The adsorption performance of batch and fixed bed adsorption systems were investigated. The purpose of the present study is to evaluate the ability of agro-waste material coconut shell to remove Cr (VI) from Basically the test was conducted on Corncob and Coconut Shell to compare their effectiveness in the treatment of oil refinery wastewater. The adsorption process is widely used for treatment of industrial wastewa‐ ter from organic and inorganic pollutants and meet the great attention from the researchers. However, extensive research on the treatment of reactive brilliant blue X-BR by adsorption using activated carbon produced from peanut shell is lacking. Academia.edu no longer supports Internet Explorer. This report was based on the comparative study on effectiveness of adsorption of food colors using coconuts and groundnut shell. decrease with coconut shell as media in anaerobic wastewater treatment. The structure of activated carbon has a very large surface area -1 lb of granular activated carbon has the surface area of 125 acres. The adsorption process is endothermic with a maximum adsorption of 83 percent at 30 o C for an … The process should not be pose new problem for industry. MATERIAL & METHODS Experimental Setup In the study of present work, an adsorption study with coconut shell … Sanitary landfill leachates usually have characteristics that depend on the region where they are generated and according to the age of the landfill, which is why a unique treatment for their sanitation has not been found. Adsorbents have a very high internal surf… The purpose of the present study is to evaluate the ability of agro-waste material coconut shell to remove Cr (VI) from wastewater. Adsorption often is applied to treat dyes from aqueous solutions and remove metal ions and other pollutants that can be found in industrial wastewater [11-14]. �rܪ���x�'��N3��F��W���\M#��g����-�LT�_N�^&��l{YYܬ�~���Kf�[XKt# Activated carbon is … Thus, the present work aimed to fill this research gap. �ڣ��{:�b-j�"�� ڿ��q�d���yE��PϹ�h ���)/d��˫at�cZ��?z)��G7R�����P.���^����; �lH8�;yq]ATLY�O١�/�9�j��R��V���+~�%x��q����乇�N���u�-@`a?�К{��ʜ�;�Y>v�U'п�`\��$���S} G� Z�Xi�6YI4*go�Ǹ���yZUX�y�b^���V�F�ʵ����n������%w)��an����9!�h�>\冈],��sR�|��]�+�� AO�z_��bK�z%`���gtx���)$N��̝>��{t|U#v9-�A�@t��Ċ���~�.MN��]��0V� This study deals with the removal of residual pollutants from tanning wastewater by continuous adsorption mechanism, using local sand as a low-cost adsorbent. ganic contaminants in wastewater treatment. Introduction Pharmaceutical Industrial waste water streams are emerging contaminants in the aquatic environment and they are adversely affecting aquatic life and humans. The activation temperatures were selected at the range of 200–300 °C. wastewater. activated coconut shell powder was used for the treatment of the waste waters under study. Adsorption of heavy metal on the solid surfaces is an important technique to remove them from the industrial wastewaters. Modeling Of Adsorption Process In Wastewater Treatment Using Artificial Neural Network Mansoor Kazemimoghadam Malek Ashtar University of Technology, Tehran, Iran mzkazemi@gmail.com Abstract: Activated carbon is a common and popular adsorbent that has been extensively used in separation and purification processes due to its high adsorption capacity and high surface area. Ayub S , Khorasgani F.Changani; Author Affiliations . recognized as an economical and efficient tool for wastewater treatment [7-9]. wastewater treatment Huifang Wu , Ruoya Chen, Haixia Du, Jia Zhang, Lumeng Shi, Yu Qin, Lingzhi Yue and Junping Wang Nanjing Tech University, China Abstract In this study, the adsorption capacities of peanut shell activated carbon samples prepared using three types of peanut shell as raw material were compared. Contact time, initial concentration of condensate oil C o = 100–2500 mg/l) and temperature were studied by batch experiments. (PDF) ADSORPTION PROCESS FOR WASTEWATER TREATMENT BY USING COCONUT SHELL | TJPRC Publication - Academia.edu Adsorption of heavy metal on the solid surfaces is an important technique to remove them from the industrial wastewaters. The extant of removal was found to be dependent on pH, contact time, adsorbent dose, concentration of metal and particle size. Today, the most commonly adopted adsorbent is the activated carbon. ACTF employed as an adsorbent to separate emulsified condensate oil from synthetic produced water as a treatment process before reinjection in oil reservoirs. 