IE20140176A1 - Sludge dewatering, drying, conditioning and handing system - Google Patents

Abstract

The present invention relates to processes and apparatus for sludge dewatering, conditioning, drying, conditioning, handling and placement for disposal or reuse principally but not exclusively waterworks and wastewater sludge, biosolids, and aerobic granular sludge. The present invention seeks to replace the traditional methods of treatment that moves sludge normally by pumping through a series of stationary processing units to a bag or liner manufactured from woven flax/hessian/burlap jute family of natural biodegradable textile material to provide a uniform mesh that acts initially for the filtering and retention of solids and the drainage of free water for dewatering and later for the movement of air for drying, pasteurisation, hygeinisation, conditioning, and mixing of sludge as required. The processes are applied to the collected sludge within the biodegradable bags that are themselves adaptable to the final reuse option that is intended including biomass energy creation. The present invention relies principally on gravity drainage, natural ventilation, recovered waste energy, insulation of collected energy, and solar energy and efficient material movement and has a much reduced carbon footprint in comparison with traditional methods. <Figure 2>

Description

Field of Invention The present invention relates to processes and apparatus for Sludge dewatering, conditioning, drying, conditioning, handling and placement for disposal or reuse principally but not exclusively waterworks and wastewater sludge, biosolids, and aerobic granular sludge.

Background to the Invention Untreated waste material, in particular waterworks and municipal sewage waste may contain, and indeed in general contains substances that are hazardous to humans and to the environment, those substances may include organic and inorganic compounds, nutrients, pathogens and particulate solids.

Thus it is desirable to treat such waste material, and in particular sewage and waterworks waste prior to disposal or reuse.

Traditional methods of treatment and disposal of such wastes are energy and labour intensive and risk damaging the environment and humans. Furthermore the 20 wastes described contain valuable compounds including embedded energy and nutrients that may be considered products rather than waste if recovered and reused economically.

Traditional methods of treatment of waterworks and municipal sewage waste 25 sludge include gravity settlement tanks, Belt Pressing, Centrifuge thickening and hydraulic Plate Pressing frequently accompanied by chemical conditioning to aid flocculation and separation of free water that may yield a sludge cake in the range of 14% to 22% and even 35% dry solids content.

In general the higher the sludge cake dry solids content achieved the greater the quantity of chemical and energy expended. However Belt Presses, Centrifuges -2and Plate Presses are expensive items of mechanical equipment and can consume 30% to 60% of the total energy consumption of a water or wastewater treatment facility.

Tradition disposal routes for waste sludge might be to land fill but this is no longer permissible due to environmental risks. Similarly land spreading of waste sludge cake requires varying degrees of pre-treatment for hygeinisation and to prevent damage to the environment by excessive discharge of principally nitrogen and phosphorus compounds that is intended to replace manufactured fertilisers.

Waste sludge used for Land spreading is subject to increasingly stringent compliance standards to ensure protection of the environment and human health. This has led to increasing degrees of further treatment including pasteurisation, thermal drying that inevitable are costly, difficult to manage and maintain and consume even more manpower and energy.

Traditional methods of treatment and disposal of waste sludge rely heavily on a multiplicity of expensive and energy-intensive individual process plants placed in series and driven principally by fossil fuel derived energy and does not sufficiently take into account the attributes and reuse potential and beneficial reuse options of the compounds contained within the sludge.

Even modern methods of solar drying within transparent structures such as greenhouses rely on complex and hence costly material movement steps for the spreading, turning, winnowing, and collection of dried sludge and do not sufficiently take advantage of natural and force draught air movement and efficient use of energy and reuse of waste energy.

The Traditional methods of treatment and disposal in particular does not sufficiently recognise the symbiotic attribute of waterworks sludge rich in inorganic hydroxides to adsorb, fix and retain phosphorus compounds that are present in increasing concentration in municipal sewage wastewater sludge and is a source of pollution. -3Judicious mixing of waterworks sludge with municipal sewage wastewater sludge creates an economic means of preventing or controlling the release of nutrient principally phosphorus compounds that is beneficial.

There is therefore a need for efficient processes and apparatus for treating principally waterworks and wastewater sludge, biosolids, and aerobic granular sludge that renders the sludge to varying degrees odourless, pathogen free, and suitable for beneficial reuse.

There is therefore a need for a process and apparatus that can economically, efficiently and safely dewater, condition, dry, condition, handle and place water and municipal sewage wastewater sludge for beneficial reuse.

The present invention seeks to replace the traditional methods of treatment that moves sludge normally by pumping through a series of stationary processing units as described above with a Bag or liner manufactured from woven flax / hessian / burlap jute family of natural biodegradable textile material to provide a uniform mesh that acts initially for the filtering and retention of solids and the drainage of free water for dewatering and later for the movement of air for drying, pasteurisation, hygeinisation, conditioning, and mixing of sludge as required. The processes are applied to the collected sludge within the biodegradable bags that are themselves adaptable to the final reuse option that is intended including biomass energy creation.

The present invention relies principally on gravity drainage, natural ventilation, recovered waste energy, insulation of collected energy, and solar energy and efficient material movement and has a much reduced carbon footprint and manpower requirement in comparison with traditional methods.

