37:
216:
29:
1171:
175:
183:
81:, can be added. These reagents cause finely suspended particles to clump together and form larger and denser particles, called flocs, that settle more quickly and stably. This allows the separation of the solids in the clarifier to occur more efficiently and easily, aiding in the conservation of energy. Isolating the particle components first using these processes may reduce the volume of downstream
52:. A clarifier is generally used to remove solid particulates or suspended solids from liquid for clarification and/or thickening. Inside the clarifier, solid contaminants will settle down to the bottom of the tank where it is collected by a scraper mechanism. Concentrated impurities, discharged from the bottom of the tank, are known as
271:
the suspended particles. To further discourage the overt mixing within the clarifier and increase the retention time allowed for the particles to settle, the inlet flow should also be distributed evenly across the entire cross section of the settling zone inside the clarifier, where the volume is maintained at 37.7 percent capacity.
230:
and circular shape. High efficiency tube settlers use a stack of parallel tubes, rectangles or flat corrugated plates separated by a few inches (several centimeters) and sloping upwards in the direction of flow. This structure creates a large number of narrow parallel flow pathways encouraging uniform laminar flow as modeled by
267:
water treatment equipment. This is done through routine inspections in order to ascertain the extent of sediment build up, as well as frequent cleaning of the quiescent zones, the inlet and outlet areas of the clarifier to remove any scouring, litter, weeds or debris that may have accumulated over time.
279:
conditions and a healthy environment for the growth of bacteria. This can cause the resuspension of particles by gases and the release of dissolved nutrients throughout the water fluid, reducing the effectiveness of the clarifier. Major health issues and problems can also occur further down the track
253:
Tube settlers capture the fine particles allowing the larger particles to travel to the bottom of the clarifier in a more uniform way. The fine particles then build up into a larger mass which then slides down the tube channels. The reduction in solids present in the outflow allows a reduction in the
295:
Addition of flocculants is common to aid separation in clarifiers, but density difference of flocculant concentrate may cause treated water to have an excessive flocculant concentration. Uniform flocculent concentration can be improved and flocculant dosage reduced by installation of an intermediate
270:
Water being introduced into the clarifier should be controlled to reduce the velocity of the inlet flow. Reducing the velocity maximizes the hydraulic retention time inside the clarifier for sedimentation and helps to avoid excessive turbulence and mixing; thereby promoting the effective settling of
165:
Methods used to treat suspended solids in mining wastewater include sedimentation and floc blanket clarification and filtration. Sedimentation is used by Rio Tinto
Minerals to refine raw ore into refined borates. After dissolving the ore, the saturated borate solution is pumped into a large settling
100:
for human consumption, is treated with flocculation reagents, then sent to the clarifier where removal of the flocculated coagulate occurs producing clarified water. The clarifier works by permitting the heavier and larger particles to settle to the bottom of the clarifier. The particles then form a
229:
Tube or plate settlers are commonly used in rectangular clarifiers to increase the settling capacity by reducing the vertical distance a suspended particle must travel. Tube settlers are available in many different designs such as parallel plates, chevron shaped, diamond, octagon or triangle shape,
266:
In order to maintain and promote the proper processing of a clarifier, it is important to remove any corrosive, reactive and polymerisable components first, or any material that may foul the outlet stream of water to avoid any unwanted side reactions, changes in the product or damage to any of the
299:
The two dominant forces acting upon the solid particles in clarifiers are gravity and particle interactions. Disproportional flow can lead to turbulent and hydraulic instability and potential flow short-circuiting. Installation of perforated baffle walls in modern clarifiers promotes uniform flow
194:
in rectangular tanks or with scrapers rotating around the central axis of circular tanks. Mechanical solids removal devices move as slowly as practical to minimize resuspension of settled solids. Tanks are sized to give water an optimal residence time within the tank. Economy favors using small
245:
Structures inclined between 45° and 60° may allow gravity drainage of accumulated solids, but shallower angles of inclination typically require periodic draining and cleaning. Tube settlers may allow the use of a smaller clarifier and may enable finer particles to be separated with
137:
necessary to treat domestic wastewater, preliminary chemical coagulation and flocculation are generally not used, remaining suspended solids being reduced by following stages of the system. However, coagulation and flocculation can be used for building a compact treatment plant (also called a
423:
Chatzakis, M.K., Lyrintzis, A.G., Mara, D.D., and
Angelakis, A.N. (2006). "Sedimentation Tanks through the Ages." Proceedings of the 1st IWA International Symposium on Water and Wastewater Technologies in Ancient Civilizations, Iraklio, Greece, 28–30 October 2006, pp.
