It's total water consumption. The comment is a response to total water consumption by coastal provinces regardless if it is agriculture, industrial or personal usages all to be by desalination.where did you get the figure of 5m3 per day? thats simply impossible .. 150L per day is normal, but American use more than that like 600L per day
I think you are confused by just divided country water usage and population .... which mostly used for agriculture, animal farm and industry. But for household water usage, most likely around 150L per day or less for China
Water quality for household requires very high but for agriculture, animal farms and industry, much less
Like I said 4000 people per plant without distribution. So with 4000 people they need to come up with $100M to build it, that's $250k per person. You know how a water treatment plant for half a million people cost? It's around $20M. Because the most expensive parts of a desalination plant is the membranes and high power usage.
High pressure pumps are used for reserve osmosis (1/3 to 1/2) water stream. The membranes needs to be cleaned constantly, typically trained (parallel) operation, so one cycle is in cleaning with an weak acid or caustic and another in operation. Membrane replacement every 5 years or so due to calcium scaling that acid cleaning won't even get out.