Expeditionyacht.org

It’s been some time since my last post on drinking water.  I’ve run into another company that’s a major supplier of water treatment equipment for the maritime and offshore industry.  They don’t just offer reverse osmosis equipment but a full range of related products for filtration, decoloration, demineralization, disinfection, softening, pH-correction … the list goes on.  Everything you need for top quality water under one roof, industrial quality equipment.  Below you can see the different elements that go into a full-feature water treatment plant. A water maker is just a small part of it.

Take for instance their neutralising/mineralising filters for the conditioning of water from Reverse Osmosis plants to improve taste and avoid  corrosion in the fresh water system.

Water with a low pH value, such as water of R/O water makers, is often corrosive and tasteless. This so-called ‘acid condition’ is due to the presence of free carbonic acid gas (CO₂) and lack of natural minerals.

To make this water neutral or slightly alkaline, it should be neutralised or mineralised. To ensure the complete removal of CO₂, the water can be filtered through a bed of neutralising filter media, named E.W.T. compound. In the low pressure filtration process, the CO₂ reacts with the E.W.T. compound and natural bicarbonates are formed. As a result, the water is no longer corrosive and, when used for drinking, a natural taste is added to the water which is otherwise insipid to the palate.

In the past is has been common practice to use marble for this purpose though the reaction is slow and equilibrium is difficult to reach and maintain. E.W.T. compound is now preferred as its action is quick and complete. Due to its special structure, E.W.T. compound is rapid and uniformly soluble.  To get full details on the different pieces, visit the Hatenboer Water website. 

No, a complete system is not an ultra-compact package so this won’t fit on a typical yacht but, for a serious explorer yacht that wants the best water for its guests, you can’t do much better.

I’m going to dedicate a special section to water. This includes tap water to shower, clean, cook, etc.  Over the last few weeks I’ve done a lot of research on watermakers, water treatment,  hydrophore systems, tap water heating and storage, making it worth a separate section.

One thing is sure: we’ll have the cleanest, healthiest and best tasting and smelling water of any vessel when we’re done! And, the hot showers will be ‘free’ using the hot cooling water of our auxiliary engines. Add that with low consumption vacuum toilets and we’re talking green, again.

HEM is a French manufacturer of watermakers and associated filter systems for yachts. They have an excellent reputation in the (MEGA) yacht world and their website is very informative.  A well-known US brand is Searecovery.

One of our goals is to have an environmentally friendly operation.  Keep the clean water around us clean.   That means dealing with sewage and grey water (water from showers, sinks, etc.).  

A holding tank on a 10.000+ mile expedition yacht doesn’t make such sense.  So, the best way to deal with this is, is to treat it before it goes overboard.  Sewage treatment is the process of removing contaminants from wastewater, both runoff and domestic. It includes physical, chemical and biological processes to remove physical, chemical and biological contaminants. Its objective is to produce a wastestream and a solid waste or sludge also suitable for discharge or reuse back into the environment.

The purpose of disinfection in the treatment of wastewater is to substantially reduce the number of microrganisms in the water to be discharged back into the environment. The effectiveness of disinfection depends on the quality of the water being treated (e.g., cloudiness, pH, etc.), the type of disinfection being used, the disinfectant dosage (concentration and time), and other environmental variables.  Common methods of disinfection include ozone, chlorine, or ultraviolet light. Chloramine, which is used for drinking water, is not used in wastewater treatment because of its persistence

Chlorination remains the most common form of wastewater disinfection in North America due to its low cost and long-term history of effectiveness. But one major disadvantage is that chlorination of residual organic material can generate chlorinated-organic compounds that may be carcinogenic or harmful to the environment. Residual chlorine or chloramines is also capable of chlorinating organic material in the natural aquatic environment. And  because residual chlorine is toxic to aquatic species, in other words, not healthy for fish…, we don’t want to use chlorine.

Ultraviolet (UV) light can be used instead of chlorine, iodine, or other chemicals. Because no chemicals are used, the treated water’s taste is more natural and pure as compared to other methods. UV radiation causes damage to the genetic structure of bacteria, viruses, and other pathogens, making them incapable of reproduction.

Dutch company HMSA has developed an advanced biological sewage treatment plant.  It needs no chlorine.   Even better, it  uses a process that is inherent self regulating. There are no adjustments and the unit will handle black and grey water.  No pretreatment, maceration or screening is required.  There are no strainers, sludge return pumps, clarifiers or airlifts needed.  And the application of fixed media permits formation of much larger biomass volume than would otherwise be possible in conventional biological systems. The media itself is virtually non biodegradable. The biomass will easily survive a week without fresh sewage entering the system. Also change of salinity (in ports or rivers) does not influence the performance.

Sludge removal is a simple and clean job, that can be done within 15 minutes, by simple operating the valves and use of the installed discharge pump.

Operating principle
Waste water enters the system at the inlet (1).   The blower (2) provides air and causes the waste water to circulate through the submerged biofilter (4) by means of the airlift (3), a simple but reliable mammoth-pump principle.  The micro-organisms that grow on the surface of the media break down the organic particles in the waste water biologically.  Treated water flows to the disinfection tank (7) via the spillover (6). The disinfection pump (8a) gives out liquid disinfectant in precisely measured doses so as to eliminate any remaining bacteria and viruses, resulting in high-quality treatment coefficients and effluent suitable to discharge overboard but, UV disinfection reactor (8b) can be installed as an alternative to this disinfection pump. Grey water can enter the unit either through the grey water inlet (13) for disinfection only, or through the inlet (1) for biological treatment The discharge pump (9) and level switches (10) automatically maintain substance levels in the disinfection tank (7). A limited amount of sludge (11) settles at the bottom of the unit and can be released through air (12) and discharged by the pump (9).