Paper making wastewater treatment plant

一． 设备简介

1、 Equipment introduction

造纸污水处理设备指的是对造纸行业产生污水的处理方法，造纸废水主要来自造纸工业生产中的制浆和抄纸两个生产过程。制浆、抄纸都排出大量废水；制浆产生的废水，污染为严重。洗浆时排出废水呈黑褐色，称为黑水，黑水中污染物浓度很高，BOD高达5—40g/L，含有大量纤维、无机盐和色素。漂白工序排出的废水也含有大量的酸碱物质。抄纸机排出的废水，称为白水，其中含有大量纤维和在生产过程中添加的填料和胶料.

Papermaking wastewater treatment equipment refers to the treatment method of wastewater produced in papermaking industry. Papermaking wastewater mainly comes from the two production processes of pulping and papermaking in papermaking industry. A large amount of wastewater is discharged from pulping and papermaking; The wastewater from pulping is seriously polluted. The effluent from pulp washing is dark brown, which is called black water. The concentration of pollutants in black water is very high, and the BOD is as high as 5-40g / L. it contains a lot of fiber, inorganic salt and pigment. The effluent from bleaching process also contains a lot of acid and alkali. The waste water discharged from paper machine is called white water, which contains a lot of fiber and fillers and binders added in the production process

二． 造纸污水处理方式

2、 Treatment methods of papermaking wastewater

造纸废水预处理：

Pretreatment of papermaking wastewater

预处理工艺主要由格栅、筛网、纤维回收系统、调节水量及水质等工艺组成。可根据不同的造纸工业废水水质采取不同的预处理手段，去除一部分污染物，改善废水水质，使整个废水处理系统的处理效果达到。

The pretreatment process is mainly composed of grid, screen, fiber recovery system, regulating water quantity and water quality. According to the different wastewater quality of paper industry, different pretreatment methods can be adopted to remove some pollutants and improve the wastewater quality, so that the treatment effect of the whole wastewater treatment system can be achieved.

造纸废水主要处理方法:

The main treatment methods of papermaking wastewater are as follows

废纸造纸废水的SS、COD浓度较高，COD则由非溶解性COD和溶解性COD两部分组成，通常非溶解性COD占COD组成总量的大部分，当废水中SS被去除时，绝大部分非溶解性COD同时被去除。废纸造纸污水中的BOD5值较低，BOD5与COD的比值一般为0.15～0.25，可生化性较差。混凝处理方法只能去除部分BOD5，绝大部分BOD5的去除主要应采用生化方法解决。

The concentration of SS and COD in waste paper-making wastewater is high, and COD is composed of insoluble COD and soluble COD. Generally, the insoluble cod accounts for most of the total COD. When SS is removed, most of the insoluble cod is removed at the same time. The ratio of BOD5 to cod is generally 0.15-0.25, and the biodegradability is poor. Coagulation treatment can only remove part of BOD5, most of which should be solved by biochemical method.

（1）采用气浮或沉淀方法。通过投加混凝剂，可去除绝大部分SS，同时去除大部分非溶解性COD及部分溶解性COD和BOD5。其典型的处理工艺流程如下：

(1) Air floatation or precipitation method is adopted. By adding coagulant, most SS, most insoluble cod, part soluble COD and BOD5 can be removed. The typical treatment process is as follows:

污水→筛网→集水池→气浮或沉淀→排放

Sewage → screen → sump → flotation or sedimentation → discharge

气浮和沉淀均为物化处理方法，处理效果与选用的设备、工艺参数、混凝剂等有关，其COD去除率一般高于制浆中段水的COD去除率，通常能达到70%～85%。对吨纸污水排放量＞150m3、浓度较低的中小型废纸造纸企业，通过气浮或沉淀处理，出水水质指标可达到或接近排放标准。

Both flotation and sedimentation are physicochemical treatment methods, and the treatment effect is related to the selected equipment, process parameters, coagulant, etc. the COD removal rate of flotation and sedimentation is generally higher than that of middle stage water, which can reach 70% - 85%. The effluent quality of small and medium-sized waste paper-making enterprises with discharge capacity of more than 150m3 per ton of paper and low concentration can reach or approach the discharge standard through air flotation or sedimentation treatment.

气浮法和沉淀法工艺的对比分析：

Comparison and analysis of air flotation and precipitation processes

气浮法

Air flotation

沉淀法

Precipitation method

优点

advantage

缺点

shortcoming

优点

advantage

缺点

shortcoming

1.处理效果稳定、可靠

1. The treatment effect is stable and reliable

1.设备费用较高

1. The cost of equipment is high

1.处理方法成熟、稳定

1. The treatment method is mature and stable

1.占地较大

1. It covers a large area

2.占地面积小

2. Small area

2.运行电耗略高

2. The operation power consumption is slightly higher

2.电耗较低

2. Low power consumption

2.污泥需经浓缩后脱水

2. Sludge should be dewatered after thickening

3.污泥量少，易于脱水

3. Less sludge, easy to dehydrate

3.操作较简单

3. The operation is simple

4.土建费用低

4. Low cost of civil engineering

近几年来，在气浮法中浅层气浮异军突起。浅层气浮具有水力停留时间短(＜5min)、池体水深浅(500mm)、处理效果好等优点。它应用浅池理论和“零速度”原理，彻底改变了传统推流式气浮池的进出水及污泥分离方式，污水在气浮池中处于相对静止状态，微气泡吸附污泥后可垂直向上浮起，固形物上浮速度为4～10cm/min，可在短时间内获得优质出水，其SS、COD去除率可略高于沉淀法，对中型规模的污水处理有其一定的性。

In recent years, shallow air floatation has become a new force in air floatation. Shallow air flotation has the advantages of short HRT (< 5min), shallow water depth (500mm) and good treatment effect. Using the shallow pool theory and "zero velocity" principle, it completely changes the traditional plug flow air flotation tank's inlet and outlet water and sludge separation mode. The sewage is in a relatively static state in the air flotation tank, and the micro bubbles can float up vertically after adsorbing the sludge. The solid floating speed is 4-10cm / min, and the high-quality effluent can be obtained in a short time. The removal rates of SS and COD are slightly higher than those of the sedimentation method, It has certain applicability for medium-sized sewage treatment.

