Urban waste water treatment per province and river basin district

Changed on: 12/05/2022 02:00

Urban waste water treatment per province and river basin district
Periods	Regions	Urban waste water treatment plants Numbers by type Total number (number)	Urban waste water treatment plants Numbers by type Trickling filters (number)	Urban waste water treatment plants Numbers by type Aeration tanks (number)	Urban waste water treatment plants Numbers by type Oxidation tanks (number)	Urban waste water treatment plants Numbers by type Oxidation ditches (number)	Urban waste water treatment plants Numbers by type Carrousels (number)	Urban waste water treatment plants Numbers by type Discontinuous systems (number)	Urban waste water treatment plants Numbers by type Parallel installations (number)	Urban waste water treatment plants Numbers by type Multi-stage installations (number)	Urban waste water treatment plants Numbers by type Compact installations (number)	Urban waste water treatment plants Numbers by type Nereda granular sludge reactor (number)	Urban waste water treatment plants Numbers by type Hybrid Nereda - active sludge system (number)	Urban waste water treatment plants Capacity pollution equivalents by type Total capacity pollution equivalents (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Trickling filters (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Aeration tanks (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Oxidation tanks (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Oxidation ditches (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Carrousels (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Discontinuous systems (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Parallel installations (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Multi-stage installations (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Compact installations (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Nereda granular sludge reactor (1 000 pollution equivalent)	Urban waste water treatment plants Capacity pollution equivalents by type Hybrid Nereda - active sludge system (1 000 pollution equivalent)	Influent waste water Quantities Volume waste water (1 000 m3)	Influent waste water Quantities Pollution Equivalents (1 000 pollution equivalent)	Influent waste water Quantities Chemical oxygen demand (COD) (1 000 kg)	Influent waste water Quantities Biochemical oxygen demand (BOD) (1 000 kg)	Influent waste water Quantities Nitrogen compounds as N (total) (1 000 kg)	Influent waste water Quantities Phosphorus compounds as P (total) (1 000 kg)	Influent waste water Quantities Copper (kg)	Influent waste water Quantities Chromium (kg)	Influent waste water Quantities Zinc (kg)	Influent waste water Quantities Lead (kg)	Influent waste water Quantities Cadmium (kg)	Influent waste water Quantities Nickel (kg)	Influent waste water Quantities Mercury (kg)	Influent waste water Quantities Arsenic (kg)	Discharge of waste water (effluent) Quantities Volume waste water (1 000 m3)	Discharge of waste water (effluent) Quantities Pollution Equivalents (1 000 pollution equivalent)	Discharge of waste water (effluent) Quantities Chemical oxygen demand (COD) (1 000 kg)	Discharge of