pollutional

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危险性和不可靠性，深井注入也会产生。

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，三价铬电镀艺已经为取代重六价铬电镀最重要技术之一。