195:
tanks; but if flow rate through the tank is too high, most particles will not have sufficient time to settle, and will be carried with the treated water. Considerable attention is focused on reducing water inlet and outlet velocities to minimize
274:
The sludge formed from the settled particles at the bottom of each clarifier, if left for an extended period of time, may become gluey and viscous, causing difficulties in its removal. This formation of sludge promotes
40:
Circular clarifier with surface skimmer visible in the lower right. As the skimmer slowly rotates around the clarifier, skimmed floating material is pushed into the trap visible above the fenced enclosure at the lower
300:
across the basin. Rectangular clarifiers are commonly used for high efficiency and low running cost. Improvements of these clarifiers were made to stabilize flow by elongation and narrowing of the tank.
32:
Three wastewater/sewage clarifiers at the ʻAikahi wastewater treatment plant in Hawaii. They appear to have a floating cover to reduce the odor because the plant is very close to a residential area.
19:
This article is about concrete and metal sedimentation tanks including continuous mechanized removal of solids. For a description of simpler settling ponds without solids removal machinery, see
241:
Because flow is temporarily accelerated between the plates and then immediately slows down, this helps to aggregate very fine particles that can settle as the flow exits the plates.
505:
292:
Improvements and modifications have been made to enhance clarifier performance depending on the characteristics of the substance undergoing the separation.
186:
Drained circular sedimentation tank showing central inlet baffles on the right with solids scraper and skimmer arms visible under the rotating bridge.
207:
are used to uniformly distribute flow from liquid leaving the tank over a wide area of the surface to minimize resuspension of settling particles.
754:
694:
407:
319:
1060:
603:
Western
Regional Aquaculture Center, University of Washington. Seattle, WA (2001). "Settling Basin Design." WRAC Publication No. 106.
246:
residence times less than 10 minutes. Typically such structures are used for difficult-to-treat waters, especially those containing
774:
36:
364:
769:
666:
1206:
258:
plastic are a minor cost in clarifier design improvements and may lead to an increase of operating rate of 2 to 4 times.
133:
reduce the content of suspended solids and pollutants embedded in those suspended solids. Because of the large amount of
564:
1055:
925:
638:
442:
351:
584:
1015:
985:
955:
502:
49:
729:
141:
Sedimentation tanks called 'secondary clarifiers' remove flocs of biological growth created in some methods of
1005:
829:
789:
154:
190:
Although sedimentation might occur in tanks of other shapes, removal of accumulated solids is easiest with
930:
1070:
837:
488:
Gorshkov, V. A., Kharionovsky A. A., "Main
Methods and Techniques of Mine Water Treatment in the USA",
142:
594:, Vol. III. Washington State Department of Ecology. Publication 9913. p. 93. Accessed 14 October 2013.
101:
bottom layer of sludge requiring regular removal and disposal. Clarified water then proceeds through
842:
203:
are used to prevent fluid velocities at the tank entrance from extending into the tank; and overflow
122:
1201:
759:
659:
384:
48:
are settling tanks built with mechanical means for continuous removal of solids being deposited by
1030:
970:
897:
739:
613:
314:
309:
276:
102:
887:
882:
847:
461:(Report). Washington, D.C.: U.S. Environmental Protection Agency (EPA). 2004. EPA 832-R-04-001.
324:
215:
404:
178:
Rectangular sedimentation tanks with effluent weir structure visible above the fluid surface.
1096:
907:
238:
They provide a very large surface area onto which particles may fall and become stabilized.
114:
8:
1010:
995:
950:
749:
652:
1136:
1101:
1045:
965:
940:
709:
689:
616:
School of
Engineering, University of Guelph, Ontario, Canada. Accessed 14 October 2013.
531:
281:
200:
97:
1196:
1175:
960:
857:
704:
634:
438:
347:
284:
system, or the health of the fish found downstream of the clarifier may be hindered.
224:
472:
166:
tank. Borates float on top of the liquor while rock and clay settles to the bottom.
1091:
1050:
1035:
935:
915:
150:
146:
1126:
1000:
714:
588:
568:
509:
411:
82:
74:
16:
Settling tanks for continuous removal of solids being deposited by sedimentation
1151:
1131:
1121:
1116:
1106:
1086:
1025:
920:
852:
794:
779:
724:
231:
93:
78:
56:, while the particles that float to the surface of the liquid are called scum.