Statement of Invention According to the invention the Sludge Bag System is a process and apparatus that provides a means of dewatering and drying principally but not exclusively waterworks and wastewater sludge, biosolids, and aerobic granular sludge. -4 In one embodiment of the invention the Sludge Bags are manufactured from woven flax / hessian I burlap jute family of natural biodegradable textile material to provide a uniform mesh that acts initially for the filtering and retention of solids and the drainage of free water for dewatering and later for the movement of air for drying.

In another embodiment of the invention the woven flax / hessian / jute bags are provided with stiffeners such as battens or rope to maintain the shape of the bag.

In another embodiment of the invention the woven flax / hessian / jute bags are reinforced with rope stiffeners to increase the lifting capacity and test lifting weight of the bag to comply with health and safety regulations.

In another embodiment of the invention the filterability of the sludge may be improved by the addition of flocculating and conditioning chemicals.

In a further embodiment of the invention the drying of the sludge may be improved by the addition of conditioning chemicals such as Quicklime that react exothermically with the sludge raising the temperature In a still further embodiment of the invention the drying and conditioning of the sludge may be improved by the addition of chemicals that raise the pH of the sludge to above prescribed levels according to the reuse and disposal application.

In one embodiment of the invention the Sludge Bags can be manufactured in varying sizes from vertical sacks to FIBICS Bulk Bags and as a horizontal bag or liner for skips, trucks and Trailers of up to 35 yard and upward.

In another embodiment of the invention the Sludge Bags can be manufactured to differing mesh openings to suit the dewatering and drying application and in particular realises an order of magnitude increase in dewatering filtration rate by adaption of the mesh opening size for aerobic granular sludge. -5In a further embodiment of the invention the Sludge Bags can be manufactured to differing textile weights from 'one-time use’ to multiple re-use.

In a still further embodiment of the invention the Sludge Bags may also be used for the short, medium and long term storage of sludge or biosolids either above or below ground or under cover.

In one embodiment of the invention the Sludge Bag System is more specifically adaptable to the dewatering and drying of aerobic granular sludge where a step change of > 1 log improvement in dewatering and drying efficiency is realised.

In one embodiment of the invention the Sludge Bags manufactured from flax / hessian I jute based textile material may be directly used in the pasteurisation and hygeinisation of sludge up to the temperature of combustion of approx. 190 deg. C In one embodiment of the invention the Sludge Bags may be used for the growth of crops either individually or collectively including bioenergy crops and crops with high water uptake characteristics thereby accelerating the dewatering and drying process.

In another embodiment of the invention the Sludge Bags are over time fully biodegradable subject to the condition of the burial ground and differing textile weight. An appropriate weight of bag may be selected in the event that it is intended that a buried bag is to be unearthed after a pre-determined period.

In a further embodiment of the invention the Sludge Bags may be suspended from integral handles or more commonly placed on open decking to allow passage of drained free water and the circulation of natural or forced drying air. The open decking may be shared with multiple bags or liners or may be individualised an example being a FIBIC bag placed on a pallet size decking designed for ease of material movement. -6In a further embodiment of the invention the Sludge Bags may be placed either singly or in multiples in boxes, trailers and skips equipped with open decking flooring as described above and drainage ports below the decking.

In a further embodiment of the invention battens may be installed in the Sludge Bag sleeves to the base, uprights and top to provide rigidity.

In a further embodiment of the invention Sludge bags may be used to line Pallet Boxes that are stackable, lift-able by fork lift truck or moveable by temporary or permanent castor or trolley type wheels.

In a further embodiment of the invention the drainage ports may be equipped with pump(s) to remove free water from below the decking.

In a further embodiment of the invention the drainage pump(s) is capable of creating a vacuum below the decking that accelerates the dewatering and drying process.

In a further embodiment of the invention a combination of drainage pumps and vacuum air pumps may be deployed that accelerates the dewatering and drying process.

In a still further embodiment of the invention vertical double cavity open decking may be placed between bags within boxes, trailers and skips to improve passage of drainage water from the sides of the bags.

In a still further embodiment of the invention decking may be placed in a liquid sludge road tanker or vacuum tank and the sludge bag i liner connected internally to the inlet nozzle and placed upon the decking and with free water collected below the decking discharged via a low level port.

In one embodiment of the invention the boxes, trailers, trucks and skips may be provided with lids and enclosed sides to prevent re-wetting from rainfall and to suppress or contain emissions. - 7Efficient material movement of stored solids is an important advantage of the invention for specific reasons according to the dewatering and drying application where a wet sludge might occupy a volume of one cubic metre whereas as a dewatered or dried sludge or biosolids may occupy half or even one twentieth or less of the original wet volume.

In one embodiment of the invention the Sludge Bags are provided with openings with ties or lifting handles at the top for easy distribution of incoming sludge.

In another embodiment of the invention of the Sludge Bags is the ability to place and connect by means of knotting lifting handles and chute ties a bag/ liner upon another bag/liner in a manner that allows easy transfer of the contents of the bags above to the bags below and thereafter the removal for reuse of the upper bags/liners.

A further embodiment of the invention is the use of the lifting handles as wraps to provide a cover to the contents of the bag most particularly when stored outdoors to prevent re-wetting from rainfall and to suppress or contain emissions.

A still further embodiment of the invention is the direct connection of the outlet chute of the bag to the suction of a pump or educator for the efficient conveying of the sludge.

