Case Study

Qatar Has The Vision To Create Reusable Water From Municipal Sewage With The Headworks BIO Compact Wastewater Treatment Plant

Background
Al Shamal is the capital city of the municipality of Madinat ash Shamal in Qatar. It is considered one of the main cities in Qatar — although the population is barely over 5,000. The name means "City of the North", located 120 Kilometers north of Doha. Al Shamal will be home to the proposed 45,330 seat Al-Shamal Stadium, one of 12 venues planned to be used in the 2022 FIFA World Cup! The population is expected to rise to 18,000 by 2030 which takes into consideration the anticipated population surge created by the construction boom ahead of the FIFA 2022 World Cup.

Accommodating just over 5,000 inhabitants, Madinat ash Shamal is the least populous municipality in the country. As it comprises the northernmost portion of the country, its historic importance is attributed to its more moderate weather and close proximity to Bahrain. The traditional mainstay of its inhabitants was fishing and pearling. Proceeding the discovery of oil, most of Al Shamal's population migrated to the capital city of Doha.

With the majority of the town's population not yet connected to a sewer network, there was an immediate need to provide a wastewater treatment plant to treat wastewater generated from the towns' population and small industries. Ashghal, the Public Works Authority of Qatar and its end user, decided to install a tanker discharge facility with a compact sewage treatment plant to produce effluent suitable for reuse in irrigation. The proposed eight-bay tanker discharge facility shall bring wastewater via tankers from septic tanks in and around the town for treatment at the plant.

The eight bay tanker discharge facility (TDF)

After approval of its process design by Ashghal, "HW Bio" was awarded the contract to be the biological process design provider under Metito, the main contractor on the project. Under the contract, HW Bio supplied three Headworks Integrated Treatment ("HIT™") compact wastewater systems, for serving the township of Al Shamal.

The HIT systems provided are each modular, compact wastewater treatment systems designed for smaller communities and industries.Each modular unit can treat up to 200 m3/d of wastewater, in total providing 600 m3/d treatment capacity and serving a population equivalent of 2,400.

The modular Headworks Integrated Treatment system – 3 x 200 m3/d

System Overview
One of the many challenges when designing such a system is to be sure to provide a solution which could handle variations in flow resulting from the number of tankers discharging at different times of the day. The plant must be able to handle inconsistent flow and loads. Additionally, having a process which requires minimal operator intervention, control and maintenance was a key design feature of the proposed system.

One of major advantage of HW Bio modular unit is its flexibility and easy mobility which allow for rapid transport by trailer to other towns outside of Al Shamal, once Al Shamal goes to Phase 2 and is connected to a permanent sewer network connected to a dedicated sewage treatment plant. This progressive plan provided Ashgal with the benefit of the transportable/mobile feature of HW Bio HIT system which can be reused as the community grows. For a full visual overview of the system from when the tanker trucks arrive to the final effluent quality, check out this video.

HIT system easily transportable by trailer to site.

Process
The total capacity of the plant is 600 m3/day and consists of three identical trains of 200 m3/day each. Each train receives wastewater pumped through a common pretreatment unit comprised of screening and grit remove. The HW Bio HIT system is designed using HW Bio proprietary Active Cell MBBR (Moving Bed Biofilm Reactor) process. Each train is comprised of four small compartments: the first two compartments are aerobic bio reactors for BOD oxidation and the second is for nitrification. Each compartment is filled with Active Cell 920 media.

HIT System with four compartment process, two stage MBBR, flocculation tank and lamella clarifier.

A coarse bubble aeration grid is provided at the bottom of the tank to ensure proper mixing and aeration. The formation of biofilm occurs in the protected surface area of the media where it brings about the conversion of the organic material in the wastewater into carbon dioxide and water in the presence of air. Both MBBR tanks are provided with media retention sieves to prevent the migration of media. No sludge recycling is necessary for this process which makes the entire system easy to operate as no MLSS control is required.

Following the MBBR sections, a solids removal process is necessary to bring effluent TSS values down to desirable levels. A lamella clarifier is used to separate the clear water from the suspended solids. The effluent from the MBBR tank is mixed with polymer in the flocculation tank, third compartment, prior to moving on to the settling tank in fourth compartment. The settled sludge is periodically drained and collected in the sludge holding tank and aerated to prevent anaerobic conditions. The biologically treated effluent is then tertiary filtered through sand filters and disinfected. The ultimate goal is to provide effluent suitable for reuse for non-potable needs such as irrigation.

Overall Plant view

Results
The HW Bio HIT system provided a complete wastewater treatment solution, the plant treats approximately 600 m3/day with and influent BOD of 315 mg/l, COD 515 mg/l and NH3 40 mg/l and achieves BOD reduction of < 15mg/l and nitrification with NH3-N of < 3 mg/l outlet respectively, thus producing effluent suitable for reuse and irrigation applications. Each treatment train has an overall footprint of only 19.2m2.

Active Cell 920 media used in the plant, with significant biofilm growth.

"The system provided by HW Bio has been one of the easiest to commission," explains Mohamed Sobeihy Commissioning In Charge at the Al Shamal Plant. "It was started up and producing effluent suitable for re-use within 3 weeks. We have noticed the system adapts well to change in flow and load compared with other technologies. As it doesn't require operator intervention, coupled with its overall ease of operation, it makes it an ideal choice, especially given the plant location is far away from the main city."

Headworks BIO designs systems to meet a variety of effluent quality requirements. And at any given time, the compact wastewater treatment system can be expanded to meet new discharge requirements or increasing flow rates. This system is suitable for labor camps, oil field worksites, oil platforms, housing complexes, resorts, universities, etc.

HW Bio is a subsidiary of Headworks International Inc. with offices in the USA, Canada, the United Arab Emirates and India. The people at Headworks are committed to providing simple solutions to complex environmental challenges, helping our customers meet and exceed their treatment standards while making operations as effortless as possible. Our MBBR technology is applicable to a wide variety of challenging industrial and municipal wastewaters to produce the water quality our customers require all the way to reusable levels when needed. Have a challenge with your wastewater? Our expert engineering team can work with you to provide a tailored solution that fits your needs while keeping in mind your company's entire operational requirements. To begin discussions, contact one of our expert process engineers at HW Bio at hw@headworksintl.com or +1.713.502.5035