Coking wastewater treatment

1, General Provisions

A pulp and paper industry is one of the serious pollution of the water environment industry.Strict control of the paper industry, water pollution, water pollution prevention guide the paper industry, the progressive realization of cleaner production and sustainable development under the Water Pollution Prevention Law of the People’s Republic of China “, specially formulated technology policy.

This policy applies to the reed, bagasse, straw and other non-wood fiber as raw material, pulp and paper companies.

(3) the relevant government departments at all levels need to strengthen macro-management of the paper industry, rely on policies and measures to adjust and optimize the structure of the enterprise, raw materials and products, to encourage the adoption of cleaner production technologies.Phasing out small-scale, backward technology, polluting enterprises to achieve a rational distribution and scale of operation to achieve coordinated development.

Vigorously develop the production of paper timber, and gradually improve the proportion of wood pulp; to expand the use of the proportion of secondary fiber; scientific and rational use of straw resources of raw materials.

Second, the control objectives

5 to the end of 2000, all paper-making enterprises to achieve the discharge standards, the paper industry development trend of environmental pollution has been the basic control, and gradually got onto the track of healthy development.

6 according to the principle of unity of development and environmental protection, combined with the characteristics of non-wood fiber pulp and waste water treatment and pollution control should be of non-wood fiber pulp and paper companies of a certain size, new straw pulp and paper companies of 3.4 million tons of pulp / yearother non-wood pulp plant of 50,000 tons of pulp / years; 17,000 tons / year alkali chemical straw plant is built the smallest of the alkali recovery.

Completion of the resolutely banned 5,000 tonnes / year of chemical pulp mills (workshop); 17,000 tons / year of small chemical pulp companies before the end of 2000 to take governance, customs, stop and turnenvironmental governance tasks.

Third, technical measures

Paper-making enterprises in the process of technological transformation and pollution control should be small energy consumption, pollution load emissions cleaner production processes; technical starting point, such as the silicon content is low, higher fiber content of straw pulp raw material.

Paper-making enterprises in the process of technological transformation and pollution control, should be small energy consumption, pollution load discharge of cleaner production processes.The silicon content is low, the high fiber content of straw, raw materials and packaging technology and less chlorine, chlorine-free bleaching process.

Strengthening the raw material to a high degree of purification, using two dry preparation or dry, wet combination preparation technology, to remove sediment and impurities in the raw materials.

11. Soda chemical pulp black liquor recommend the use of conventional combustion method alkali recovery technology as the core of the wastewater treatment complete sets of technology.

(1) efficient extraction of black liquor.Black liquor extraction rate of more than 85%.

(2) new full plate falling film evaporator or tube ─ ─ board with black liquor evaporation.

(3) efficient black liquor combustion technology.

(4) consecutive causticizing technology

(5) to maintain the free base technology: the protection of the alkali or alkali cooking, in order to maintain the free base into the Evaporation of black liquor concentration to achieve the purpose of the viscosity reduction.

12 semi-chemical pulp, lime, chemical mechanical pulp wastewater treatment recommended by anaerobic - aerobic treatment technology to meet emissions standards

Sulfite pulping is not appropriate to expand the development of existing enterprises, pulp and waste water should be the comprehensive utilization of technology to meet emissions standards.

13 washing, selection, drift the middle of the wastewater to secondary biological treatment technology.

14 paper machine white water separation of fiber a closed recycling technology.

15 production and water recycling technologies:

(1) drift the wash jiangshui for the washing of unbleached pulp.

(2) The remainder of the paper machine water, condensate for pulp washing or bleaching.

16 encourage wastewater treatment technology research:

(1) cooking synchronization in addition to silicon-based technology to improve the black liquor physical and chemical properties.

(2) the development of efficient extraction equipment of the black liquor, black liquor extraction rate of more than 90%.

(3) Delignification technology, to minimize pollutant emissions

17 This is not the promotion of technology:

(1) separate coagulant for the treatment of pulp black liquor.

(2) run the test without the production of pollution control technology (other types of alkali recovery technology and the comprehensive utilization technology)