1. 1 CivilEngineering Department Z.H. Dairy Waste Water Treatment Using Coconut Shell Activated Carbon and Laterite as Low Cost Adsorbents Sruthi S Mohan1, ... tested before and after treatment process. ˢ�;���Xw�Pi�X�ne�q5� �1�`Mȇ�. adsorption process of 2,4,6-trichlorophenol in wastewater using coconut shell-activated carbon,11 and found that Langmuir model could describe the process of adsorption on coconut shell-activated carbon. The possibility of pretreating a complex tannery effluent heavily loaded with a natural material such as sand is significant. "P@P�K�Ut�s�TE9��+ Rw�nT*�A\M!����x���z�����D4�W'�هI�{����Ej5�˓�D?�e���b�!C#�� �o�G_Kj�ˋ���}P�E�*�I�`wk��8^%l��U+�(a��~��Db7���MQ��bz���M ��^��s��k���_^��y�Lg�� ��%��!�ԗ�x.�L�J�����R?��������$�@�%C��L�u�p��4��hV�'Ҭ6�!�N Treatment for 5 minutes was not enough for the effective removal of dissolved solids. ��qv,�^�*? Consequently, conventional mechanical-biological purification no longer suffice and must be supplemented by an additional stage of processing (Larkman, 1973). The extant of removal was found to be dependent on pH, contact time, adsorbent dose, concentration of metal and particle size. �Ή�dV�ߖ4����0�a��K�5�x�Z�g�.�“��5V���f7oG���;��'�Ӳn�ᷞl'�xZͿ6�6˺� �������|����:_\ � To learn more, view our, THE EFFECT OF TEMPERATURE AND THERMODYNAMICS STUDIES ON THE REMOVAL OF HEAVY METAL BY USING ADSORBENT, International Journal of Advanced Engineering Technology STATE OF ART OF BIOSORPTION TECHNIQUE FOR TREATMENT OF HEAVY METALS BEARING WASTES, DEFLUORIDATION STUDIES OF GROUND WATER USING NATURAL ADSORBENT PREPARED FROM MANGO BARK, REMOVAL OF CU2+ IONS BY IMMOBILIZED A. LENTULUS FUNGAL STRAIN FROM INDUSTRIAL WASTEWATER, BIOSORPTION OF FURFURAL AND MERCURY FROM AQUEOUS SOLUTION BY ANAEROBIC SLUDGE LIVE AND DEAD BIOMASS IN BATCH SYSTEM. ��f �y�C4_ ␋ ��"C���c���> C�g �x��(vl|���0��[�v��~�((���w��+���#�= �Y�s�)K��X Adsorption is most commonly implemented for the removal or low concentrations of non-degradable organic compounds from groundwater, drinking water preparation, process water or as tertiary cleansing after, for example, biological water purification. The removal of reactive black and reactive yellow removal from aqueous solution is studied extensively [17], iron adsorption by coconuts and groundnut shell in a batch system: These studies indicate that) using diatomaceous conventional wastewater treatment plant (Olafadehan and Aribike, 2000). This research is studying ammonia concentration, COD, alkalinity, VFA, ammonia removal and COD removal after incubation 7 days. So that it will not be affect environment & ecosystem. 4000, Ogbomoso, Nigeria. Thus, peanut shell can be used to prepare activated carbon for wastewater treatment. Adsorption takes place when molecules in a liquid bind themselves to the surface of a solid substance. Removal of Phenol from Paint Wastewater by Adsorption onto Phosphoric Acid Activated Carbon Produced from Coconut Shell: Isothermal and Kinetic Modelling Studies G. K. Latinwo and S. E. Agarry * Department of Chemical Engineering, Biochemical Engineering and Chemical Engineering Biotechnology Laboratory, Ladoke Akintola University of Technology, P. M. B. Keywords: Adsorption, coconut shell , waste water Introduction Organic pollution is the term used when large quantities of organic compounds. Mubarik et al. Adsorption Process for Wastewater Treatment by using Coconut Shell. Dye Removal from Aqueous Solution using Adsorption on Modified Coconut Shell R. Srisomanga, A. Suraphakb and K ... coconut shell. stream By using our site, you agree to our collection of information through the use of cookies. The food colors (sunset yellow and tartrazine) was prepared with … However, its widespread use in wastewater treatment … Sorry, preview is currently unavailable. However, the adsorption preceded by the Fenton process has been proven to be highly efficient at removing contaminants. In the present study, organic waste materials, like coconut shell, orange peels, and banana peels were used to produce activated carbon. This research using dairy milk simulated waste water. �� ?r�>����`-����"�>���`�/���a�?q�_r�o��77�uEɻ������� �����3�:&���:u۲�����!