Correct answer is (b) Bacterial Sulfate Reduction
The explanation: Bacterial Sulfate is the technique that helps in removing nitrogen and phosphate from wastewater. This takes places with the help of an Anoxic Packed Bioreactor that if usually packed with wood and Iron. Chemical precipitation is used to remove heavy metals by use of chemicals which ultimately leads to precipitation of the heavy metals. Also, activated Alumina, chemical precipitation and reverse osmosis is used to filter out heavy metals.