This code gets all the values in column I, then checks the data from every row starting with the last inner array in the outer array of data. You must delete rows from the bottom up.
function removeRows() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sh = ss.getSheetByName('Sheet2');
//getRange(start row, start column, number of Rows to get, number of Columns to Get)
var dataInColumn_I = sh.getRange(1, 9, sh.getLastRow(), 1).getValues(); //Get a two dimensional array
var thisCellValue,
numberOfRowsInSheet = dataInColumn_I.length;
for (var i=numberOfRowsInSheet;i>0;i-=1) {
thisCellValue = dataInColumn_I[i-1];
if (thisCellValue === "5555555555") {
sh.deleteRow(i);
};
};
};