In light of the hazards and uncertainties associated with subsurface waste disposal, deep well injection may create pollutional problems.

由于地表下废水处置的危险和不，深井注入也会产污染。

At present, trivalent chromium electroplating process has became one of the mostimportant techniques to taking place of the seriously pollutional hexvalent chromiumelectroplating process.

目前，三价铬艺已经成为取代重污染六价铬的最重要技术之一。