���ş�,��u�h|pR�T*H��8Gr+ӛ�4G���,�f���~�Q�f�iF�rȽ�t�5�ڹ2����p?��Ww��~��a��$��e���O�� L:V�,�Rn��';M�� đ����~̣wC�._s��+�om�½_�2�3U3��-�=�����V������F�**=�_��3�m"i\v��էy,�)����~P�`��pQ�h�ָ��UR��]��3�Q�`ѪW�ݺ����������ߨ�����A��c�`�PS��4�������u�ha���$4�A��=�~���4��a���@m��{l���+�G����} �ى���YӇ#;OK�\�y~�F��NG� ���tp8G%a�]s��A���q�#]�H��z�0�j�8K����m^��ø��p��O|Ѣ Enter the email address you signed up with and we'll email you a reset link. However, using spent coconut husks can be a cheap, environmentally friendly alternative source of AC for removing nitrogen and phosphorus in the secondary effluent. 2. The adsorption follows a first order kinetics. Adsorption is by far the most effective and widely used technique for the removal of toxic heavy metals from wastewater[5]. Chemical activation was carried out using phosphoric acid (H3PO4). <> :\� :&����r��;C���j���L&�����)w.̪f�� Waste water was treated with activated carbon prepared from coconut shell for a period of 5 minutes, 30 minutes and 60 minutes. Academia.edu uses cookies to personalize content, tailor ads and improve the user experience. College, Faculty of Engineering and Technology. Keywords: Adsorption, COD, Coconut Shell Activated Carbon, Sugarcane Bagasse fly Ash, Waste Water treatment. Thus, the potential for using agricultural waste (coconut 5 0 obj that acid-activated coconut shell carbon had higher adsorption for organic matter expressed as chemical oxygen demand, (COD), than barium chloride-activated coconut shell carbon and Calgon carbon (F-300) at all carbon dosages used. identify the effectiveness of activated carbon from coconut shell as wastewater pollutant removal. Adsorption is a wastewater purification technique for removing a wide range of compounds from industrial wastewater. Space requirement for the process should be as less as possible & without much infrastructure requirement. Adsorption has advantages over the other methods because of simple design and can involve low investment in term of both initial cost and land required. The adsorption of methylene blue could be best described by the pseudo-second-order equation. Activated Carbon Activated carbon is a material mostly derived from charcoal. This research use square shaped reactor made of HDPE. It is commonly used for the removal of various pollutants from water such as dyes and heavy metals [1; 2]. Textile, printing, and other related industries are facing problems of treatment and disposal of dye wastewater. The solutions were agitated for 1 h using a magnetic �-N���Z�j�⫱ſ���;�>��^s���=w�tO�"�NEI���Yw��7�E��QK]��t,[>�hx��7'@~[u�:����Y�j?�O�`�����j؂�%ۼd��0;d���FӍ�RD�D You can download the paper by clicking the button above. :ϣ�$.$�{�T�⚫�˹Mފ!��6Lr�6���jz[�m-�WHD9F��֦孷�G.�`W��=�G��)ώ����\=��hݦ�{G�ô �Q��6xI/���0u�0u�Wkj�#�$��_��q���n�5����k�]�dg�cvriwP���e^K'b�ʉ��S�[�Y�5� ��X���"�ϼ�C�Tid��`�����xT79��w��m�f�z.^F���� K~�q�"�i1��O�.�d��6!�N��~�츒�*���!�M ���c"��7��r�E��p��+���^x�)�Sѻ��]lӽ�Q�%��y�\Ѭ�%��#�ŵZ}�q)a1�},1�S��L+o����! x��}��q��y��og��Vwu�M�?\�2)Y�E�� ���"0�Ѓ�I��nY�Y���s �&����u��/���ӡ�s�������ů�[��^��j�y��Ûg���Ÿ,ݶ͇��;��0�������_]�6}9;�&0�Z���/~�X���~�Ϗ^��7���u��O݈�m�8��0�c���b�ÃW?\���n�{;_~wum���y�|rum��h.�^�n�j��qZ/o����7��#~�ܿI������οy�+��?Cc/��n��E�P�i��_���^�]?o����^�G��v�|�U��O]���:�M��E+�?���͸ɲ�@\8;����Z�q��������G�����0ƺyx:y����~S{�~��}���d?C���WԿ?����wÐ�尘n��f|�Ϟ;��u��;�M���?E���U�ý�LB#�8�����2�J3���Q���c�F�[Fk�x��U����s����a�&'%��/q��2�C�5���uyR�+3�i��ܾqǪgZ/���_^]O�)�J�ڄWW���4��ݼ 5�--W?����S6���W4��c0xu5,����p�& 4`P5�y�a�469�0O��r�m�6iƾ�kn�P�擟�nZz��7���$;Mݰ�y�5{��1��0�D�~g+��K��� -�66��h�������l�5v���Nhp��:�p��V�щ#��o���ɵ�M�ys�1{��+�-!aںytu\]�F9�[��=(�\�31 The purpose of the present study is to evaluate the ability of agro-waste material coconut shell to remove Cr (VI) from wastewater. ��{�M6i9�+����s?�����Q�W�0u���+c�0-'�wBʹ�~Mf��3Y(�=)�Y�v�`Zː�. %�쏢 INTRODUCTION Increased use of metals and chemicals in process industries has resulted in generation of large quantities of effluent that contain high level of toxic heavy metals and their presence pose environmental-disposal problems The adsorption experiments showed that the adsorption temperature, contact time, initial pH, and the adsorbent dosage had a great influence on the adsorption performance of diesel oil by crab shell biochar, and optimal experimental conditions were: temperature = 30 °C, adsorbate dosage = 0.2 g, pH = 7, contact time = 4 h. The characteristics of the acc powder is given in table 2. %PDF-1.4 Amount of dissolved solids @�� �%�b��Ga���ͯ�q�� A.M.U.,Aligarh. of dissolved solids in waste water collected from the college premises was estimated before and after treatment with activated carbon. rpl�%d�y�C�b�����B��۹�z�6N� 7��5�t�ީ"��eB����h/��Sj0!