waste water (effluent) Quantities Biochemical oxygen demand (BOD) (1 000 kg)	Discharge of waste water (effluent) Quantities Nitrogen compounds as N (total) (1 000 kg)	Discharge of waste water (effluent) Quantities Phosphorus compounds as P (total) (1 000 kg)	Discharge of waste water (effluent) Quantities Copper (kg)	Discharge of waste water (effluent) Quantities Chromium (kg)	Discharge of waste water (effluent) Quantities Zinc (kg)	Discharge of waste water (effluent) Quantities Lead (kg)	Discharge of waste water (effluent) Quantities Cadmium (kg)	Discharge of waste water (effluent) Quantities Nickel (kg)	Discharge of waste water (effluent) Quantities Mercury (kg)	Discharge of waste water (effluent) Quantities Arsenic (kg)	Sewage sludge Wet sewage sludge by destination Total wet sludge (1 000 kg)	Sewage sludge Wet sewage sludge by destination Agriculture (1 000 kg)	Sewage sludge Wet sewage sludge by destination Wet oxidation (1 000 kg)	Sewage sludge Wet sewage sludge by destination Composting (1 000 kg)	Sewage sludge Wet sewage sludge by destination Landfill (1 000 kg)	Sewage sludge Wet sewage sludge by destination Incineration (1 000 kg)	Sewage sludge Wet sewage sludge by destination Cement industry (1 000 kg)	Sewage sludge Wet sewage sludge by destination Co-incineration at power plants (1 000 kg)	Sewage sludge Wet sewage sludge by destination Other destinations (1 000 kg)	Sewage sludge Dry solids by destination Total dry solids (1 000 kg)	Sewage sludge Dry solids by destination Agriculture (1 000 kg)	Sewage sludge Dry solids by destination Wet oxidation (1 000 kg)	Sewage sludge Dry solids by destination Composting (1 000 kg)	Sewage sludge Dry solids by destination Landfill (1 000 kg)	Sewage sludge Dry solids by destination Incineration (1 000 kg)	Sewage sludge Dry solids by destination Cement industry (1 000 kg)	Sewage sludge Dry solids by destination Co-incineration at power plants (1 000 kg)	Sewage sludge Dry solids by destination Other destinations (1 000 kg)	Sewage sludge Nutrients and heavy metals Ashes (1 000 kg)	Sewage sludge Nutrients and heavy metals Nitrogen compounds as N (1 000 kg)	Sewage sludge Nutrients and heavy metals Phosphorus compounds as P (1 000 kg)	Sewage sludge Nutrients and heavy metals Copper (kg)	Sewage sludge Nutrients and heavy metals Chromium (kg)	Sewage sludge Nutrients and heavy metals Zinc (kg)	Sewage sludge Nutrients and heavy metals Lead (kg)	Sewage sludge Nutrients and heavy metals Cadmium (kg)	Sewage sludge Nutrients and heavy metals Nickel (kg)	Sewage sludge Nutrients and heavy metals Mercury (kg)	Sewage sludge Nutrients and heavy metals Arsenic (kg)
2018	Nederland	323	2	58	67	47	119	2	12	15	1	.	.	29,942	108	10,260	5,074	1,131	9,821	49	1,076	2,332	91	.	.	1,773,436	26,406	1,016,606	426,326	94,116	13,307	138,509	17,029	438,978	36,314	405	20,818	210	6,659	1,773,436	1,909	69,057	7,415	14,006	1,676	8,432	2,463	66,133	1,883	132	7,946	54	3,011	1,250,205	0	0	0	132,909	880,373	6,533	227,003	3,388	303,618	0	0	0	31,908	197,799	6,009	67,174	728	89,104	17,575	9,768	114,825	11,311	299,297	25,033	301	7,488	159	3,194
2019	Nederland	317	2	59	59	46	117	1	11	13	1	6	2	29,784	108	10,165	4,881	1,152	9,747	40	1,054	1,512	91	672	363	1,904,102	26,818	1,039,372	427,966	94,209	13,555	.	.	.	.	.	.	.	.	1,904,102	2,019	73,296	7,765	14,391	1,767	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