20:
1190:
809:
734:
560:
191:
458:
1156:
1040:
990:
862:
819:
138:"package treatment plant"), or for further polishing of the treated water.
70:
1146:
1141:
1065:
1020:
980:
877:
784:
581:
478:(Report). Wastewater Technology Fact Sheet. EPA. 2000. EPA 832-F-00-016.
28:
1111:
975:
675:
196:
174:
119:
Sedimentation tanks have been used to treat wastewater for millennia.
892:
744:
182:
129:
is removal of floating and settleable solids through sedimentation.
872:
764:
699:
199:
and promote effective settling throughout available tank volume.
799:
247:
134:
814:
804:
126:
53:
719:
644:
368:
365:
Clarifier basics: How do clarifiers work I Clarifier design
204:
296:
diffused wall perpendicular to the flow in the clarifier.
535:
255:
867:
69:
Before the water enters the clarifier, coagulation and
631:
Physicochemical
Processes for Water Quality Control.
592:
Stormwater
Management Manual for Western Washington
582:"Hydrologic Analysis and Flow Control Design/BMPs."
532:"Advantages of different lamella clarifier designs
254:clarifier footprint when designing. Tubes made of
459:Primer for Municipal Wastewater Treatment Systems
1188:
660:
453:
451:
667:
653:
465:
320:List of waste-water treatment technologies
88:
448:
405:"Tube Settler Systems For Clarification."
379:
377:
214:
181:
173:
35:
27:
399:
397:
395:
108:
105:before being sent for storage and use.
1189:
546:
544:
495:
374:
219:Tube settler installation in clarifier
648:
482:
433:Steel, E.W. & McGhee, Terence J.
234:. These structures work in two ways:
490:International Journal of Mine Water,
427:
392:
597:
541:
403:Brentwood Industries, Inc. (2013).
13:
1056:Ultraviolet germicidal irradiation
287:
14:
1218:
926:Agricultural wastewater treatment
344:Water and Waste-Water Technology.
336:
1170:
1169:
503:"Mining & Refining Borates."
389:McGraw-Hill (1972). pp. 449–453.
210:
986:Industrial wastewater treatment
956:Decentralized wastewater system
622:
606:
574:
553:
524:
515:
363:Smith, Aaron (April 5, 2020). "
64:
59:
674:
633:John Wiley & Sons (1972).
530:Smith, Aaron (March 8, 2020).
437:(5th ed.) McGraw-Hill (1979).
417:
357:
155:rotating biological contactors
1:
1006:Rotating biological contactor
346:John Wiley & Sons (1975)
330:
169:
559:SBS Enviro Concepts (2008).
261:
7:
492:4 (1983), Spain. pp. 27-34.
303:
85:processes like filtration.
10:
1223:
1207:Industrial water treatment
1071:Wastewater treatment plant
838:Adsorbable organic halides
435:Water Supply and Sewerage.
222:
112:
18:
1165:
1079:
906:
843:Biochemical oxygen demand
828:
682:
512:Accessed 13 October 2013.
414:Accessed 14 October 2013.
160:
571:Accessed 14 October 2013
508:10 November 2013 at the
1031:Sewage sludge treatment
971:Fecal sludge management
931:API oil–water separator
898:Wastewater surveillance
410:29 October 2013 at the
315:Dissolved air flotation
310:API oil-water separator
89:Potable water treatment
888:Total suspended solids
883:Total dissolved solids
848:Chemical oxygen demand
629:Weber, Walter J., Jr.
386:Wastewater Engineering
325:Total suspended solids
220:
187:
179:
42:
33:
755:Industrial wastewater
580:Foroozan, L. (2001).
218:
185:
177:
39:
31:
1097:Groundwater recharge
614:"Solids Separation."
587:3 March 2011 at the
501:Rio Tinto Minerals.
383:Metcalf & Eddy.
115:Wastewater treatment
109:Wastewater treatment
1011:Secondary treatment
996:Membrane bioreactor
951:Constructed wetland
750:Infiltration/Inflow
612:Zytner, Richard G.
521:Weber, pp. 128–131.