A still further embodiment of the invention is the design of the apparatus used to raise, move, place and re-suspend the Sludge bags for easy material movement and for connection to pump or educator suctions or discharge into an alternative container.

Efficient and flexible material movement of stored solids in the bags/liners is an important advantage of the invention for specific reasons according to the dewatering and drying application where a dewatered sludge may be placed outside and subject to natural freezing according to the anticipated and prevailing weather conditions and the dewatering efficiency and subsequent drying efficiency -8will be aided by a natural process beneficial to some categorises of sludge where the ‘freeze thaw’ process allows release of otherwise bound water in addition to free water.

In one embodiment of the invention is the use of waste warm air from air blowers, pumps and other heat emitting equipment that is conveyed into the sludge bag by an apparatus comprising a series of lances or under-decking sparge pipes to accelerate the drying process.

In another embodiment of the invention is the flexibility of the design of the Air lance apparatus or sparge pipes Apparatus whereby the position of penetration of the lances into the drying sludge or discharge nozzles of the sparge pipes may be varied from time to time to speed the drying process and to improve the consistency of drying sludge.

In another embodiment of the invention the coupling of an compressor or blower system attached to the sludge lance(s) allows mixing and turnover of sludge where required within a bag thereby accelerating the process of drying and reducing the risk of septicity.

In another embodiment of the invention is the use of solar panels / heater exchangers / heat pumps to collect / recover and concentrate the heat en-route to the sludge bag / liner system.

A further embodiment of the invention is the use of natural or fan assisted forced cooling air from heat emitting process air blowers housed within acoustic covers or containment structures principally on wastewater treatment plant as the source of waste warm air.

A still further embodiment of the invention is the use of warm air as a means of raising and maintaining the temperature of the drying sludge above that required for pasteurisation and hygienisation. - 9 In one embodiment of the invention is the use of hot air directly from blowers and compressors as a means of raising and maintaining the temperature of the drying sludge above that required for pasteurisation and hygienisation.

In another embodiment of the invention is the use of warm or hot air as describes above in combination or sequence with exothermic conditioning chemicals to achieve pasteurisation and hygienisation.

In another embodiment of the invention compressed air is used in combination with a pneumatically driven rotary mixer head to churn up the sludge contents of a sludge bag in order to expose fresh surface area and channels thereby increasing the rate of drying and reducing the risk of septicity.

In a further embodiment of the invention is a series of temperature probes placed within the bagged sludge that records the temperature of pasteurising sludge over a prescribed interval for the purpose of verification and compliance with regulatory requirements.

In a still further embodiment of the invention is a series of pH probes placed within the bagged sludge that records the pH of conditioning sludge over prescribed times for the purpose of verification and compliance with regulatory requirements.

In one embodiment of the invention is an Apparatus for containing heat within the sludge being raised in temperature for the purpose of pasteurisation whereby bag(s) are placed in a container apparatus created from Insulated panels applied to the exterior of new or refurbished boxes, skips, trucks and Trailers of up to 35 yard and upward equipped with floor decking and drain ports, air lancing apparatus, and insulated panel cover and end doors, or created from Insulated panels applied to the interior of steel or composite cages generally to the dimension of boxes, skips, trucks and Trailers of up to 35 yard and upward equipped with floor decking and drain ports, air lancing apparatus, and Insulated Panel cover and end doors. - 10In another embodiment of the invention the insulated box may be constructed as a pipe or vessel with a predetermined volume with sludge fed in batches and retained at the appropriate temperature and duration to achieve the desired pasteurisation standard.

In one embodiment of the invention is the use of the Sludge bags as containers for the growth of crops and in particular the selection of type of crops that aid dewatering of the contained sludge such as Willow and Poplar.

In another embodiment of the invention is the use of the specifically selected crops or microorganisms to capture and extract or decompose pollutants contained within contaminated sludge.

In a further embodiment of the invention vertical Sludge Bags are provided with chute(s) at the base and horizontal bags/liners with chute(s) at the end for ease of transfer of sludge or solids from bag to bag or to another container type.

Efficient material movement and placement of stored solids is a key advantage of the invention for specific reasons according to the dewatering and drying application where a waterworks sludge rich in spent coagulant hydroxides and having the know properties of adsorbing and retaining phosphorus and phosphorus compounds and other nutrients may be stored separately for reuse or mixed as layers or to varying degrees of homogeneity with biosolids rich in nutrients in order to achieve a desired reuse outcome.

Examples of desire outcomes include but are not limited to: In one embodiment of the invention placement of 100% singular coagulant rich waterworks sludge on the edge of a buffer zone or feeder channels to a watercourse to act as a temporary or permanent adsorption barrier to phosphate run-off following tree felling or in response to long term over fertilisation.

In another embodiment of the invention the Sludge Bag may be used as a nutrient addition apparatus to fertilise forestry or biomass crops at an appropriate rate by means of a mixed waterworks / biosolids to increase yield and in combination with - 11 100% singular waterworks sludge the Sludge Bags may act as a protective barrier to phosphate run-off as described above.

In another embodiment of the invention Sludge Bags may be used as a barrier for the protection of sensitive watercourses and groundwater.