2020	Nederland	315	2	58	56	44	118	1	10	14	1	9	2	29,713	108	10,152	4,615	1,133	9,884	40	956	1,598	91	774	363	1,938,476	27,031	1,056,480	428,585	93,686	13,297	133,000	14,130	433,742	28,269	435	17,391	194	6,449	1,938,476	1,986	72,302	7,512	14,320	1,644	9,156	1,862	68,981	1,244	82	7,143	26	2,603	1,263,335	0	0	0	5,613	1,063,157	14,514	126,468	53,582	308,360	0	0	0	1,480	250,382	13,614	30,765	12,119	91,789	19,111	11,170	120,715	12,003	325,845	25,755	311	7,939	143	3,247
2018	The river Eems	16	0	7	3	0	4	0	0	2	0	.	.	1,134	0	366	102	0	270	0	0	396	0	.	.	68,615	864	34,297	15,103	2,853	389	6,864	641	12,603	1,387	14	383	12	207	68,615	85	3,344	425	496	50	525	95	1,210	49	4	108	3	104	45,253	0	0	0	0	0	0	45,253	0	11,172	0	0	0	0	0	0	11,172	0	4,242	552	274	5,034	384	12,350	987	10	333	6	109
2019	The river Eems	16	0	7	3	0	4	0	0	1	0	0	1	1,134	0	366	102	0	270	0	0	56	0	0	340	75,107	877	34,519	14,855	2,954	406	.	.	.	.	.	.	.	.	75,107	94	3,701	454	535	65	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
2020	The river Eems	16	0	7	3	0	4	0	0	1	0	0	1	1,134	0	366	102	0	270	0	0	56	0	0	340	78,835	959	38,332	14,910	3,129	440	6,775	482	15,832	914	11	429	12	188	78,835	121	4,683	475	713	62	461	58	1,557	35	2	164	3	64	48,346	0	0	0	0	48,346	0	0	0	11,574	0	0	0	0	11,574	0	0	0	4,583	927	416	5,347	405	12,500	1,030	9	338	5	208
2018	The river Rijn (North Rijn)	38	1	0	5	4	24	1	1	1	1	.	.	1,565	54	0	222	45	1,054	40	17	41	91	.	.	89,276	1,177	45,090	18,435	4,234	638	5,450	732	18,247	1,318	17	667	10	336	89,276	99	3,927	332	502	89	304	93	2,890	62	7	231	3	164	66,485	0	0	0	0	66,485	0	0	0	14,288	0	0	0	0	14,288	0	0	0	3,808	975	539	3,572	386	5,536	664	5	329	4	73
2019	The river Rijn (North Rijn)	38	1	0	5	4	24	1	1	1	1	0	0	1,565	54	0	222	45	1,054	40	17	41	91	0	0	101,744	1,173	44,506	18,157	4,310	621	.	.	.	.	.	.	.	.	101,744	102	4,127	334	490	85	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
2020	The river Rijn (North Rijn)	38	1	0	5	4	24	1	1	1	1	0	0	1,521	54	0	178	45	1,054	40	17	41	91	0	0	105,753	1,243	47,463	19,412	4,543	639	5,599	888	18,260	1,356	19	580	10	322	105,753	100	4,013	313	494	81	377	83	3,007	64	7	199	3	158	71,852	0	0	0	0	71,852	0	0	0	15,285	0	0	0	0	15,285	0	0	0	4,404	1,045	577	4,308	577	11,718	1,117	10	347	5	99
2018	The river Rijn (East Rijn)	73	0	12	19	11	23	0	3	5	0	.	.	6,863	0	1,465	1,924	262	2,814	0	212	186	0	.	.	341,893	6,133	243,688	90,839	20,154	2,868	22,933	3,054	99,723	5,777	89	3,280	43	1,143	341,893	355	12,937	963	2,485	301	1,208	429	13,648	329	29	1,207	10	414	251,093	0	0	0	95,902	22,891	0	132,301	0	60,938	0	0	0	23,241	5,464	0	32,233	0	19,030	3,591	1,937	21,596	2,583	71,488	4,971	60	1,728	34	600
2019	The river Rijn (East Rijn)	73	0	13	15	13	22	0	2	5	0	2	1	6,885	0	1,545	1,874	314	2,683	0	190	186	0	72	23	359,539	6,179	245,781	93,963	20,535	3,013	.	.	.	.	.	.	.	.	359,539	378	13,685	1,049	2,586	327	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
2020	The river Rijn (East Rijn)	73	0	13	14	13	23	0	2	5	0	2	1	6,849	0	1,509	1,742	314	2,814	0	190	186	0	72	23	365,571	6,114	239,818	97,276	21,032	2,974	26,145	2,790	104,541	6,002	90	3,171	39	1,214	365,571	381	13,503	1,079	2,773	299	1,849	332	16,472	242	9	1,167	2	429	281,660	0	0	0	5,613	162,661	0	84,808	28,579	62,425	0	0	0	1,480	33,037	0	21,077	6,830	19,007	3,867	2,211	23,488	2,468	73,538	4,661	62	1,704	30	563