143:secondary treatment
1176:Category: Sewerage
1137:Septic drain field
1102:Infiltration basin
1046:Stabilization pond
966:Facultative lagoon
830:Quality indicators
710:Blackwater (waste)
690:Acid mine drainage
567:2013-10-29 at the
563:; "Tube Settlers"
282:water purification
221:
188:
180:
131:Primary clarifiers
103:several more steps
73:reagents, such as
43:
34:
1184:
1183:
961:Extended aeration
908:Treatment options
858:Oxygen saturation
705:Blackwater (coal)
683:Sources and types
225:Lamella clarifier
151:trickling filters
123:Primary treatment
1214:
1173:
1172:
1092:Evaporation pond
1080:Disposal options
1051:Trickling filter
1036:Sewage treatment
936:Carbon filtering
916:Activated sludge
669:
662:
655:
646:
645:
617:
610:
604:
601:
595:
578:
572:
557:
551:
548:
539:
528:
522:
519:
513:
499:
493:
486:
480:
479:
477:
469:
463:
462:
455:
446:
431:
425:
421:
415:
401:
390:
381:
372:
361:
355:
342:Hammer, Mark J.
340:
147:activated sludge
75:polyelectrolytes
1222:
1221:
1217:
1216:
1215:
1213:
1212:
1211:
1202:Water treatment
1187:
1186:
1185:
1180:
1161:
1127:Reclaimed water
1075:
1001:Reverse osmosis
902:
824:
790:Reverse osmosis
715:Boiler blowdown
678:
673:
643:
625:
620:
611:
607:
602:
598:
589:Wayback Machine
579:
575:
569:Wayback Machine
558:
554:
549:
542:
529:
525:
520:
516:
510:Wayback Machine
500:
496:
487:
483:
475:
471:
470:
466:
457:
456:
449:
432:
428:
422:
418:
412:Wayback Machine
402:
393:
382:
375:
362:
358:
341:
337:
333:
306:
290:
288:New development
264:
227:
213:
172:
163:
117:
111:
91:
83:water treatment
67:
62:
24:
17:
12:
11:
5:
1220:
1210:
1209:
1204:
1199:
1182:
1181:
1179:
1178:
1166:
1163:
1162:
1160:
1159:
1154:
1152:Surface runoff
1149:
1144:
1139:
1134:
1132:Sanitary sewer
1129:
1124:
1122:Marine outfall
1119:
1117:Marine dumping
1114:
1109:
1107:Injection well
1104:
1099:
1094:
1089:
1087:Combined sewer
1083:
1081:
1077:
1076:
1074:
1073:
1068:
1063:
1058:
1053:
1048:
1043:
1038:
1033:
1028:
1026:Settling basin
1023:
1018:
1013:
1008:
1003:
998:
993:
988:
983:
978:
973:
968:
963:
958:
953:
948:
943:
938:
933:
928:
923:
921:Aerated lagoon
918:
912:
910:
904:
903:
901:
900:
895:
890:
885:
880:
875:
870:
865:
860:
855:
853:Coliform index
850:
845:
840:
834:
832:
826:
825:
823:
822:
817:
812:
807:
802:
797:
795:Sanitary sewer
792:
787:
782:
780:Produced water
777:
772:
767:
762:
757:
752:
747:
742:
737:
732:
727:
725:Combined sewer
722:
717:
712:
707:
702:
697:
692:
686:
684:
680:
679:
672:
671:
664:
657:
649:
642:
641:
626:
624:
621:
619:
618:
605:
596:
573:
552:
550:Weber, p. 130.
540:
523:
514:
494:
481:
473:Package Plants
464:
447:
426:
416:
391:
373:
369:aqua-equip.com
356:
354:, pp. 223–225.