In another embodiment of the invention Sludge Bags may be used in the construction of Integrated Constructed Wetlands (ICW) by placement of singular or mixed bags to the periphery and base of the wetland basin or excavation and infilled with higher nutrient mixed biomass biosolids.

In another embodiment of the invention the Sludge Bags may be initially filled with wet waterworks sludge that is allowed to dry and encrust the base and walls and thereafter the interior filled with biosolids thereby creating a form of grow bag with integral barrier to the run-off of excessive nutrient principally phosphorus compounds.

In another embodiment of the invention Sludge Bags may be used in the construction of Eco-amenity parks in a similar manner to an ICW and planted with Short Rotation Crops (SRC) such as poplar, willow and coppiced natural indigenous fauna that create a habitat suitable for wildlife and yield locally harvested and consumed biomass.

In another embodiment of the invention Sludge Bags may be used in the construction of ICW’s with zero discharge adjacent to a highly sensitive watercourse.

In a further embodiment of the invention Sludge Bags may be used to aid in the construction of Biomass forestry and Bio-energy crops on reclaimed used Bog or Wetland.

In a further embodiment of the invention Sludge Bags may be used in the construction of Biomass forestry and Bio-energy crops aside or as a replacement to privately held Bog or Wetland and to provide a substitute green energy crop. -12In a still further embodiment of the invention Sludge Bags containing sludge conditioned to the required standard may be used to aid in the construction of nurseries and community farms for the growth of food and other crops.

In one embodiment of the invention efficient and flexible material movement of stored solids in the bags/liners is an important feature of the invention for specific reasons according to the dewatering and drying application where a dewatered sludge may be placed and arranged inside a transparent building, covered structure or tunnel for the entrapment of solar energy and thermally ventilated in a particular manner by means of skirts and vents for the purpose of enhancing at high energy efficiency the drying process.

In another embodiment of the invention all the steps of dewatering, conditioning and drying may be accomplished in the Solar tunnel by pumping liquid sludge directly to the bags.

In a further embodiment of the invention the transparent cover may be placed directly on and over the bag, new or refurbished boxes, skips, trucks and Trailers for the beneficial use of solar energy.

In a further embodiment of the invention the Sludge Bags may be dyed black to increase the absorption of solar energy.

In a further embodiment of the invention the Containers, trucks, skips and Trailers may be painted black to increase the absorption of solar energy.

In a further embodiment of the invention the Sludge Bags may be rotated or tumbled to break-up sludge cake and expose the interior to new drying air pathways.

It is known that domestic wastewater sludge settles in Septic tanks and Imhoff tanks and similar settlement and sludge storage tanks in concentration from 4% dry solids to 8% dry solids and upward. It is also known that raw sewage sludge - 13combined with humus solids and other biological sludge can settle individually or co-settle with raw sewage sludge in Septic tanks and Imhoff tanks and similar settlement and sludge storage tanks in concentration from 3% dry solids to 8% dry solids and upward.

It is also known that heavier sludge will preferentially settled as a layer on the base of such settlement tanks while lighter solids particularly those infused with fats, oils and grease will form a scum layer on the liquid surface.

Such Septic tanks and Imhoff tanks and similar settlement and sludge storage tanks are frequently de-sludged by road tankers and trucks often equipped with vacuum pumping or direct pumping. The de-sludging operation of necessity disturbs the settled sludge layer such that a high proportion of the tank contents are removed and to effectively remove the surface scum layer virtually al! the contents of the Septic tank, Imhoff tanks and similar settlement and sludge storage tank needs to be removed.

It is known that as a consequence of the de-sludging operation generally as described above the dry solids of sludge collected in the road tanker is much reduced and can be less than half or one-third or one-quarter or even less of the dry solids of the original sludge and scum layers contained within the Septic tank, Imhoff tank or similar settlement and sludge storage tank and as a consequence the transportation and subsequent processing of collected sludge is thus rendered highly inefficient.

In one embodiment of the invention the Sludge Bags or Sludge Bag Liners are deployed in the various skip, trailer, truck and road tanker arrangements described earlier whereby sludge removed from the Septic tank, Imhoff tank and similar settlement and sludge storage tanks is pumped into the Sludge Bag I Liner that acts as a Bladder and filtrate is returned to the Septic tank, Imhoff tank and similar settlement and sludge storage tanks thereby returning the dry solids of the collected sludge and scum to nearer their original dry solids concentration. - 14 In another embodiment of the invention the return of filtrate that has drained from the Sludge Bag serves to re-seed the Septic tank with microorganisms that improve its efficiency.

In another embodiment of the invention the addition of conditioning chemicals as described earlier may improve the filtration efficiency and improve the quality of the returning filtrate.

► In a further embodiment of the invention boxes, skips, trucks, trailers and road tankers of up to 35 yard and upward equipped with Sludge Bags / Liners deployed for the purpose of emptying Septic tanks may be retained at that site for the purposed of release of most of the free water and equipped with covers and odour treatment equipment.

In a further embodiment of the invention the drain port for the discharge of free water is equipped with a water trap so that vacuum tanker fill operation will not be interrupted by breaking vacuum.

In a still further embodiment of the invention the collected septic tank sludge is retained in the Sludge Bags ! Liner or screened, conditioned where desired and transfer to other Sludge Bags /Liners and the filtrate is allowed to evaporate rather than being returned to a wastewater treatment plant thereby removing the risk of process upset.