2018	The river Rijn (Central Rijn)
2019	The river Rijn (Central Rijn)
2020	The river Rijn (Central Rijn)
2018	The river Rijn (West Rijn)	120	1	17	26	13	50	0	7	6	0	.	.	13,016	54	4,710	2,022	171	3,953	0	760	1,346	0	.	.	788,501	11,495	433,835	191,226	42,808	5,821	62,216	5,470	168,978	16,378	187	6,535	93	3,258	788,501	845	29,834	3,382	6,564	805	3,851	898	24,238	932	64	2,628	28	1,508	548,947	0	0	0	29,092	467,018	0	49,449	3,388	133,530	0	0	0	6,690	102,343	0	23,769	728	36,366	7,943	4,277	52,946	4,320	130,569	11,967	123	2,799	74	1,670
2019	The river Rijn (West Rijn)	118	1	17	25	13	49	0	7	5	0	1	0	12,876	54	4,593	1,990	171	4,010	0	760	866	0	432	0	859,488	11,759	448,805	191,796	42,740	5,835	.	.	.	.	.	.	.	.	859,488	881	31,108	3,317	6,584	810	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
2020	The river Rijn (West Rijn)	116	1	17	24	11	49	0	6	6	0	2	0	12,860	54	4,602	1,963	153	4,016	0	662	952	0	459	0	868,245	11,879	462,761	189,110	41,499	5,684	57,983	5,674	169,235	13,717	160	6,423	88	3,110	868,245	826	29,325	2,995	6,282	733	3,549	733	23,990	567	42	2,782	14	1,289	573,616	0	0	0	0	506,953	0	41,660	25,003	140,822	0	0	0	0	125,846	0	9,688	5,288	37,845	8,770	4,977	54,156	4,670	139,057	12,467	119	3,008	67	1,720
2018	The river Maas	55	0	15	6	17	16	0	0	1	0	.	.	6,053	0	2,786	581	637	1,686	0	0	363	0	.	.	398,762	5,739	222,227	93,924	20,311	3,061	34,968	5,948	124,304	10,289	83	8,864	40	1,255	398,762	415	15,004	1,818	3,186	312	2,160	792	21,550	457	22	3,387	8	587	280,099	0	0	0	2,835	270,731	6,533	0	0	71,152	0	0	0	672	64,471	6,009	0	0	21,022	3,883	2,313	25,424	2,920	64,471	5,067	81	1,970	34	448
2019	The river Maas	52	0	15	4	14	16	0	0	1	0	2	0	6,021	0	2,742	491	606	1,686	0	0	363	0	132	0	420,740	5,737	224,086	92,064	19,692	3,085	.	.	.	.	.	.	.	.	420,740	451	16,554	2,130	3,370	354	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
2020	The river Maas	52	0	14	3	14	16	0	0	1	0	4	0	6,046	0	2,756	427	606	1,686	0	0	363	0	207	0	430,317	5,699	224,044	89,885	19,474	2,976	31,454	3,643	108,624	5,360	129	5,885	37	1,121	430,317	443	16,415	2,151	3,244	342	2,580	563	21,335	302	18	2,500	2	438	232,913	0	0	0	0	218,399	14,514	0	0	66,010	0	0	0	0	52,396	13,614	0	0	21,230	3,862	2,550	27,499	3,132	75,411	5,324	94	2,211	29	423
2018	The river Schelde	21	0	7	8	2	2	1	1	0	0	.	.	1,312	0	934	223	16	43	10	86	0	0	.	.	86,388	998	37,470	16,798	3,757	530	6,079	1,185	15,123	1,164	15	1,089	12	460	86,388	110	4,013	496	773	120	385	156	2,597	54	6	386	2	234	58,329	0	0	0	5,080	53,249	0	0	0	12,539	0	0	0	1,305	11,233	0	0	0	4,637	631	428	6,253	719	14,882	1,378	22	329	8	293
2019	The river Schelde	20	0	7	7	2	2	0	1	0	0	1	0	1,302	0	919	202	16	43	0	86	0	0	36	0	87,485	1,093	41,674	17,131	3,978	595	.	.	.	.	.	.	.	.	87,485	112	4,121	481	826	126	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
2020	The river Schelde	20	0	7	7	2	2	0	1	0	0	1	0	1,302	0	919	202	16	43	0	86	0	0	36	0	89,756	1,136	44,064	17,991	4,009	583	5,044	654	17,250	921	26	904	9	493	89,756	115	4,363	499	814	127	340	93	2,620	34	5	332	1	225	54,946	0	0	0	0	54,946	0	0	0	12,243	0	0	0	0	12,243	0	0	0	4,720	640	439	5,918	750	13,621	1,156	16	332	6	234
Source: CBS.

