WO2017135911A1

WO2017135911A1 - Innovative membrane systems based on membrane distillation for advanced treatment of leachate waters

Info

Publication number: WO2017135911A1
Application number: PCT/TR2016/050571
Authority: WO
Inventors: Coskun AYDINER; Berna KIRIL MERT; Esra CAN DOGAN
Original assignee: Gebze Teknik Universitesi
Priority date: 2016-02-05
Filing date: 2016-12-29
Publication date: 2017-08-10

Abstract

The present invention relates to providing a more sensitive and sustainable management of the leachate waters compared to the conventional pressure-driven membrane systems, thanks to the advanced treatment of the leachate waters coming out of the domestic/industrial solid waste sanitary landfills, with the innovative membrane systems based on membrane distillation technology, which focuses on an operation where (i)-more preferable technical performance levels are achieved thanks to having higher quality in discharge waters and lower volumes in membrane concentrates and where (¾)-lower unit treatment costs are achieved thanks to the cost-free coverage of the MD heating requirements by making use of the low pumping energy consumption of the MD and the heat obtained by burning the landfill gases in the landfill cogeneration unit, together with producing less discharge water due to reduced in-house concentrated waste loads; and additionally where (Hi)- the MD concentrate is utilized by making use of its inert heat by incinerating said concentrates and disposal thereof outside the landfill; and which benefits from eco-innovative in-house concentrated waste management practices based on a versatile return/distribution where membrane concentrates are not just returned to the landfill and where said concentrates do not pose a burden on the treatment plant.

Description

DESCRIPTION

INNOVATIVE MEMBRANE SYSTEMS BASED ON MEMBRANE DISTILLATION FOR ADVANCED TREATMENT

OF LEACHATE WATERS Technical Field of the Invention

The present invention relates to providing a more sensitive and sustainable management of the leachate waters compared to the conventional pressure-driven membrane systems, thanks to the advanced treatment of the leachate waters received from domestic/industrial solid waste sanitary landfills, with the innovative membrane systems based on membrane distillation technology, which focuses on an operation where (i)-more preferable technical performance levels are achieved thanks to having higher quality in discharge waters and lower volumes in membrane concentrates and where (¾⁾-lower unit treatment costs are achieved thanks to the cost-free coverage of the MD heating requirements by making use of the low pumping energy consumption of the MD and the heat obtained by burning the landfill gases in the landfill cogeneration unit, together with producing less discharge water due to reduced in-house concentrated waste loads; and additionally where (in)- the MD concentrate is utilized by making use of its inert heat by incinerating said concentrates and disposal thereof outside the landfill; and which benefits from eco-innovative in-house concentrated waste management practices based on a versatile return/distribution where membrane concentrates are not just returned to the landfill and where said concentrates do not pose a burden on the treatment plant.

Prior Art

Various methods such as recovery, fumigation, hydrolysis and composting are utilized in the disposal of solid wastes. However, scientific studies and field implementations illustrate that sanitary landfills are still the most economical solution for the disposal of domestic and industrial solid wastes. Yet, sanitary landfilling generates solid waste leachate waters, which are hard and expensive to treat. Leachate water can be defined as the extracted portion of the dissolved and suspended materials leaching from the solid waste. These waters stem from the liquids generated by the degradation of wastes through surface drainage and the flows from rain waters and ground waters going inside the sanitary landfill.

Leachate waters usually have a dark color, odor and they contain high levels of organic and inorganic contamination loads. It is characteristic of the leachate water that it contains contaminations in 4 different groups: Organic compounds (aromatic hydrocarbons, phenols, pesticides, etc.) stemming from dissolved organic materials (such as volatile fatty acids and humic materials) and chemical residues in low concentrations; inorganic contaminants (Ca , Mg , Na , K , L , Fe , Mn , CI^", S0₄ ^2", HCO₃); heavy metals (Cd⁺², Cr⁺³, Cu⁺², Pb⁺², Ni⁺², Zn⁺²); and microorganisms (coliforms). Treatment of leachate water is usually considered according to the landfill duration or BOD₅/COD ratio. If this ratio is 1, leachate water is defined as new; it said ratio is lower than 0.1, it is defined as old leachate water. New leachate waters are characterized in that the COD content of the volatile fatty acids, which are the by-product of the anaerobic degradation at the landfill, is higher than 5 g/1, and that they have low nitrogen concentration (<400 mg/L), whereas old leachate waters are characterized with NH₃>400 mg/L, high persistent organic compound contents and low bio-degradable organic portions (BOD₅/COD=0, 1).

Conventional leachate water treatment technologies can be classified in 4 main topics. These are; (¾⁾-direct returning to landfill without subjecting the leachate waters to any external treatment process (bioreactor landfilling), (ii) -treatment in conjunction with domestic wastewater, (¾z)-aerobic and anaerobic treatment, and f/^'v -physical and chemical methods such as settling or flotation, aeration, chemical settling. In Turkey, the management of the sanitary landfill leachate water is carried out in 48% as returning to landfill, 36% as transportation to treatment plants, 12% as discharge to sewage and 4% as unknown methods.

