IONICS INC <ION> 4TH QTR NET Shr 11 cts vs 24 cts Net 419,000 vs 938,000 Revs 16.2 mln vs 16.9 mln Year Shr 25 cts vs 95 cts Net 952,000 vs 3,001,000 Revs 64.6 mln vs 68.8 mln Backlog 30.3 mln vs 31.9 mln NOTE: 1986 net includes nonrecurring gain 383,000 dlrs in quarter and charge 175,000 dlrs in year.