In one embodiment of the invention where dewatered sludge processing plant is available the Sludge Bag System can omit the dewatering phase and accept thickened sludge for further processing as described above.

In another embodiment of the invention direct heating energy, for example from the process air blowers, may be used typically at the later stages of the drying phase to accelerate the pasteurisation and drying process and to achieve near 100% dry solids content. - 15In another embodiment of the invention the biomass sludge may be dried to near or approaching 100% dry solids such that the dry residual sludge has a calorific value similar to lignite or turf and rendering it suitable for reuse and disposal by direct combustion.

The advantages of the invention are many.

A simple and flexible system that can be matched and adapted to the sludge reuse application with minimal cost in comparison with traditional methods.

A system that is easy to use and requires little supervision, labour input or reliance on instrumentation in comparison with traditional methods.

A unitary system in that the Sludge Bags / Liners may be used for all the desired processing steps from initial dewatering, to conditioning, drying, pastuerisation, transportation, storage and eventually temporary placement or final disposal of sludge that is not available by traditional methods.

The sludge bags avoid the use of collecting dewatered or dried sludge by means of front loaders that is of necessity as messy and hazardous task.

The use of a compressor system attached to the sludge lance(s) allows mixing and turnover of sludge where required within a bag speeding the process of drying and reducing the risk of septicity.

The use of waste heat allows efficient drying of dewatered sludge in comparison with conventional dewatering and thermal drying methods.

The ability to easily protect dewatered sludge from re-wetting and the use of ‘freeze-thaw’, and purpose ventilated solar tunnels to aid dewatering and drying reduces the cost of treatment prior to final re-use in comparison with traditional methods. -16The use of conditioning chemicals including exothermic chemicals and waste heat including storage in enhance insulated boxes and pipes allows production of pathogen free sludge to the degree required at a fraction of the cost of traditional methods.

The use of Sludge pumping eductors and trolleys for material movement provides an integrated and flexible means of treatment and material movement that is adaptable to the sludge origin and reuse requirement.

The use of biodegradable Sludge Bag material to selected textile weight allows flexible and environmentally appropriate final reuse of sludge.

The use of the Sludge Bag I Liners on the one hand to protect the environment from excess nutrient pollution while on the other hand to provide a source of nutrient to increase crop yield at a low cost.

The use of Sludge Bags I Liners for the collection of sludge and scum from Septic tanks, Imhoff tanks and similar settlement and sludge storage tanks significantly reduces the cost of transportation and disposal as the collected sludge has a significantly higher dry solids content. A traditional vacuum road tanker that has the capacity to empty one septic tank could be replaced with a road tanker or truck of equal capacity equipped with a Sludge Bag Liner that is capable of emptying three such Septic tanks thereby reducing the collection frequency and associated costs by two-thirds.

The use of Sludge Bags / Liners in road tankers, trucks and trailer for the collection of sludge from Septic tanks and the like and for the removal of most of the free water at the Septic tank site allows further conditioning of sludge at sludge hubs without risk of upsetting wastewater treatment processes. - 17 Brief Description of the Drawings The invention will be more clearly understood from the following description of a preferred embodiment thereof which is given by way of example only with reference to the accompanying drawings, in which.

Fig. 1 is a diagrammatic representation of a Sludge Bag arranged as a mini-bulk bag with cover, reinforcement battens, strengthening ropes, chute, handles and ties.

Fig. 2 is a diagrammatic representation in plan and view of Sludge Bags installed in a container on open decking and with vertical double cavity open decking placed between bags to allow passage of drained free water and passage of drying air.

Fig. 3 is a diagrammatic representation in plan and view of a Sludge Bag Liner in the form of a container lining installed on open decking with handles, ties and end chute being fed via a Feed manifold with flexible hose couplings normally with conditioned liquid sludge.

Fig. 4 is a diagrammatic representation of Sludge Bags installed and tied one above the other to allow transfer of material from the upper bag to the lower bag.

Fig. 5 is a diagrammatic representation of a Sludge Bag Liner in the form of a container lining installed on open decking with handles, ties and end chute, the container being equipped with Air manifold, couplings, air sparge pipes and lances with waste heat from process Air blowers used to increase drying efficiency.

Fig. 6 is a diagrammatic representation of a pumping arrangement whereby a conditioning chemical and in particular an exothermic conditioning chemical such as quicklime is dosed into sludge being pumped into a Sludge Bag liner that is itself housed in a insulated container for pasteurisation of sludge. Fig. 6 also illustrates an insulated pipeline adapted for the same purpose and the use of recovered waste air from process air blowers. The pumping package may be - 18used for the transfer of raw, conditioning, dewatered and dry sludge and acceleration of the dewatering and drying process.

Fig 7 is a diagrammatic representation of the Sludge bag liner installed in a trailer and highlighting the provision of a translucent cover, vent to control the direction of drying air, condensate guttering and downpipes.

Fig. 8 is a diagrammatic representation of a forklift trolley used for the material movement of Sludge Bags containing sludge and mounted on pallet type decking.

Fig 9 is a diagrammatic representation of under decking drainage in pallet format.

Fig. 10 is a diagrammatic representation of a purpose ventilated solar tunnel showing to aid clarity a single sludge bag on pallet type decking with bag support frame.