Returning leachate waters directly to landfill without any treatment is not a sustainable method in practice without any external treatment; and is usually implemented in summer months in order to provide a consistent leachate water flow rate and quality before the commissioning of the treatment plant. In sanitary landfills with returning operation, whether they are of a bioreactor type or not, (¾⁾-biomethane production can be reduced through inhibition by increasing the amounts or inorganic materials and especially ammonia; (¾⁾-leachate water collection systems can be blocked in a shorter time than expected; (¾z)-performance decrease due to the increase of contamination and blockage in membrane processes can increase the costs of treatment and (iv)-due to the increase of field leachate water load in time, the risk of said water leaching to the ground and underground waters through the ground cover increases. Direct return operation is not preferred in winter months due to increased amounts of leachate water related to the increased precipitation. For this reason, the winter operation in facilities working with returns in Turkey is discharge to the sewage system. Furthermore, at the first stage of transitioning to energy generation by landfill gas, especially in the first 1-2 years of operation in the facility, return of leachate water to landfill area cannot be performed. In this period, as it can be necessary to discharge the leachate water over the collection chimneys, it is possible to encounter situations where, in contrast to return to the landfill area, leachate water is discharged outside the area more often.

Regarding the removal of the solid materials and dissolved organic/inorganic materials in the leachate waters, conventional physical/chemical and biological treatment processes are implemented; however, it is not possible to achieve treated water with a dischargeable quality at high treatment efficiency levels with conventional treatment systems. Hence, even though the best technologies exist; it is not possible to treat leachate waters, which contain high (COD=10.000-50.000 mg/L) and very high (COD >50.000 mg/L) contamination, so as to achieve a dischargeable quality for sewers and it is really difficult to treat leachate waters with low (COD=l .000-10.000 mg/L) contamination so as to achieve a quality appropriate for direct discharge to receiving environment. Therefore, an additional treatment which utilizes advanced treatment technologies after the conventional treatment processes is required in the treatment of leachate waters. In this respect, the treatment of leachate waters is performed via treatment facilities with "conventionale advanced treatment with multi-step sequential technological practices. In the post- conventional advanced treatment of leachate waters, the appropriate process(es) are selected among adsorption, pressure-driven membrane processes (conventional membrane technologies) and ozonization, advanced oxidation such as UV, H₂0₂, Fenton, photo-Fenton, electro-oxidation. Simultaneous use of sequential treatment systems in multiple steps increases operation risks as well as causing high leachate water disposal costs.

While leachate waters have high COD, BOD₅, ammonia nitrogen; their mostly low BOD₅/COD and COD/NH₄ ⁺-N ratios negatively affect the biological treatability of such waters. Although activated sludge systems are widely used in the treatment of leachate waters, the most significant disadvantages of these systems for said waste waters are non-satisfactory quality of sludge settling, requirement of excessively long aeration periods, high energy requirements, excessive generation of biological treatment sludge and inhibition due to high ammonium ion concentration. Even though anaerobic treatment has the advantages of allowing the degradation of organic materials in leachate waters in the absence of oxygen and less generation of biological residual sludge, less energy consumption, biogas generation, less phosphor dosage requirement for the development of anaerobic bacteria, high levels of organic material removal; said technology has the main disadvantages such as the heavy metals preventing the biological degradation of organic contaminants, ammonia toxicity and over-dependence of the process to the changes in the temperature and pH of the leachate water.

Regarding the advanced treatment of leachate water via adsorption, toxic heavy metals and organic contaminants can be successfully removed from the aqueous environment thanks to the use of various adsorbent materials. High removal efficiency can be achieved with adsorbents such as vermiculite, illite, kaolin, active alumina and active carbon. However, excessive amounts of adsorbent consumption as well as frequent maintenance requirements of the adsorption columns due to blockages, are the main reasons preventing this treatment from becoming widespread in the practice. With regards to the chemical oxidation of leachate water, a significant problem in terms of treatment efficiency occurs due to the fact that not all organic materials oxidize to C0₂. As a result of oxidation, by-products, which are usually biodegradable, are generated and these organic materials require further advanced biological treatment.

