生活污水处理装置2: In the early 1970s. the only facilities for sewage management onboard ships were biological systems and holding tanks. Yet, by the end of the decade, anti-pollution rules had been forced and enforced, and two new sewage treatment concepts had been developed: "physical-chemical" and electro catalytic oxidation. And which system to choose became, and continues to be a difficult decision to make. Biological technology requires a steady and relatively constant intake of solidified sewage so that aerobic bacteria can feed on it in order to keep the discharge within regulatory limits. This process of arability strips oxygen from the water, producing more water, carbon dioxide and new bacteria. Experts in this field say that the problem with this type is that it needs to be de-sludged on a regular basis, and if installed on offshore platforms, the only altemative to the illegal pumping of sludge into the sea is to call in the honey barge. Moreover, biological systems need to operate day in day out, so if the vessel in which this type of system is installed doesn't operate continuously, then this type of system may prove a wrong choice. An extended aeration, however, is said to minimize the build up of biological sludge in the treatment tank by retaining it for such a period as to allow the bacteria to digest the incoming organic waste. The sewage, in this process, is fed directly to an aeration tank, where air from fine bubble diffusers raises the dissolved oxygen level and coalesces with the waste products. The bacteria thrives in this environment and devours the organic substance, converting it into water, carbon dioxide and new bacteria cells. The mixed liquid is then displaced into a settling tank by further incoming sewage, where the biological sludge consolidates under inactive conditions. It is then withdrawn for recycling to aeration tank, and it is this recycled sludge which contains the bacteria that digests the incoming sewage.