AboutPaques Environmental Technology India Pvt Ltd
Paques has developed biological treatment systems especially for the paper industry. At the moment, innovative processes make it possible to produce paper without discharging effluent. A significant reduction in both energy and water consumption is achieved. Paques has over 250 full scale references in the pulp and paper industry treating process water of various pulp and paper mills of which already many paper mills are operating without waste water discharge.
Water is required in almost every step of the production process of pulp and paper. The wastewater streams vary greatly in concentration and composition (e.g. COD, BOD, suspended solids, wood extractives, sulphur, pH). Due to stricter rules and regulations with regard to fresh water intake and wastewater discharge, efficient water management has become essential to the industry.
Over 250 of Paques installations treat Pulp and Paper effluents worldwide. This experience, combined with decades of expertise in biological purification, physical separation and filtration, enables Paques to design, build and deliver a custom-made and cost-effective purification process. The BIOPAQ® IC bioreactor is the most popular and dynamic anaerobic reactor of its kind. It has been copied, but never rivaled.
Paques' technology results in low energy use and minimum sludge production, keeping operational costs low. Biogas production from the anaerobic reactor becomes increasingly important as a source of renewable energy. In most cases this even results in a positive energy balance for the entire purification plant. Paques has integrated biological treatment in the closed water loop, resulting in significant improvements in the quality of the process water.
Products and Services
Anaerobic COD removal
In anaerobic treatment, bacteria convert organic compounds (COD) to biogas in an environment without oxygen. Not only do the bacteria remove contaminating compounds from the effluent, thereby reducing discharge costs, they produce green energy at the same time.
Organic components (COD) are converted to CH4 + CO2 + BIOMASS
The generation of biogas from agricultural waste, municipal slurries and wastewater has been gaining interest from scientists, industry and municipalities' interest is rapidly growing now, since renewable energy sources are favored to limit global warming. Biogas consists mainly of methane and some carbon dioxide. It can be utilized as a fuel for power generation, steam production and drying processes.
Paques started the design and supply of installations for COD conversion into biogas in the early nineteen eighties with the application of the BIOPAQ® UASB (Up flow Anaerobic Sludge Blanket) reactor. This was an invention of Professor Gatze Lettinga from Wageningen Agricultural University in the Netherlands. The reactor was scaled up from pilot to full scale and deployed for many types of wastewater.
Paques quickly became global market leader in this field of anaerobic treatment. Its position was further strengthened by the development of a new type of anaerobic reactor called the BIOPAQ® IC (Internal Circulation) reactor. Both the BIOPAQ® UASB reactor and the BIOPAQ® IC reactor are used for wastewater treatment with a wide range of carbohydrate concentrations, i.e. from 1,000 to 20,000 mg COD/l.
Within this range the bacteria form compact granules with very good settling characteristics. Above this range the bacteria tend to grow in a more flocky structure and for this Paques developed the BIOPAQ® UASB plus reactor.
For more concentrated wastewaters containing fine organic particles and/or fat and proteins, Paques designed the BIOPAQ® AFR (Anaerobic Flotation Reactor).
Paques' reactors are found in all kind of industries and applications, such as Food, Pulp and Paper, Beer and Beverages, Distilleries and Chemical and Pharmaceutical.
Aerobic COD removal
In an aerobic treatment system, air is injected which is used by aerobic bacteria to convert BOD to carbon dioxide and water.
Organic components + O2 are converted to H2O + CO2 + BIOMASS
Primary treatment for solids removal and anaerobic treatment are usually followed by aerobic treatment.
Paques offers different solutions the aerobic post treatment, such as
- Activated sludge for surface water discharge quality
- Flash aeration for oxidation of odorous compounds
- CIRCOX® airlift technology for situations with a very limited space available
- BIOPAQ® UBOX for the compact combination of anaerobic and aerobic treatment
Activated sludge system
The activated sludge system consists of an aeration stage - and an anoxic/oxic compartment if nitrogen has to be removed - and secondary sedimentation with sludge return. Options are first quality surface aeration, fine bubble aeration and jet aeration.
After secondary clarification, further treatment can consist of filtration, de-nitrification (for achieving very low nitrogen concentrations) or effluent softening. For nitrogen removal at higher concentrations and filtration, see ANAMMOX® and ASTRASAND®.
When treated water will be reused or if water will pass through a sewer, flash aeration is often required. The main reason is odour control, but it will also remove some additional COD, especially when the aeration tank is followed by solids removal such as DAF (Dissolved Air Flotation).
Biogas is increasingly important as source of sustainable energy. When biogas is produced through any form of anaerobic digestion, it will be mostly polluted with hydrogen sulphide. The concentrations can vary from 200 ppm up to several volume %.
Removal of H2S is often required for reasons of health, safety, environment and corrosion of equipment such as gas engines, boilers and piping. Desulphurization is also is necessary when biogas is upgraded to natural gas quality and injected in the grid.
Of the many methods available, THIOPAQ® is the most elegant. This technology is very reliable (> 98% uptime) and shows deep removal of hydrogen sulphide. Importantly, the caloric value of the biogas is retained as it does not dilute biogas with air or oxygen.
THIOPAQ® technology is used to desulphurise
- Vent air
- Landfill gas
- H2S containing gases from the oil and gas industry
Fresh water is increasingly expensive and the pressure grows on the available water supplies as the world population grows and the climate changes. Alternatives for the water balance in factories are eagerly sought after. Besides the higher costs for fresh water, the costs for discharging water go up as well. Reusing wastewater kills two birds with one stone: it reduces fresh water intake and the discharge of wastewater.
In the paper industry, recycling of water and wastewater is already common practice. The water is mostly reused for making paper pulp. Paques also has a growing number of references in the food and beverage industry, where water is frequently reused as boiler feed water and for cleaning.