabular} & - & \begin{tabular}{c} High pollutant tolerance \\ and reduction efficiency \\ \end{tabular} \\ \hline [PERSON] et al. (2017) & PM & - & \begin{tabular}{c} _Chlorophyllum consum,_ \\ _N. galuzna_, _N. eallatta_ \\ 'Bostoniensis’, etc. \\ \end{tabular} & - & \begin{tabular}{c} High PM \\ reduction efficiency \\ \end{tabular} \\ \hline Treesubsumtor and & CO2 & Potted plants & \begin{tabular}{c} _S. kurkii, S. trifisciata,_ \\ _C. composum,_ \\ _D. sanderiana_, etc. \\ \end{tabular} & \begin{tabular}{c} Sandy loam \\ soil mixture \\ \end{tabular} & \begin{tabular}{c} High CO2 \\ absorption efficiency \\ \end{tabular} \\ \hline [PERSON] et al. (2017) & PM & - & \
\begin{tabular}{c} _Arlisi japonicus,_ \\ _Hedera helix_ \\ \end{tabular} &
\begin{tabular}{c} Organic soil and rice \\ husk-derived \\ \end{tabular} & \\ \hline \hline \end{tabular}
\end{table}
Table 4: _Cont._[PERSON] et al. [22] tested the reduction of PM and CO\({}_{2}\) concentrations with a green wall located on the first floor of a six-level office building, specifically on a corridor wall in the stairwell. Measurements of CO\({}_{2}\), PM, temperature, and relative humidity were taken using an air quality monitor, photosynthetically active radiation meter, anemometer, and passenger flow counter. The system showed a 17% reduction in CO\({}_{2}\) levels and a reduction of PM2.5 by 40%, demonstrating high air purification performance.