Even 100 x 100 meters is a decently sized city block and that's pretty good depending on how much they cost. Considering it took California decades to clean up

Even 100 x 100 meters is a decently sized city block and that's pretty good depending on how much they cost. Considering it took California decades to clean up Los Angeles air using new technology and regulations, Im pretty sure Beijing residents wouldn't have a problem seeing a pretty, oversized Porta potty every 50 meters if it meant clean air. Taking into account the long term strain on healthcare of polluted air (it makes almost everything worse), this might be an economically viable solution