In the last 15-20 years, pressure driven processes comprising microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes have been successfully added to the physical-chemical and biological conventional treatment technologies in the world for the treatment of leachate water until it reaches discharge standards. MF and UF processes are the most basic membrane processes utilized in industrial practices. The operational pressures in said processes are between 0.5-5 and 1-10 bar, respectively. With regards to contaminant separation sizes; it is possible to remove solid particles, microorganisms and partially colloidal materials with MF process; and solid and colloidal materials, organic materials with large molecular sizes (5000 Da and above) with UF process from the water and waste water environments. In industrial practices, MF process is utilized for the separation of liquid-solid mixtures, whereas UF process is used for the separation of liquid-solid and organic-inorganic mixtures. Another reason for preferring both processes in various industrial practices is to reduce the unit treatment costs by increasing the performance of the NF and/or RO processes located thereafter, depending on the contents of the waste water to be treated. NF process is between UF and RO processes in terms of operation pressure (5-30 bar) and contaminant removal size; it is used for the removal of multivalent dissolved inorganics and organic materials with medium to large sizes (1000 Da and above) from water and waste water environments. In the industry, it is preferred in treatment practices focused on recovery based on selective removal of organic-inorganic and inorganic-inorganic mixtures. RO process is a membrane process which forms the last step of the pressure driven membrane processes and which has the lowest molecular separation size. In the process, thanks to the operations carried out at high pressures between 10-130 bar (usually 20-60 bar), organic materials with very low (100-1000 Da) molecular weight and monovalent inorganics can be treated with effective separation performance (respectively >80% and >99% for organic and inorganic). This methods is used commonly in practice for obtaining high quality, clean water from domestic and industrial waste waters for water recovery and industrial use, notably for obtaining drinking water from sea water.

In the advanced treatment practices of leachate water, where pressure driven membrane processes are utilized at a single step, certain success cannot be achieved most of the time in terms of obtaining outlet water with a desirable quality. Following the conventional treatment of leachate waters, advanced treatment with multi-step membrane process applications (such as; "UF+NF" membrane system for old leachate waters with relatively low contamination levels (COD=l .000-10.000 mg/L) and "UF+NF+RO" membrane system for new leachate waters with relatively high (COD=10.000-50.000 mg/L) or very high (COD>50.000 mg/L) contamination levels) are widely used in practice. For the advanced treatment of leachate water with treatment systems including conventional membrane processes; the operations at high pressures with high energy costs and the requirements for more frequent cleaning and earlier-than-expected replacement of membranes due to contamination, negatively affect the unit treatment costs. On the other hand, obtaining treated water at a rate relatively lower than the inlet flow rate due to concentrated waste formation at higher volumes causes treatment to be performed at higher costs per unit treated water. In other words, high contamination loads of leachate waters require multi- step integrated operations in both conventional and traditional membrane systems; and this reduces the treated water amount for the fixed facility capacity, while increasing the leachate water treatment costs per unit treated water. Hence, in the integrated advanced treatment practices carried out with various combination of pressure driven conventional membrane processes; even though each membrane process can achieve a maximum 80%-90% water recovery despite the high osmotic pressure occurring in the concentrated flow (10%-20% concentrated flow), a concentrated waste flow at a rate of approximately 27%-50% of the inlet waste water flow rate and 19%— 36% of said flow rate can still occur for the three-step membrane system and two-step membrane system respectively.

Membrane concentrates are waters/waste waters which occur as a result of the passing the target water/waste water through the membrane, which are, most of the time, not re-usable due to their more intensive contents and which require more treatment or disposal. The challenges faced in the management and disposal processes of concentrated wastes are the most essential techno-economic limiting factors in the effective use and proliferation of integrated membrane process practices on the field. Although variable depending on the waste water to be treated; (i) -sanitary landfilling, (ii) -burning via incineration or (Hi) -discharge to a central waste water treatment plant' are the main practices for the disposal methods of membrane process concentrates in Turkey. However, said disposal methods are generally utilized in the disposal of concentrates with low/very low volume due to the technical and economic limitations encountered in practice. In the incineration process, inertly disposable final wastes can be obtained from concentrated flows and thus, it is prevented to have liquid wastes to be discharged into the receiving environment {zero liquid discharge). Yet, in order to eliminate the economic limitations posed by the high operational costs related to excessive energy consumption in the process; the equivalent fuel calorific value of the concentrate to be disposed is expected to be at least at the level of the low quality lignite with 2500-3500 kcal/kg, which is mined in Turkey. On the other hand, it is obvious that concentrates, which are appropriate for burning in terms of organic material content and fuel calorific value, can be obtained when membrane concentrate is concentrated to a low volume as part of the activity for removing high organic contents in a membrane process. In this respect, considering the practice of "burning domestic/urban waste water treatment sludges in cement factories and the final disposal thereof via sanitary landfilling" , which is successfully implemented in Turkey as well as many other developed and developing countries for the purpose of environmental protection; disposal of the waste water concentrate flows, which are rendered appropriate for burning in terms of calorific value, in techno-economic and environmentally more lucrative methods compared to transportation to treatment facilities and discharge to sewer system, is possible thanks to incineration and sanitary landfilling of the remaining inert waste. Concentrate flows arising from the advanced treatment of leachate waters with pressure driven conventional membrane systems, are usually disposed of by returning said wastes to the solid waste landfills. Not only the contaminant concentrations but also the high volumetric amounts in such flows transferred to the landfill area under constant operation, increase the contamination load of the raw leachate water going to conventional treatment at the first stage over time. This strains the efficient operational capacity of the conventional system. As a result of the operation based on the return of high-volume membrane concentrates to the landfill area in the advanced treatment of leachate waters with conventional membrane systems; due to the membrane concentrates, the volumes of which cannot be reduced, the performance efficiency in the membrane systems decay over time and certain problems arise with regards to complying with the standards for discharging to the sewer or the receiving environment. Because, the fact that the return of concentrates directly to the landfill area gives rise to additional maintenance-repair and membrane cleaning-replacements costs for the treatment plant, increases the costs for the disposal of leachate waters. Therefore, it is necessary to implement practical operations which better satisfy the needs for leachate water treatment in terms of treatment efficiency and disposal costs, through the improvement of existing treatment technologies or the development of innovative advanced treatment technologies. With practical solutions to be developed, it is desired to eliminate the negative environmental effects of over-the-limit discharges in operations without sufficient treatment efficiency or without the infrastructure for discharge to sewage system, on the soil and surface/ground waters.

