BioPetroClean, a Tel Aviv, Israel-based water purification company, has closed its second round of financing with $5 million from 21 Ventures, which invested $3.5 million in its first round. The money will help the company set up a sales network and fund a number of new projects, according to Globes.

Founded in 2006, the company uses a biological technology, called Active Chemostat Treatment (ACT), to treat waste water in oil sludge and other organic pollutants. BPC develops unique bacterial “cocktails” tailored to handle specific water samples by using proprietary methods, maintaining them in large chemostats, or bioreactors, in a balanced state of growth.

By keeping the bacterial cells’ concentration low, the process minimizes the formation of aggregates — maximizing the surface available for biodegradation to occur, thus increasing its efficiency. The resulting water is practically sludge-free and can either be returned to the environment directly or processed further. BPC says the process is fully automated and that it can easily be modified and adapted for use in a variety of situations — oil refineries, marine ports, storage tanks and others — which helps lower its operational costs.

The company is currently running trials of its technology at a number of facilities in Israel and other countries, including South Africa, and has collaborated with BP and Shell. The latest round values the company at roughly $10 million.