Explanation of symbols

Table description

This table presents the most significant results of the annual survey Public treatment of urban waste water. The results are presented per province and river basin district (Rijn, Maas, Eems and Schelde) and include:
- number and capacity of the urban waste water treatment plants by type of treatment;
- the volume and concentration of organic matter, nutrients and heavy metals in the waste water running into waste water treatment plants (influent) and the volume of treated waste water (effluent). As of 2017, data on heavy metals are only inventoried for even years.
- the volume and destination of the sludge released, with nutrients and heavy metals. As of 2017, sludge data are only inventoried for even years.
Additional data on urban waste water treatment plants, process technology, energy consumption, generation of energy and sludge dewatering can be accessed on the Dutch version of StatLine.

Data available from: 1981

Status of the figures:
The figures in this table are definitive.

Changes as of 12 May 2022:
The figures of 2020 has been added.
Due to new information on 2019, total influent load of CZV and total Pollution Equivalents of the influent has increased with 4 percent in 2019 compared to the previous version. This results for the two parameters also in small changes in underlying classifications.

When will new figures be published?
New figures on 2021 will be published by March 2023.

Description topics

Urban waste water treatment plants

The number and capacity of urban waste water treatment plants in the Netherlands where nearly all domestic waste water and waste water from the private sector is treated. The plants are all operated by regional water quality control authorities.

Numbers by type

Number of sewage water treatment plants broken down by method of treatment.

Total number: The total number of urban waste water treatment plants in the Netherlands.

Trickling filters: Waste water is sprinkled over a layer of porous stones covered with bacteria (biofilm). Thus, organic compounds in the waste water are degraded.

Aeration tanks: Pre-settled waste water runs through an intensively aerated basin containing active sludge (bacteria). Organic pollutants are degraded by oxygen and active sludge. The treatment process takes up only a short period of time and the sludge load is high which is typical of aeration basins.

Oxidation tanks: Operates by the same principle as the aeration tank but the sludge load is significantly lower. The resulting sludge is highly mineralised and will therefore decompose more slowly.

Oxidation ditches: In oxidation ditches, waste water is directed through a aeration circuit several times. The process takes up 2 or 3 days. Consequently, the sludge load is extremely low.

Carrousels: This technology is chiefly applied in large installations. Typical of carrousels are the depth (between 2 to 4 metres) and the aeration method.

Discontinuous systems: Oxidation basins and oxidation ditches. Waste water is let in batch-controlled.

Parallel installations: Various combinations of treatment systems (so-called 'streets') are applied in one installation.

Multi-stage installations: A serial process consisting of two systems, for instance, a trickling filter and an aeration basin. The waste water runs through both stages.

Compact installations: A system consisting of a basin subdivided into four segments. Waste water flows into the aeration segment. Subsequently, the sludge is separated in the central aeration zone. Then part of the sludge is conditioned in the reaeration zone and led back into the aeration zone. The other part (surplus sludge) is stabilised in the sludge mineralisation zone and subsequently removed.

Nereda granular sludge reactor: In the Nereda granular sludge reactor the wastewater is purified by micro-organism clogged in natural granular structures of high density. These granules have a high biological activity and make it easy to separate the micro-organisms from the treated wastewater.

As from 2019 this new treatment type is distinghuished separately in Statline. In the period 2011-2018 already 4 Nereda systems became operational. Until 2019, these installations were classified as oxidation tanks and/or discontinous systems.

Hybrid Nereda - active sludge system: System consisting of a parallel operated Nereda granular sludge reactor and activated sludge system.

In the Nereda granular sludge reactor the wastewater is purified by micro-organism clogged in natural granular structures of high density. These granules have a high biological activity and make it easy to separate the sludge from the treated wastewater.

In activated sludge systems the wastewater is treated in bassins with flocculated sludge . This sludge clumps exists of microorganisms that feed on the the organic pollution in wastewater.

