Sadly, the search engine reports many duplicate results. For example, I searched: "arid land reforestation", and results were (https://screenshots.firefox.com/wl6JuVa5sbWNgy2o/www.qwant.c...):

* 1st: http://haringey.store/reforestation/in/reforestation_in_arid...

* 2nd: http://haringey.store/reforestation/in/reforestation_in_arid...

* 4th: http://maestron.store/reforestation/in/reforestation_in_arid...

* 5th: http://pipcoins.store/reforestation/in/reforestation_in_arid...

etc, etc. All of which were "bad" websites. It's a shame because some good results (science direct, …) were inside the lot. The content isn't even a pdf.

You should implement a "unique" webpage result fingerprint in order to avoid showing duplicates (well, I suppose it's easier said than done..).