Fig. 11 is a diagrammatic representation of the placement and reuse of biodegradable Sludge Bags containing dried coagulant waterworks sludge arranged in a manner to protect a watercourse from high phosphorus run-off.

Fig. 12 is a diagrammatic representation in plan view of how Bags might typically be arranged and used to aid in the construction of an Integrated Constructed Wetland (ICW) Fig. 13 is a diagrammatic representation in sectional view of how Bags might typically be arranged and used to aid in the construction of an Integrated Constructed Wetland (ICW) including protection from pollution from below.

Fig. 14 is a diagrammatic representation of a Pallet box or container to accept a Sludge bag or Sludge bag liner and capable of being moved by forklift or trolley wheels.

Fig. 15 is a diagrammatic representation of a Sludge bag liner installed as a bladder within a Vacuum road tanker. -19Detailed Description Referring to drawing Fig. 1 there is an apparatus according to the invention comprising a Sludge bag or liner 1 manufactured from woven flax / hessian / burlap jute family of natural biodegradable textile material to provide a uniform 5 mesh. The Sludge bag can be provided with Lifting handles 2 and the bag or liner 1 may be strengthened by attaching Rope 3 to form a much strengthened lifting cage. The Sludge bag or liner may be given further support by means of Battens 4 placed in sleeves or stitched in to the textile material. The bag or liner 1 may be provided with a Cover 6 that can be secured by means of judiciously placed 5 10 Ties. The bag may be provided with a central or off-set discharge chute 7 that can be closed by Ties 5.

Referring to drawing Fig. 2 there is an apparatus according to the invention comprising Perforated drainage decking 9 that may be installed in a container, 15 trailer or similar static or mobile container to support the Sludge bags or liner 1 that may be further equipped with Vertical perforated decking 10 for the draining of free water and passage of drying air. Water collected in the plenum below the decking may be discharged via a Drain port 11 that may be equipped with a valve. The container housing the Sludge bags or liner 1 may be provided with a Container 20 cover 8.

Referring to drawing Fig. 3 there is an apparatus according to the invention as illustrated in Fig 2 and comprising a Sludge feeding manifold 12 equipped with an appropriate number of Manifold couplings 13 that can accept Flexible distribution 25 pipes or hoses 14. Each hose 14 may be equipped with a Hose discharge nozzle . The Sludge bag liner 1 may be equipped with an Off-set discharge chute 16 with Ties 5.

Referring to drawing Fig. 4 there is an apparatus according to the invention 30 comprising a Sludge bag or liner 1 manufactured from woven flax I hessian / burlap jute family of natural biodegradable textile material to provide a uniform mesh. A Sludge bag 1 may be placed on top of the other for convenience or to transfer the contents from an upper to a lower bag and can be provided with Lifting -20handles 2, Ties 5, Discharge chute 7, Cover 6, and Decking 9 in the form of a perforated pallet for the drainage of free water and the distribution of drying air.

Referring to drawing Fig. 5 there is an apparatus according to the invention as illustrated in Fig 2 and Fig. 3 and also comprising a system for the collection of waste warm air from for example Process air blowers 17 enclosed in Insulated acoustic covers 18 that can be equipped with Cooling fans 19. The Cooling fans 19 can be attached to a Air manifold 20 with a Non-return valve or flap 21. The air manifold can be supplemented by hot air directly from the Process air blowers 17 by opening a valve 27. The Air manifold 20 can feed the required number of Air manifold couplings 22, Air flexible tubing 23, and Movable Air Sparge Lances 24 that can be embedded in the sludge. Alternatively or in combination drying air may be directed to below the Perforated decking 9 via an Under decking manifold 25. The Movable Sparge Lances 24 and Under decking manifold 25 can be equipped with air orifices to encourage even distribution of drying air.

Referring to drawing Fig. 6 there is an apparatus according to the invention as illustrated in Fig 2 and Fig. 3 and Fig. 5 and also comprising a system for pumping via a suitable Sludge pump 27 and conditioning the feed liquid sludge by the addition of a flocculating chemical such as is provided for in Polyelectrolyte dosing set 28. The sludge may be further conditioned by the addition of pH correcting and exothermic chemical such as quicklime as is provided for in Powder hopper 29 and mixing eductor.

The delivery pipe of the sludge pump is equipped with a Flow meter 30 that may feed into a Enlarged and insulated pipe section or vessel 31 for the purposes of providing the required residence time at a pre-determined minimum temperature as recorded by a Temperature sensor 32. The conditioned sludge can be delivered into the Sludge bags or liner 1 by a Feed sludge manifold 12 equipped with Couplings 13 and Flexible pipe 14. Heat loss and drying efficiency may be improved by insulating the Container with permanent or temporary Structural insulating panels 33. The Sludge pump 27 may be equipped with a Gearbox 34 coupled to an Electric motor 35 or External drive coupling 36 for example a diesel engine. The pumping and conditioning dosing systems and feeder may be -21 installed on a Skid 37 that may be mountable on a trailer and containers or demountable for remounting at the Users convenience.