Membrane distillation (MD) process; is a membrane process which develops various wastewater treatment practices and which is preferred more and more in the practice, due to (i)-its operability in flexible environmental conditions, (¾⁾-it's very high efficiency in the removal of dissolved organic and inorganic contaminants and (iii)-bemg able to allow operation at lower costs compared to pressure driven conventional membrane processes when the thermal energy required for heating is provided at low costs. MD is a membrane process whose driving force is temperature, which utilizes micro-porous membrane and which allows high-quality treated water to be obtained with high leaching performance (generally excluding volatile organics, >99% for dissolved organics and inorganics (up to 97% for ammonia)) on waste waters. Since the process can perform separation at >99% efficiency even in waters with very high osmotic pressure, such as RO concentrates and waters with high salinity, it can be operated at much higher water treatment rates (90%-%97) compared to pressure driven membrane processes and it allows for obtaining concentrated waste flows with much less volumetric amounts (3%-% 10). In the process, the water flow, which is in the feed flow at a certain temperature difference between feed and outlet water, is prevented from going through the membrane pores without applying additional pressure and water is allowed to pass through the membrane in the steam phase. The water steam passing through the membrane is condensed by cold flow and treated water is generated. Thus, nonvolatile components are prevented from going to the water steam phase and a filtrate flow with very high purity is obtained compared to conventional distillation. Despite newly developed varieties, the process is mainly implemented under 4 different technological principles which are direct contact, air throughput, and vacuum and sweeper gas. Although the efficiency of the process in wastewater treatment is well known, in the recent years focus has stayed mainly on the field scale treatment practices of different wastewaters. The main elements preventing the process from becoming widespread are that it required membranes durable enough for long period operations and that the energy requirement necessary for maintaining the thermal difference between the feed and filtrate flows in operation is high. In recent years, thanks to the manufacturing of new membrane materials and development of special membrane modules targeted for field operations, said technology is being allowed to become widespread in various industrial practices. On the other hand, in cases where the thermal energy required for heating the inlet water flow is obtained directly from an inert heat source or indirectly from an external energy source with the desired economical qualities, it is well known that the process allows for more preferable economic operations, compared to conventional membrane processes, thanks to certain studies conducted in recent years. MD process can be successfully implemented in the treatment of water and wastewaters, recovery of domestic and industrial water, obtaining juice concentrates, desalination of hard water and sea water, reduction of the volume of membrane concentrates and salt recovery from RO membrane concentrates.

In the known art, the Chinese patent document numbered CN101928094 provides a technology for the treatment of leachate waters coming out of domestic/industrial solid waste sanitary landfills. Said technology comprises the steps of converting garbage waters into nitrate, performing the membrane operation with ultrafiltration membrane, utilizing nanofiltration membrane and reverse osmosis membrane, performing electro-osmotic treatment to treated water and finally performing distillation.

According to the Chinese patent document numbered CN104211245 in the known art, a membrane process practice for the treatment of leachate waters is mentioned. Said practice comprises the steps of separating the calcium ions from garbage waters, increasing surface tension to preferably lb mN/m and performing membrane distillation afterwards.

However, the practices mentioned in these documents are insufficient in terms of achieving the desired results.

Objectives and Brief Description of the Invention

The main objective of the present invention is to provide a more techno-economically preferable, more sensitive and sustainable management of the leachate waters coming out of the domestic/industrial solid waste sanitary landfills, compared to the waste water treatment systems formed by conventional advanced treatment systems; thanks to the innovative membrane systems based on MD technology; with a focus on obtaining discharge water with higher quality and lower membrane concentrate volumes and performing treatment at lower costs while considering various concentrate disposal options.

