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

由于地表下废的危险性和不可靠性，深井注入也会产染。

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，三价铬电镀工艺已经成为取染六价铬电镀的最要技术之一。