As from 2019 this new treatment type is distinghuished separately in Statline. In the period 2013-2018 already 2 hybrid Nereda - activated sludge sytems became operational. Until 2019, these installations were classified as parallel installations.

Capacity pollution equivalents by type

Capacity urban waste water treatment plant:
A value that indicates how much organic pollution theoretically can be treated by a waste water treatment plant.

The pollution equivalent is the official unit that quantifies the pollution in waste water; one pollution equivalent = 150 g TOD (Total Oxygen Demand).
One pollution equivalent is the daily quantity of oxygen-demanding material in the waste water of one person. The degree of pollution in the waste water produced by the private sector is also expressed in pollution equivalents.
This unit is used as of 2010, so for previous years no values are available.

Total capacity pollution equivalents

Trickling filters: Waste water is sprinkled over a layer of porous stones covered with bacteria (biofilm). Thus, organic compounds in the waste water are degraded.

Aeration tanks: Pre-settled waste water runs through an intensively aerated basin containing active sludge (bacteria). Organic pollutants are degraded by oxygen and active sludge. The treatment process takes up only a short period of time and the sludge load is high which is typical of aeration basins.

Oxidation tanks: Operates by the same principle as the aeration tank but the sludge load is significantly lower. The resulting sludge is highly mineralised and will therefore decompose more slowly.

Oxidation ditches: In oxidation ditches, waste water is directed through a aeration circuit several times. The process takes up 2 or 3 days. Consequently, the sludge load is extremely low.

Carrousels: This technology is chiefly applied in large installations. Typical of carrousels are the depth (between 2 to 4 metres) and the aeration method.

Discontinuous systems: Oxidation basins and oxidation ditches. Waste water is let in batch-controlled.

Parallel installations: Various combinations of treatment systems (so-called 'streets') are applied in one installation.

Multi-stage installations: A serial process consisting of two systems, for instance, a trickling filter and an aeration basin. The waste water runs through both stages.

Compact installations: A system consisting of a basin subdivided into four segments. Waste water flows into the aeration segment. Subsequently, the sludge is separated in the central aeration zone. Then part of the sludge is conditioned in the reaeration zone and led back into the aeration zone. The other part (surplus sludge) is stabilised in the sludge mineralisation zone and subsequently removed.

Nereda granular sludge reactor: In the Nereda granular sludge reactor the wastewater is purified by micro-organism clogged in natural granular structures of high density. These granules have a high biological activity and make it easy to separate the micro-organisms from the treated wastewater.

As from 2019 this new treatment type is distinghuished separately in Statline. In the period 2011-2018 already 4 Nereda systems became operational. Until 2019, these installations were classified as oxidation tanks and/or discontinous systems.

Hybrid Nereda - active sludge system: System consisting of a parallel operated Nereda granular sludge reactor and activated sludge system.

In the Nereda granular sludge reactor the wastewater is purified by micro-organism clogged in natural granular structures of high density. These granules have a high biological activity and make it easy to separate the sludge from the treated wastewater.

In activated sludge systems the wastewater is treated in bassins with flocculated sludge . This sludge clumps exists of microorganisms that feed on the the organic pollution in wastewater.

As from 2019 this new treatment type is distinghuished separately in Statline. In the period 2013-2018 already 2 hybrid Nereda - activated sludge sytems became operational. Until 2019, these installations were classified as parallel installations.

Influent waste water

Data on concentrations and quantities of pollutants in the waste water running into urban waste water treatment plants (influent).

Quantities

Volume waste water: The annual volume of influent waste water.

Pollution Equivalents: The pollution equivalent is the official unit that quantifies the pollution in waste water; one pollution equivalent = 150 g TOD (Total Oxygen Demand).
One pollution equivalent is the daily quantity of oxygen-demanding material in the waste water of one person. The degree of pollution in the waste water produced by the private sector is also expressed in pollution equivalents.
This unit is used as of 2010, so for previous years no values are available.

Chemical oxygen demand (COD): Chemical oxygen demand (COD). Measure of the amount of oxygen consumed when a substance is degraded chemically.