The advantages of the MD process in its utilization focused on the treatment of domestic and industrial solid waste sanitary landfill leachate waters, with the innovative membrane systems provided in the present patent are as follows: (i) operability at environmental or atmospheric pressure without requiring additional pressure, (ii) less pumping energy requirement (~0.4-0.6 kWh/m³) compared to conventional membrane processes (~0.9-1.3 in UF, ~ 1.3 -2.0 in NF, and ~3.0-5.5 kWh/m³ in RO) as the pumping of water does not require high pressure and reduction in the water pumping costs accordingly, (Hi) high contaminant removal efficiency (>95% dissolved organic,≡97% ammonia and >99% dissolved inorganic) even for waters with high contaminant concentrations and loads, and thus significantly contributing to the increase of discharge quality of not only old but also very new leachate waters to receiving environment/sewer, (iv) generation of concentrated waste flows at lower volumes and allowing a more efficient membrane concentrate management due to being operated at higher water recovery levels compared to conventional membrane processes, and most importantly (v) obtaining the energy (~20-150 kWh/m³), which is required to create the necessary temperature difference between the leachate water inlet and treated water outlet flows in the process, directly from the landfill gas cogeneration unit on the landfill area without any additional costs and thus performing the leachate water treatment at a lower unit treatment cost compared to conventional membrane processes. Based on said advantages, thanks to the innovative advanced treatment systems formed by including the MD process into the advanced treatment systems comprising conventional membrane processes; the challenges of treatment which are encountered in the existing leachate water treatment facilities based on "conventionale traditional advanced treatment' and which have been described in detail, are completely eliminated. With said innovative systems, an eco-innovative waste management approach, which (¾⁾-generates membrane concentrate flows at low volumes, (¾⁾-which can be operated at higher treatment efficiency levels at lower costs and which

of membrane concentrated flows in multi- faceted options, is formed-. Thanks to the innovative leachate water treatment facilities of the present invention, which follow the aforementioned management approach, solutions which are (i)-more preferable on the field techno-economically, (¾⁾-more sensitive to the environment and (iii)-rs\ore sustainable compared to existing technological solutions, can be provided for the treatment of sanitary landfill leachate waters. The innovative advanced treatment of leachate waters of the present patent, which adds the MD process, at a level which satisfies the contaminant load content of the leachate water and the treatment needs required for discharging to sewer/receiving environment, to the membrane system configurations of the conventional membrane processes, with various operational contents utilized in the advanced treatment of leachate waters; is rendered possible by the use of improved membrane systems where "MD process is in the First, Second and Third Stages." The technological design layouts of the developed innovative advanced treatment systems, including the multi-faceted and efficient membrane concentrate management with MD applications at the L, II. and III. stages, have been presented respectively in Figures 1, 2 and 3 in the general process flow diagram of the whole leachate water treatment plant. Each innovative system that is developed decreases the total concentrate load of the advanced membrane treatment system thanks to the disposal of the MD concentrate outside the field via incineration. In such systems, membrane concentrates are not returned to the landfill area; operations that are more environmentally-friendly are performed within the in-house multi-faceted disposal options. Thus, all possible negative conditions, which could possibly arise at the solid waste sanitary landfill area and the leachate water treatment plant due to the return of membrane concentrates, are eliminated and an eco-innovative concentrated waste management approach is implemented, where over-the-limit discharges in case of emergencies is no longer relevant. Detailed Description of the Invention

The membrane systems based on membrane distillation, provided to achieve the objectives of the present invention, are illustrated in the annexed drawings.

In the drawings;

Figure 1: Leachate water treatment plant process flow diagram generalized for the innovative leachate water advanced treatment system (I) with effective membrane concentrate management, where the MD process is in the "J Stage of the Advanced Treatment',

Figure 2: Leachate water treatment plant process flow diagram generalized for the innovative leachate water advanced treatment system (II) with effective membrane concentrate management, where the MD process is in the "ZZ. Stage of the Advanced Treatment" and

Figure 3: Leachate water treatment plant process flow diagram generalized for the innovative leachate water advanced treatment system (III) with effective membrane concentrate management, where the MD process is in the "HZ Stage of the Advanced Treatment'.

The pieces shown in the figures are enumerated and the numbers correspond to the following:

1) Landfill

2) Landfill-cogeneration unit transmission line

3) Landfill-conventional treatment system transmission line

4) Cogeneration unit

5) Steam emissions

6) Flow collection and distribution structure

7) Conventional treatment system transmission line

8) Conventional treatment system

9) Conventional treatment system outlet line

10) Cogeneration unit and/or heat exchanger transmission structure

11) Heat exchanger transmission line

12) Heat exchanger

13) Feed line from heat exchanger

14) Cogeneration unit-heat exchanger feed line

15) Heat exchanger-cogeneration unit return line

16) Cogeneration unit transmission line

17) Feed line for MD inlet flow collection and transmission to MD

18) Transmission structure for MD inlet wastewater flow collection and transmission to MD