Referring to drawing Fig. 7 there is an apparatus according to the invention as illustrated in Fig 2 and Fig. 3 and Fig. 5 and Fig. 6 and also comprising a system for the use of solar energy to further enhance the drying process by equipping a container with a Translucent cover 38, Vents 39 for the correct flow direction of drying air, Gutters and pipes 40 for the capture and correct routing of any condensate.

Referring to drawing Fig. 8 there is an apparatus according to the invention as illustrated in Fig 1 for the transfer and movement of sludge bags or liners by use of Forklift trolley and trucks 41 where the Perforated drainage decking 42 is in pallet style and may be equipped with Up-stands 43 for the further support of Sludge bags and liners 1.

Referring to drawing Fig. 9 there is an apparatus according to the invention whereby 41 Perforated drainage decking 41 may be provided in pallet style with Openings 42 to accept forklift forks and Up-stands 43 with or without Cross members 44 to provide support to Sludge bags and liners 1 and for their ease of movement.

Referring to drawing Fig. 10 there is an apparatus according to the invention whereby Pallets 44 supporting 1 sludge bags (only one shown for clarity) and liners may be easily moved in and removed from a Solar tunnel 45 for the purposes of accelerating drying and equipped with equipment as shown in Fig 1, Fig 2, Fig 3, Fig 4, Fig 5, Fig 6, Fig 7, Fig 8, and Fig 9. For illustration purposes drawing Fig. 10 shows a Translucent cover 38, Vent 39, Perforated pallet decking 42, Sludge feed manifold 12, Drying air manifold 20, Movable Air Sparge Lances 24, Under decking air manifold 25, Access doors 47, Drain port 13, and a Sludge bag 1 that may contain a Bio-energy crop 46 that aids dewatering and drying.

Referring to drawing Fig. 11 there is an apparatus according to the invention whereby Sludge bags and liners 1 that contain dried coagulant waterworks sludge -22may be placed in a Drainage ditch or channel 48 that conveys run-off water high in a nutrient such as phosphate for the purpose of adsorption and protection of Rivers and streams 49 arising out of over-fertilisation of Crops and forestry 50.

Referring to drawing Fig. 12 there is an apparatus according to the invention whereby Sludge bags 1 containing dried coagulant sludge with excellent phosphate adsorption properties might typically be arranged to form a barrier to the periphery of an excavation and used to aid in the construction of an Integrated Constructed Wetland (ICW). The excavation might normally be below Ground level 49 but can be constructed above ground level for the intensive cultivation of Crops 48 including bio-energy crops.

Referring to drawing Fig. 13 there is an apparatus according to the invention whereby Sludge bags 1 containing dried coagulant sludge with excellent phosphate adsorption properties might typically be arranged to form a barrier to the periphery and base of an excavation and used to aid in the construction of an Integrated Constructed Wetland (ICW) and for the cultivation within the interior of bio-energy crops 48. Sealing of the base of the excavation or above ground embanked structure provides additional security that phosphate will not be release particularly when the Water table 50 can be high.

Referring to drawing Fig. 14 there is an apparatus according to the invention whereby Sludge bags or liners 1 may be contained and supported within a Pallet box 51 with integral under decking for the drainage of free water and distribution of drying air. The Pallet box 51 and Sludge bag 1 may be moved by conventional Forklift trolley or equipped with a Wheeled trolley base 52.

Referring to drawing Fig. 15 there is an apparatus according to the invention whereby a Sludge bag 1 may be used as an expandable bladder within a Sludge road tanker 53 that has been equipped with Perforated decking 9. The Sludge bag bladder 54 is provided with a Chute 55 connected to the Inlet port 55 of the tanker and sludge may be pumped into the tanker or drawn in by means of a Vacuum pump 57. The outlet port can be provided with a Water trap 58 so as not to break the vacuum during a fill operation.

Claims (30)

Claims

1 - A bag manufactured from naturally biodegradable woven mesh textile such as flax, hessian, burlap and jute for the filtering and retention of solids and the drainage of free water for dewatering, handling, and the movement of air for the drying of sludge comprising: - a set of handles with flaps for the lifting, covering and tying of the bag - a chute with ties that can form a collar for the transfer or emptying of the contents including to a bag below or the suction of a pump / educator - open decking below and aside bags to allow passage of free water and the movement of drying air - decking with lifting and support apparatus arranged to be moved by forklift or craneage to aid movement of bags

2. - A bag as claimed in claim 1, wherein: - the bag is manufactured from naturally biodegradable woven mesh textile such as flax, hessian and jute and suitable for storage and temporary or final placement of sludge.

3. - A bag as claimed in claim 1, wherein; - the mesh opening size and type may be varied to suit the dewatering and drying application

4. - A bag as claimed in claim 1, wherein: - the weight of the naturally biodegradable textile may be varied to suit a preferred degradation period

5. - A bag as claimed in claim 1, wherein: - the contents of the bag may be transferred to another bag or pump suction

6. - A bag as claimed in claim 1, wherein: - mixed sludge may be applied either as an outer coating of fully coagulant single sludge to act as a barrier for phosphorus with inner layers of nutrient rich sludge or a mixed sludge to varying degrees of homogeny

7. - A bag as claimed in claim 1, wherein: - battens may be installed in sleeves to the base, uprights and top to provide rigidity - rope may be installed in the form of a cage to the base, crossmembers uprights top and lifting handles to provide strength