Biochemical oxygen demand (BOD): Biological oxygen demand (BOD). Measure of the amount of oxygen consumed when a substance is biodegraded.

Nitrogen compounds as N (total): The total amount of nitrogen in organic compounds (e.g. proteins) and inorganic compounds (e.g. nitrate and ammonium)

Phosphorus compounds as P (total): The total amount of phosphates and other phosphorus compounds in waste water, measured as phosphorus (P).

Copper

Chromium

Zinc

Lead

Cadmium

Nickel

Mercury

Arsenic

Discharge of waste water (effluent)

Data on concentrations and quantities of pollutants in treated waste water (effluent) discharged from urban waste water treatment plants.

Quantities

Volume waste water: The annual volume of effluent waste water.

Pollution Equivalents: The pollution equivalent is the official unit that quantifies the pollution in waste water; one pollution equivalent = 150 g TOD (Total Oxygen Demand).
One pollution equivalent is the daily quantity of oxygen-demanding material in the waste water of one person. The degree of pollution in the waste water produced by the private sector is also expressed in pollution equivalents.
This unit is used as of 2010, so for previous years no values are available.

Chemical oxygen demand (COD): Chemical oxygen demand (COD). Measure of the amount of oxygen consumed when a substance is degraded chemically.

Biochemical oxygen demand (BOD): Biological oxygen demand (BOD). Measure of the amount of oxygen consumed when a substance is biodegraded.

Nitrogen compounds as N (total): The total amount of nitrogen in organic compounds (e.g. proteins) and inorganic compounds (e.g. nitrate and ammonium).

Phosphorus compounds as P (total): The total amount of phosphates and other phosphorus compounds in waste water, measured as phosphorus (P).

Copper

Chromium

Zinc

Lead

Cadmium

Nickel

Mercury

Arsenic

Sewage sludge

Residue of treated waste water consisting of suspended solids and excess active sludge (biomass). Sewage sludge is measured including water (see Total wet sludge) or as dry solids.

Wet sewage sludge by destination

The volume of wet sewage sludge, i.e. including water by destination (processing method).

Total wet sludge: Total wet sludge discharged.

Agriculture: Application of manure or soil improver in agriculture. Due to rigid legislation impossible since 1995.

Wet oxidation: Wet oxidation of sludge in so-called VerTech installations: the sludge is oxidised under high pressure in a deep shaft.

Composting

Landfill: Dumping of sludge on regional landfill sites or special sludge depots.

Incineration: Incineration of sludge in special sludge incineration plants or in household waste incinerators.

Cement industry: Co-incineration in cement ovens.

Co-incineration at power plants: Sewage sludge used as a secondary fuel at a power plant.

Other destinations: Mainly reuse.

Dry solids by destination

Discharged sewage sludge in kilogrammes of dry solids by destination (processing method). Dry solid is the residue of sewage sludge after evaporation at 105 degrees centigrade.

Total dry solids

Agriculture: Application of manure or soil improver in agriculture. Due to rigid legislation impossible since 1995.

Wet oxidation: Wet oxidation of sludge in so-called VerTech installations: the sludge is oxidised under high pressure in a deep shaft.

Composting

Landfill: Dumping of sludge on regional landfill sites or special sludge depots.

Incineration: Incineration of sludge in special sludge incineration plants or in household waste incinerators.

Cement industry: Co-incineration in cement ovens.

Co-incineration at power plants: Sewage sludge used as a secondary fuel at a power plant.

Other destinations: Mainly reuse.

Nutrients and heavy metals

The total weight of nutrients and heavy metals removed with the sludge. Most heavy metals adsorb strongly to the sludge particles.

Ashes: The residue of non-inflammable, inorganic matter after incineration.

Nitrogen compounds as N: The total amount of nitrogen in organic compounds (e.g. proteins) and inorganic compounds (e.g. nitrate and ammonium).

Phosphorus compounds as P: The total amount of phosphorus in sewage sludge is analysed as P205 (diphosphorus pentoxide) converted to P total.

Copper

Chromium

Zinc

Lead

Cadmium

Nickel

Mercury

Arsenic