19) MD inlet wastewater flow

20) MD process

21) Final treated outlet water from MD process MD concentrate return line

MD process-membrane process feed line

Membrane process

Final treated outlet water from Membrane process

Membrane process-cogeneration unit and/or heat exchanger transmission structure return line

Return line of the transmission structure for membrane process-MD inlet wastewater flow collection and transmission to MD

Membrane process-guiding structure transmission line

Distribution structure

Distribution structure-guiding structure transmission line

Guiding structure

Guiding structure-flow collection and distribution structure return line (32)

Line for sending to incineration

Distribution structure-landfill return line

First stage membrane process wastewater collection structure

First stage membrane process feed line

First stage membrane process

First stage membrane process outlet line

First stage membrane process wastewater collection structure return line

First stage membrane process-guiding structure transmission line

First stage membrane process-landfill return line

Second stage membrane process

Second stage membrane process outlet line

Second stage membrane process-cogeneration unit and/or heat exchanger transmission structure

Second stage membrane process-cogeneration unit transmission line

Feed line to structure for cogeneration unit-MD inlet wastewater flow collection and transmission to MD

Transmission structure-heat exchanger transmission line at second stage membrane process

Feed line from heat exchanger at second stage membrane process 49) Second stage membrane process-membrane process wastewater collection structure return line

50) Second stage membrane process-distribution structure feed line In the configurations of the innovative leachate water advanced treatment system with "MD implementation at the I. stage (J)", the general operational lines of which are illustrated in Figure 1, there are a total of 4 different system combinations where MD is implemented alone and one of the processes among UF, NF or RO is implemented after MD. In the operation of the system, first the raw leachate waters collected from the domestic and industrial solid waste sanitary landfill areas with leachate water and landfill gas collection infrastructure, is transferred to the leachate water treatment plant via the conventional treatment system landfill-conventional treatment system transmission line (3). The transfer of the raw leachate water to the conventional treatment system (8) is based on the optional return of such waters from advanced treatment via the membrane concentrate guiding structure-flow collection and distribution structure return line (32), mixing at the flow collection and distribution structure (6) and feeding to the system through a common conventional treatment system transmission line. The leachate waters treated at the conventional treatment system are transferred to the advanced treatment system through the conventional treatment system outlet line (9). Conventionally treated leachate waters are mixed with the concentrate flow of the membrane process after the MD at the cogeneration unit and/or heat exchanger transmission structure (10), before the advanced treatment steps. In order to heat the flow before MD inlet, the transfer of the mixed wastewaters to MD process is performed through the heat exchanger transmission line (11) to the heat exchanger (12); optionally, the mixture can also be transferred to the cogeneration unit via the cogeneration unit transmission line (16). The flow which loses its heat can also be transferred to the cogeneration unit (4) via the heat exchanger-cogeneration unit return line (15), in order to be re-heated. The pre-MD treated leachate water heated with the heat exchanger and the post-MD membrane process concentrate mixed wastewater is fed to transmission structure for MD inlet wastewater flow collection and transmission to MD (18) via the feed line from the heat exchanger (13), and then, directly to the MD process via the MD inlet wastewater flow (19). The heat generated by burning the landfill gases arriving at the cogeneration unit (4) via the landfill-cogeneration unit transmission line (2), can also be used for directly heating the MD inlet flow. The hot or heat-removed steam emissions (5) generated during cogeneration are released to the atmosphere; the optionally heated MD inlet flow can be returned to the system via the feed line for MD inlet flow collection and transmission to MD (17). Furthermore, the hot liquid or gas flow heated at the cogeneration unit can be transferred to the heat exchanger (129 via the cogeneration unit-heat exchanger feed line (14) in order to allow the heat transfer process to be carried out at the heat exchanger (12). The heated inlet flow fed to the MD process (20) generates final treated outlet water from MD (21) after treatment, at a quality which is dischargeable to the sewer/receiving environment. The MD concentrate is transmitted to the MD concentrate collection and distribution structure (29) via the MD concentrate return line (22) and then, transferred to the line for sending to incineration (33) for final disposal outside the plant. In case it is technically and economically lucrative, disposal of the MD concentrate sent to incineration for industrial hazardous waste storage can also be considered. Optionally, o portion of the MD concentrate can either be transferred directly to the landfill (1) via the distribution structure-landfill return line (34) or to the membrane concentrate distribution structure to the conventional treatment system (3) via the distribution structure-guiding structure transmission line (30). In the event that the MD outlet water is not of a quality appropriate for discharging to sewer/receiving environment, said water is directly transferred to the membrane process (24) in the next stage via the MD process-membrane process feed line (23). The final outlet water (25) of the membrane process-treated leachate waters, the treatment of which is completed, is discharged tot eh sewer or to the receiving environment; whereas the membrane concentrate transferred to the cogeneration unit and/or heat exchanger transmission structure (10) which enables transmission to cogeneration unit (4) and/or heat exchanger (12) via the membrane process-cogeneration unit and/or heat exchanger transmission structure return line (26), for heating the MD inlet wastewater. The post-MD membrane process (23) concentrate can optionally be transferred to the transmission structure for MD inlet wastewater flow collection and transmission to MD (18), which is right before the MD process (20), depending on the operational preferences, heating requirements and heating conditions. Another optional practice for post-MD membrane process (24) concentrate, depending on operational preferences, is to transfer a portion of this water to the membrane concentrate guiding structure to conventional treatment system (31) via the membrane process-guiding structure transmission line (28). As a result, thanks to the MD concentrate, which occurs with a concentrate flow at low volume due to the high treatment efficiency in the MD process, being taken outside the treatment plant for final disposal; all of the membrane concentrates collected at the guiding structure (31) are fed back to the conventional treatment system (8) via the guiding structure- flow collection and distribution structure return line (32) and the cyclical disposal of all membrane concentrates are provided with mass load minimization.

