The Study On The Abr-Constructed Wetland Process For The Wastewater Containing LAS

In recent years, the rapid development of China's detergent industry including anionic surfactants account for more than 70%. With LAS as the representatived by its main feature is stability and poor degradation of performance.When LAS along with the industrial wastewater or domestic wastewater discharged into the rivers and lakes, it will produce toxic effects on fish. And it will produce a kind of white foam which seriously affected the exchange between water bodies and air oxygen.All of these impacts polluted the human living environment. Not only that, LAS have a certain degree of harm on the human body skin, blood, liver and electrolyte metabolism, so how can the degradation of LAS and efficient energy consumption has become a hot issue of global concern.Current methods for the degradation of LAS are mainly physical, chemical, biological methods. As the physical and chemical method in dealing with high costs, the "secondary pollution" and other drawbacks, this paper examined a large number of related literatures and decided to adopt the biological treatment of detergent wastewater.Combined system of ABR-constructed wetland to achieve energy-saving emission reduction feasibility analysis.Compared aerobic precoating start method with low load start method to start the ABR. 1# reactor used the aerobic precoating start method and the 2# reactor used the low load start method, 1# reactor had some advantages of paramenter indicators than 2# reactor.When changed the operating paramenter of the situation at the same time, 1# reactor could recovery the stability operation as soon as possible and COD removal rate was less volatile.It reflected a better resistance to shock loading capacity, while the 2# reactor time-consuming and affect the test progress.After the success of the start the granular sludge was black and plump,the diameter was about 2.0 mm.It is observation of micro-organisms by photograph that the broadly is similar in 1# and 2# reactor, but the 1# reactor bacteria is more than 2# reactor.So this explained the superiority in various indicators of 1# reactor.By changing the parameters such as hydraulic loading, residence time, surface loading rate to study the degradation of performance of constructed wetlands. The results showed that, when the pH value was 5.8-7.5, COD has a higher removal rate, the ORP value is inversely proportional to the relationship between COD removal rate.At the same time the lower artificial loading rate (ALR), the better effect of the COD treatment. But when the ALR is in the 40-50g/(m~2·d), the COD removal rate has stabilized. So, the plant roots can work if the surface loading rate in the appropriate circumstances. However, too high surface loading rate will impact of plant roots on COD degradation effect. Hydraulic load is one of the important parameters in wetland which serious impact on the COD removal rate. When the hydraulic load is less than 0.15m~3/(m~2·d),the COD removal rate remained at 83%. There is a positive linear correlation between the HRT and TP removal rate, and the best HRT is 24h. Plants are the main subjects of purification ability, TP removal rate increases from 60% to more than 90% after planting the reed. The reed could maintain the TP removal rate rely on its own conversion, rather than solely on soil cumulative.It is the way of gradually increasing the feed concentration of LAS to domesticate the species adapt to the toxicity to complete the degradation. The COD,LAS,TP degradation performance are the main parameter in the process of domestication. Though the microscope to observe the micro-organisms then scans the sludge by electron microscopy, at last using X-ray diffraction analysis of the sludge components. The results showed that the concentration of LAS below 100mg/L, the COD removal rate can reach 70%, TP removal rate remained at 80%. When the influent COD concentration 500mg/L, the LAS removal rate drops to 80%. That is to say that the degradation capacity of system at this time has reached a certain limit. It is found of sulfate-reducing bacteria in the micro-organisms which could produce the H2S to poison the methanogens. While the Fe and S are the main elements in all ABR compartments by sludge component, suggesting the rules crystal ball material which found by scanning electron microscopy is pyrite.ABR-constructed wetland combined process can efficient removal low concentrations of LAS, and the effluent COD concentrations meet the National Integrated Wastewater Discharge Standard (GB18918-2002). The microbial community which has been trained by ABR compartment reaches the wastewater treatment requirements. The methanogenic bacteria of higher activity can ensure the operation stablely and efficiently. The test verifies the feasibility of combined process to degrade the refractory organics. This combined process not only using ABR to treat refractory organic, but also consider the efficient characteristics in constructed wetland. Both of them are low energy consumption reactors which meet the modern water treatment requirements. It is a combination of technology that should be promoted.