高密度沉淀池適用于飲用水生產(chǎn)、污水處理、工業(yè)廢水處理和污泥處理及高鹽水軟化(脫硬、除硅)等領(lǐng)域。
高密度沉淀池主要的技術(shù)是載體絮凝技術(shù),這是一種快速沉淀技術(shù),其特點(diǎn)是在混凝階段投加高密度的不溶介質(zhì)顆粒(如細(xì)砂),或沉淀池底部濃縮污泥回流,利用介質(zhì)的重力沉降及載體的吸附作用加快絮體的“生長”及沉淀。
高效沉淀池設(shè)計非常緊湊, 它把混凝池、絮凝池、沉淀池和污泥濃縮集合于一體。
混合反應(yīng)區(qū):混合過程中應(yīng)使混凝劑水解產(chǎn)物迅速地擴(kuò)散到水體中的每一個細(xì)部,使所有膠體顆粒幾乎在同一瞬間脫穩(wěn)并凝聚,這樣才能得到好的絮凝效果。該過程是靠攪拌器的提升混合作用完成泥渣、藥劑、原水的快速凝聚反應(yīng),然后經(jīng)葉輪提升至推流反應(yīng)區(qū)進(jìn)行慢速絮凝反應(yīng),以結(jié)成較大的絮凝體。
絮凝反應(yīng)區(qū):絮凝反應(yīng)區(qū)也就是慢混區(qū),由可調(diào)速攪拌機(jī)控制加藥后混合水的攪拌速度,以促進(jìn)礬花的增大,使礬花密實(shí)均勻。 絮凝反應(yīng)區(qū)中污水在助凝劑和回流污泥的作用下,形成高濃度的懸浮泥渣層來增加顆粒碰撞機(jī)會,有效吸附膠體、懸浮物、乳化油、COD及金屬離子等污染物。污泥回流,不僅可以節(jié)省藥劑投加量,而且可使反應(yīng)區(qū)內(nèi)的懸浮固體濃度維持在最佳水平,從而達(dá)到優(yōu)化絮凝反應(yīng)的目的。
斜管沉淀區(qū):在沉降區(qū)域設(shè)置許多密集的斜管,使水中懸浮雜質(zhì)在斜管中進(jìn)行沉淀,水沿斜管上升流動,分離出的泥渣在重力作用下沿著斜管向下滑至池底,再集中排出。這種池體可以提高沉淀效率50~60%,在同一面積上可提高處理能力3~5倍。斜管的的安裝傾度一般和水平方向呈60°,這個傾度可以保證沉淀在斜管上的污泥可以順利地滑向底部而不至于淤積。斜管的剖面是六邊型可以得到較大的有效沉淀面積。
High-density sedimentation tanks are used in the fields of drinking water production, sewage treatment, industrial wastewater treatment and sludge treatment as well as softening (dehardening and silica removal) of highly saline water.
The main technology of high density sedimentation tank is carrier flocculation technology, which is a kind of rapid sedimentation technology, characterized by adding high density insoluble media particles (e.g. fine sand) in the coagulation stage, or concentrated sludge reflux at the bottom of the sedimentation tank, the use of gravity settling of the media and the adsorption of the carrier to accelerate the flocs of the “growth” and precipitation.
High-efficiency sedimentation tank is a very compact design, which combines coagulation tank, flocculation tank, sedimentation tank and sludge thickening into one.
Mixing reaction area: the mixing process should make the coagulant hydrolysis products spread to every fine part of the water body rapidly, so that all the colloidal particles are destabilized and coagulated almost at the same instant, so as to get a good flocculation effect. The process relies on the lifting and mixing effect of the stirrer to complete the rapid coagulation reaction of sludge, chemicals and raw water, and then lifted by the impeller to the push-flow reaction area for slow flocculation reaction to form larger flocs.
Flocculation reaction area: flocculation reaction area is also known as the slow mixing area, by the adjustable speed mixer to control the mixing speed of the mixed water after dosing, in order to promote the increase of alum flowers, so that the alum flowers are dense and uniform. In the flocculation reaction area, the sewage in the coagulant aid and the role of returning sludge, the formation of a high concentration of suspended sludge layer to increase the opportunity of particle collision, effective adsorption of colloids, suspended solids, emulsified oil, COD and metal ions and other pollutants. Sludge reflux can not only save the dosage of chemicals, but also keep the concentration of suspended solids in the reaction area at the optimal level, so as to achieve the purpose of optimizing the flocculation reaction.
Inclined pipe sedimentation area: many dense inclined pipes are set up in the sedimentation area, so that the suspended impurities in the water are precipitated in the inclined pipes, the water rises and flows along the inclined pipes, and the separated mud and sludge slides downward to the bottom of the tank under the effect of gravity, and then is discharged centrally. This pool body can improve the sedimentation efficiency 50~60%, in the same area can improve the processing capacity 3~5 times. The installation inclination of the inclined pipe is generally 60° to the horizontal direction, and this inclination can ensure that the sludge deposited on the inclined pipe can slide to the bottom smoothly without being silted up. The profile of the inclined pipe is hexagonal to get a larger effective sedimentation area.