TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Apparatus: The apparatus further comprises a further forward osmosis unit configured to be supplied with a further source water and with the diluted draw solution output from the forward osmosis unit, the further forward osmosis unit configured to osmotically transfer water from the further source water into the diluted draw solution, where output from the further forward osmosis unit comprises additionally diluted draw solution and concentrated further source water, where the diluted solution concentrated by the draw solution concentration unit comprises the additionally diluted draw solution, and where output of the draw solution from the draw solution concentration unit is supplied to the forward osmosis unit. The further source water is provided from a same supply as the source water. Source water comprises seawater. The apparatus also comprises at least one bioreactor configured to perform biological reactions on the concentrated further source water. At least one bioreactor includes at least one of anaerobic bioreactor configured to produce biogas and an anaerobic bioreactor configured to biodegrade pollutants in the concentrated further source water. The draw solution comprises a draw solute selected from at least one of: water-soluble inorganic chemicals and water-soluble organic chemicals. The water-soluble inorganic chemicals include at least one of aluminum sulfate (Al2(SO4)3), magnesium sulfate (MgSO4), sodium sulfate (Na2SO4), potassium sulfate (K2SO4), ammonium sulfate ((NH4)2SO4), iron sulfate (Fe2(SO4)3), aluminum chloride (AlCl3), magnesium chloride (MgCl2), sodium chloride (NaCl), calcium chloride (CaCl2), ammonium chloride (NH4Cl), potassium chloride (KCl), iron chloride (FeCl3), aluminum nitrate (Al(NO3)3), magnesium nitrate (Mg(NO3)2), calcium nitrate (Ca(NO3)2), sodium nitrate (NaNO3), potassium nitrate (KNO3), ammonium bicarbonate (NH4HCO3), potassium bicarbonate (KHCO3), sodium bicarbonate (NaHCO3), potassium bromide (KBr) and their relative hydrates; and where the water-soluble organic chemicals include at least one of methanol, ethanol, acetone, glucose, sucrose, fructose, dextrose, chitosan, dendrimer and 2-methylimidazole-based chemicals. The draw solution concentration unit further comprises at least one of: a reverse osmosis membrane unit and a membrane distillation unit. It comprises at least two reverse osmosis membrane units connected in tandem and sharing same feed of diluted draw solution. Draw solution concentration unit further comprises two nanofiltration units, where permeate from a first of the two nanofiltration units is fed to a second of the two nanofiltration units. Retentate from the second of the two nanofiltration units is fed to the first of the two nanofiltration units. The draw solution comprises seawater, and further comprising a further forward osmosis unit configured to be supplied with a further draw solution and with the diluted seawater output from the forward osmosis unit, the further forward osmosis unit configured to osmotically transfer water from the diluted seawater into the further draw solution, where output from the further forward osmosis unit comprises diluted further draw solution and seawater, where the diluted solution supplied to the draw solution concentration unit for production of water comprises the diluted further draw solution, and where output of the further draw solution from the draw solution concentration unit is supplied to the further forward osmosis unit. In apparatus for producing biogas from source water, the draw solution comprises seawater and the source water comprises wastewater. Preferred Method: In recovering water from source water, supplying the draw solution to the forward osmosis unit comprises supplying the draw solution from the draw solution concentration unit. Concentrating the diluted solution comprises subjecting the diluted draw solution to at least one pass of nanofiltration. Concentrating the diluted solution comprises subjecting the diluted draw solution to two passes of nanofiltration, where permeate from the first pass of nanofiltration is used as a feed source in the second pass of nanofiltration, where retentate from the first pass of nanofiltration is supplied as the draw solution to the forward osmosis unit; and where retentate from the second pass of nanofiltration is supplied as feed to the first pass of nanofiltration. The method further comprises, prior to step (d), supplying the diluted draw solution and a further source water to a further forward osmosis unit; osmotically transferring water from the further source water into the diluted draw solution in the further forward osmosis unit; outputting additionally diluted draw solution and concentrated further source water from the further forward osmosis unit; and where the diluted solution supplied to the draw solution concentration unit in step (d) comprises the additionally diluted draw solution output from the further forward osmosis unit. It also comprises performing biological reactions on the concentrated further source water in a bioreactor. Performing biological reactions comprises at least one of producing biogas and biodegrading pollutants in the concentrated further source water. The draw solution comprises seawater, and further comprises, prior to step (d), supplying a further draw solution and the diluted seawater output form the forward osmosis unit to a further forward osmosis unit; osmotically transferring water from the diluted seawater into the further draw solution in the further forward osmosis unit; outputting seawater and diluted further draw solution from the further forward osmosis unit, and where the diluted solution supplied to the draw solution concentration unit in step (d) comprises the diluted further draw solution. Supplying the further draw solution to the further forward osmosis unit comprises supplying the further draw solution from the draw solution concentration unit.