an increasing trendp < 0.001
In general, the aliphatic C values and methoxyl/N-alkyl C showed an increasing trend in the solar ponds during an evaporation/irradiation treatment ( r = 0.91; p < 0.001), while the O-alkyl C ( r = −0.84, p < 0.001), total aromatics ( r = −0.79; p < 0.05) and carboxyl/amide C ( r = −0.77; p < 0.001) exhibited an opposite trend.