334:
332:
329:
328:
327:
322:
317:
312:
305:
302:
289:
286:
263:
260:
243:
242:
239:
223:Main article:
212:
209:
192:conveyor belts
171:
168:
162:
159:
113:Main article:
110:
107:
96:, water being
94:Drinking water
90:
87:
79:ferric sulfate
66:
63:
61:
58:
21:Settling basin
15:
9:
6:
4:
3:
2:
1219:
1208:
1205:
1203:
1200:
1198:
1195:
1194:
1192:
1177:
1168:
1167:
1164:
1158:
1155:
1153:
1150:
1148:
1145:
1143:
1140:
1138:
1135:
1133:
1130:
1128:
1125:
1123:
1120:
1118:
1115:
1113:
1110:
1108:
1105:
1103:
1100:
1098:
1095:
1093:
1090:
1088:
1085:
1084:
1082:
1078:
1072:
1069:
1067:
1064:
1062:
1059:
1057:
1054:
1052:
1049:
1047:
1044:
1042:
1039:
1037:
1034:
1032:
1029:
1027:
1024:
1022:
1019:
1017:
1016:Sedimentation
1014:
1012:
1009:
1007:
1004:
1002:
999:
997:
994:
992:
989:
987:
984:
982:
979:
977:
974:
972:
969:
967:
964:
962:
959:
957:
954:
952:
949:
947:
944:
942:
939:
937:
934:
932:
929:
927:
924:
922:
919:
917:
914:
913:
911:
909:
905:
899:
896:
894:
891:
889:
886:
884:
881:
879:
876:
874:
871:
869:
866:
864:
861:
859:
856:
854:
851:
849:
846:
844:
841:
839:
836:
835:
833:
831:
827:
821:
818:
816:
813:
811:
810:Sewage sludge
808:
806:
803:
801:
798:
796:
793:
791:
788:
786:
783:
781:
778:
776:
773:
771:
768:
766:
763:
761:
758:
756:
753:
751:
748:
746:
743:
741:
738:
736:
735:Cooling water
733:
731:
730:Cooling tower
728:
726:
723:
721:
718:
716:
713:
711:
708:
706:
703:
701:
698:
696:
695:Ballast water
693:
691:
688:
687:
685:
681:
677:
670:
665:
663:
658:
656:
651:
650:
647:
640:
639:0-471-92435-0
636:
632:
628:
627:
615:
609:
600:
593:
590:
586:
583:
577:
570:
566:
562:
561:sbsenviro.com
556:
547:
545:
537:
536:wordpress.com
533:
527:
518:
511:
507:
504:
498:
491:
485:
474:
468:
460:
454:
452:
445:, pp. 469–475
444:
443:0-07-060929-2
440:
436:
430:
420:
413:
409:
406:
400:
398:
396:
388:
387:
380:
378:
370:
366:
360:
353:
352:0-471-34726-4
349:
345:
339:
335:
326:
323:
321:
318:
316:
313:
311:
308:
307:
301:
297:
293:
285:
283:
278:
272:
268:
259:
257:
251:
249:
240:
237:
236:
235:
233:
226:
217:
211:Tube settlers
208:
206:
202:
198:
193:
184:
176:
167:
158:
156:
152:
148:
144:
139:
136:
132:
128:
124:
120:
116:
106:
104:
99:
95:
86:
84:
80:
76:
72:
57:
55:
51:
50:sedimentation
47:
38:
30:
26:
22:
1157:Vacuum sewer
1041:Sewer mining
991:Ion exchange
945:
941:Chlorination
863:Heavy metals
820:Urban runoff
760:Ion exchange
740:Fecal sludge
630:
623:Bibliography
608:
599:
591:
576:
555:
526:
517:
497:
489:
484:
467:
434:
429:
419:
385:
359:
343:
338:
298:
294:
291:
273:
269:
265:
252:
244:
228:
189:
164:
140:
130:
121:
118:
92:
71:flocculation
68:
65:Pretreatment
60:Applications
45:
44:
25:
1147:Storm drain
1142:Sewage farm
1066:Vermifilter
1021:Septic tank
981:Imhoff tank
878:Temperature
785:Return flow
775:Papermaking
250:materials.
232:Stokes' law
1191:Categories
1112:Irrigation
976:Filtration
676:Wastewater
331:References
197:turbulence
170:Technology
145:including
46:Clarifiers
946:Clarifier
893:Turbidity
745:Greywater
277:anaerobic
262:Operation
248:colloidal
1197:Sewerage
873:Salinity
765:Leachate
700:Bathroom
585:Archived
565:Archived
506:Archived
424:757–762.
408:Archived
304:See also
98:purified
800:Septage
280:of the
201:Baffles
135:reagent
1174:
815:Toilet
805:Sewage
770:Manure
637:
441:
350:
161:Mining
127:sewage
54:sludge
720:Brine
476:(PDF)
205:weirs
41:left.
1061:UASB
635:ISBN
439:ISBN
348:ISBN
153:and
77:and
534:".
367:".
256:PVC
125:of
1193::
868:pH
543:^
450:^
394:^
376:^
157:.
149:,
668:e
661:t
654:v
538:.
371:.
23:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