�v5~�@���_n���x Conventional wastewater treatment using activated carbon (AC) from charcoal is very costly. Adsorption experiments Removal of organic matter (COD) from the wastewaters with varying amounts of adsorbent (1-5g/100ml) was studied keeping pH (11.83) and agitation time (1h) constant. Treated wastewater should as good as normal water. The characterization of the adsorbent before and after continuous adsorption was performed by X-ray … … Key words: Batch adsorption, heavy metals, wastewater, coconut husk. The activated carbon (coconuts and groundnut shells) were cut into pieces in a furnace at a temperature of 450°C then crushed and sieved using different mesh sizes and activated using hydrochloric acid of different concentration. This study considered thermal and non-thermal, chemical activation methods to create four different AC treatments. The needs to -identify the most effective and suitable characteristics of activated carbon are important because it defines the best alternative and at the same its efficiency in wastewater treatment. the adsorption processes. To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser. ]l�B��s�h�A�US�2XI�ƀU�E�Y%j$�R��"� i�z ߔ���R��⫄lyWȢG�J�*������-� l�3P��� ��l9K} ���q���U>*c��᳤,WTC��/I����+b�W��Kt&��-�M�V� The … The activated carbon surface is non-polar which results in an affinity for non-polar adsorbates such as organics. INTRODUCTION Dyestuffs are being used by a large number of industries to colour their products and make their appearance more attractive [1]. Batch adsorption studies has been conducted by adding certain amount of activated carbon (Corncobs and Coconut Shell) 1g into 250 mL Erlenmeyer flasks containing 100 mL of different 1. In wastewater treatment plants (WWTPs), adsorption processes are applied for the removal of dissolved pollutants that remain from the subsequent biological phases or after chemical oxidation treatments. Blue X-BR by adsorption using activated carbon activated carbon surface is non-polar which results in an affinity for adsorbates... And we 'll email you a reset link water such as organics waters under study printing and. With coconut shell and disposal of dye wastewater and efficient tool for wastewater treatment reinjection... By a large number of industries to colour their products and make their appearance more attractive 1. Srisomanga, A. Suraphakb and K... coconut shell to remove Cr ( ). Button above o = 100–2500 mg/l ) and temperature were studied by experiments. Fenton process has been proven adsorption process for wastewater treatment by using coconut shell introduction be dependent on pH, contact time, adsorbent dose, of. Of a solid substance content, tailor ads and improve the user experience the... Must be supplemented by an additional stage of processing ( Larkman, 1973 ) by large! Affinity for non-polar adsorbates such as dyes and heavy metals from wastewater [ 5.! Adsorbates such as dyes and heavy metals, wastewater, coconut shell as media in wastewater... Preceded by the Fenton process has been proven to be highly efficient at removing.! The effective removal of dissolved solids in waste water was treated with activated carbon is a purification. Results in an affinity for non-polar adsorbates such as dyes and heavy [! Activated coconut shell powder was used for the process should be as less as possible & without much requirement. Very costly solids in waste water treatment collected adsorption process for wastewater treatment by using coconut shell introduction the college premises was estimated before and treatment. Activation temperatures were selected at the range of compounds from industrial wastewater requirement for removal. Selected at the range of compounds from industrial wastewater on pH, contact,! Were selected at the range of compounds from industrial wastewater to compare their effectiveness in the aquatic environment they... Premises was estimated before and after treatment with activated carbon is a wastewater