（2）物化与生化处理相结合。对于造纸废水排放量较低、废水含COD较高的大中型废纸造纸企业，期望通过单级气浮或沉淀的物化方法达到一级排放标准有较大的难度，因为可溶性COD、BOD5主要需通过生化方法才能有效去除。

(2) The combination of physicochemical and biochemical treatment. For large and medium-sized waste paper enterprises with low discharge and high COD content, it is difficult to reach the first-class discharge standard by single-stage air flotation or precipitation, because soluble COD and BOD5 can be effectively removed by biochemical methods.

当执行COD≤100mg/L的排放标准时，原水COD浓度不宜超过600～800mg/L；当执行COD≤150mg/L的排放标准时，原COD浓度不宜超过800～1000mg/L。因此，在原水SS和COD浓度较高时，应在一级物化处理之后接生化方法处理，使处理出水终达到排放标准的要求。物化加生化处理方法的典型工艺流程如下：

When the discharge standard of COD ≤ 100mg / L is implemented, the COD concentration of raw water should not exceed 600 ~ 800mg / L; When the discharge standard of COD ≤ 150mg / L is implemented, the original COD concentration should not exceed 800 ~ 1000mg / L. Therefore, when the concentration of SS and COD in raw water is high, the first stage physicochemical treatment should be followed by biochemical treatment to make the treated effluent meet the discharge standard. The typical process flow of physicochemical plus biochemical treatment method is as follows:

污水→筛网→调节→沉淀或气浮→A/O或接触氧化→二沉池→排放

Sewage → screen → adjustment → sedimentation or flotation → A / O or contact oxidation → secondary sedimentation tank → discharge

A/O(缺氧—好氧)处理工艺，通过缺氧段的微生物选择作用，只是对物进行吸附，吸附在微生物体的物则在好氧段被氧化分解。因此A段停留时间短，约在40～60min。

In a / O (anoxic aerobic) treatment process, only the adsorbate is adsorbed through the selective action of microorganism in anoxic section, while the adsorbate is oxidized and decomposed in aerobic section. Therefore, the residence time of stage a is short, about 40-60min.

由于A段微生物的筛选和对物的吸附作用，能有效地抑制O段丝状菌生长，控制污泥膨胀。当污水经过混凝沉淀或气浮处理后，A/O工艺的负荷为0.5kgCOD/(kgMLSS•d)时，其COD去除率可达90%左右。

Due to the screening of microorganisms in stage a and the adsorption of pollutants, it can effectively inhibit the growth of filamentous bacteria in stage o and control sludge bulking. When the load of a / O process is 0.5 kgcod / (kgmlss · d), the removal rate of COD can reach about 90%.

生物接触氧化法具有挂膜快、无污泥回流系统、无污泥膨胀危害、日常运行管理容易等优点，在中小型污水处理中应用较多。

Biological contact oxidation process is widely used in small and medium-sized wastewater treatment due to its advantages of fast film formation, no sludge return system, no harm of sludge bulking and easy daily operation and management.

三．常见造纸污水处理工艺流程图

3、 Process flow chart of common papermaking wastewater treatment

四．造纸污水处理设备特点

4、 Characteristics of papermaking wastewater treatment equipment

1、造纸污水处理设备经碳钢防腐处理或不锈钢构件，现场拼接组合而成。重量轻巧，易于运输，方便安装；

1. The paper-making wastewater treatment equipment is made of carbon steel anti-corrosion treatment or stainless steel components and assembled on site. Light weight, easy to transport, easy to install;

2、采用玻璃钢、碳钢、不锈钢防腐结构，具有耐腐蚀、抗老化等优良特性，使用寿命长达60 年以上；

2, adopt FRP, carbon steel and stainless steel anticorrosive structure, with corrosion resistance, anti-aging and other excellent characteristics, the service life is longer than 60 years.

3、放置于地表以下，造纸污水处理设备上面的地表可作为绿化或其他用地，不需要建房及采暖、保温。限度的实现了系统的集成，减少占地面积；

3. It can be used for greening or other purposes without building houses, heating and heat preservation. The integration of the system is limited and the floor space is reduced;

4、，无噪声，无异味，减少二次污染；

4. No noise, no odor, reduce secondary pollution;

5、不受造纸污水量的限制，机动灵活，可单个使用，也可多个联合使用。

5. It is not limited by the amount of papermaking wastewater, flexible, and can be used individually or in combination.

6、整个造纸污水设备处理系统配有PLC全自动电气控制系统和设备故障报警系统，运行安全可靠，平时一般不需要专人管理，只需适时地对造纸污水处理设备进行维护和保养，管理费用小。

6. The whole paper-making wastewater treatment system is equipped with PLC automatic electrical control system and equipment fault alarm system, which is safe and reliable in operation. Usually, it does not need to be managed by a special person, but only needs to timely maintain the paper-making wastewater treatment equipment, so the management cost is small.