x Abu Dhabi, UAESaturday 22 July 2017

Dubai hotel is UAE's first to use large-scale composting

A Dubai hotel is the first in the UAE to use large-scale composting.

A gardener at Madinat Jumeirah hotel sprays liquid fertiliser produced from food scraps using the Bokashi process. The leftover solid waste is buried and used as compost.
A gardener at Madinat Jumeirah hotel sprays liquid fertiliser produced from food scraps using the Bokashi process. The leftover solid waste is buried and used as compost.

DUBAI // Less than a year ago, the contents of the 30 plastic bins along the walls of a long, narrow room in Dubai's Al Qasr hotel would have been of little use - nothing more than common rubbish.

The fruit and vegetable peels and scraps, about 70kg every day, would have been disposed of, ending up about 30km north in Dubai's nearly overflowing landfill.

Now, however, those two tonnes of waste a month are transformed into plant food using a novel composting method.

Developed in Japan in 1982, the process, called Bokashi, involves placing the waste in specially designed plastic buckets along with a patented mix. Bacteria then ferments the waste to leave a usable compost.

Al Qasr is the first hotel in the country to use the method. The project started with Marco Rupp, the director of engineering at Madinat Jumeirah, who had planned to begin composting on a large-scale using a process called vermiculture.

"This involves using earth worms," said Mr Rupp, from South Africa, where the method is widely used.

Importing the worms proved difficult, however. Then a colleague introduced Mr Rupp to Bokashi.

"We started a trial in Magnolia, our vegetarian restaurant," he said. "It turned out to be a workable process, which we expanded."

Although all kinds of food can be composted, the hotel has focused on fruit and vegetable scraps because they are the easiest to separate.

Fruit and vegetables also comprise the bulk of kitchen waste.

While the technology itself is simple and can be used at home, implementing the scheme on a large scale required some effort.

"It needs dedicated staff, a full briefing, and you need to follow through," said Christian Gradnitzer, the executive chef at the Madinat Jumeirah resort.

Al Qasr has six commis chefs responsible for cutting fresh fruit and vegetables.

Their scraps are carried to the loading bay area of the hotel, where they are chopped up further and transferred into one of the 120-litre plastic bins.

Each day, three bins are filled with waste, which are then sprinkled with the Bokashi mix and left for 10 days.

"It looks like sawdust," said Mr Rupp, holding up a clear plastic bag with the reddish-brown mix.

The bacteria that ferment the waste are similar to those used to make yogurt, cheese and bread.

After 10 days in the cool, air-conditioned room, the waste bins are taken to a small outdoor nursery.

Surrounded by large pots of blooming desert roses, the composting area could easily be mistaken for a small garden.

But on the inner side of the two lines of desert roses are three pits, less than a metre wide and about 10 metres long.

Each is divided into three compartments, with signs indicating how long waste has been buried in each compartment.

It takes a week to fill each compartment with food scraps and green waste from landscaping, and the mixture needs nine weeks underground to become compost. It is then used in the hotel's lush gardens.

"This waste helps to restore the healthy balance of bacteria in the soil, which could potentially result in improved crop performance and moisture retention of the soil - something which is vital, particularly at this time of the year," Mr Rupp said.

Since the first batch of compost was only produced in March, it is too early to be able to tell how the natural plant food has affected landscaping.

"We are, however, extremely confident that over time the plants will benefit greatly from natural compost," he said.

vtodorova@thenational.ae