You can use sewage treatment plant (STP) for treating the waste water and then use it for irrigation purposes or lavatory use

Thank you for your answer Karthick, shall I know any sustainable technique used for seawater treatment in hotel industry, because Sri Lanka is widely practiced beach hotels for their tourism developments.

Reverse Osmosis is the commercially available and quite cost effective technique

1 stage :Recycle the waste water  by common instrumental technology.

2 stage :apply suitable filtration process.

3 stage : purification : use Reverse Osmosis techniques.

All these are economical and available in market.

 Thank you very much Dr. Virendra. You gave me more details.

On line published work available for these well developed techniques 

Hello Disna Eheliyagoda,

that’s a tricky question and there is no standard solution.

It depends on the quantity and the quality of your wastewater.

Step 1: First of all, you should think about the separation of black water from grey water

Step 2: Black water could be treated with an anaerobic 3-chamber system. The output should be enriched with nutrients and could be used as a fertilizer for the hotel garden… keep in mind that local hygienic regulations sometimes give extra instructions for the reuse of black water.

Step 3: aerobic gray water treatment…. In this stage, you can also insert the output of step 2.

Step 4: A Pond with plants for further nutrient extraction and to collect the treated water.

Step 5: reverse osmosis to purify the water.

I am not too deep in this whole wastewater topic, but that´s how I would try it.

Greetings

Jan

#PS. I send you a link, that might interest you

Dear Jan-Henrik,

Thank you so much for your detailed information. This is very much useful.

I'm sorry, for me your question is not clear:

Desalination technologies (usually RO) are not recommended for wastewater.

 Dear Ricardo,

I want to develop a wastewater treatment plant using sea water.

Hi Disna, just to clarify, you have to:

- catching sea water.

- remove salts of it.

- supply sweet water to the hotel

- treat the hotel wastewater and the osmosis waste waters.

So:

- The brine from osmosis does not require treatment, it is not contaminated, it simply has more salts => directly to sea.

- Hotel sanitary wastewater + backwash of osmosis sand filters plus osmosis reagents drains, can be sent to a conventional sanitary wastewater treatment plant. The salinity will not be very high because the hotel supply is sweet water.

I HOPE TO HAVE UNDERSTOOD YOUR PROBLEM. REGARDS

Dear Ricardo,

Thank you very much and your answer is great.