In the configurations of the innovative leachate water advanced treatment system with "MD implementation at the II. stage (11)" , the general operational lines of which are illustrated in Figure 2, there are a total of 10 different system combinations, the membrane processes of which include two or three stages. The operational functioning of the system is carried out on the same basis as the system with "MD implementation at the I. stage (If for all processes from (1) to (34) in the layout where raw leachate water is transferred to the treatment plant from the landfill, treated and where the collected membrane concentrates are returned to the landfill area. The different operational points are related to the existence of a conventional membrane process at the first stage and the management of concentrated flows. In the system, the leachate waters, which are conventionally treated and which come out of the conventional treatment system (9), are first mixed with the concentrate waters coming from the first stage membrane process wastewater collection structure return line (39) at the first stage membrane process wastewater collection structure (35) and the mixed wastewater is transferred to the first stage membrane process (37) via the first stage membrane process feed line (36). The leachate waters treated at the first stage membrane process are transferred to the cogeneration unit and/or heat exchanger transmission structure (10), placed before the heat exchanger (12), via the first stage membrane process outlet line (38); after that, said water is transferred to the MD process (20) and the advanced treatment steps, which are the same as those in the system with MD implementation at the I. stage, are carried out. The concentrate of the first stage membrane process is transferred directly to the guiding structure to conventional treatment system (31) via the first stage membrane process wastewater collection structure feed line (39) and the first stage membrane process- guiding structure transmission line (40). According to the optimum management requirements with waste minimization in practice, this concentrated flow can optionally be fed to the MD concentrate distribution structure-landfill return line (34) via the first stage membrane process-landfill return line (41) and can be returned to the landfill (1).

In the configurations of the innovative leachate water advanced treatment system with "MD implementation at the IK stage (III)", the general operational lines of which are illustrated in Figure 3, there are a total of 2 different system combinations, the membrane processes of which three stages. In the layout where the raw leachate water is transferred to the treatment plant from the landfill, treated and where the collected membrane concentrates are returned to the landfill area; the operation of the system does not include the following of the cogeneration unit and/or heat exchanger transmission line (10), heat exchanger transmission line (11), feed line from heat exchanger (13), cogeneration unit transmission line (16) and feed line for MD inlet flow collection and transmission to MD (17) among the processes of heating the MD inlet water as there is a membrane process before MD at the second stage; and does not include the following of MD process-membrane process feed line (23), membrane process (24), final treated outlet water from Membrane process (25), membrane process-cogeneration unit and/or heat exchanger transmission structure return line (26), return line of the transmission structure for membrane process-MD inlet wastewater flow collection and transmission to MD (27), membrane process- guiding structure transmission line (28) and first stage membrane process wastewater collection structure return line (39) as there is no membrane process after MD. However, apart from the aforementioned processes, the operational functioning of the system is carried on the same operational basis as the systems (1) with MD implementation at the I. and II. stages. The different operational points are related to the membrane process (42) implemented at the second stage, heating the MD inlet flow and the management of concentrated flows. In this respect, the outlet waters coming out of the first stage membrane process outlet line (38) are directly taken into second stage membrane process (42) and the pre-MD advanced treatment process is maintained. Second stage membrane process outlet waters are transferred to the second stage membrane process-cogeneration unit and/or heat exchanger transmission structure (44) via the second stage membrane process outlet line (43) for heating as MD inlet flow. The optional heating process at cogeneration is carried out by transferring said waters to the cogeneration unit (4) via the second stage membrane process-cogeneration unit transmission line (45) first; and then transferring the heated flow to the transmission structure for MD inlet wastewater flow collection and transmission to MD (18) via the feed line to structure for cogeneration unit-MD inlet wastewater flow collection and transmission to MD (46). The heating process at the heat exchanger (12) is carried out by taking the water to the heat exchanger (12) via the second stage membrane process-cogeneration unit and/or heat exchanger transmission structure (44) and via the second stage membrane process transmission structure-heat exchanger transmission line (47); heating and transferring to the transmission structure for MD inlet wastewater flow collection and transmission to MD (18) via the feed line from heat exchanger (48) at the second stage membrane process. The second stage membrane concentrate is transferred directly to the first stage membrane process wastewater collection structure (35) via the second stage membrane process-membrane process wastewater collection structure return line (49); and thus the in-system recycling is performed. Said concentrate flow can also be disposed of by feeding it to the MD concentrate return line (22) via the second stage membrane process-distribution structure feed line (50), depending on the volume and content quality at the field.