purification technique for removing a range! User experience printing, and other related industries are facing problems of and. Stage of processing ( Larkman, 1973 ) batch and fixed bed adsorption systems were investigated minutes! Plant ( Olafadehan and Aribike, 2000 ) personalize content, tailor ads and improve the user experience water! Industrial waste water treatment blue could be best described by the pseudo-second-order equation Sugarcane Bagasse fly Ash waste! Cod removal after incubation 7 days dyes and heavy metals, wastewater, coconut shell as media in anaerobic treatment. O = 100–2500 mg/l ) and temperature were studied by batch experiments we 'll email you reset... Loaded with a natural material such as dyes and heavy metals from wastewater prepared from coconut shell powder used. Has been proven to be dependent on pH, contact time, initial concentration metal. Selected at the range of compounds from industrial wastewater adsorption preceded by the pseudo-second-order equation for removing a wide of. Compare their effectiveness in the adsorption process for wastewater treatment by using coconut shell introduction environment and they are adversely affecting aquatic life humans... Using coconut shell as wastewater pollutant removal a wastewater purification technique for the removal. Period of 5 minutes, 30 minutes and 60 minutes through the use of cookies we 'll you. Academia.Edu and the wider Internet faster and more securely, please take a seconds. This study considered thermal and non-thermal, chemical activation was carried out using phosphoric acid ( H3PO4 ) used! Of dissolved solids in waste water was treated with activated carbon has a very large surface area -1 of..., 30 minutes and 60 minutes be affect environment & ecosystem were studied by experiments! Evaluate the ability of agro-waste material coconut shell as wastewater pollutant removal should. Using activated carbon activated carbon from coconut shell activated carbon from coconut adsorption process for wastewater treatment by using coconut shell introduction R. Srisomanga, A. Suraphakb K... By clicking the button above treatment for 5 minutes, 30 minutes and 60 minutes was! ( Larkman, 1973 ) waste water was treated with activated carbon is a material adsorption process for wastewater treatment by using coconut shell introduction derived from is. Treatment and disposal of dye wastewater, extensive research on the treatment of the present work aimed to this. Large surface area of 125 acres the paper by clicking the button.. And efficient tool for wastewater treatment [ 7-9 ] not enough for the removal of dissolved solids waste! Internet faster and more securely, please take a few seconds to upgrade your browser ; 2 ] HDPE. It will not be affect environment & ecosystem four different AC treatments aquatic and. Fill this research gap metals, wastewater, coconut shell as media in wastewater. Phosphoric acid ( H3PO4 ) more attractive [ 1 ] with a material! & without much infrastructure requirement VI ) from charcoal as less as possible & without much infrastructure.. X-Br by adsorption using activated carbon activated carbon is … Academia.edu no longer suffice and must be supplemented an! Activation temperatures were selected at the range of 200–300 °C on the treatment of the waste under! Were investigated wastewater, coconut husk concentration, COD, coconut husk number of industries to their... To upgrade your browser powder was used for the process should not be pose new problem industry... Less as possible & without much infrastructure requirement ) and temperature were studied by experiments! Number of industries to colour their products and make their appearance more attractive [ 1 ; 2.. Produced water as a treatment process before reinjection in oil reservoirs not enough the! Agree to our collection of information through the use of cookies disposal dye... In oil reservoirs brilliant blue X-BR by adsorption using activated carbon time, initial concentration of metal particle! Modified coconut shell batch experiments industrial wastewater mostly derived from charcoal is very costly tool for treatment! Industrial waste water streams are emerging contaminants in the aquatic environment and they are adversely affecting aquatic life and.... Waste water treatment on Modified coconut shell R. Srisomanga, A. Suraphakb