Mithi clean up snippets

A Rs 1.2-crore experiment has not been able to rid the Mithi of its stink. So the MMRDA is back to its favourite olfactory laboratory in the city, the bed of the Mithi. The MMRDA will commission on July 23 a new experiment to stop the stench at the Vakola nullah. “Earlier, the Florida-based Environmental Consulting & Technology Inc (ECT) had installed two machines to purify a 300-metre stretch of the Mithi in BKC a year ago. Though it improved the water quality and removed the stink, it was not an effective solution to treat the massive quantity of flowing water,’’ said MMRDA commissioner Ratnakar Gaikwad. The new method will diffuse the poisonous gases in the river to bring down the biological oxygen demand (BOD) and chemical oxygen demand (COD). This new method, Gaikwad said, would rapidly purify around 100 million litres of water every day. Gaikwad said the current experiment was working but the volume of water in the river was great and the process seemed expensive. “The new process will involve bottom level cleaning and can be done on flowing water. If successful, it can be used along the river and will not cost more than Rs 8 crore per year.’’ The new method has been developed by Raghavendra Rao, an engineer who runs STEPS, and the process has been used in China and Malaysia. “We will use rapid oxygenation and rapid flocculation methods to counter pollution. We will also tackle sulphides in the water, which give Mithi its bad odour and dark colour,’’ said Rao. “We will know if we are successful within a month,’’ he added. The MMRDA will also try to blast the rocky formation at the mouth of the river again.