The invention relates to a method for removing heavy metal from sludge and a device, belongs to the technical field of environmental protection and particularly relates to the removing method for the heavy metal in the sludge The method is characterized in that a repeatedly freezing and thawing pretreatment process is utilized to enhance an electric treating process of cathode liquid backflow, thereby obviously improving the efficiency in removing the heavy metal A constructed treating device is utilized to perform repeated freezing and thawing pretreatment on the initial sludge; and then the sludge is placed into a sludge chamber; direct current voltage is applied to cathode and anode ends; the cathode liquid backflow process is externally adopted so as to neutralize the cathode and anode liquid; and the electrifying time is 144h The method has the positive effects that the mobility of the heavy metal in the initial sludge is enhanced from the source; the electric removing efficiency of the heavy metal is obviously increased; no external material is added into the system; and the method is an environment-friendly and feasible enhancing method

Method for removing heavy metal from sludge and device thereof

The invention relates to a composite upflow-type sludge anaeroic digestor, which is composed of a reaction area, a down flow area, a settling area and a gas-liquid separation area. The upflow-type sludge anaeroic digestor comprises a main body of the digester, a sludge inlet pipe, a sludge outlet pipe and a biogas pipe arranged at the top of the main body of the digester. The reaction area is provided at the lower part of the main body of the digester, a filling material is provided at the upper part of the reaction area, a biogas aerator is provided at the bottom of the reaction area and a biogas pump is connected at the bottom of the reaction area, a gas-liquid separation area is provided at the upper part of the main body of the digester; the reaction area is communicated with the down flow area through an upflow pipe, the lower part of a down flow pipe is communicated with the bottom of the reaction area, the digester also comprises a pulse electrophoretic separation area connected with the sludge outlet pipe, an insoluble electrophoresis anode is provided in an electrophoresis area, bacteria can be added in the sludge outlet pipe and leached, the filling material is an elastic stereo honeycomb-type biological filling material. The anaeroic digestor is capable of raising the reaction efficiency of the reaction area, separating the metal from the sludge and minimizing the environmental pollution.

Composite upflow-type sludge anaeroic digestor

The utility model integrates bio-leaching technology and electric technology together. The sludge is leached first, and then processed electrokinetically. The model is used to purify sludge and recycle heavy metals. A component equipped in the model comprises a graphite electrode and an air drain to generate electrode zone, an aeration pipe to generate bio-leaching zone, baffle plates to separate the electrode zone and bio-leaching zone, and a group of sample connections. The traditional technology separates the leaching treatment and electrokinetical process, thus causes secondary pollution to the environment and lowers heavy metals' removal efficiency because of its original organic-combining form. The utility model has solves the problem for the integrating processes. Experiments shows that the removal efficiency of Cu and Zn has reached to 80% and 96% in sludge respectively, meanwhile the removal efficiency of Cu and Zn has reached to 98% and 96% in leaching liquid respectively.

Tian Guangming Yu

Papers

Biological leaching and electric technology integrated reactor