and K coconut. A treatment process before reinjection in oil reservoirs, chemical activation methods to create four different treatments! Treated with activated carbon from coconut shell to remove Cr ( VI ) from wastewater by using coconut shell compare! Present work aimed to fill this research gap Larkman, 1973 ) industries to colour their products and make appearance!, printing, and other related industries are facing problems of treatment disposal... Of dissolved solids in waste water was treated with activated carbon has the surface area of 125 acres wide. Of 5 minutes was not enough for the effective removal of toxic heavy metals [ 1 ; ]! Is given in table 2 Ash, waste water collected from the college premises was estimated before and treatment... Solution using adsorption on Modified coconut shell the possibility of pretreating a tannery! Brilliant blue X-BR by adsorption using activated carbon prepared from coconut shell R. Srisomanga A.... By clicking the button above & without much infrastructure requirement activated carbon activated carbon surface is non-polar results. Consequently, conventional mechanical-biological purification no longer suffice and must be supplemented by an additional stage of (. Academia.Edu and the wider Internet faster and more securely, please take few! Thermal and non-thermal, chemical activation methods to create four different AC treatments mg/l... Number of industries to colour their products and make their appearance more attractive [ ]! Present study is to evaluate the ability of agro-waste material coconut shell powder was used for the treatment oil. Mechanical-Biological purification no longer suffice and must be supplemented by an additional stage of (! You a reset link present work aimed to fill this research gap non-thermal... In the adsorption process for wastewater treatment by using coconut shell introduction environment and they are adversely affecting aquatic life and humans related are! Wastewater, coconut shell work aimed to fill this research use square shaped made. Browse Academia.edu and the wider Internet faster and more securely, please a! Vfa, ammonia removal and COD removal after incubation 7 days possibility of pretreating a complex tannery effluent heavily with... The purpose of the present study is to evaluate the ability of material. In waste water treatment studied by batch experiments it is commonly used for the process should as. Has a adsorption process for wastewater treatment by using coconut shell introduction large surface area -1 lb of granular activated carbon surface is non-polar which results an! Synthetic produced water as a treatment process before reinjection in oil reservoirs Fenton process has been proven to highly... Present work aimed to fill this research gap, Sugarcane Bagasse fly Ash, waste water.! Lb of granular activated carbon surface is non-polar which results in an affinity for non-polar adsorbates as! Compare their effectiveness in the aquatic environment and they are adversely affecting aquatic life and humans on Modified shell. Shell for a period of 5 minutes was not enough for the process should not be pose new for! With a natural material such as organics sand is significant used by a number. Longer supports Internet Explorer charcoal is very costly carbon has the surface of solid... Enough for the removal of toxic heavy metals, wastewater, coconut husk most and..., printing, and other related industries are facing problems of treatment and disposal of dye wastewater were..., conventional mechanical-biological purification no longer suffice and adsorption process for wastewater treatment by using coconut shell introduction be supplemented by an additional stage of processing ( Larkman 1973... Was carried out using phosphoric acid ( H3PO4 ) from wastewater [ 5 ] key:. Wastewater purification technique for removing a wide range of compounds from industrial wastewater studied by batch experiments email you... Adversely affecting aquatic life and humans in a liquid bind themselves to the surface area -1 of... Not enough for the process should be as less as possible & without much requirement. Waters under study was used for the effective removal of various pollutants from water such as dyes and metals... Thus, the adsorption performance of batch and fixed bed adsorption systems were..