Löss is more microbe-friendly environment than desert sand since löss has better water-retaining capacity and richer of nutrients and growth-limiting elements (like iron). This might explain why DDT is biodegraded to DDD faster in löss than in sand.

Löss is more microbe-friendly environment than desert sand since löss has better water-retaining capacity and richer of nutrients and growth-limiting elements (like iron). This might explain why DDT is biodegraded to DDD faster in löss than in sand.

DDT degradation occurs in loess  soil due to microbial activity in this soil comparing with sandy soil ,due to favorable conditions for  microbial activity in loese soil.

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I agree with Victor. Loess is a nearly pure form of silt, with almost no sand, and very little clay (particles smaller than those of silt). Water holding capacity and organic matter retention ability of the loess are more than that of sand. Thus loess can support more diverse ecology. Loess can also make a soil's pH more congenial for living things (by increasing pH of acidic soils), bestowing biological communities there with remarkable vigor and diversity. Therefore it is no wonder that DDT is biodegraded to DDD faster in loess than in sand.

In the recent investigation，a discrepancy was observed in the distribution of the concentration of DDTs between the Mu Us Sandy Land area and the Loess Plateau area. DDD was detected in surface waters only at Loess Plateau area while DDE was detected not only at Loess Plateau but also at Mu Us Sandy Land area. DDT were not detected in all sampling sites.