All combinations of the MD-based leachate water advanced treatment systems of the present patent are provided below in detail:

^■S Advanced treatment system combinations with MD implementation at the I.

Stage, (I)- Even if the biological treatment of the leachate water is performed by utilizing membrane biological reactor (MBR), one of the following options may be used.

OO-i MD

00-2 MD + UF*

00-3 MD + F - (I)- MD + RO

* UF can be operated by utilizing one of the hybrid UF processes, such as polymer- and micellar-enhanced processes, effective in removal of organic materials. Advanced treatment system combinations with MD implementation at the II. Stage, (II)- If the biological treatment of the leachate water is performed by utilizing MBR, one of the last 3 options ((II)— 8, -9 or -10) can be used and the first 7 cannot be used.

(II)- 1 MF + MD

(II)-2 MF + MD + UF*

(II)-3 MF + MD + NF

(II)-4 MF + MD + RO

(II)-5 UF* + MD

(II)-6 UF* + MD + NF

(II)-7 UF* + MD + RO

(II)-8 F + MD

(II)-9 F + MD + RO

(II)- 10 RO + MD

* UF can be operated by utilizing one of the hybrid UF processes, such as polymer- and micellar-enhanced processes, effective in removal of organic materials.

Advanced treatment system combinations with MD implementation at the III Stage, (III)- If the biological treatment of the leachate water is performed by utilizing MBR, both options can be used without UF* at the first stage. In this case, (III)— 1 and (III)— 2 designs have the same contents as (II)— 8 and (II)- 10, respectively.

- (III)-l UF* + NF + MD - (III)-2 UF* + RO + MD

Claims

1) MD-based advanced leachate water treatment system having various operational configurations and different technological combinations, where leachate waters occurring at domestic and industrial solid waste sanitary landfill areas are treated at an advanced level to generate discharge water for the sewer/receiving environment at a higher quality compared to conventional membrane treatment systems, where the membrane concentrate waste flows have reduced volume and mass load; characterized in that it includes the membrane process (24) comprising of conventional membrane processes and the MD process (20) which has the capacity for filtering the leachate water at a high treatment efficiency and for generating concentrated flow in less volume, and which is added to the first stage membrane process (37) and/or second stage membrane process (42) at the L, II. and III. stage; which is used for the purpose of obtaining a higher quality discharge water at larger amounts by treating the leachate water to generate less membrane concentrate waste flow.

2) A system according to Claim 1, characterized in that it comprises, the following in order to decrease the volume/mass load of the treatment plant membrane concentrates;

- MD process which provides water treatment performance at high volumes (20),

- heat exchanger (12) and/or cogeneration unit (4) where the concentrated MD waste is sent to be heated in order to make use of the fuel calorific content of the concentrated waste and

- line for sending to incineration (33), where said waste is sent to be burned via incineration for final disposal outside the landfill (1).

3) A system according to Claims 1 and 2, characterized in that; in order to carry out sustainable and eco-innovative concentrated waste management; to eliminate operational problems encountered in cases where concentrated waste flows are only returned to the landfill (1); and to not create additional treatment burden on the treatment plant; the concentrated waste disposal practices within the treatment facilities are carried out;

- based on multi-faceted return/distribution with flow collection and distribution structure (6), cogeneration unit and/or heat exchanger transmission structure (10), transmission structure for MD inlet flow collection and transmission to MD (18), distribution structure (29), guiding structure (31), first stage membrane process wastewater collection structure (35) and second stage membrane process-cogeneration unit and/or heat exchanger transmission line (44).

4) A system according to Claims 1, 2 and 3, characterized in that it includes; for enabling the treatment of sanitary landfill leachate waters at lower costs compared to conventional advanced treatment systems;

- an MD process (20) which consumes less pumping energy in order to reduce leachate water pumping costs; which can be operated at higher concentrating rates in order to reduce the total in-house membrane concentrate waste load; and which generates more discharge water with less concentrated wastes thanks to higher contaminant removal efficiency for reducing unit treatment cots per treated water unit,

- a line for sending to incineration (33) which allows membrane concentrates to be disposed of outside the landfill, in order to reduce the concentrated waste disposal costs and - a cogeneration unit (4) where landfill gas is burned in order to provide the heat requirement of the MD without any cost.