Transport and retention of hydrochar-diatomite nanoaggregates in water-saturated porous sand: Effect of montmorillonite and phosphate at different ionic strengths and solution pH.

•Phosphate favors hydrochar-D transport at pH 6.0 but not at pH 9.0.•Transport of hydrochar-D nanoaggregates was inhibited by M over a wide pH range.•Organo-mineral clusters of hydrochar-D with M was prone to fill the sand pores.•M preferentially attachment with sand increased the hydrochar-D retention.•Copresence of M and phosphate slightly affect the deposition of hydrochar-D.