8. - A bag as claimed in claim 1, wherein: - the bag is dyed black to improve solar energy gain

9. - A bag as aimed in claim 1, wherein: - the mesh opening size and textile weight may be adapted for the drainage of free water for dewatering, handling, and the movement of air for the drying of granular aerobic sludge thereby realising an order of magnitude greater capacity and performance in comparison with conventional aerobic sludge

10. - A box, container, trailer or truck equipped with open perforated decking below and aside single or multiple sludge bags and liners and comprising as required: - decking to various degrees for the passage of free water and the movement of air - loose or sealed cover - transparent solar cover - odour treatment of exhaust ventilated air - free water drainage port - vacuum assisted drainage ports and pumping of water and or air - drying air ports - air sparges or lances below decking air manifolds - sludge feed manifolds - mobile conditioning and pumping - insulation panels and cover - solar panels, heat exchangers and heat pumps

11. - A box, container, trailer or truck as claimed in claim 10, wherein: - permanent or temporary open decking may be applied to the base, walls and as vertical up-stands to allow the passage of free water and the movement of drying air.

12. - A box, container, trailer or truck as claimed in claim 10, wherein: - the bags are replaced with naturally biodegradable woven mesh textile material applied directly to the open decking described above as a permanent or temporary arrangement.

13. - A box, container, trailer or truck as claimed in claim 10, wherein: - a loose, sealed or insulated cover is provided to protect the sludge from the elements principally rain and to reduce emissions.

14. - A box, container, trailer or truck as claimed in claim 10, wherein: - a drainage port that collects free water from below the decking and allow discharge via a pipeline or channel to filtrate acceptance storage tankage

15. - A box, container, trailer or truck as claimed in claim 10, wherein: - a drainage port is fitted with a pump to rapidly remove drainage water from below the decking to aid dewatering.

16. - A box, container, trailer or truck as claimed in claim 10, wherein: - the drainage pump described above has the capability to create a vacuum below the decking that accelerates the dewatering and drying process or a separate vacuum pump is provided for the same purpose.

17. - A box, container, trailer or truck as claimed in claim 10, wherein: - the lances and sparge pipes placed within, below or aside the sludge bag(s) are movable to allow increase in drying rate and to increase the homogeneity of drying sludge.

18. - A box, container, trailer or truck as claimed in claim 10, wherein: - single or multiple bags may be placed in to or aside of each other including to compensate for the reducing sludge volume arising from the drying process.

19. - A box, container, trailer or truck as claimed in claim 10, wherein: - insulated panel lining may be applied on a temporary or permanent basis to the exterior or interior to allow efficient retention of heat to aid the drying, pasteurisation and hygienisation processes.

20. - A box, container, trailer or truck as claimed in claim 10, wherein: - A fixed or temporary pumping, conditioning chemical dosing system and or bag forklift or crane assembly(s) for the purposes of pumping and conditioning raw, dewatered and drying sludge.

21. - A box, container, trailer or truck as claimed in claim 10, wherein: - A fixed or temporary transparent roof is provided for the capture of solar energy.

22. - A box, container, trailer or truck as claimed in claim 10, wherein: - is painted black to increase solar gain.

23. - An insulated box, container, trailer or truck or pipe as claimed in claim 10, wherein: - the required monitoring and surveillance instrumentation is provided to control and record the processing steps and parameters to determine compliance with conditioning, pasteurisation and hygienisation standards.

24. - A box, container, trailer, tanker or truck as claimed in claim 10, wherein: - The sludge bag is installed in the tanker in the form of an expandable bladder for the collection and concentrating of the sludge. - the sludge collection and free water porting and pumping is arranged to return filtrate directly to a Septic tank, Imhoff tank or other sludge settlement and storage tank.

25. - A solar tunnel configured to accept and house bags, liners, boxes, and containers that is provided with purpose designed louvers and vents attached to decking or air lances and to the tunnel outlet that routes drying air through the sludge and out of the tunnel powered by solar convention generated by the capture of solar energy within the tunnel.

26. - A pallet box with the accoutrements as described herein the above claims and lined with a removable sludge bag Liner capable of lifting and stacking by a forklift truck and equipped with temporary or permanent castor or trolley type wheels.

27. - A box, container, trailer or truck as claimed in claim 10, or Solar tunnel as claimed in claim 25, wherein: - Waste or direct heating energy for example from the process air blowers is used typically at the later stages of the drying phase to accelerate the pasteurisation and drying process and to achieve near 100% dry solids content.

28. - A box, container, trailer or truck as claimed in claim 10, or Solar tunnel as claimed in claim 25, wherein: - Sludge is dried to near or approaching 100% dry solids such that the dry residual sludge has a calorific value similar to lignite or turf and rendering it suitable for reuse and disposal by direct combustion. -28

29. - A box, container, trailer or truck as claimed in claim 10, or Solar tunnel as claimed in claim 25, wherein: - Sludge is dried sufficiently or to near or approaching 100% dry solids such that pathogen concentration limits may be achieved without the 5 need to sustain a pasteurisation temperature for a predetermined period.

30. - Sludge dewatering, conditioning, drying, conditioning, handling and placement for disposal or reuse system of principally but not exclusively 10 waterworks and wastewater sludge, biosolids, and aerobic granular sludge as described with reference to the accompanying description and / or drawings.